THE COMPLEAT Ship-Wright.

Plainly and Demonstratively Teaching the Proportions used by Experi­enced Ship-Wrights, according to their Custome of Building; both Geome­trically and Arithmetically performed.

To which is added, Certain Propositions in Geometry, the use of a Diagonall SCALE, to draw a Draught, with the Making, Graduating, or Marking of a Bend of Moulds, and ordering of the same. The Extra­ction of the Square Root, with a Table of Squares.

Also, a way of Rowing of Ships, by heaving at the Capstane, usefull in any Ship becalm'd; with other things usefull in that ART.

By EDMUND BUSHNELL Ship-Wright.

LONDON, Printed by W. Leybourn for George Hurlock, and are to be sold at his Shop at Magnus Church corner in Thames-Street, neer London-Bridge, 1664.

TO THE READER.

Friendly Reader,

THe Matter contained in this Treatise, is written onely for the good and profit of my Countrymen, who are still in that capacity that once I my self was; that is, igno­rant of what they should know in their Trades, and desire Instruction; not that I presume to teach those long experienced Ship-Wrights, whose actions hath declared their Abilities to the whole World, in their Building of so Gallant, and Serviceable a Fleet of Ships, as at present his Majesty, the King of England, is furnished withall, no King having the like, either for Offence, or Defence: yet their knowledge they desire to keep to themselves, or at least among so small a number as they can; for although some of them have many Servants, and by Indenture [Page] (I suppose) bound to Teach them all alike the same Art and Mystery that he himself useth; Yet it may be he may Teach some one, and the rest must be kept ignorant, so that those Ship Wrights, although bred by such knowing Men, yet they are able to teach their Servants nothing, more then to Hew, or Dub, to Fay a Piece when it is Moulded to his place assigned, or the like: but if occasion require, that the greatest part of these Men, by be­ing Carpenters of Ships, or the like, may be remo­ved from England to Virginia, or New-England, or the like Countryes, where Timber is plenty for their use, yet through their ignorance, they durst not undertake such a Work: For their sakes I have written this Book, wherein the Reader shall finde instructions sufficient for Moulding of any Ship, or Vessell whatever, with the Masting of them, drawing of Draughts, and all in a very plain and exact Method, which I am confident will be un­derstood by the meanest capacities, if they can but read English, and have the benefit of a little A­rithmetick as Adition, Substraction, Multiplica­tion, Division: be diligent, and I shall be thereby incouraged, if need be, to help thee farther in the Art.

Farewell,
Thy Friend, Edmund Bushnell.

THE CONTENTS.

  • Ch. I. OF Geometricall Problemes Page 1
  • Ch. II Of your SCALE Page 4
  • Ch. III Concerning the drawing your Draught upon Paper Page 6
  • Ch. IV. Shewing, how to sweep out the Bend of Moulds upon a Flat Page 9
  • Ch. V. The Description of the Rising Lines aftward on, and forward on; with the Narrowing Lines, and Lines of Breadth: As also the Narrowing of Lines at the top of the Timbers Page 12
  • Ch. VI. Shewing the Making and graduating, or marking of the Bend of Molds Page 15
  • Ch. VII. Arithmetically shewing how to frame the body of a Ship by Segments of Circles: being a true way to exa­mine the truth of a Bow Page 22
  • Ch. VIII. How to Extract the Square Rooot Page 31
  • Ch. IX. A Description of the Table of Squares Page 39
  • Ch. X. Shewing, how to hang a rising line by severall sweeps, to make it rounder aftward, then at the beginning of of the same Page 53
  • [Page] Ch. XI. Concerning Measuring of Ships Page 59
  • Ch. XII. Concerning the Masts of Ships Page 62
  • Ch. XIII. Concerning Rowing of Ships, when they are be­calmed. Page 65

ERRATA.

PAge 7, Line 9, Read Halses
8 16 come not fowl
8 21 faied
11 2 at f or G
12 23 afore
13 2 afore
13 19 aftward
14 15 L o
14 28 [...]/ [...]
15 25 dele off
16 7 Sirmarks
18 [...] none, that
18 11 at the top
19 2 stick
20 29 you h [...]w to
22 5 make a
23 3 & 5 3/5
54 16 12 foot
57 1 two last numbers.

Books Printed and Sold by George Hurlock, at Mag­nus Church-Corner in Thames-Street, neer London Bridge.

SEamans Kalender, or Ephimerides of the Sun, Moon, and certain of the most notable fixed Stars, &c.

Norwoods Doctrine of Triangles, with Logarithmes, lately printed, ex­actly corrected, and much inlarged by the Author himself. Norwoods Epi­tomy, applyed to plain and Mercators sailing Norwoods Sea mans Practice, containing a Fundamentall Probleme in Navigation, experimentally verified. Safeguard of Saylors, or Great Rutter, by Ro. Norman. Sea mans secrets. A Table of Gauging all manner of Vessels, by Jo. Goodwin. Path-way to per­fect sailing, by Richard Poltar▪ Pitiscus his Doctrine of Triangles, with Canons. Navigator by Cap. Charles Saltonstal, newly printed, with additions, shewing the Deceipts of the plain Charts used in our time, and a way to prove the projection of any Plain Chart. Dary's description and use of a Vniversall Quadrant. Seamans Dictionary, or the Exposition and Demonstration of all the parts and things belonging to a ship▪ together with an Explanation of all the Termes and Phrases used in the practique part of Navigation, by Sir Hen­ry Manwarring.

Exact Tables of Naturall and Artificial Sincs, Tangents, Secants and Lo­garithms, and an Institution Mathematicall, containing their constructions and use in the solution of all Triangles Plain and Spherical, and the application thereof in Astronomy, Dialling, and Navigation.

Seamans Glass, now newly published, with the addition of many propositi­ons in Navigation, Astronomy, and Dialling, not before printed.

The Compleat Canoneer, shewing the principles and grounds of the Art of Gunnery, as also several Fire-Works for Sea and Land.

The Advancement of the Art of Navigation, or Sea-mans Canon of Tri­angles, shewing by a new Canon of Sines, Tangents, and Secants, how to re­solve all Cases of right lined Triangles, onely by looking into the Tables, without any Calculation. Particularly applyed to all the three kindes of Say­ling, viz. by the Plain Chart, Mercators Chart, by a Great Circle; and to the Art of Surveying.

Trigonometria Brittannica, or the Doctrine of Triangles, in folio, exhibiting the Logarithms of all numbers, from one to a hundred thousand, and the Sines and Tangents to the hundred part of a Degree, with Mr. Gellibrands Do­ctrine of Triangles, faithfully translated from the Latin Copy.

The Sector on a Quadrant, containing the Description and use of three [Page] general Quadrants, accommodated for the ready finding the Hour and Azi­muth universally in the equal Limbe.

The Compleat Modellist, shewing how to raise the Model of any Ship or Vessel, either in proportion, or out of proportion▪ and to find the length and bigo [...]ss of every Rope, in all Vessels exactly, with the weight of their An­chors and Cables.

There is a new Book▪ called the Pilots Sea-Mirror, which is a Compendium of the largest Wagoner, or the lightning Sea-Collumbe; Containing all Di­stances or thwart Courses of the Eastern, Northern, and Western Navigations, with a general Tide Table, for every day, and the Change and Full of the Moon exactly for eight years, also Courses and Distances throughout the Straights. Printed for George Hurlock, at Magnus Church Corner, by London Bridge.

The Saints Anchor-hold in all stormes and Tempests, Published for the support and comfort of Gods people in all times of Trial, by John Davenport Pastor of the Church in New-Haven in New-Ingland.

There will shortly be made publick a Book, Intituled, The Mariners Compass Rectifled, containing, First, a Table shewing the hour of the day, the Sun be­ing upon any point of the Compass. Secondly, Tables of the Suns rising and setting. Thirdly, Tables shewing the points of the Compass, that the Sun and Stars rise and set with. Fourthly, Tables of Amplitudes; all which Tables are Calculated from the Equinoctial, to 60 degrees of Latitude, with Tables of Latitudes and Longitudes, after a new order, with the description and use of all those Instruments that are in use in the Art of Navigation, either for Operation or Observation.

THE COMPLEAT Ship-wright.

CHAP. 1. Of Geometricall Problemes.

BEfore we proceed to draw the Draught of any Ship or Vessel, it will be necessary to be acquainted with some terms in Geometry: as to know what a Point and a Line mean­eth, which every Book treating of Geome­try plainly teacheth, and therefore we shall passe that by, supposing that none will endeavour to study the Art of a Ship-wright, that is ignorant of these things; and therefore leaving these Definitions, I will proceed to some Geometrical Problemes necessary to this Art.

PROB. 1. How to draw a Parallel Line.

PArallel lines are such lines as are equidistant one from another in all parts, and are thus drawn. Draw a line of what length you please, (according to your occasion) as the line A B, then open the com­passes to what distance you pleas, or as your occasions require, and set one foot of the compasses▪ towards one end of the given line, as at A, with the other foot make a piece of an arch of a circle, over or under the given line, as the arch C, keeping the compasses then at the same distance, make such another arch towards the other end of the line, setting one foot in B, and with the other describe the arch D, then laying a Ruler to the outside of these two arches, so that it may exactly touch them, draw the line C D, which will be parallel to the given line A B, or equidistant, for so signifieth the word Parallel, to be of e­qual distance.

[figure]

PROBL. 2. How to erect a Perpendicular, from a point in a right line given.

LEt there be a point given in the line A B, as the point C, whereon to raise a perpendicular.

Set one foot of the compasses in the given point C, and open them to what distance you please, as to the point E, make a little mark at E, and keeping the compasses at the [Page 3] same distance, turn them about, and make a mark at the point F, in the line A B: Then remove the compasses to one of those marks at E or F, and seting one foot fast therein, as at the point F, open the other foot wider, and therewith draw a small arch over the point C, as the arch D, then keeping the compasses at the same distance, remove them to E, and seting one foot in E, with the other foot draw another little arch, so as to crosse the former arch in the point D, through the crossing of these two arches A D, draw a line to the given point C, as the line D C, which shall be perpendicular to the line A B.

Diverse other wayes there are to raise a perpendicular, which I shall leave to the farther practice of such as desire diversity of wayes, and proceed to the rai­sing of a Perpendicular on the end of a line.

[figure]

PROBL. 3. To raise a Perpendicular on the end of a line.

DRaw a line at pleasure, or according to your worke, as the line A B: On the end thereof as at B, set one foot of the Compasses, and open them to what widenesse you please, as to C, and keeping fast one foot at B, pitch one foot by adventure in C, then keeping one foot of the compasses in C, and at the same distance, remove the foot that was in B, to the point D in the line A B: then (keeping the com­passes stil at the same distance) lay a ruler to the points D and

[figure]

[Page 4] C, & with your compasses set off the distance from C to E: Lastly, draw the line E B, which will be perpendicular or square to the end of the given line A B.

There are other wayes to effect this, which I shall leave to farther practice of the learner, this being the properest for our purpose.

PROB. 4. From a Point given, to let fall a Perpendicular upon a Line given.

FRom the point C, let it be required to let fall a perpen­dicular upon the line A B, proceed thus: Fix one foot of the compasses in the point C, and open them to a greater distance then just to the line A B, and make with the same extent the two marks E and F, in the given line A B, then divide the distance betweene the two points E and F into two equall parts in the point D, then lay a Ruler to the given point C, and to the point D, and draw the line C D, which will be perpendicular to the given line A B.

[figure]

CHAP. II. Of your SCALE.

BEing perfect in the raising and letting fall of perpen­diculars, and in the drawing of Parallel lines, you may proceed to draught: but first I will unfold unto [Page 5]

[figure]

you the use of a Diagonall Scale of Inches and Feet, whose use is to represent a foot measure, or a Rule so small, that a Ship of 100 foot by the Keel, may be demon­strated on a common sheet of pa­per, really and truly to be so ma­ny foot long, and so many foot broad, of such a depth, and of such a height between the Decks. And therein, the first thing to be considered is, the length of the platform, and of the Vessel you intend to demonstrate, to the end you may make your Scale as large as you can, because the lar­ger the Scale is, the larger will the draught be, and so the measure of the demonstration will be the larger, and more easie to unfold. The Scale adjoyning consisteth (as you see) of 12 feet in all, 11 thereof are marked with figures downwards, beginning at 1, 2, 3, 4 and so to 11: the first at the top is sub-divided into inches by di­agonal lines, as the distance be­tween the first line of the Scale and the first diagonal line is one inch, the second is 2, and the third 3 inches, and so to Six. The way to demonstrate the Scale, you see, is very easie: Draw Seven lines parallel to each other, and of what length you please, to retain what number of Feet you please, then beginning at the top, set off with the compasses [Page 6] the length of your Feet both allow and aloft, then draw lines thwart the parallel lines, to every foot of the Scale, and set numbers to them, beginning at the second foot 1, and to the third 2, to the fourth 3, and so forward, leav­ing the first Foot to be divided into Inches by the Diago­nall lines, as you see in the foregoing Scale.

CHAP. III. Concerning the drawing your Draught upon Paper.

HAving fitted your Scale ready, draw a line to repre­sent the Keele of the Ship, as you see in the draught following of 60 foot long by the Keele, and 20 foot broad: the streight line that representeth the Keele is marked with A B. Then draw a line underneath of equall length to signifie the bottome of the Keele. Then next you may proceed to the Stern-post, as the line A C will sig­nifie the foreside or the inside thereof, racking the one quarter of his length aft, and for the length of the Stern-post it must be directed to the built of the Ship, as whether she be to be a deep Ship or a shallow Ship, so that the draught of the water ought to be respected first, and then the lying of the Ports for the convenience of Ordnance, for that the upper transome of the Buttock, commonly is just under the Gun-Room ports, to the upper edge of the said transome we understand the length of the Stern-post, although if the Stern-post were continued to the height of the Tiller, and another Transome fard there for the Tiller to run on, it would steady the quarters of the Vessel very much, and do good service.

[Page 7]The Stern-post being drawn, we may proceed to draw the Stem, which in the following Draught is not so much racked as was the old proportion of England, which was the whole breadth of the Ship, for then it should be 20 foot, but it is no more then 15 foot, just ¾ of the breadth, for too much racke with the Stem doth a great deale of damage to any Ship, if we consider that in this small Vessel, had we given 5 foot more Racke, all the weight of the Ships Head, and Boltspreet, Foremast, Manger, Halsps, Brest-hooks aloft, had been so much farther forward, where there would have been want of Bodie to lift it, so that it must of neces­sity be detriment to the Vessel when she saileth against a head sea, and a great strain to her. Now it will be very good to spend as much of this racke as we can under the water, for it will help the Ship to keepe a good Winde, by giving her something more Body in the water.

Next draw the Water-line, in the following draught sig­nified by the pricked line; it is drawn to 9 foot height afore, and to 10 foot height abaft from the upper edge of the Keele, and higher abaft then afore, for the most Ships saile by the Sterne, and also for that the Guns should lie something higher abaft then afore from the water.

Then proceed to hanging of the Waals, and here you see the lower Waalle drawne from the head of the Sterne-post, to signifie that it should lie against the end of the Transome, that the Transome Knees might be bolted to the Waals without board to one foot and an halfe under the Water­line, a little before the middle of the Water line, and at 9 foot high on the Stem, and the next Waale parallel to the lower Waale, one foot and an half asunder, so that the upper Waale will lie just at the waters edge, in the mid-ships, the upper edge of the Gun-deck will lie one foot aboye the water line abaft, and halfe a foot above water on the Stem; [Page 8] so then letting the lower sell of the Ports be two foot from the Gun-decks▪ the lower edge of the Ports wil be three foot from the water abaft, and two foot and an halfe afore, in the middle of the Gun-deck 2 foot 9 inches, sufficient for so small a Vessel, a greater Vessel would require to have the Guns something farther from the water, then if another Waale be required, first set off the Ports in their places, that the Waale may ly above the Ports, or else he would be cut with the ports in pieces, the upper Deck with height respecting the bignesse of the Ship, having respect to not o­ver building small Ships, to damage their bearing of Sail.

Then for the Head, the length of the Knee would be two thirds of the breadth, so then the Knee of the Head in this Draught will be 12 foot 8 inches long, and for his place, as low as conveniently he can, provided that the Rails of the Head, fall not fowl of the ha [...]shols, because that in placing of the Knee low, giveth room to round the Head, and steeve it to content: The place of the Knee will be at, or very neer, the upper Waal, the upper edge of the Knee against the upper edge of the uper harping, which will be very well for the lower Cheeks of the head to be faced against, for by that means they wil be clear of any Seame to avoid Leak­ings, and will very well bolt the end of the harping, if a Brest-hook be fastned also within board against them, will very well fasten all together.

Then for the steeving of him, and rounding the Knee, a regard must be had to the lying of the Boltspreet, leaving room enough for the Lyon and Scrowl under the Boltsprit. Then▪ for the rounding of the Rails, round them most at the after ends.

For the heights between Decks and Steeridge, Cabine, Fore-Castle, those heights are commonly mentioned in contract by the Master or Owners building.

[Page]

Place this Draught at Page 8

CHAP. IV. Shewing, how to sweepe out the Bend of Moulds upon a Flat.

FIrst, draw a line, as the line AB, then in the mid­dle thereof, as at the point C, raise a perpendi­cular, as is the line CM, perpendicular to the line AB; then set off the halfe breadth, on either side, at the Points AB, and draw the two lines IA, and KB, parallels to CD, signifying the breadth of the Vessell 20 foot; then draw the two lines EF, and HG, signifying the breadth of the Floare thwart Ships, 8 Foot, more then one third part of the breadth, which was formerly an old Proportion; so that according to that it should have been but 6 Foot 8 Inches.

Herein any may do as they please, give more or less; my judgment is, rather more then less: for, that it maketh a Vessell to carry more in Burden, and I con­ceive it may, if it be well ended forward, it will not damage the Sayling: I also think, it doth stiffen a Ves­sell on this account. Our English Vessells have been used to have their breadth lying at the height of the Halfe Breadth, then observing 1/3 breadth for the length of the Floare Thwart Ships, it maketh the Vessells Bo­dy to be very neare a Circle, as is a Cask, which cau­seth such Vessells to be easie to slew in the Water; yet I would not exceed neither, or run into extreams here­in, but if I were to make a Vessell stiff, I would that [Page 10] the Halfe Breadth be more then the draught of Water, which causeth that the Body be stronger in the Wa­ter, and will not Slew so easily. Now to sweep out the Sides under Water, I draw the Diagonall lines DA,

[figure]

and DB; then I divide the Diagonall lines into 9 parts, and set off 2 of them from the Corners A and B, to the points e, then I set off the Dead Rising, which is 4 Inches, one Inch to a Foot, for halfe the breadth represented in the Figure above, by the little line paral­lel to FG: from which Dead Rising, take with the Compasses the Distance that will draw a piece of an Arch from [...] to [...], and so as one foot of the Compas­ses [Page 11] stand in the line EF, and exactly touch the points at the Dead-Rising, at f or g, and touch also the points e, over which point falls at ⊙, in EF, or ⊙ in HG, wherewith I describe the Arch e F, or e G, which is by the Scale in the Draught 4 Foot 8 Inches: then for the other part of the Side upwards, seek for a Point in the breadth line IK, at which, if one foot of the Compasses be set, and the other foot opened to the Extreame Breadth, will also draw, or signifie an Arch to meet with the other Lower Arch, on the Diagonall line at e, which is at the points ⊙ and ⊙; thus the point ⊙, between D and K, neere H, Sweepeth the contrary Side I e, and so the point ⊙, between DI, neere E, Sweepeth the contrary side at K, extend the same Sweepe also above the Breadth line above Wa­ter 3 or 4 Foot, the length of this Sweepe is 12 Foot 9 Inches: then set off the Tumbling Home, at the Height of the two first Haanses, at the Maine Mast and Foarcastle, 2 foot of a side; then draw a line from the said 2 Foot of Narrowing, at the points o v, till it break off on the back of the Sweep, on either side. This kinde of Demonstration I conceive most suitable to our following discourse of Arithmeticall Work, I could have cited other wayes, but I Judge this way suffici­ent.

CHAP. V. The Description of the Rising Lines aftward on, and forward on; with the Narrowing Lines, and Lines of Breadth: As al­so the Narrowing Lines at the top of the Timbers.

DRaw a Hanging line on the Draught, from the Keele, from the middle of the Keele to the height of the Water line, on the Post which will be the Rising line, as the line DE; this line DE is supposed to be sweept, or drawn by a Semidiameter of a Circle, extended on a Perpendicular raised at the point E, for if it be shorter then such a Semidiameter of the true Cir­cle, it will make a fuller line then it should be, and so must not be so long, or else it will make a breach at the beginning of the line; this, if the Centre be supposed to be Abaft such a Perpendicular, that should draw a Rising line Abaft, I say, that it will shorten the Rising line, and make it fuller then it should be; or then if it be farther forward, it will be straighter then a Circle, and also be a breach at the beginning of the Rising line; therefore it should be a Circle, I say, whose Semidiame­ter will be on the Perpendicular line, at the beginning of any such Rising line, on the Heele, either Afoare, or [Page 13] Abaft, and the like ought to be for all other crooked lines, as the narrowing lines Abaft, or Afoare, or at the Narrowing of the Floare, or other Circular lines, as Hanging of Waals, and the like; the way whereof I shall describe, to finde the lengths of all such Sweeps by Arithmetick; as also the true Rising, Narrowing of any Timber, according to exact peeces of Circles, very usefull for the setting of Bows, to trie whether they hang to a true Sweepe or no: I shall demonstrate it, I say, in the following discourse, and in this place end what I intend to say. For Demonstration then, At ¾ of the Keele forward I draw a Rising line forward to the height of the Water line, forward on the Stemm, as you see the line op; and the little line, between these two lines, parallel to the inside of the Keele, marked Eo, is the dead rising 4 inches high, as in the bend of Moulds it is parallel to FG, the height of the breadth from the Mid-Ship forward is the lower Edge of the upper Waale; but afterward on it is the pricked line, between the Water line and the lower Waale, on the Post, which runneth forward to the edge of the Waale, and hath Figures set to it, to signifie the places of the Timbers marked 1, 2, 3, 4, 5, to 15; as you see answers to the Figures on the Keele: and the Letters set to forward on, signifie the places of the Timbers forward, marked ABCD to L, in the middle of the Vessel: the places marked with a Cipher signifie the Flats, which have onely Dead rising, although they ought to have, some of them, something more Dead rising then each other; and those that have least, to be placed in the middle of the rest, that so there be no Clings in the Buldge, but that it have also a little Hang­ing [Page 14] in it, it will seeme the fairer: Then I draw a straight line, parallel to the bottome of the Keele, as is the line FG, parallel to the line AB, the Keele, and distant 10 foot by the Scale, which is the halfe breadth of the Vessell; for this line signifieth a line stretched from the middle of the Sterne-Post to the middle of the Stem, called by Ship-wrightes, a Ram-line: Parallel to this Middle line I draw another line straight, marked nm, and is 4 foot asunder from the Middle line, to signifie the halfe length of the Floare thwartships, as in the Bend of Moulds EF is distant from DC 4 Foote: then I draw a Crooked line Abaft, within this line nm, to signifie the narrowing of the Floare, to bring, or forme the Vessels way Abast, as you see the line ik; Abaft and Afoare it is represented by the line lo: then here in this Draught I draw a Sweepe, or a piece of a Circle, from the point G, the marke of the Timber G, on the Keele, to the halfe breadth of the Stemm, to the point G on the Stemm, signifying the Sweep of the Harping, and is Sweept by the breadth of the Ves­sell 20 Foot; the piece of the Pricked Circle Abaft at the Starne, which is drawn by a Centre on the line FG, is the length of the Transom thwart the Starne, as is the Arch FS, the length whereof is 8 Foot, which doubled is 16 Foot, for the whole length: which is ⅘ of the breadth 20 Foot, the length of the Sweepe that sweepeth it is the length of the Starnpost to the bot­tome of the Keele 14 Foot ⅓, then the Crooked line, from the end of the Transom, or from the point S, and toucheth the Keele at the point p: this Arch Sp, is the narrowing line Abaft at the breadth, and the Crooked pricked line within the Keele, marked with TR, is a [Page 15] Rising line, to order a hollow Moulde by the Timbers, are placed at 2 Foot Timber and Roome, as you may see by the Scale, the line drawne from the Poope to the Foar-Castle, marked by the letters VW, is a line signifying the breadth of the Vessell, at the top of the side, from the top of the Poope to the Fore-Ca­stle, the top of the Poop is in breadth 10 Foot, halfe the breadth at the beame; the use of this line is in ordering of the Moulds, to stedy the Head of the Top-Timber Mould, to find his breadth aloft.

CHAP. VI. Shewing the Making and gradua­ting, or marking of the Bend of Molds.

REpaire to some House that hath some Roome or other broad enough to demonstrate the breadth of the Vessell, and height enough for the top of the Poope in the length of the Roome; or else if you cannot finde such a Roome convenient, lay boards together, or planks, that may be large enough for your business, as in the following Scheame you see; First, a long square made for the breadth of the Vessell, as in the following Figure IABK: then make the Moulds by their Sweepes, and make Sirmarks to them for the laying of them together in their true places, off first the Mould, for the Floare being made, you may make a Sirmarke by the line EF, on the head of the [Page 16] Floare Mould, and another on the foot of the Navill Timber Mould, at the same place, to signifie, that those two marks put together, they are in their true places, and will compare so when any Timbers are Molded by them: those Sirmarks must also be marked off on the Timbers, and so in putting the Timbers up in the frame, a regard being had to compare Sirmarks with Hir­marks, each Timber will finde his own place, and come to his own breadth, and give the Vessell that forme as­signed her by your Draught, if it be wrought by it, and so for all the other Moulds.

In making your Moulds, that they may be smaller and smaller upwards, and not all of a bigness, you may measure the depth of the Side in the Mid Ships Cir­cular, as it goeth from the Keele to the top of the Side, as here the Side, as it Roundeth, is 26 foot, and in depth at the Rounheads, or at the end of the Floare, is one Foot, as m m; and at the other end, at the head of the Timber is but halfe a Foot, as at n n, so then draw­ing two lines, as the lines n m, represents the diminish­ing of the Moulds in thickness upwards, as those two lines representeth; as if you would finde the thickness of the Timbers at the breadth, take your 2 Foot Rule, and measure the length from the end of the Floare at the point F to I, at the breadth in the crooked body, and it is 11 Foot 9 Inches, signified at the Sirmarks there, those two lines shew the thickness to be 9 Inches; and so thick ought the Moulds to be at the breadth of the Vessell.

By this Proportion the Moulds being made and Sir­marked to the body of the Vessell, and that they must be marked, or ordered, to finde the decrease of her bulks [Page 17]

[figure]

body in the Midships, and to come to her way Abast, that the Water may pass to her Rudder to make her Stere, repaire to the Draught, and first set off her Risings thus; Example, We will begin at Timber 3 Abast, and his Rising is 7 inches: therefore draw a line pa­rallel [Page 18] to the Base, or Ground line F G, as the line 3 3; 7▪ Inches, from it then take the narrowing of the Floare with the Compasses off 3 also, and it is here 4 Inches, shewed by the little Spot, or Cross, in the Rising line 3 3, then seeking for the Narrowing at the breadth for Timber 3, there is none that sheweth that she keep­eth the same breadth at 3 still, 20 Foot, but seek for the height of the breadth, and it will lie higher at 3, then in the Midships, by 6 Inches, signified by the little marke in the line A I, a little above I, at the point 3; then for the breadth at top of the Side, finde that at the point 3, in the line V W, drawn to that end, and you will finde that it is narrower there by 2 Foot 7 Inches, then at the breadth, or Tumbleth Home, so much at the height, 24 Foot signified by an Occult dark line, drawn from the top of the Poope to the Foarcastle, to order▪ the height of the Head of the Toptimber Mould, an­swering to the Narrowing of the same, at the line V W; and this point for 3 falls at the little Cross Marke 3, in the upper part of the figure: For the next Example we will set off on our Platforme the rising narrowings of Timber 6, and 6 risth from the Keele 1 foot 7 inches, as you see the parallel▪ line 6 6 for breadth, the same still at the breadth, but the height of the breadth is high­er by one foot, then at the Midship, signified by the mark at 6, in the line; at the breadth, the Tumbling home, 1 foot▪ 7 inches and a halfe, at the height of 25 foot 4 inchos, at the point 6, and so proceed of all the rest, be­ginning at one till you come aft▪ to the fashion Pieces; when you have set off all the heights of Risings, nar­rowings of the Floare, narrowings of the Breadth, height of the Breadth, at the Breadth of the Vessel, [Page 19] and also of the Head of the Toptimber: Then at each point of the Floare, still in a Naile, or a Gimblet, or some such thing, as suppose we begin here at 3, stick one in the Midship line at 3, another in the little Cross, at the narrowing of the Floare at 3; another at the height of the Breadth at 3; another at the little cross, at the head of the Toptimber for 3; then if you have a lower Futtocke Mould, and an upper futtocke Mould, otherwise a navell Timber Mould, and a futtocke Mould, naile them together with small Nailes, and lay the Sirmarks of the floare Mould, and futtock Mould to the Gimblet that sticketh at the shortning of the floare; for by this meanes the floare Mould and futtock Mould is hauled downward: then make a mark at the cross, in the Midship line C D, setting to the marke of 3 for Timber 3, which will be the shortning of the Floare; then be sure the Navell Timber Moulds touch the Gimblet at the breadth, and at the narrowing of the floare, keeping the lower Sirmark thereto; and make a marke on the Futtocke Mould, at the upper Gimblet, for the rising alow lifteth up the Moulds high­er; and if there be any Crossing at the foot of the Navell Timber, and Head of the Floare Mould, marke it, and set to the marke 3 to it, that you may know to lay them together again, and keeping the Futtocke Mould fast, lay to the Toptimber Moulde the breadth Sirmarke of the Toptimber Moulde, to the Gimblet at the breadth, so have you no more Sirmarkes on the Toptimber Moulde but one, and guide the head of him till a line stretched from the Cross, at the head of the Toptimber, till it compareth with the right part of the Toptimber Mould, then regard the Crossing of the [Page 20] foot of the Toptimber Mould, and the back of the futtocke, and marke it, setting to the proper Marke 3 to it, that laying those markes together again, they may finde their own places again, so having finished for this Roome 3, take up the Moulds, and remove the Gimblets to the next, as to 6, here in our Example, and stick the Gimblets at all the markes of 6, then lay down the Mouldes again, laying down the floare Moulde to the Sirmarke of 6, on the narrowing of 6, and to the Gimblet, sticking on the Midship line of D C, and right on the same line, at the crossing, make a marke on the floare Mould, which will be the nar­rowing of the floare; then lay down the futtocke Mould, the Sirmarke on the foot to the Gimblet, on the narrowing of the floare, and keeping the Mold to touch the Gimblets at both places, make a marke for the breadth Sirmarke at 6, on the futtoke Mould, and set to 6; then lay down the Toptimber Mould, the breadth Sirmarke thereof to the Gimblet, sticking at the height of the breadth, that the backside of the up­er end may randge faire, by a right line from the cross at the uper end of the Toptimber at 6, by the back of the Toptimber Mould, a straight line may compare therewith▪ then keeping fast the Mouldes so till you have marked the crossing of the foot of the Toptim­ber Mould, by the back of the futtocke, marke it on the foot of the Toptimber Mould, and set to the marke of 6, so that when you are in any other place, as in the Woods a hewing of a Frame, where you to every place his Timber, you may be able to lay your Moulde together, and moulde it according to your Draught: We will lay down the taking of one bend of Timbers [Page 21] moreafte, where the breadth is narrowed, as at Tim­ber 13, take his rising off, and measure it by the Scale, and it will be 6 foot 8 inches, which set off on your Plat-forme, and draw thereto a Parallel line, to the Ground line A B, as is the line 13 13, then take off the narrowing of the floare, as at 13, it is 2 foot 2 in­ches; set that off on the line 13, from the line E F, as at the little cross thereon, then take off the narrowing of the Breadth at 13, and it will be 8 inches; draw therewith a little parallel line, parallel to I O, as is the parallel line 13 13, then seek the height of the breadth, as at 13, it will be from the uper edge of the Keele 12 foot 3 inches, and crosses the parallel line, at the low­er end of it, just then for the tumbling of the Top­timber it will be 3 foot 3 inches, and at the height of 27 foot 7 inches, at the little Cross 13: Now for the order of the hollow Mould, the little round piece of an Arch, in the Scegg of the Vessell, as it were, take off all the Risings, and mark them on the Rising Staffe, on one edge, that they may be known from the other Ri­sings; as here, for Timber 13, take off the hollow Ri­sing, which will be at 1 foot 10 inches, set it off on the rising Staff, at 1 foot 10 inches from one end, and the use of it will be in Moulding, set off the height of this hol­low Rising on the middle line of the Timber, when the Mouldes are laid to pass, and strike a line from this Ri­sing, on the middle line, untill it breakoff on the back of the Moulds, then lay the hollow Mould to the low­er part of the britch of the Timber, and at the halfe breadth of the Keele, and so bear in the other end till it just touch the streightline, made by the hollow Rising, and the back of the Moulds, and this mouldeth the [Page 22] lower part, or britch of the Timber, and bringeth in the hollow very faire; the same orders may be obser­ved afoare, as abaft, on the other side of the Moulds, and marked with letters, to be known from them abaft: Then for the height of your Waals, you may marke a marke at every third or fourth Timbers, which you re­solve to make frame Timbers; I say, you may make a marke at every third or fourth Timber, for the height of the upper edge, or lower edge of the Waale, and so bring on the Waale fair by those markes on the one side, and with a level finde the height of the other side by the former.

Now I have briefly touched the Demonstration of a Ship, by Projection, I shall now come to an Arithmeticall way, farr surpassing any Demonstration for exactness.

CHAP. VII. Arithmetically shewing how to frame the body of a Ship by Segments of Circles: being a true way to examine the truth of a Bow.

LEt A B represent the length of a Rising line 12 foot long, or 144 inches, the height whereof let be B C, 5 foot, or 60 inches, to finde the side D E, or D A, the radius of the circle A C, whereto A D is the Semidia­meter; multiply the side A B 144 in­ches in it self, and so cometh 20736, which sum di­vide

144
144
576
576
144
20736

[Page 23] by the side B C, the height of the rising 60 inches, and so cometh 345, and 3 [...]6/60, which is abreviated 3; unto this 345 [...]/ [...] must be added again the height of the Rising, the side B e, 60, which make 405 3 of an inch, which is the whole Diameter of the Circle, the half whereof is 202 1/ [...] inches, and something more, near [...]/4, therefore we will avoide the fraction, and account it 203▪ inches, or 16 foot 11 inches, which is the length of the Sweep, or the side D E, and so in all other Sweeps given whatsoever; the Rule is generall, and holds true in all things: as to finde the Sweepe at once, that will round any Beame, or other piece of Timber that is to be Sweept; remembring, that if it be a Beame, you are to finde the Sweepe you take but the half of his length.

23(3
20736(345
6000
66

Example, As if the Beame be 30 foot in length, and to round one foot, you must Work by 15, the halfe length of the Beame; and turne 15 foot into inches, by multiplying 15 by 12, so cometh 180 inches: re­member the length of the Rising line, if it be to finde the Sweepe, it must be multiplied by it selfe, or the halfe length of the Timber must be Multiplied in it selfe, as 180 by 180, so cometh 32400, which must be divided by 12 the rounding, cometh in the quotient 2700, to which must be added the 12 again, the rounding of the piece, and so it is 2712 the whole Circle, the halfe of this 2712 is 1356 for the length of the Sweep, and so in all other matters where the Sweepe is requi­red: This I read in Mr. Gunters Book, where he calls it the halfe Chord, being given, and the Versed fine, to finde the Diameter, and Semidiameter of the circle thereto be­longing:

[Page]

[figure]

[Page 25] Now this half Chord in our Work is the length of the Rising line, and the height of the Rising on the Post is that in our Work, which he represents by the name of the Versed sine, where remember to multiply the length of the Rising line by itself, if it be a Rising line, and divide by the height of the Rising, and to the di­vision add again the height of the Rising, so have you alwayes the whole Circle, divide it by 2, so have you the length of the Sweepe.

Example in the Draught foregoing.

Where the length of the Rising line is from the point E, to the point i, 32 foot; and half the height thereof is the line D i, 10 foot: turne both Summs into inches, as 32 foot multiplyed by 12 produ­ceth, adding the ½ foot 6 inches, 390 inches length for the Rising line: then turn the height of the Rising into in­ches, as 10 foot multiplied by 12, pro­duceth 120 inches, from which 4 in­ches must be substracted, because of the dead Rising is 4 inches, so then the height is 116 inches: Now multiply the length 390 inches by it self, 390 maketh 152100.

390
390
000
3510
1170
152100

This Multiplication of the summ 152100, must be divided by 116 in­ches, the height of the Rising, and so cometh in the quotient of the de­vision 1311 inches; unto this 1311 inches, must be added the 116 inches, the height of the Rising 116/1427, and it maketh 1427, which is the whole

112
3323
46344
152100 (1311
116666
0111
11

[Page 26] Circle: divide it by 2, to finde the half of it, so have you in the quotient 713 inches ½ inch for the length of the Sweep, which divided by 12, to bring it into feet, maketh 59 feet, 5 inches and a halfe, and so for all other Circular lines whatever, when the length is known, and the rounding of them also known; as for the hanging of Waals, the height of them known in the Midships from the Keele, sub­stracted from the height, at the Post, and that will be the hanging of them, which is the same with the height of the Rising line on the Post, in the Arithmeticall Work, and is the same with the Versed sine in Geometry; these I think Examples sufficient, to signifie the Construction of this way of Working by Sweepes.

1
1427 (713
222

It followeth now that I shew the manner of finding the Risings of Timbers by Arithmetick also.

To finde the Rising of the line F E, in the Figure foregoing.

The Sweepe being first found to be as before 203 in­ches, as the side D E signifieth, then there is known the side E G, 108 inches; now these two sides being given, we are to finde the third side D G, so here is made a right Angled Triangle, two sides thereof are given to finde a third, which to do, proceed thus; Mul­tiply the two sides given by themselves, and substract the Multiplication of the shortest side, from the Mul­tiplication made of the other sides, and extract the square Root of the remainder, so have you the third side sought for.

[Page 27]

Example in the following Triangle.

Having the side D C, 12 foot, which is 144 inches▪ and the side A C, 10 foot, otherwise 120 inches; to finde the side D A, multiply the sides given, in themselves, which is called squaring of them: as, multiply the side D C, 144 inches, by 144 inches, so cometh 20736. Then multiply the other side A C 120 also by it self, so cometh in the quotient 14400, which must be substracted from the o­ther Multiplication, as you see, so cometh in the quotient 6336, from which the greatest square must be extracted, cal­led extraction of the square root,

144
144
576
576
144
20736
120
120
000
240
120
14400
20736
14400
6336

[Page 28] which is 79 inches, and almost another by the Fraction, that is 6 foot, and very near 8 inches.

1
595
147
6 [...]3 [...](79
14

Note, These Demonstrations, this and the former, are laid down by the first Scale, made to shew the Demonstration of a Scale in this Book, at the beginning.

Another Example.

So in the last Figure foregoing but one, the side D E, 203 inches, which squared, or multiplied in it self, is 41209.

203
203
609
000
406
41209

Then the other side G E, 108, multi­plied in it selfe, which is squaring of it, is 12664, as you see.

108
108
864
000
168
11664

Which substracted from the other mul­tiplication, as 11664 substracted from 41209, resteth 29545, the square Root ex­tracted from it, or the side of the greatest square that can be taken from the substra­ction being found, is 171, and ¾; which 171 ¾, substracted from 203, the length of the Sweepe for one side, is al­wayes the length of the Sweepe, resteth 31 inches ¼, for the Rising of the line E F, and the like for any other Rising.

41209
11664
29545
(3
156(08
29549( [...]7
.2.
34

Another Example.

As at the place K I, the Rising thereof is required, the side D I is as D E, 203 inches.

Note, The length of the Sweepe being found, al­wayes is one of the sides, in the finding the Rising of any Timber, and is alwayes one of the numbers, which when you have squared, note in a piece of Paper by it self, where you may al­wayes see what it is, so that in the finding of Risings, after the Sweepe is found, all you have to do, is to know how many feet, or inches, the Timber you seek for is removed from the beginning, or foot of the Rising line, which is the second side, and in this third Example it is 11 foot, or 132 inches K I, from the foot of the line A, which squared, is 17424, which must be substracted from the square made of Radius, which in the other example is 41209, and so resteth 23775, from which extract the side of the Square therein contained, and it is 154 inches and ¼, which sub­stracted from the length of the Sweep, leaveth 48 inches for the Rising, and ¾ inches, or 4 foot, and ¾ of an inch, and so much is the Rising of the said Timber.

132
132
264
396
132
17424
41209
17424
23775
10
132(69
23785(154
.2.0.
3

One Example in the Draught, The length of that Sweepe we found heretofore to be 713 inches, then we [Page 30] will seek to finde the Rising for Timber 13, standing aft from the point E, or foot of the Rising line 324 in­ches, these are the given Sides; then proceed; square the Semidiameter of the Sweepe 713, so it maketh squared 508363; then square the distance of the Tim­ber 13, which is 324, and it maketh 104976; these substracted from the former figures, resteth 403387, the square Root thereof is 635 ¼, nearest, which sub­stracted from the Radius 713, resteth 77 inches and ¼, that is 6 foot 5 inches, which with 4 inches Dead Ri­sing, is 6 foot 9 inches ¼; and so much is the Rising of Timber 13 from the Keele.

I suppose these Examples are sufficient to illustrate the truth and plainness of this Arithmeticall Work, for the truth of it; it hath this to say for it self, that it is the very exact truth it self: The great Objection may be, that many know not the way to Extract the Square Root, and therefore cannot attaine to this Work, by reason of that let, or hinderance.

To this I Answer, There are many Books that will instruct thee in it, that thou mayest buy, or borrow; but to answer thee better, I will briefly shew thee the man­ner of Extracting the Square, not doubting but thou canst performe Addition, Substraction, Multiplication, and Division already.

CHAP. VIII. How to Extract the Square Root.

KNow then that a square number hath its sides equall every way, as are the sides of 4, repre­sented by ⸬ pricks; and you see that every way of all the 4 sides it containeth 2, and so 2 times 2, make 4, which is the squaring of a number, so you see ⋮⋮⋮ 9 pricks is a square, or 9 is a square number, whose side is 3, and 3 times 3 make 9, but 2 times 3 is not a square number, as you see :::, being but 2 one way, and the other way 3, that make but 6; so then all the numbers between 4 and 9, are not square numbers: by the like reason, a square, made of the Next square number 4 is 16, for 4 times 4 is 16, as by the Pricks you may see it repre­sented here, every of the 4 sides con­taining 4, make a squared number of 16, and all the numbers that are between 9 and 16, as 2 times 4, or 3 times 4, are not squares, but have a fraction annexed to them; so also any number betwen 16 and 25, are not squares, as 4 times 5, or 2 times 5, or 3 times 5, these are not square numbers, but 5 times 5 is a squared number, and ma­keth 25, where note, that to square a number, and to extract the square root, is two different things; for when we say, to square a number, is to multiply it in it self, or by it itselfe; or

[figure]
[figure]

[Page 32] when we say, or speake of a number squared, it is a number multiplied in it self, but to extract the square Root, is to finde the side of the square in a number gi­ven, or the extracted square Root is the square Root found in any given number.

Thus you may conceive of the Squares of 6, for 6 times 6 make 36; 7 times 7 make 49; 8 times 8 make 64; 9 times 9 make 81; 10 times 10 make 100: there is all the squares made of the 9 Figures, ex­pressed by this little Table annexed, as against each Figure is the square made of them, as 2 times 2 is 4, so is 4 a­gainst 2, as you see.

1 1
2 4
3 9
4 16
5 25
6 36
7 49
8 64
9 81
10 100

Now to extract the square Root from greater numbers, as from 144 proceed thus, write downe the summe given, as followeth, and make a quo­tient on the right hand, as you see, then set pricks under every other figure beginning at the right hand, and set pricks towards the left hand, under every other figure, so in this number 144, consisting of 3 figures, there is 2 pricks, and so many figures must the quotient consist of; then begin at the left hand of the summ, and say, or enquire for the greatest square in the figure, or figures, over the first prick, at the left hand, which here is but 1, therefore you can take but 1, for 1 is alwayes the Square, or Cube of 1, therefore write 1 in the quotient, and substract that 1 from the 1 over the left hand prick,

144 (
. .
0
144 (1
. .

[Page 33] and Cancell it, nothing remainining, write a Cipher over it, as you see, so have you one figure of the quoti­ent, then double your figure found in the quotient, as 2 times 1 is 2; write that 2 under the figure between the next prickes, which is the Divisor for the second figure, then say, how many times 2 can I have in 4, over the Divisor, I say 2, therefore I write 2 in the quotient, saying, 2 times 2 is 4, which substract from the 4 over head, Cancell the Divisor, and the 4 over head, and write a Cipher over it, then square the last figure found in the quo­tient, saying, 2 times 2 is 4, which substract from the 4 over the prick, and so resteth 0, therefore cancell the 4, and write Ciphers over head, signifying, that the number given to finde the roote of, is a just square number, the roote or side is 12, the proofe hereof is by Multiplication of the quotient in it self, as 12 by 12 make 144, which, if it be the same with the summ gi­ven to be Extracted, it is rightly done▪ if it do not a­gree, it is not true.

000
144 (12
.2.

Example of another Summ.

Let 625 be given to finde the Square Root of it, write down the summ, make a quotient, and set pricks under every other figure; then enquire for the greatest square in the figure, over the pricke, at the left hand; I say, 2 is the greatest square can be taken: for 3 times 3 is 9, and here the figure is but 6; so I write 2 in the quotient, and square it, saying, 2 times 2 is 4, taken from 6, so resteth 2; I cancell the 6, and write 2

2
625 (2
. .

[Page 34] over it, as you see, then double the fi­gure in the quotient, saying, 2 times 2 is 4; this 4 is the second Divisor, I write it between the two next pricks, and say, how many times 4, can I have in 22, and I finde 5 times; for 5 times 4 is 20, taken from 22, the figures over 4, so resteth 2; therefore I write 5 in the quotient, and saying, 5 times 4 make 20▪ therefore I cancell the 4 Divisor, and the 22, and write 2 overhead, then square the last figure found, 5 by 5 make 25, taken from 25 over head▪ resteth nothing, so the number given is a square number.

2
625 (2
.4.
22
625 (25
.4.
22
625 (25
.4.

A Summ of 5476, given to finde the nearest Square Root in it, write down the Summ, and make a quotient and prick underneath, as afore shew­ed; say, What is the greatest Square in the figures over the left hand prick? and I finde it to be 7, for 7 times 7 make 49, but 8 times 8 make 64, 10 too much, there­fore I write 7 in the quotient, and take 7 times 7, that is 49 from 54, so resteth 5, which I write over the prick, and Cancell the 5 and the 4; then I double the figure in the quotient, which maketh 14, for the Divisor, I write the first figure of the Divisor, if there be more then 1 under the figure, be­tween the two next pricks, and all the other figures, in their places, toward the left hand; then inquire how many times can 1 be taken from 5, overhead, and I finde it may be taken 4 times; I write therefore 4▪

5
5476 (7
. .
1
51
5476 (74
. .
14

[Page 35] in the quotient, and say, 4 times 1 is 4, from 5; so rest­eth 1: I Cancell the 1 and the 5, and write 1 over the 5, then I say, 4 times 4 make 16, from 17 resteth 1: I Cancell the 4 Divisor, and write 1 over 7, and Cancell the other 1 and the 7; then I square the last figure found, for so it must be at every prick, 4 times 4 make 16, which I substract from the 16 over the last prick, and so I see no­thing remaineth, that sheweth the sum given, to be a just square summ.

10
510
5476 (74
. .
14

Example of another Summ.

As if 528563 be given to finde the greatest side of the Square therein, I write down the Summ, as followeth, and make the quotient, and set the pricks under every other figure, as you see; and seeing there is 3 pricks, it telleth, that there must be 3 figures in the quotient, then beginning at the figures over the left hand pricke, I take the greatest square in 52, and I finde it 7, for 7 times 7 make 49; therefore I write down 7 in the quotient, and Sub­stract 49 from 52, so resteth 3, there­fore Cancell the 52, and write 3 over the 2, as you see; then double the quotient 7, it ma­keth 14, for a new Divisor, which write down, the first figure thereof, under the figure between the two next pricks, namely 4 under 8, and the other figure of the Divisor one place far­ther to the left hand, under the 3, as you see; then take the Divisor 1 as many times as you can, from the fi­gure

3
528563 (7
. . .
3
528563 (7
. . .
14

[Page 36] 3 over head, so as that after the Division be made, there may be the square of the last figure of the quoti­ent, taken from the figures over the next prick, as I can take 1 but 2 times from 2, therefore I write 2 in the quotient, and Cancell the Divisor 1, saying, 2 times 1 is 2, from 3; so resteth 1: I Cancell the figure 3 also, and write 1 overhead, as you see: then 2 times 4 is 8, from 8 over head resteth nothing; therefore I Cancell the se­cond figure of the Divisor, 4 and 8, and write a Cipher over 8, as you see; then the next place being a prick, I must square the last figure found, say­ing, 2 times 2 make 4, from 5; the figure over the prick resteth 1, as you see; therefore I Cancell the 5, and write 1 over it, as you see, and here is a fraction of 101.

1
30
528563 (72
14
1
301
528563 (72
14

Then for a new Divisor, Double the quotient 72, and it makes 144, which is a new Divisor, the first fi­gure thereof write under the figure between the next pricks, as the first 4 under 6, in the summ; and the other figures towards the left hand, in the order as you see: then, how many times 1 in 10 over head, and I see I cannot take 8 times, for that there will not be left to take out the other figures from, nor for the square of the last figure, which if it were 8, would be 64 from the figure over the pricke, therefore I take but 7, for by a light examination I see that will doe, there­fore I write down 7 in the quotient, and proceed to the

1
301
528563 (727
14 4
14

[Page 37] Division, thus, 7 times 1 is 7, from 10 over head remaineth 3, which I write down, and Cancell the 10, as you see; then 7 times 4 is 28, from 31 over head, so remaineth 3, which I also write down, and Cancell the 31; then again, 7 times 4, the other figure of the Di­visor, is also 28, which taken from 36 over head, resteth 8, which I write down over 6, and so Cancell the 36, and then the Summ standeth as you see.

13
301
528563 (727
14 4
14
133
301
528563 (727
14 4
14
133
3018
528563 (727
14 4
14
133(3
530 [...]8 (4
528563 (727
14 4
14

Then lastly, square the last figure of the quotient, 7 times 7 make 49, taken from 83, the figures over the prick, resteth 34, as a fraction, and the Summ is finished: But in regard here is a fraction, by that it tells you, that the Summ given was no square num­ber; and the greatest square therein is 727, the proofe is by Multiplication adding in the fraction thus, 727 Mul­tiplied by 727, make 528529, then adding in the fra­ction of 34, maketh it 528563, the just Summ gi­ven.

But some may Object, and say, That this is a very tedi­ous way of Work, and will take up a great deale of time; It is true, it is more labour then demonstration, but the truth of it might very well plead for patience to Work it, but it is not necessary you performe all the parts by it, that is, in every particular: as the exact hanging of the Waal at every Timber, but it may suffice [Page 38] at every third or fourth Timber, to finde the hanging of the Waals, onely the Risings alow, afoare and abaft, I would work to every Timber there.

But to make it more briefe, here followeth a Ta­ble that the numbers are therein contrived to the same purpose, to avoide the tedious Extraction of the Root, and onely use Addition and Substraction, onely being but a very little difference between the finding the Ri­sings by this Table, and by the Draught, for in this kinde of Arithmeticall Work, it mattereth not, whether or no there be any Draught drawn at all, or no, if the buil­der onely note in his Book the length by the Keele, and the breadth at the Beame, the Racke of the Stem, Racke of the Post, depth of the Water, to Sayle in depth of the Hould, height of the Waals abaft, afoare, at the Midships, and all the remarkable things to be noted, he may be able to Build a Vessell, and never draw a Draught at all, and yet affirm his Worke to be absolutely true, according to Art, and a great deale more exact then by Draught: I shall in few words shew you the use of the Table, and so conclude.

CHAP. IX. A Description of the Table of Squares.

TO save the Practitioner a labour of Extracting of Roots, for here they are ready done to thy hand of purpose, and all the use of Arithmetick required is onely Substraction, as Example in the Figure of the Sweep foregoing, being found to be 203 inches, as you saw it found before, which is, I say, alwayes one side of the Triangle, made of the side DI, then know­ing the length of [...]I, 132 inches, which is the distance of the point, of which the Rising is sought at; seek in the Tables, under the Title of inches, at the head of the Tables, for 132, you will finde it in the second Page, and the twelfth line; and right against it, in the same line, under the next Title of Squares, you have 17424, the square made of 132, which Substract from the Square made of 203, which is 41209, which is found in the second Page of the Tables, and the third line: Now the other number 17424, Substracted from 41209, so resteth 23775; seek the number nearest to it in the Ta­ble, under the Title of Squares, which you will finde in the second Page, 34 line, you finde not just the same number, for in stead of 23775, you finde 23716 too little by 59, and the Root answering thereto, is in the same line, under the Title of inches, towards the left [Page 40] hand, which is 154; now if you take the next square lower to the left hand 35 line, it is 24025, 250 too much, so you may see it is nearer to the 34th line, because there it was too little but by 59, so that you may see it will be ¾ of an inch less then the number of inches, belonging to the 35th line, and about ¼ of an inch more then the numbers in the 34th line; so that you see it is answered, the third side D 0 is 154, and ¼ of an inch, which Substracted from the whole Sweep 203, leaveth 48¾ inches for the Rising, so you have no need of extraction of the Rootes by these Ta­bles, it is already done to your hand; the Columne that is between the inches and the squares, and written feet in­ches in the head, is to shew you, how may feet, and inches of the foot any number of inches is; as here, the number 203 inches sought, and found in the Tables, in the second page, and third line, just against it, in the same line, between that and the squares, is 16—11, shewing that it is 16 feet and 11 inches; or if the square were given, as 41209, found at the second page, and third line, next toward the left hand, you have 16 foot, 11 inches; and if you seek for it in inches, in the third Columne toward the left hand, and the same line, you have 203 inches: Thus is it very ready to reduce inches into foot measure, or feet into inches.

Another Example.

In the same figure, to finde the Rising at the point F, the sweep being 203 inches, as before is said, is alwayes one side, throughout the whole Work of the same Ri­sing line is 41209, as is found in the second page, the [Page 41] third line; the other fide from the point A to F, is 9 foot, or 108 inches, whose square is 11664, found in the first page, and the 28th line; now sub­stract the square made of the side A F, 11664, from the square of the side D E, so remain­eth 29545

41209
11664
29545

Seek in the Table of squares for that number, and I finde in the second page, and 12 line, and the sixth Co­lumne, 29584, the nearest number to it, yet it is a little too much near the ¼ of an inch; and toward the left hand in the same line, the next Column under the title feet inch, you finde 14; 4 signifying that to be 14 foot, 4 inches: and in one Columne more to the left hand, and the same line, you see under the Title of inches 172 over the head you tituled inches, which must be subracted from 203 inch, so re­maineth 3 inches for the Rising of F E, which is 2 foot, 7 inches, as in the first page of the Table, and the 31 line.

203
172
031

These few Examples I think may be sufficient to shew the use of the following Tables of squares, the benefit where of may be very great, for such as shall make use of the same: If any desire the finding of the Fractions of these squares, when he findeth not his just figures in the squares, let him do thus, substract the Figures under his number, from the Figures above his number, which shall be the denominator, then these Figures given, sub­stracted, from which the next squares less, shall be the denominator to that Fraction.

As for Example, In the foregoing figures, after substra­ction, should have been 29553; the nearest agreeing in the Tables, is 29584, the next lesser square number in the Table is 29241, which is more a great deale too lit­tle, [Page 42] then the other is too great; then substract the lesser square number 29241, from 29584, and so resteth 343, which must be the deno­minator, then again substract the true number given, 29553, the next lesser square number in the Table is 29241, which must be sub­stracted, I say, from the true number given, 29553, and so resteth after substraction 312, which is the Numera­tor to the Fraction, and must be thus written, [...] so then the number belonging to 29584, is 171 inches, and 312/343 parts of an inch, which being abreviated, is something more then ¼ of one inch, and not full ⅞ of one inch.

29584
29241
343

Thus he that pleaseth may finde the rising of any Timber, or narrowing of any place by these Tables and the help of Substraction, exactly to any Circle whatsoe­ver, but it may suffice, that a Man, going to his Tables, may see which square his figures have greatest affinity with, and may estimate the difference near enough, with­out seeking for the fraction, which will be easily known by much practise herein.

HEre followeth a Table of Square Roots, ready Ex­tracted, from one Inch to 1300 Inches, which is to 108 foot▪ and 4 Inches, and it is thus contraved, That from one Inch, to 840 Inches, all the Inches are reduced into Feet and Inches▪ for the ease and help of Workmen, who alway take their Measures by Feet and Inches; but from thence to the end of the table you have the Inches onely, and the Squares thereof against them as the Titles over every Page do make appear.

[Page 43]

A Table of Square Roots.
Inch Feet Inches Squares
1   1 1
2   2 4
3   3 9
4   4 16
5   5 25
6   6 36
7   7 49
8   8 64
9   9 81
10   10 100
11   11 121
12 1 00 144
13 1 1 169
14 1 2 196
15 1 3 225
16 1 4 256
17 1 5 289
18 1 6 324
19 1 7 361
20 1 8 400
21 1 9 441
22 1 10 484
23 1 11 529
24 2 00 576
25 2 01 625
26 2 2 676
27 2 3 729
28 2 4 784
29 2 5 841
30 2 6 900
31 2 7 961
32 2 8 1024
33 2 9 1089
34 2 10 1156
35 2 11 1225
36 3 00 1296
37 3 1 1369
38 3 2 1444
39 3 3 1521
40 3 4 1600
41 3 5 16 [...]1
42 3 6 1764
43 3 7 1849
44 3 8 1936
45 3 9 2025
46 3 10 2116
47 3 11 2209
48 4 00 2304
49 4 1 2401
50 4 2 2500
51 4 3 2601
52 4 4 2704
53 4 5 2809
54 4 6 2916
55 4 7 3025
56 4 8 3136
57 4 9 3249
58 4 10 3364
59 4 11 3481
60 5 00 3600
61 5 1 3721
62 5 2 3844
63 5 3 3964
64 5 4 4096
65 5 5 4225
66 5 6 4356
67 5 7 4489
68 5 8 4624
69 5 9 4761
70 5 10 4900
71 5 11 5041
72 6 00 5184
73 6 1 5329
74 6 2 5476
75 6 3 5625
76 6 4 5776
77 6 5 5929
78 6 6 6084
79 6 7 6241
80 6 8 6400
81 6 9 6561
82 6 10 6724
83 6 11 6889
84 7 00 7056
85 7 1 7225
86 7 2 7396
87 7 3 7569
88 7 4 7744
89 7 5 7921
90 7 6 8 [...]00
91 7 7 8 [...]81
92 7 8 8464
93 7 9 8649
94 7 10 8836
95 7 11 9025
96 8 0 9226
97 8 1 9409
98 8 2 9604
99 8 3 9801
100 8 4 10000
101 8 5 10201
102 8 6 10404
103 8 7 10609
104 8 8 10816
105 8 9 11025
106 8 10 11236
107 8 11 11449
108 9 0 11664
109 9 1 11881
110 9 2 12100
111 9 3 12321
112 9 4 12544
113 9 5 12769
114 9 6 12996
115 9 7 13225
116 9 8 13456
117 9 9 13689
118 9 10 13924
219 9 11 14162
120 10 0 14400
[Page 44]121 10 1 14641
122 10 2 14884
123 10 3 15229
124 10 4 15376
125 10 5 15625
126 10 6 15876
127 10 7 16029
128 10 8 16384
129 10 9 16641
130 10 10 16900
131 10 11 17161
132 11 00 17424
133 11 1 17689
134 11 2 17956
135 11 3 18225
136 11 4 18496
137 11 5 18769
138 11 6 19044
139 11 7 19321
140 11 8 19600
141 11 9 19881
142 11 10 20164
143 11 11 20449
144 12 00 20736
145 12 01 21025
146 12 2 22416
147 12 3 21609
148 12 4 21904
149 12 5 22201
150 12 6 22500
151 12 7 22801
152 12 8 23104
153 12 9 23409
154 12 10 23716
155 12 11 24025
156 13 00 24336
157 13 1 24649
158 13 2 24964
159 13 3 25381
160 13 4 25600
161 13 5 25921
162 13 6 26244
163 13 7 26569
164 13 8 26956
165 13 9 27225
166 13 10 27556
167 13 11 27889
168 14 00 28224
169 14 1 28561
170 14 2 28900
171 14 3 29241
172 14 4 29584
173 14 5 29929
174 14 6 30276
175 14 7 30625
176 14 8 31076
177 14 9 31329
178 14 10 31684
179 14 11 32041
180 15 00 32400
181 15 1 32761
182 15 2 33124
183 15 3 33489
184 15 4 33856
185 15 5 34025
186 15 6 34596
187 15 7 34969
188 15 8 35344
189 15 9 35721
190 15 10 36100
191 15 11 36481
192 16 00 36864
193 16 1 37249
194 16 2 37636
195 16 3 38025
196 16 4 38416
197 16 5 38809
198 16 6 39204
199 16 7 39601
200 16 8 40000
201 16 9 40401
202 16 10 40844
203 16 11 41209
204 17 00 41616
205 17 1 42025
206 17 2 42436
207 17 3 42849
208 17 4 43264
209 17 5 43681
210 17 6 44100
211 17 7 44521
212 17 8 44944
213 17 9 45369
214 17 10 45796
215 17 11 46224
216 18 0 46656
217 18 1 47089
218 18 2 47524
219 18 3 47961
220 18 4 48400
221 18 5 48841
222 18 6 49284
223 18 7 49729
224 18 8 50176
225 18 9 50625
226 18 10 51076
227 18 11 51529
228 19 0 51984
229 19 1 52441
230 19 2 52900
231 19 3 53361
232 19 4 53824
233 19 5 54289
234 19 6 54656
235 19 7 55225
236 19 8 55696
237 19 9 56069
238 19 10 56644
239 19 11 57121
240 20 0 57600
[Page 45]241 20 1 58081
242 20 2 58564
243 20 3 59049
244 20 4 59536
245 20 5 60025
246 20 6 60516
247 20 7 61009
248 20 8 61504
249 20 9 62001
250 20 10 62500
251 20 11 63001
252 21 0 63504
253 21 1 64009
254 21 2 64516
255 21 3 65025
256 21 4 65536
257 21 5 66049
258 21 6 66564
259 21 7 67081
260 21 8 67600
261 21 9 68121
262 21 10 68644
263 21 11 69169
264 22 0 69596
265 22 1 70425
266 22 2 70756
267 22 3 71289
268 22 4 71824
269 22 5 72361
270 22 6 72900
271 22 7 73441
272 22 8 73984
273 22 9 74529
274 32 10 75076
275 22 11 75575
276 23 0 76176
277 23 1 76729
278 23 2 77284
279 23 3 77841
280 23 4 78400
281 23 5 78961
282 23 6 79524
283 23 7 80089
284 23 8 80656
285 23 9 81225
286 23 10 81796
287 23 11 82369
288 24 0 82944
289 24 1 83521
290 24 2 84100
291 24 3 84681
292 24 4 85264
293 24 5 85849
294 24 6 86436
295 24 7 87025
296 24 8 87616
297 24 9 88209
298 24 10 88804
299 24 11 89401
200 25 0 90000
301 25 1 90601
302 25 2 91204
303 25 3 91809
304 25 4 92416
305 25 5 93025
306 25 6 93636
307 25 7 94241
308 25 8 94864
309 25 9 95481
310 25 10 96100
311 25 11 96721
312 26 0 97344
313 26 1 97969
314 26 2 98596
315 26 3 99225
316 26 4 99856
317 26 5 100489
318 26 6 101124
319 26 7 101761
320 26 8 102400
321 26 9 103041
322 26 10 103684
323 26 11 104329
324 27 0 104976
325 27 1 105625
326 27 2 106276
327 27 3 106929
328 27 4 107584
329 27 5 108241
330 27 6 108900
331 27 7 109561
332 27 8 110224
333 27 9 110889
334 27 10 111556
335 27 11 112225
336 28 0 112896
337 28 1 113569
338 28 2 114244
339 28 3 114921
340 28 4 115600
341 28 5 116281
342 28 6 116964
343 28 7 117349
344 28 8 118336
345 28 9 119025
346 28 10 119716
347 28 11 120409
348 29 0 121104
349 29 1 121801
350 29 2 122505
351 29 3 123206
352 29 4 123909
353 29 5 124604
354 29 6 125311
355 29 7 126025
356 29 8 126736
357 29 9 127449
358 29 10 128164
359 29 11 128881
360 30 0 129600
[Page 46]361 30 1 130321
362 30 2 131044
363 30 3 131779
364 30 4 132496
365 30 5 133225
366 30 6 133956
367 30 7 134689
368 30 8 135424
369 30 9 136161
370 30 10 136900
371 30 11 137640
372 31 0 138384
373 31 1 139129
374 31 2 139876
375 31 3 140625
376 41 4 141676
377 31 5 142129
378 31 6 142984
379 31 7 143641
380 31 8 144400
381 31 9 145161
382 31 10 145924
383 31 11 146689
384 32 0 147456
385 32 1 148225
386 32 2 149006
387 32 3 149769
388 32 4 150544
389 32 5 151321
390 32 6 152210
391 32 7 152831
392 32 8 153664
393 32 9 15444 [...]
394 32 10 155236
395 32 11 156025
396 33 0 156816
397 33 1 157609
398 33 2 158104
399 33 3 159201
400 33 4 160000
401 33 5 160801
402 33 6 161604
403 33 7 162409
404 33 8 163216
405 33 9 164025
406 33 10 164836
407 33 11 165649
408 34 0 166464
409 34 1 167281
410 34 2 168100
411 34 3 168921
412 34 4 169744
413 34 5 170569
414 34 6 171396
415 34 7 172225
416 34 8 173056
417 34 9 173889
418 34 10 1747 [...]4
419 34 11 175561
420 35 0 176400
421 35 1 177241
422 35 2 178084
423 35 3 178959
424 35 4 17977 [...]
425 35 5 180625
426 35 6 181476
427 35 7 182329
428 35 8 183184
429 35 9 184041
430 35 10 184900
431 35 11 185761
432 36 0 186624
433 36 1 187789
434 36 2 188 [...]56
435 36 3 1898 [...]5
436 36 4 190096
437 36 5 190960
438 36 6 191044
439 36 7 192721
440 36 8 193600
441 36 9 194481
442 36 10 195364
443 36 11 196249
444 37 0 197136
445 37 1 198025
446 37 2 198916
447 37 3 199809
448 37 4 200704
449 37 5 201601
450 37 6 202509
451 37 7 203401
452 37 8 204304
453 37 9 205 [...]90
454 37 10 206116
455 37 11 2070 [...]5
456 38 0 207936
457 38 1 208849
458 38 2 209 [...]64
459 38 3 210681
460 38 4 2116 [...]0
461 38 5 212521
462 38 6 213444
463 38 7 214369
464 38 8 215296
465 38 9 2162 [...]5
466 38 10 217156
467 38 11 218089
468 39 0 219024
469 39 1 219961
470 39 2 220 [...]0
471 39 3 221841
472 39 4 222784
473 39 5 223729
474 39 6 224676
475 39 7 225625
476 39 8 226576
477 39 9 227429
478 39 10 228484
479 39 11 229141
480 40 0 2304 [...]
[Page 47]481 40 1 231361
482 40 2 232324
483 40 3 233289
484 40 4 234216
485 40 5 235225
486 40 6 236196
487 40 7 237 [...]69
488 40 8 238144
489 40 9 239121
490 40 10 240100
491 40 11 240981
492 41 0 2420 [...]4
493 41 1 243049
494 41 2 244036
495 41 3 245025
496 41 4 246016
497 41 5 246509
498 41 6 247004
499 41 7 249001
500 41 8 250000
501 41 9 251001
502 41 10 252004
503 41 11 253009
504 42 0 254016
505 42 1 255025
506 42 2 256036
507 42 3 257049
508 42 4 258064
509 42 5 269081
510 42 6 260100
511 42 7 261121
512 42 8 262144
513 42 9 363169
514 42 10 264196
515 42 11 265225
516 43 0 266256
517 43 1 267289
518 43 2 268324
519 43 3 269361
520 43 4 270400
521 43 5 271441
522 43 6 272448
523 43 7 273529
524 43 8 274576
525 43 9 275625
526 43 10 276676
527 43 11 2777 [...]9
528 44 0 278784
529 44 1 280 [...]41
530 44 2 280900
531 44 3 281961
532 44 4 284 [...]24
533 44 5 2870 [...]9
534 44 6 285156
535 44 7 286225
536 44 8 287296
537 44 9 288369
538 44 10 290444
539 44 11 290521
540 45 0 291600
541 45 1 292681
542 45 2 293764
543 45 3 294849
544 45 4 295936
545 45 5 297025
546 45 6 298016
547 45 7 299209
548 45 8 300304
549 45 9 301401
550 45 10 302500
551 45 11 303601
552 46 0 304704
553 46 1 305809
554 46 2 306916
555 46 3 308025
556 46 4 309136
557 46 5 310 [...]49
558 46 6 311364
559 46 7 312481
560 46 8 313600
561 46 9 314721
562 46 10 315844
563 46 11 316969
564 47 0 318096
565 47 1 319225
566 47 2 320356
567 47 3 321489
568 47 4 322624
569 47 5 323761
570 47 6 324900
571 47 7 326041
572 47 8 327184
573 47 9 328329
574 47 10 330276
575 47 11 330625
576 48 0 331776
577 48 1 332929
578 48 2 384048
579 48 3 335241
580 48 4 336400
581 48 5 337561
582 48 6 338724
583 48 7 340089
584 48 8 341056
585 48 9 3422 [...]5
586 48 10 343396
587 48 11 344669
588 49 0 345744
589 49 1 346921
590 49 2 348100
591 49 3 349281
592 49 4 350464
593 49 5 351649
594 49 6 352836
595 49 7 353925
596 49 8 354216
597 49 9 355409
598 49 10 356 [...]04
599 49 11 358801
600 50 0 360000
[Page 48]601 50 1 361201
602 50 2 362404
603 50 3 363609
604 50 4 364816
605 50 5 366025
606 50 6 367236
607 50 7 368449
608 50 8 369664
609 50 9 370881
610 50 10 372100
611 50 11 373321
612 51 0 374544
613 51 1 375769
614 51 2 376996
615 51 3 378225
616 51 4 379456
617 51 5 380689
618 51 6 381924
619 51 7 383161
620 51 8 384400
621 51 9 385641
622 51 10 386884
623 51 11 388129
624 52 0 389376
625 52 1 390625
626 52 2 391876
627 52 3 393129
628 52 4 394384
629 52 5 395641
630 52 6 396900
631 52 7 398161
632 52 8 399424
633 52 9 400489
634 52 10 401956
635 52 11 403225
636 53 0 404496
637 53 1 405769
638 53 2 407044
639 53 3 408321
640 53 4 409600
641 53 5 410881
642 53 6 412164
643 53 7 413449
644 53 8 414736
645 53 9 416025
646 53 10 417316
647 53 11 418609
648 54 0 429904
649 54 1 421201
650 54 2 422500
651 54 3 423801
652 54 4 425104
653 54 5 426403
654 54 6 427716
655 54 7 429025
656 54 8 430336
657 54 9 431449
658 54 10 432969
659 54 11 434181
660 55 0 435600
661 55 1 436921
662 55 2 438244
663 55 3 439569
664 55 4 440896
665 55 5 442225
666 55 6 443556
667 55 7 444889
668 55 8 446224
669 55 9 447561
670 55 10 448900
671 55 11 450241
672 56 0 451544
673 56 1 452829
674 56 2 454276
675 56 3 455625
676 56 4 456976
677 56 5 458329
678 56 6 459684
679 56 7 461041
680 56 8 462400
681 56 9 463761
682 56 10 465124
683 56 11 466489
684 57 0 467856
685 57 1 469225
686 57 2 470596
687 57 3 471939
688 57 4 473344
689 57 5 475721
690 57 6 476700
691 57 7 477841
692 57 8 478864
693 57 9 480269
694 57 10 481636
695 57 11 482825
696 58 0 484416
697 58 1 485809
698 58 2 487204
699 58 3 488601
700 58 4 490000
701 58 5 491401
702 58 6 492804
703 58 7 494209
704 58 8 495616
705 58 9 497025
706 58 10 498436
707 58 11 498849
708 59 0 501264
709 59 1 502681
710 59 2 504100
711 59 3 505521
712 59 4 506944
713 59 5 508669
714 59 6 509796
715 59 7 511225
716 59 8 512656
717 59 9 514089
718 59 10 515824
719 59 11 516961
720 60 0 518400
[Page 49]721 60 1 519841
722 60 2 521284
723 60 3 522729
724 60 4 524176
725 60 5 525625
726 60 6 526976
727 60 7 528529
728 60 8 529984
729 60 9 521421
730 60 10 522900
731 60 11 524361
732 61 0 535844
733 61 1 537289
734 61 2 538656
735 61 3 540225
736 61 4 541696
737 61 5 543169
738 61 6 544644
739 61 7 546031
740 61 8 547600
741 61 9 549081
742 61 10 550564
743 61 11 552049
744 62 0 553436
745 62 1 555025
746 62 2 556516
747 62 3 558009
748 62 4 559504
749 62 5 561001
750 62 6 562500
751 62 7 564001
752 62 8 565504
753 62 9 567009
754 62 10 568516
755 62 11 570025
756 63 0 571536
757 63 1 573049
758 63 2 574564
759 63 3 576081
760 63 4 577600
761 63 5 579121
762 63 6 580644
763 63 7 582169
764 63 8 583696
765 63 9 585225
766 63 10 586756
767 63 11 588289
768 64 0 589824
769 64 1 591361
770 64 2 592900
771 64 3 594441
772 64 4 595984
773 64 5 597529
774 64 6 599076
775 64 7 600625
776 64 8 602176
777 64 9 604729
778 64 10 606284
779 64 11 607841
780 65 0 608400
781 65 1 609961
782 65 2 611524
783 95 3 613099
784 65 4 614656
785 65 5 616225
786 65 6 617796
787 65 7 619369
788 65 8 620944
789 65 9 622521
790 65 10 624100
791 65 11 625681
792 66 0 627964
793 66 1 628849
794 66 2 630466
795 66 3 632125
796 66 4 633616
797 66 5 635209
798 66 6 637404
799 66 7 638401
800 66 8 [...]
801 66 9 641601
802 66 10 642204
803 66 11 644809
804 67 0 646416
805 67 1 648025
806 67 2 649836
807 67 3 651249
808 67 4 652864
809 67 5 654481
810 67 6 656100
811 67 7 657721
812 67 8 659344
813 67 9 660969
814 67 10 662596
815 67 11 664225
816 68 0 665856
817 68 1 667429
818 68 2 669124
819 68 3 671771
820 68 4 672400
821 68 5 674041
822 68 6 675684
823 68 7 677329
824 68 8 678976
825 68 9 680625
826 68 10 682276
827 68 11 684129
828 69 0 685584
829 69 1 688241
830 69 2 688900
831 69 3 689661
832 69 4 692224
833 69 5 693889
834 69 6 695556
835 69 7 697225
836 69 1 698896
837 69 9 700569
838 69 10 702244
839 69 11 703921
[...] [...] [...] [...]

[Page 50]

Inch Squares
841 707281
842 708964
843 710649
844 711336
845 714025
846 715716
847 717309
848 719004
849 720801
850 722500
851 724 [...]01
852 725904
853 727609
854 729216
855 721025
856 732736
857 734449
858 736164
859 737681
860 739600
861 741321
862 743044
863 744769
864 746396
865 748225
866 749956
867 753689
868 753824
869 755161
870 756900
871 758641
872 760384
873 762129
874 763776
875 765625
876 767376
877 769129
878 770884
879 772641
880 774400
881 777161
882 777924
883 779589
884 781456
885 783225
886 784996
887 786769
888 788544
889 790321
890 792100
891 793081
892 795664
893 797449
894 799236
895 801025
896 802816
897 804609
898 805904
899 808201
900 810000
901 811801
902 813604
903 815400
904 817216
905 819025
906 820836
907 822649
908 824464
909 826281
910 828100
911 829921
912 831741
913 833569
914 835369
915 837225
916 839056
917 840789
918 842724
919 844561
920 846400
921 847241
922 850084
923 851929
924 853746
925 855625
926 857476
927 859329
928 861 [...]84
929 863041
930 864900
931 866761
932 868624
933 870489
934 872356
935 874225
936 876096
937 877869
938 879844
939 881721
940 883600
941 885481
942 886364
943 889249
944 881136
945 893025
946 894916
947 896809
948 898704
949 900601
950 902500
951 904401
952 906304
953 908209
954 910016
955 912025
956 913936
957 915849
958 917764
959 919681
960 921600
961 923521
962 926444
963 928369
964 929296
965 931225
966 933256
967 935089
968 937024
969 939961
970 940900
971 942741
972 944784
973 946729
974 948676
975 950625
976 952576
977 954529
978 956484
979 958441
980 960400
981 962361
982 964324
983 966 [...]89
984 968256
985 970225
986 972196
987 974169
988 976144
989 978121
990 980100
991 982081
992 984064
993 986049
994 988036
995 990025
996 992016
997 994009
998 996004
999 998001
1000 1000000
[Page 51]1001 1002001
1002 1004004
1003 1006009
1004 1008016
1005 1010025
1006 1012036
1007 1014049
1008 1016064
1009 1018081
1010 1020100
1011 1022121
1012 1024104
1013 1026196
1014 1028196
1015 1030225
1016 1032256
1017 1034289
1018 1036324
1019 1038361
1020 1040400
1021 1042441
1022 1044484
1023 1046529
1024 1048576
1025 1050625
1026 1052676
1027 1054729
1028 1056784
1029 1058841
1030 1060900
1031 1060961
1032 1065024
1033 1067089
1034 1069156
1035 1071225
1036 1073296
1037 1075369
1038 1077444
1039 1079521
1040 1081600
1041 1082681
1042 1085764
1043 1087 [...]49
1044 1089936
1045 1092025
1046 1094116
1047 1096209
1048 1098304
1049 1100401
1050 1102550
1051 1104601
1052 1106704
1053 1108809
1054 1110916
1055 1113025
1056 1115136
1057 1117249
1058 1119364
1059 1120489
1060 1123600
1061 1125721
1062 1127844
1063 1129969
1064 1132096
1065 1134225
1066 1136358
1067 1138489
1068 1140624
1069 1142761
1070 1144900
1071 1147041
1072 1149184
1073 1151329
1074 1153476
1075 1155625
1076 1157976
1077 1159929
1078 1162074
1079 1164241
1080 1166400
1081 1168561
1082 1170724
1083 1172889
1084 1175056
1085 1177225
1086 1179396
1087 1181569
1088 1183744
1089 1185921
1090 1188100
1091 1190281
1092 1192464
1093 1194649
1094 1196836
1095 1199025
1096 1201216
1097 1203409
1098 1205604
1099 1207801
1100 1210000
1101 1212201
1102 1214404
1103 1216609
1104 1218816
1105 1221025
1106 1223396
1107 1225449
1108 1227664
1109 1229881
1110 1232100
1111 1234321
1112 1236544
1113 1238769
1114 1240969
1115 1242625
1116 1245459
1117 1247689
1118 1249924
1119 1252161
1120 1254400
1121 1256 [...]41
1122 1258884
1123 1261029
1124 1263376
1125 1265625
1126 1267876
1127 1270029
1128 1272384
1129 1274641
1130 1276900
1131 1279161
1132 1281426
1133 1283689
1134 1285956
1135 1288225
1136 1287496
1137 1292769
1138 1294094
1139 1297321
1140 1299640
1141 1301881
1142 1304164
1143 1306449
1144 1308736
1145 1311025
1146 1313316
1147 1315509
1148 1317904
1149 1320201
1150 1322500
1151 1324801
1152 1327104
1153 1329409
1154 1331716
1155 1334025
1156 1336336
1157 1338649
1158 1340964
1159 1343381
1160 1345600
[Page 52]1161 1347921
1162 1350244
1163 1352569
1164 1354396
1165 1357225
1166 1358556
1167 1361689
1168 1364124
1169 1366921
1170 1368900
1171 1371240
1172 1373584
1173 1375929
1174 1378276
1175 1380625
1176 1382979
1177 1383329
1178 1387284
1179 1390041
1180 1392400
1181 1394761
1182 1397124
1183 1399489
1184 1401856
1185 1404225
1186 1406606
1187 1408904
1188 1411124
1189 1413711
1190 1416100
1191 1418481
1192 1420864
1193 1423249
1194 1425639
1195 1428025
1196 1430416
1197 1432809
1198 1435204
1199 1437601
1200 1440000
1201 1442401
1202 1444804
1203 1447209
1204 1449616
1205 1452025
1206 1454436
1207 1456849
1208 1459264
1209 1461681
1210 1464100
1211 1466521
1212 1468944
1213 1471369
1214 1473796
1215 1476225
1216 1478656
1217 1480989
1218 1483924
1219 1485961
1220 1488400
1221 1490841
1222 1493244
1223 1495729
1224 1498246
1225 1500125
1226 1503076
1227 1505529
1228 1507984
1229 1510441
1230 1512900
1231 1515361
1232 1517824
1233 1520289
1234 1522656
1235 1525225
1236 1527696
1237 1530169
1238 1334244
1239 1535121
1240 1537600
1241 15400 [...]1
1242 1542564
1243 1545049
1244 1547536
1245 1550025
1246 1552516
1247 1555009
1248 1557504
1249 1560001
1250 1562500
1251 1565001
1252 1567504
1253 1570009
1254 1572416
1255 1575025
1256 1577536
1257 1580049
1258 1582564
1259 1585081
1260 1587600
1261 1590121
1262 1592644
1263 1595169
1264 1597706
1265 1600225
1266 1602756
1267 1605289
1268 1607824
1269 1609361
1270 1612900
1271 1615441
1272 1617984
1273 1620529
1274 1622076
1275 1625625
1276 1628176
1277 1530729
1278 1633464
1279 1635841
1280 1638400
1281 1640961
1282 1643524
1283 1645989
1284 1645656
1285 1651225
1286 1653796
1287 1656369
1288 1658944
1289 1661521
1290 1664100
1291 1666681
1292 1669264
1293 1671849
1294 1674336
1295 1677025
1296 1679616
1297 1682209
1298 1683804
1299 1687401
1300 1690000

CHAP. XI. Shewing, how to Hang a Rising line by severall Sweeps, to make it rounder aftward, then at the be­ginning of the same.

IF any be desirous to have a Rising line rounder aft­ward then it is at the foar part of it, they must proceed thus; first Work by the Sweep that they would have first, and then begin again, and finde the other Sweep, that they would have the roundest; An Example of this will make it more plain, as in the following Figure will appear.

Let D E represent the length of a Rising line E I, the height thereof 8 foot, on the after end thereof; first I finde the Sweep that Sweepeth it, by Multiplying of 20 foot the length, which is 240 inches: for if you look in the Tables, under the Title of Feet-Inches, for 20 feet, you will see in the next Columne, toward the left hand, 240, over head is written Inches, signifying, that in 20 feet is 240 inches; and just against it, and in the same line, toward the right hand, under the Title of Squares, you will see written 57600, signifying, that the square of 240 is 57600, these numbers you will finde in the second Page of the Tables, and the last line, the seventh, eighth, and ninth Columns.

[Page 54]This squared number 57600, made by the Multiplication of D E, 240 in­ches, must be divided by the height of the Rising line assigned E I, 8 foot, or 96 inches, so remaineth in the quotient 600, to which must be added the height of the Rising, as is afore taught, and they make 696, which is the Diameter of the whole Circle: the half thereof is 348 inches, which is 29 foot, as you may see by dividing it by 12; or else, if you turne to the Tables, and seek under the Title of In­ches for 348, you will see in the same line, toward the left hand, 29 feet, which you will finde in the third Page, and the 28th line, the seventh and eighth Co­lumn; then I Work by that Sweep to 3/5 of the length of the Rising line, or 12 foot of the same, at the point C it is represented, at which point I seek the Rising C B, I seek in the Table for the Square made of 144, and I finde it in the second Page, 24 line, at the first Columne; and toward the right hand, under the Title of Squares, I finde 20736, which is the Square made of 144: then I seek for the Square made of the Sweep, or side A B, 348 inches, and I finde it in the Tables to be 121104, from this 121104 I Substract the other Square, made of the side D C, 144 being 20736, and there remaineth 100368, whose Root I finde in the Tables, in the third Page, and the 37th line, and the sixth Columne, 100489, which is too much by neare 121; but the other number afore it being much more too little, the number answering hereunto is 316 inches, and near ¼, Substracted from 348, the whole side lea­veth 31 inches ¼, or two foot 7 inches ¼ for the Ri­sing,

0
30
57600 (600
9666
89
121104
20736
100368

[Page 55] at the point C: Now to make a rounder Sweep aftward on, or at the other end of the line, as from B to F, which runeth higher up, or Roundeth more, as from I to F: Here will be something more of trou­ble to finde the Sweep that shall exactly touch the two points assigned, as from B to F▪ then to finde the former Sweep. Now the Demonstration wil shew it to be thus.

[figure]

[Page 56]Let B and F be the two points to which the Sweep is confined to touch; draw a streight line from B to F, as you see, and so you have a Right lined Triangle, made of the sides B H, the length of the line to be swept by the second Sweep, and the side H F, the height of the same, together with the Subtending side B F; then a streight line drawn from the middle of the side B F, and perpendicular, or square, to the same line B F, and extended, till it touch the side D A, the place where it toucheth shall be the Centre of the same Sweep, as is the line G H, passing through the middle of the side B F, at the point O, which to finde Arithmetically, pro­ceed thus; finde first the length of the side B F, as be­fore is taught, of two sides of a Right Angled Tri­angle given, to finde the third side, which will be found to be 134 ½ inches, the halfe whereof is 67 inches, ¼ from B to O, then if a perpendicular be let fall from O to the line B H, it will cut that Base line also in halves, as at the point P, being 48 inches: then again, finde the side O H, and that will be, in this Example, equall to the side B O, but in other cases it may not so fall out: So then, those two sides being known, as the side O H, 67, ½ inches, and the side P H, 48 inches, and the whole length of the side K H, 240 inches, you may then Work by the Rule of Three, saying, if 48, the side P H, give 67 ½ inch, for the side O H, what will 240 give, for the side K H, as thus;

If 48 give 67 ½, what will 240

240 2
67 144
1680 4640
1440 16080 (335
  48888
16880 44

[Page 57]If you Multiply the two first numbers together, and divide by the first number, you will beget in the quotient 335, for the length of the whole side G H.

I here neglected the ½ inch in this Multiplication, for the ½ inch should have been Multiplied into the 240, by adding to the Summ 16080, 120, the halfe of 240, and it maketh 16200, which divided by 48, maketh 337 ⅓ inches for the whole side G H; So then, these two sides being found, find the side G K, thus, as before is taught, look in the Table of Squares for the Square made of the side 337, and it will be 113569, from which Substract the Square made of 240, the other side, being 57600, there resteth 55969, as you may see, for that number sought for in the Tables, and you find the nearest number to it, to be 56069, and the roote of it to be 237, for the side G K, to which must be added the Rising of the point C B, or K D, which is all one, and is as we found it before to be, 31 ¼ in­ches, added to 237, maketh 268 ¼ inches, or 22 foot 4 inches; shewing, that at 22 foot 4 in­ches, from the point D, towords G, will be the point where the Centre of the Rounder Circle ought to stand: Then again, you have the side G K, found as before, to be 237, and the side K B 144, and if you work as is taught before, but remember, that if the longest side be sought for, as is now in the last side sought for, G B being the longest side, you must add the squares made of the other two sides together, and the square of those two Summs shall be the longest side G B, 277 inches, that is 23 feet, 1 inch, which is the length of the second Sweep: and so have you the length of the Sweep. The same order you may observe to round your Sweep as often as you please.

113569
57600
55969
237
31 ¼
268 ¼

If any have knowledge of the Doctrine of Triangles, it may be found more readier, that I leave to those that know the use thereof.

[Page 58]Note also, that when you seek for any number in the Tables, take heed that you minde the number of Figures you seek for, to agree in number with those that directeth you to seek for them.

As for Example, In the other figures abovementioned, 55969, they are in number 5, by their places, as you see; then repairing to the Table, I finde 559504, but telling the Figures, I see that they are in number 6, but should be but 5: therefore this number, represented in the seventh Page; and the 28th line, and third Columne, is not the place I seek for, then I turne toward the beginning of the Table, till I see that the Columnes of Squares contain but 5 figures, and there seek the nearest number agreeing to 55969, and in the second Page, 37th line, last Column, I finde 56069, the nearest agreeing to it, which is the place answering to the other directory figures.

Note also, That the Example of finding the Sweep afore­going, is laid down by the small Scale of the Draught, by which you may trie it for your better directions.

And in that Table you may see that any farther then 70 foot, being the end of the seventh Page, I have not menti­oned the Feet and Inches belonging to the number of Inches, but have left it out because they are of little use any further, because that will reach farr enough for the length of any Rising line of any Ship whatever: If any be desirous to convert any of the following numbers into inches, he may do it by Dividing by 12.

Thus I think I have spoken enough to the Ingenuous, concerning the singular use of the Tables, or of this way of Working by Segments o Circles.

CHAP. XII. Concerning Measuring of Ships.

60
20
1200
10
120100

I Shall say something concerning it; the Shipwrights have to themselves a custome of measuring at London, or on the River of Thames thus, they multiply the length of the Keel into the bredth of the Ship, at the broa­dest place, taken from outside to outside, and the product of that by the half bredth, this second product of the mul­tiplication they divide by 94 or sometimes 100, and ac­cording to that division, the quotient thereof; they are paid for so many Tuns; as suppose in the former draught being in length 60 foot and 20 foot broad, 60, being multiplyed by 20, the bredth, produce 1200, that 1200 being again multiplied by 10, the half bredth produce 12000, if you divide by 100, you need do no more than cut off the two last figures toward the right hand, which shall be the answer and rendreth the Ship to be 120 Tuns, but if you divide the sum 12000 by 94, you wil have 127 2/3 of a Tun very neer, but this cannot be the true a­bility of the ship to carry or lift, because two ships by this rule of equall breadth and length shall be of equall burthen, notwithstanding the fulness or sharpness of those Vessels, which may differ them very much, or the one ship may have more timber than the other in her building, & so shall carry less than the other: But the true way of measure must be by measure of the body and bulk of the ship underwater, for if one ship be longer in the floor than another of the same bredth and length, she shall be more in burthen than the [Page 60] other; as a Flemish ship shall carry more than a French or Italian Vessell of the same length and bredth; Therefore I say the measure of the ship being known by measuring her, as a piece of timber may be measured of the same form, to the draught of water assigned her, the weight of the same body of the same water that the ship swimmeth in shall be the exact weight of the ship; and all things therein; load­ing, rigging, victuals included therein: then if the ship be measured to her light mark as she will swim at being lan­ched, the weight of so much water being taken or substrac­ted from the weight of the water when she is laden, the residue shall be the weight that must load her, or her abili­ty of carrying, called her burden, by this means you may know the weight of the ship light, and what she will car­ry to every foot of water assigned to her, which cannot be done by no general rules in Arithmetick because of their great irregularity, according to the differing minds of Shipwrights; you may if you please first measure the content of the Keel and Post and Stem-rudder, all of it that is without the Plank, and under the water line, and note it by it self, then measure the body of the ship in the Midships, made by the square made of the multiplying of the depth of the water line, and the bredth, then you may find; the content of the want by the circular part of the ship under water, being narrower downward, and substract this from the whole content of the squared body of the depth of the Water-line and bredth of the ship, and this shall be the solid content of that part of the ship, I mean in solid foot measure of 1728 inches to the foot, then proceed to the fore part or the after part of the ship, and to 3 or 4 Timbers more, find the mean bredth at the narrowing aloft at the water-line, and alow at the floor and the mean depth, and measure that piece of [Page 61] the ship, as I told you of the middle part of the Ship, and so measure the whole Ship by pieces and add them toge­ther, and so many feet as it maketh, so many feet of water shall be the weight of the said ship; and the reason may be considered thus; there is a ponderosity in warer, but there is a greater in the ayre, onely to the heaviest of things; and there is a ponderosity in water it self, but not so much as in other things more solid as in Iron: Suppose a Gun or an Anchor of Iron, it sinketh in the water, but yet it is not so heavy in the water as in the ayre, by the weight of so much water as shall make a body of the same water equal to the body of the Gun or Anchor in magnitude; which weight substracted from the weight of the Iron bo­dy weighed in the ayre, and so much must be the weight of it in the water.

Again, if a body be lighter in weight, than water of the same bigness, it hath an ability of lifting in the water, and can lift or carry so much as is that difference, as a piece of cork or wood of firr-trees, being lighter than water, it swimmeth on the face of the water, and refuseth to be de­pressed without more weight added to it.

Thus a ship being a concave body, is made capable of lifting according to the greatness or littleness of this con­cavity, respect being had to the greatness of the Timber put into it, or the nature of it, all which maketh a ship swim deeper or lighter in the water.

I have proved by the Thames water, that fresh Water is lighter then salt water, so then salt water being heavier than fresh, causeth that a ship swimmeth deeper in the fresh water than in salt.

I shall not need to say any thing more concerning the mesauring, for it will be understood by those that have any [Page 62] Judgment in the mesuring of triangles, the matter it self be­ing but a nicity rather than usefll: I only touched it to shew those that are so curious minded, which way they may ac­complish their desires; I shall forbear to give examples, because it will much increase my Treatise, and augment the Price, which might prove more prejudicial to youngmen than advantagious.

CHAP. XIII. Concerning the Masts of Ships.

FRom the length and bredth is gained the Mainmasts length, and all the other Masts as wel as yards, is deri­ved from thence, and there is different proceedings in this case, according to the largeness of the Ships, thus, the main Masts of small Ships to be three times as long as the Ship is in bredth; as a ship of 20 foot broad, by the same rule must have a Mast of 60 foot long.

Others for greater Ships, add the bredth to the length, and to that the half bredth, which some they divide by 5, and the quotient is the number of yards, as a ship 114 foot long and 34 foot in bredth, as the bredth added to the length, and the half bredth added together, make 165, that divided by 5, yields 33, and so many yards is the length to be of that Mast, the fore-mast must be a yard shorter at the head, that is to say besides the height of the step, which commonly in most ships the step of the fore-mast standeth higher from the bottom of the ship than the step of the Main-mast; the foremast must be shorter by that difference, and one yard more, or the bigness of the ship considered, 4 foot shorter at the head, or besides the difference below,

114
34
17
165
10
165 (33
55

The Top-masts two thirds of the length of the lower Masts.

[Page 63]The Main-yard to be 2/ [...] and [...]/22 of the Main-mast, as in the Mast aforementioned of 60 foot long, two thirds of 60 is 40, and the 2/12 of 60 is 5, added to 40 make 45, for the length of the main yard.

The foreyard to be 6/7 of the Main-Yard, as the Main­yard being 45 foot, divide 45 by 7, so cometh 6 in the quo­tient, and a fraction remaining of 3, signifying 3/7, so that the 1/7 of 45 will be 6 and 3/7, you must take 6 times so much, a [...] 6 times 6 makes 36, and if you take 6 times 3/7 make 18/7, that is, two whole numbers, and 4/7 remaining, which ad­ded to 36, make 38, and 4/7 of a foot for the length of the fore-yard.

The Top-sail Yards must be half the length of the lower Yards, the Mizne Yard usualy is made of equal length with the fore-yard, the Crosjack yard, of equal length with the Main top-sail yard, and the mizen Top-sail yard to be half the length of the Crosjack yard.

The mizen Mast to be of the length of the Main-top mast from the upper Decks, and so much longer as is the height of the ship between Deck, the Boltspreete to be of length equal to the fore-mast from the upper Deck of the Fore-castle upwards.

For the bigness of these Masts, to a yard in length, ¾ of an inch, or else ¼ of an inch to the foot, and so of yards like­wise, only the Boltspreet somthing bigger, would be the better if he be made as big as the fore-mast.

The Spritsail yard in length [...]/ [...] of the Boltspreete, the Spritsail to psail yard as of the rest, to be 1/2 the spritsail yard, the mizen yard in bigness, but [...]/ [...] inch to a yard: And di­recting my discourse to Young-men that desire instructi­ons, I will avoid troubling of them as neer as I can with Arithmetick, therefore I will shew them the sweeping out of Mast and Yards, for the filling up their Quarters accor­ding [Page 64] to circles. Thus, make a half circle equal▪ in diamiter to the bigness of the Mast, in the partners, or if it be a Topmast, equal to his bigness in the Cap; as suppose for to make a Mast 60 foot in length, then by the former directions ¼ of an inch for his bigness to a foot, rendreth him to be 15 inches

[figure]

thorow, but for a Main-mast it is alwaies better that they be made bigger, to everie 6 inches ad ½ of an inch more, so then this Mast will be 16 ¼ inches, I make a sweep of 16 ¼ inches, as from A to B, supposing the feet of the small scale, to be inches, draw, the Sweep or Arch A C B, 15 inches from A to B, than at the Centre draw a line perpendicular to A B, as from D to C, divide the perpendicular into four equal parts, with the compasses, & set off 3 of them, on the perpen­dicular from D to E, and through that point draw a line pa­rallel to A B, as is the line f g, which shall be the bignesse of the Mast at the Hounds, then middle the space between D & E as at h, and draw the line i k, which shall be the big­ness of the Mast at the middle, then two other lines drawn again through the middle between D h & another between h E, shall be the bigness of the Mast in the quarters, so then take off from the sweep, the bigness at each place from the midle line D C, to the arch, & in like māner middle the mast [Page 65] from the Partners to the Hounds, and quarter it, and strike a middle line from end to end, and at each place set off the thickness given you by your Sweep, for the length of the Heads of the Masts, you may allow to every foot 1 inch ¼ of an inch from the head to the uper part of the Crostrees, the length of the Trestle trees to be 1/3 of the Ships breadth, and in depth halfe the thickness of the Head, at the Hounds, and for the thickness, halfe the thickness of the Head, at the very end of the Head of the Mast, for yards you may draw the Sweep of them to their bigness at the Slings, and let the ends of them be but one third of the bigness in the Slings, accordingly draw your sweep, and fill him out in the quarters, according to the Circle, which I shall leave now to your practice, hoping, what I have spoken shall be well taken of the ignorant, who desire instructions.

CHAP. XIV. Concerning Rowing of Ships, when they are becalm'd.

I Have here invented a meanes of Rowing of a Ship, by the heaving at the Capstane, where will be many benefits; First, of a greater purchase of strength, for it is evident, that 10 Men at a Capstane shall heave a Ship a Head, when 30 Men shall not Haall her a Head by hand, nay 50; neither shall they be so soon tired, for that Owers are a great weariness to the Armes, beside a double motion of the body, as when the stroak is fetched, to way down the Ower, that the blade may be elivated out of the Water, where it must be kept so, untill another

[Page 66]

[figure]

[Page 67] stroak be fetched, and then great strength put to the Ower by the Armes, or else heavy bodies, will not be moved: beside, if you have never so many Owers as you can put, they all fetch their stroak at once, but when Rowed by hand, one is likely to fetch a stroak before another, so that much of the strength is lost by a disagreement in the la­bour: But to proceed to the description of this inven­tion.

Let the two lines, C D, and C D, represent the sides of the Ship, 16 foot broad, as is the line C C, 16 foot long, by the Scale of the Draught; and let the two long squares, d d, and d d, represent the two Bitt-pins, with the Cross-piece of, let the Black, between the two Bit-pins, represent a Roule, or Windless, with a Surdge in the mid­dle, as is the Surdge of a Crab, or Capstane; in the two ends of this Roule let there be placed two Winches, as you may see represented by Cranks, a and a; let there be made a hollow place in the Head of the Bit-pins for these two Winches to rest in, that they may turne round in them, and bide in them: then let there be two pieces of Timber, equall in length, to the space of the Ship you would have filled with Oares, represented by the two black lists, marked b b, and b b; then let there be fitted two small pieces, made of good Ashe, or some good strong Wood, of equall length as is the two black Lists, n L, m L, fastned into the pieces of the frame, as at the points L and L, by a Boult, but so, that they may play on that Boult, and the other ends must be with a Hoale made in the ends, put over the handles of the Cranks, at n and m, then in the two long pieces for the frame let the Oares be fixed, as at the points 1, 2, 3, 4, 5, 6, 7, of each side of the Ship representing 7 Oares of a side, they may be fastned in the Frame, by a Mortis made therein, and a Tenent on the Oar, made to go slack, in that the Oar may play, and have liber­ty [Page 68] to fetch a Stroak, in the middle whereof must be placed a Iron bolt, to fasten him, and keep the Oar from launch­ing in and out, and on the Roughtre, or side of the Ship▪ as in C D and C D, must be placed Thoule pins to each Oare, as in Boats that Row; then must you have a Halser splised together, in manner of a Viall, that must take two or three turnes about the Roule, in the Surdge, as you may imagine, at the middle of the Black Roule, or notch therein, and pass from thence to the Capstane, with two or three turnes there also; then this Viall also, reeved thorough some other Blocks, as in manner of Snach block, and these blocks placed between the Capstane and the Roule, you may thereby increase that purchase so, as that it may heave very easie, and with great strength, so as to be able to Row a Ship a Head in a calme, or in little winde, two, threee or four leagues, a watch or more, according as the Ingine shall be better or worse fitted; for if you marke in the Figure of the Work, and suppose the Viall Reeved, and by heaving of the Capstane, shall turne the Roule, as the Crankes goeth round, it shall carrie with it about, and then the small pieces shall cause the frame to pass forward to and again, to fetch a stroake with the Oares.

FINIS.

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