OF THE
Sail-maker's CONTRACT.

ALL Holland Duck, great Noyals, Suffolk, and the like, to be sowed with a double flat Seam. All smaller sort of Canvas to be sowed with a round Seam.

Bolt Rope to be Cross-stitch'd at every 12 Inches in Length with three Cross-Stitches, and the Rope to be of the Diameter as follows.

That all Sails which are made of Pertrees, Vittroy, and such Canvas, shall have a round Seam in the middle of each Cloth; to be allowed for flat Seamed Sails 3 d. ¼ per Yard, and for round Seamed Sails 2 d. ¾ per Yard.

Sail-making may in some Measure be called Tayloring, the Difference being only this; the Taylor fits Garments for Men, Women and Children, and the like, and the Sail-maker fits Sails as Powers of Wings, to drive of draw all sorts of Ships, Boats or Barks.

Bishop Wilkins speaking concerning Flying, tells us, that is a Person ever so heavy had Wings proportionable to his Weight, he might very probably fly as well as the smallest Bird; that is, if the Wings fitted to any Person's Body would cover a Body of Air Equiponderate to the Weight of the Person to whom they belong'd to, then such Wings would as well bear such a Person in the Air, as Bladders of Cork would bear up a Person in the Water, and keep him from sinking.

It must be observed, that Air to Water is as 1 to 800, of thereabouts, so that 800 Foot of Air is but equal to 1 Foot of Water. The Weight of a Square Foot of Water is near 63 Pound, but a Foot of Air is not much above one Ounce and a Quarter.

The Weight of a Man, that is one with another, is near equal to 2 Foot and a half of Water, or 2000 Foot of Air; so that each Wing of such a Man ought to be 1000 Foot, of 31 Foot 7/10 Square; but the chiefest Difficulty would be to perswade a man to use such Wings, and also to be brought to know how.

The Variety of Considerations that would be in such an Attempt, I am perswaded would not be found near so many as to well and truly suit a Ship with Sails fit and convenient, according to the Nature of her various Body, and to place them in such a direct Position, that they might effect the Ship's Body, as well to force the Motion, as to Trim her well and make her Steer.

Sir William Petty in his Duplicate Proportion, says, that by wetting Sails the interspers'd Apertures between the Threads are lessen'd, and doth make the Sails, as it were, bigger; but he then also reflects, that such important Positions are not minded and accounted for; nay, they are not so much as mention'd in the Writings and Discourses of Ship-wrights, or Sea-faring Men.

Now this Reflection may lead us to one of the material Cases which ought to be minded by the Sail maker, and that is to the Choice of good Canvas, which would be that which has the finest Threads, and is the closest and neatest wrought; which must consequently be the heaviest and strongest, and the Vacuities, as was afore mention'd, must be the least, according to the Bigness of the Thread which the Cloth or Canvas is composed with

There is a French Book published by the express Command of the King at Paris, which has in some measure nicely considered the most advantageous Situation of the Sails in any Ship, according to the various Angle of Incidence of the Wind upon them.

He seems to reflect, treating of one Ship's chasing another, and to miss her, wherein, says he, one may easily see what ought to be observed when one gives Chase to a Vessel which is to Leeward; for if on one Side to make more way you go more large, that is to say, if you for that Reason make a greater Angle with the Line of the Wind and Course, you ought to do it so as not to miss your Chase; for which Reason you ought to compare the Quantity you fall to go to the Vessel, to the Way you will make more than him in falling that Quantity; otherwise, says he, you will fall into the Inconveniency of what the French call English Chase, which is to say falling a Stern and going to Leeward; a very pretty Reflection this in a Scholar, since the French was never counted otherwise to the English.

The same Author proceeds, and tells you, that in the Crookeding of the Sails, some Part is so far from assisting and forcing the Motion of the Ship, that it really is opposed and hinders the Ship; for, says he, it is to be noted, that the Difference of crookeding the Sails makes Ships hold the Wind more with their Top-sails than with their Low sails, and that it is impossible to get off from a Lee-shoar with the latter; and the Reason he gives is this, that the Top-sails are stretch'd out by the great Yards as much as can be, before the Wind is let into them; so that the Wind can hardly make them crooked; but it is not the same with the Low sails, for as soon as you begin to stretch them, the Wind gets in and makes such a great Curve, that you can scarce flat them; however, it is not by the Wind's getting in before the Sheets and Tacks are close aboard and drawn to their Places, for that could be prevented, and done when the Sails are Shivering; but this Defect is chiefly caused by reason that the Ship's Breadth is much less than the Length of the great Yard, and consequently the lower Part of the Sail must be haled more Curving than the upper Part, provided that the Sails are cut Square as usual, and made as long at the Bottom as at the Top, or Head of the Sail.

And such Considerations would put us upon shaping the Sails to the greatest Advantage as could possibly be, to increase the Motion of the Ship, which is the second principal Part that belongs to the Sail-maker's Art, there being one Part still behind, which is to suit the Ingredients proper in composing the Sail, and bringing of such Materials to general Heads; of which Part I shall be more particular at present than of the other two.

And first as to the Stitching Part, I find the common Allowance in the greatest Extent is 108 Stitches in a Yard's Length, or 3 Stitches in every Inch; so that there is ⅓ of an Inch between every two Needle Pricks, and the smallest Allowance is 90 Stitches in a Yard's Length, or 5 Stitches in every two Inches; so that there is 2/5 of an Inch between every two Stitches.

Now as to the Reasonableness of such a general Number, as 108, 100, and 90 Stitches, and neither more or less in sowing of Seams, I am of Opinion that no discreet Sail-maker will allow of it to be absolute without farther Consideration, and a more particular Guide to assist the Case; since there ought to be as much Regard to the Goodness of the Sail Cloth; the Evenness and Strongness of the Twine; the exact Gauge of the Workman in nicely spacing his Stitches; the well joyning and equally stretching of the Cloth, that the lmpulse may have the like Effect upon one Cloth as it has upon the other.

Nay, to see to the Keenness and good Temper of the Needle, and that the Drill may be made in the interspers'd Apertures, and not as near as possible to cut the Threads of the Sail Cloth.

However, I am not speaking against setting the Workman a Bound to the Order of his Work; for indeed that ought to be in all Occupations; but am only prying into this Set of Number, and observing whether it agrees to Rule or not.

As to the Nature of a flat Seam, where 108 Stitches are allowed of in every Yard of Work, it must needs be more proper than the round Seams, provided that the Selvages be full strong, and there be sufficient hold taken of them in Sewing, since the round Seam can never be sew'd so true, and that Ridge be laid so smooth and direct as the flat Seam can; and therefore every round Seam is as so many Stops, and opposed to the Motion of the Ship, and is also more liable to be rubb'd than the flat Seams are.

There ought to be a Regard had to the Strength of the Twine, that it be full as strong and equal to the Strength of the Intervals which are between the Stitches, and as near as possible, that the Cloth be equal in Strength, Age, and Nature of the Soil where it was first producted; also that the Twine be as much like the Cloth, that it may (as Vitruvius says by Timber) sympathize by a kind of Original Kindred.

And that in the repairing of Sails, such Regard ought to be had not to mend old Cloth with New, since the New will be more apt to stretch and bag with the Impulse, being neither serviceable as to the Increase of the Motion, nor any ways strengthning the Patch, but rather tearing the Old to pieces, much sooner than if the Repair was made with Cloth of the same equal and alike Age to that which it patches.

That there may be a great deal of good Management used in shifting of Sails as they grow old, and putting them into Places which are not so often in Use, as where they were before; as to instance in Main and Fore Topsails, and Main and Fore Courses, they are Sails which are generally used above all others, and also such as are the principal Safe-guard of the Ship. Their Strain in the haling Tacks and Sheets are 3 to 1 more than the Sprit-sail, Main Stay-sail, nay Mizon and Mizon Stay-sail, altho' at sometimes a Ship is put to lye by under her Mizon; but then if the Sail is blown away, the Damage will be only the Loss of the Sail, since it is the most easily shifted of any other Sail in the Ship; so that the Top-sails and Courses may be converted into such Sails after they are very well worn.

But not resting here, to shew what good Husbandry may be in such Cases, the large Ship's Sails may be so ordered, that after they are very well worn, they may be converted for smaller Ships; since the Strength requisite will be according to the Area's there are between one Sail and another, which is as follows.

The Area's of a first Rate to that of a Third are as 4 to 3, so that when a first Rate's Sails are a Quarter worn, they may be converted to make Sails for a third Rate, and perhaps prove better at new working than at first, since all the damaged and defective Cloth will appear, and may be shifted.

The Area of the second Rate Sails to that of a fourth is as 3 to 2; so that after they are ⅓ worn, they will do after the same manner for the small Ship. A third Rate to a fourth is as 4 to 3, and a third to a fifth is as 2 to 1; a fourth Rate to a fifth is as 3 to 2, and a fourth to a sixth is as 9 to 5, and a fifth to a sixth is as 7 to 6; besides, there be Vessels of a lesser Denomination than what I have mention'd, as Fire-ships, Bomb-Vessels, Hoys, Lighters, of several Degrees, all which, together with the daily Issues which are required in the Navy, as Awrings, Tarpawlins, painted Canvas, covering for Decks, Hammocks, and the like, manifest that there need not be scarce any Waste made of the Publick Sail Cloth, or that continual common and most consuming Custom of selling the Publick Sail Cloth at common Sales, a Matter so general, that it's impossible for His Majesty's Officers to know whether His Majesty's said Store is sold or imbezzled; nay, according to the common Custom, it will be very hard to define whether our very large Navy's Sail Cloth is not used for most of the Merchant's Shipping, since the Mark that distinguishes it is so easily taken out.

But perhaps it may be objected, that the Charge of taking large Sails to pieces, and new Sew them, will be more considerable than to buy new; but that is soon answer'd, for the Sewing is but the same as it will be charged to you in making new Sails, besides buying the Cloth.

Another Objection may be, that perhaps Ships Reparations may not so nicely jump together, and that one Ship's Sails may not be in a Condition to be shifted when the other Ship doth necessarily require it. But to this may be answer'd, that no Man would be guilty of courting Impossibilities, neither would I be thought guilty of proposing Methods that could not be comply'd with: Notwithstanding, if it cannot be done throughout the Navy, it's hard if it cannot be done in half, or if not in half, it would be a great many Thousand Pounds in the Governments way, if it could be done in a Quarter Part of our large Navy; since you may see by the Number of Yards of Canvas which is converted to Sails in the six Sizes, from a first Rate Ship to a sixth, is at least 15645, and it cannot be thought any ways proper for any Ship to go to Sea with less than two such Suits of good Sails, which then would be double the Number, or 31290 Yards. I shall, count this at 3 s. per Yard for Cloth and making, the Sum will be 4692 Pounds for six Ships; but it's believed that the Navy of England has of one sort or another 200 Sail of Shipping belonging to it, and then the Sum of Money to find them two Hundred Sail of Ships Sails proper and convenient to proceed to Sea, will be 154836 Pounds, and half such a Sum I presume may be got or lost thro' good or ill Management in three or four Years time. Not that I would have any one to imagine, that I have been nicely inspecting or calculating the exact Quantity of Canvas, or what the Sum has or is likely to be for doing such a Part of the Marine Publick Service, but only by the way I thought proper to hint this most important Position, believing, and being almost positive I am not far off from the Matter of Fact either one way or another.

In the next Place I shall proceed to consider of the Nature of binding the Sails, or of the Bolt-Rope.

The Bolt-Rope is a binding Bar, or Fence for the Sail, such a Safe-guard, that it's very probable if it was not for such a binding Rope, a Sail would not be for Use or Service. How this Rope was first sized I cannot lay, whether by a Rule, or attain'd to the Perfection it's at by Experience; however, I am of Opinion, that there may be Detriment as well in under-sizing as oversizing such a Material, and I therefore shall consider this Case, and give my Opinion of it as follows.

First, I shall consider of the particular Area's of the Main Sails, from which I presume all other Sails Area's may be depended on.

And these particular Calculations agree, one to another near enough, for our present Work, to our general Calculation of the whole Quantity of Canvas I deem to be proper for to make Sails for each Rate.

The first Rate's Main Sail, containing 608 Yards multiply'd by 9 is 5472 Feet, and so many Feet being contain'd in the superficial Area of the Main Sail, is equal to so many Ounces and Quarters of Air, which is 6840 Ounces, or 527 Pound and a half, which is a Weight much inferiour to the Weight of the Sail, and therefore here must be an Impulsion of Air to cause a Crookedness in the Sail, and forcing the Ship forward, as it may be observed in gentle easy Gales, that the Sails reverberate, and are never steady till the Impulse of Wind is more Ponderous, and an over Ballance for the Weight of the Sail; which is the chief Reason that smaller Bodied Ships are sooner effected with a little Wind, than those that are bigger; and it would be really very Diverting to make Tryals of this Natural Cause; and observe the Increase and Decrease of the Air's Weight, by the different Degrees of Swelling that may be observed in Ship[']s Sails, whose Superficial Area's may be some bigger and some lesser, and at the same time very near together; nay, it may be also seen in the same Ship, by the upper and lower Sails, what Difference there is in the Air's Weight in the different Heights between the Atmosphere and the Horizon; but to proceed,

As to the different Degrees of Impulse, it will be very hard to define them, and how and in what manner the Sails are affected by the Violence of the Wind, it being really very amazing to see what Difference there is between a most clear and serence Calm, when as it's term'd there is scarce, or not one Breath of Wind, and at another Time when the Air is so violently agitated, that without the Help of any Sail, the most huge large bodied Ships which are now in being, are almost blown beyond the Water's stopping of them.

The Air, as it's observed by our famous Writers, is a springy Resilient Body, or made up of Bodies that are almost in the Nature of a Watch's Spring, endeavouring to unrowl themselves, and become streight; but being hinder'd by Bodies of the same Make and Form, are hurried and drove one to the Hindrance and Retarding of the other.

Now the best and most familiar Way that I shall account at present for this extream Impulsion of the Wind upon the Sail, is to allow it as in the Case of the Water's Resistance upon the Ship's Bows, or Foremost Part, which is, that this Impulse of Wind upon the Sail in the Greatest Extremity, shall be equal to half that Solid which shall be composed by multiplying the Length of the Sail by the Depth, and again by a square Number made by that Length and Depth; not that I have such an undeniable Maxim to fix this Principle upon, as there is in the Case of the Resistance of the Water upon the Ship; since the Ship is at the Top of the Water, and on the other Hand is wholly under the Force of the Air, and therefore I believe that this Weight and Force of Air ought to be accounted for from the Atmosphere's Height to the Object it vaporates upon; however, I shall first set down the Weight that this Sail may be expected to bear by the aforesaid Calculation.

608 multiply'd by 24 6/10, it's 15256.8, which being halfed, is 7128.4 Yards multiply'd by 9, is 64155.6 Feet, or so many Ounces and a quarter.

And by such a Calculation it's found that the Weight of Air that affects the first Rate's Main Sail is 5012 Pound, which will be but equal to 79 Feet of Water and 35/65 Parts, which can never be the Weight of the Air that affects such a Sail in the greatest Extremity, and therefore I shall endeavour to find a new Calculation to suit this Work.

The healing of a Ship might in some measure paint out to us an Idea of this Force or Impulse on the Sail, it being accounted for that it requires more Force to make a Body revolve, than it doth to cause the same Body to make a sliding Motion; nay, the rowling and tumbling of the Water may assure us that the Force of Wind is very great to cause such a ponderous Body to make such huge large Waves, as may sometimes be observed between two Summets, as the upper Ridges of the Waves are term'd; but to wave such Discourse, I shall consider what Weight of Air may be between the Atmosphere and the Object.

The Atmosphere is the lower Part of the Region of the Air with which our Earth is encompassed all round, and into which the Vapours are carried up either by Reflection from the Sun's Heat, or by being forced up by the subterraneous Fire.

The Pressure of the Atmosphere Mr Boyle undertakes to demonstrate from many Experiments.

The Height of the Atmosphere is variously conjectur'd: Kepler makes it about 8 Miles, but Ricciolus makes it probably at least 50 Miles high; Mr. Boyle makes the common Height of the Atmosphere when the Mercury in the Boroscope is at 30 Inches to be 35000 Feet, or 7 Miles; but this is upon a Supposition, that all our Air is of the same Density and Weight from the Surface of the Earth to the Top of the Atmosphere.

The same Honourable Philosopher, by an Experiment mentioned in Dr. Harris's Dictionary, allows that a Column of Air 1 Inch in Diameter and 3 Inches long, weighs 14 Pound 2 Ounces, and above 3 Drams of Mercury Troy Weight. Hence, says he, knowing the Proportions of Cylinders, 'tis easy to calculate the Weight of a Cylinder of Mercury, and consequently of Air to the Top of the Atmosphere of any given Diameter; for as 1, the Square of the Diameter of the Cylinder above mentioned, is to the Square of the given Diameter of the Cylinder sought.

In Mr. Boyle's Description of his Statical Baroscope he tells us, that he found a Pillar of Air incumbent on a Square Inch, to weigh 48 Pound 1 Troy, from which Account the Weight of the whole Air all round the Globe is counted to be 8,900,405,732,208,000,000 Pound Troy.

Mr. Hally, by undoubted Experiments, found, that the Weight of Mercury to Water is as 31½ to 1, or very near, and that the Specifick Gravity of Air to Water is as 1 to 800, so that the Weight of Mercury to Air is as 10800 to 1; and that a Cylinder of Air of 10800 Inches, or 900 Feet, is equal to 1 Inch of Mercury; so that were the Air of an equal Density like Water; the whole Atmosphere would be no more than 5 1/10 Miles high.

The Wind is defin'd to be a Stream or Current of the Air, and where such Current is perpetual, and fix'd in its Cause, 'tis necessary that it proceed from a permanent unintermitting Cause.

Then if a Square Column of 1 Inch has 18 Pound 1/8 Weight incumbent upon it, what may such a large Ship's Main Sail, which is 787968 Inches, and that brought into 18 Pounds 1/8 is 14177980.16 Pounds, which is equal to 225110.79 Feet of Water; but the Water that resists such a great Ship is 16800 Feet, and the Water that bears her at her lightest Draught of Water is 66296, and it being found from Experience, that 66296 Feet of Water is but equal to the Weight of the Ship it so bears, therefore we plainly find that the Ship is but little affected with the Weight of the still and gentle Air, before its disturbed and drove into violent Motions.

By Mr. Hally's Observation its found that a Cylinder of Air containing 900 Feet, is but equal to a Cylinder of Mercury of 1 Inch Diameter, so that 900 Feet of Air is but equal to 14 Pound 2 Ounces 3 Drams, and by this Observation the Weight of Air on such a large Ship's Sail is 714 Pound 11 Ounces 7 Drams, and this is the Weight of the still Air before it is moved or provoked to Motion.

And here is a Bolt-Rope sized from the biggest Ship's Main Sail, to a Sail that the Superficial Area will not contain as much Canvas as will make a small Boat a Main Sail, it being but 20 Yards, which is little more than 6 Yards and a half long, and 3 Yards broad: For you are to undersland that these Superficial Area's is not according to so many Yards by the Breadth of every Cloth, but so many Yards Square, since no Sail-Cloth as ever I could observe, contains more than ¾ of a Yard Breadth, or thereabouts; but that is not to our Inquiry: For as you may observe this Method of reducing the Bolt Rope, which will really be the right, according to the Impulse or Stress upon each Sail, will allow but of a very small Rope for the little Sails, since a Sail, whose Superficial Area contains 20 Yards, the Bolt-Rope appears by this Calculation not half an Inch in the Circumference, as you may see it is but 44/100, the Diameter of which is but 14/100, little more than ¼ of an Inch. A much smaller Rope, I presume, than ever was apply'd to make a Bolt Rope for the smallest Boat; and therefore in the next Place I shall consider a little further of the Application of the Bolt-Rope, according to the Weight of the Sail Cloth, and Number of the Sails.

It is as common, as any one Part of the Marine Discipline to see a small Boat and a large Ship's Canvas of one Substance, and is not of the same Specie, the Difference will be very small, which causes that large Difference which is found in the Area's of Boats Sails to the Area of a Ship's Sails; for according to my preceeding Observation of the Proportional Quantity of Canvas, which I deem needful, to be apply'd to any Vessel's Sails, nay, what in Reality most Ships have allowed them, or rather more, a Boat of 20 Foot long ought to have 4634 Yards of Canvas converted into her Sails, and not only 400 Yards of Cloth according to a running Measure, but a Superficial Area of 68 multiply'd by 68 Yards; when it's very rare to see in such a Boat's Sail above 25 Yards, which is little more than half such a Quantity; so that I presume the Number of Yards is made up With the Thickness of the Cloth, and of Consequence the Bolt-Rope ought to be allowed of, according to what Number of Yards there should be in the Number of Sails, and not according to what Number of Yards there are, since it plainly appears, that the said Number, according to the Square made, by multiplying the Length of the Boat into its self, is made up by the Thickness of the Sail Cloth, and then the Rope suitable to make a Binding for such a Boat's Sail will be 67/100 of an Inch Circumference, whole Diameter will be 22/100, almost ¼ of an Inch; and by such a Rule may be found the Dimensions of the Bolt-Rope suitable and agreeable for any small Boat's Sail. But as to the Goodness of the small Rope in Proportion to great, I shall particularly consider of it when I come to the Branch of Rope-making, though there should be something said to the Goodness and Magnitude of the Twine in Proportion to the Strength of the Canvas, and Quantity of the Area contain'd in the Sail; but I shall wholly refer it, till I come to that Part of the Rope-making in general.

I shall end this Part with just mentioning what a Sail-maker may reasonably earn in a Day, according to the Allowance aforementioned.

First, he is allowed for flat Seams in Duck, Suffolk, and the like Sail Cloth 3 d. ¼ for every Yard he sews, and to put in from 108 to 90 Stitches; however, I shall allow of 100 Stitches in the Medium. Then from Four to Eight, only taking out 2 Hours for Breakfast and Dinner all the Year round, there will be 14 Hours, which multiply'd by 6+, makes 840 Minutes; and provided a Man can make 5 Stitches in the hard Canvas every Minute, and hold it; and in consideration the round Seam'd Cloth is generally softer than the other, I shall allow that he may make one Stitch more in a Minute, which is 6; then he will earn at searing the hard Cloth 11 s. 4 d. ½ per Day, and for the other 12 s. 10 d. per Day.

But provided, that instead of working from Four to Eight, he works from Six to Six, and allowing 1 Hour and a half for Breakfast and Dinner, it's 10 Hours and a half, which multiply'd by 60 it's 630 Minutes; then at the same Allowance of 5 Stiches in a Minute for the thick Canvas, and 6 Stitches in thin, the Sailmaker earns on the former 8 s. 5 d. ½, and on the latter 9 s. 7 d. ½, and it's very probable he may comply with such a Number of Stitches in such a Time, and do his Work very well.

Sutherland, William: Prices of the Shipbuilding Adjusted: or, the Mystery of Ship-Building Unveiled. Being a Brief Explanation of the Value of the Labouring Part in Ship-Building; from a Ship of the biggest Magnitude to a small boat. First, Shewing the Working the whole Ship, according to the Length, Breadth, Depth and Girth; and then by Sub-divisions shews the value of every particular Part.
D.L., London, 1717. p 244-253.
Second part of Britain's Glory: or, Shipbuilding Unvail'd, 1717.

Transcribed by Lars Bruzelius.

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