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six inches nearer the end; cut the temporary seizing on the cross, open out the clinch, put in the dead-eye, drive the clinch down, keeping the dead-eye with a little cant against the pull of the laniard.

Two seamen should turn in a dead-eye, with 11-inch rope, in a workmanlike manner, in two hours.

The cutter-stay method had its origin, as its name indicates, in the forestays of cutters. As a sail was set on the stay, this plan admitted of its hauling down snugly.

Fig. C is a fair representation of the plan with an improvement in the method of securing the standing part of the laniard by splicing it into an eye-bolt in the channels,

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Rigging Screws. There is still another plan of setting up rigging, as represented in Fig. D, by screws. When not to be used, a small iron plate keys on top of the screw, which keeps it from working, and the thread should be thickly smeared with tallow, covered with parcelling and marled. Whenever screws are used, it must be remembered that sufficient end should be turned up to allow it to be turned in afresh after knotting or splicing, in the event of its being shot or carried away. The same contingency should be provided for in all rigging. This plan is not considered advantageous in setting up wire rigging, as it makes the whole too rigid.

In the service the use of these (or similar) turn-buckles is confined to places where no give is required, as in the case of chain topping lifts for waist launches. Rule* for Finding the Size of the Fore and Main Shrouds, based on the area, in square feet, of the mainsail, topsail, and topgallant sail. Rankin, in his work, gives a rule for finding the direct pressure of wind, in *Book of Allowances, Bureau of Equipment and Recruiting, 1881.

Fig.D

pounds, on the sails, that is, when it strikes them at right angles, as follows: "Divide the square of the velocity of the wind in knots by 150 for the direct impulse on a flat surface in pounds on the square foot." Assuming the velocity of wind in a storm to be 53 miles per hour, and applying this rule of Rankin, the pressure on the sails will be found to be 19 pounds per square foot of surface. Bracing the lower yards at an angle of 35° with the keel, the wind strikes the sails at an angle of 55°. A simple calculation shows that at this angle the pressure is reduced to 15.6 pounds per square foot. Therefore, multiply the area of these sails by 15.6 and the actual angular force exerted will be the result; and this will be the support in pounds required for the mast. Now find the angle of support, or the angle which the shrouds make with the mast. A convenient method is to take a line from a lower dead-eye abreast the mast, and carry it to the centre of the mast horizontally, so as to form a right-angle with it, and measure its length in feet. Then measure from this point on the mast the distance to the upper side of the trestle-trees. Now divide the length of the line taken from the dead-eye by the above measurement on the mast, and the result will be the tangent of the angle of support. Then to the log. cosec. of the angle of support add the log. of the angular force, and the result will be the power of support required in pounds for that angle; but for greater security add one-half of this amount to it, and the result will be the total power of support desired. Divide the total power of support thus obtained by the number of shrouds proposed for one side; the quotient will be the breaking-strain of a single shroud, which seek in the table of strength for the required size. This table is given in Appendix A.

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In fore-and-aft rigged vessels, the sail-area used in the computation will be that of the main-sail and main gaff-topsail.

This rule involves the same principles as those of Rear-Admiral T. O. Selfridge, adopted and used by him in the preparation of the allowance tables for 1870.

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Nat. number corresponding to log. 5.70666 is.... 508927
Add ....

Power of support. . . . .

254463

763490 pounds.

If we allow 10 shrouds, one shroud will be one-tenth of the total power, which will be 76349 pounds. Corresponding to this number in Appendix A, the size of shroud will be 104 inches hemp, or 5 inches wire.

NOTE. The angle of support in this case is 19° 15', that being the mean of the angles of the fore and main, and is taken from the constructor's draught.

APPENDIX D.

STAYING MASTS BY THE USE OF BATTENS.

To guard against the injury which the lower masts of ships have frequently sustained in consequence of the injudicious manner in which they have been stayed and the lower rigging set up, the following suggestions should be of value when fitting out or when setting up lower rigging at any time.

To regulate the setting up of rigging, and to determine if a lower mast is straight, a middle line should be cut on each of its sides and upon the after part. These lines should be painted a different color from the rest of the mast, and extend from the trestle-tree to the heel.

At the upper part of each line a small eyebolt should be placed, and on the line near the deck another such eyebolt. A rope line fastened to the upper one, and rove through the lower, and pulled tight, will, if the mast be straight, coincide with the middle line cut upon it; or, if not straight, the fact will be evident by the cut line and the rope not being parallel. The amount by which parallelism is departed from will represent any curve the mast has taken.

As the lines are to be cut from the heel of the mast to the tressle-tree, by knocking up a side wedge, any curvature that may exist below the wedges may be seen. Consequently, should the rigging be set up with the wedges in, or with them altogether withdrawn, the side lines will afford the means of detecting any bending in the mast, from the crushing tendency of the combined strains upon the stays and shrouds, and of deciding when these ropes should be relaxed. The middle lines used in conjunction with straight-edged battens present an easy and a safe way of seeing that the mast, when being stayed, is not pulled more than slightly out of the position it is permanently to have.

First, as to the correct athwartship position. If a batten about seven (7) or eight (8) feet long be placed upright on the middle line of the deck, considerably abaft the mast, and its edge can be made to coincide by eye with the middle line on the after part of the mast, the mast will be upright by the shrouds; or, if the edge and the middle line do not agree, the divergence will show to which side, and by how much, the mast inclines.

Second, as to the rake. If a batten standing on the deck, with a rake equal to that which the mast is to have to the deck, be used with the side middle line, and its edge and the middle line coincide, the rake of the mast must be correct; or, if they do not coincide, the direction and extent of their disagreement will show how much the mast is out of place in a fore-and-aft direction.

The rake of the mast has reference to the keel; but as the deck and the keel are not parallel, the angle between their planes must be considered, when deter

mining the angle the batten shall have to the deck, in order that it may have the assigned angle to the keel. This correction may be readily made, and the batten be set at the required angle in a firm base or foot, parallel to the deck.

The lower masts should be placed with such rake as may be shown in the drawings of the ship's original construction, or as may have been subsequently decided as preferable; and in the event of experience rendering it advisable to alter the rake of the masts, every particular relative to the change should be noted in the log-book, and reported in the sailing qualities.

APPENDIX E.

TABLES

Showing the Length, Breadth, and Strength of Flax_and_Cotton Canvas, as used in the U. S. Navy. Together with the Number, Length, and Breadth of Strips cut crosswise and lengthwise, used in the Test of Strength, and the Average Weight required of them, before received for use.

FLAX CANVAS.

Flax canvas to be 20 inches wide, and each bolt to contain 80 running yards. The blue thread in Nos. 1, 2, 3, and 4 to be 18 inches from the selvage; and in Nos. 5, 6, and 7 to be 18 inches; and in Nos. 8 and 9 to be 1 inch. The warp and filling to be spun exclusively of long, well-dressed, water-rotted flax of the best quality, without any mixture of shorts or tow. The yarns to be evenly spun and of proper fineness; the warp to be rather more twisted than the filling. The warp and filling, from Nos. 1 to 4, inclusive, to be double thread; Nos. 5 and 6 double warp and single filling: and Nos. 7, 8, and 9 single warp and filling.

No description of weaver's dressing, or any pressing or beating to be used in the manufacture.

Three strips to be cut lengthwise and three crosswise will be used to test the strength, each to be 1 inch wide and 20 inches long, except Nos. 8 and 9, which will be 14 inches wide.

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COTTON CANVAS.

Cotton canvas to be 22 inches wide and to contain 80 running yards to the bolt. In Nos. 1, 2, and 3, the blue thread must be 13 inches from the selvage; in Nos. 4, 5, and 6, 14 inches; in Nos. 7 and 8, 1 inch; in Nos. 9 and 10, inch; and in the cotton ravens, 7 inch, from the selvage. The filling should be stronger than the warp in all numbers. In testing, three strips crosswise and three strips lengthwise will be cut; the strips to be each 1 inch wide and 22 inches long, except in Nos. 8, 9, and 10, which will be cut 14 inches wide and 22 inches long.

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I. Rowing to Seaward. As a general rule, speed must be given to a boat rowing against a heavy surf. Indeed, under some circumstances, her safety will depend on the utmost possible speed being attained on meeting a sea. For if the sea be really heavy, and the wind blowing a hard, on-shore gale, an approaching heavy sea may carry the boat away on its front, and turn it broadside on, or up-end it. A boat's only chance in such a case, is to obtain such way as shall enable her to pass, end on, through the crest of the sea, and leave it as soon as possible behind her. If there be a rather heavy surf, but no wind, or the wind off shore and opposed to the surf, as is often the case, a boat might be propelled so rapidly through it that her bow would fall more suddenly and heavily after topping the sea than if her way had been checked.

It may also happen that, by careful management, a boat may be made to avoid the sea, so that each wave may break ahead of her, which may be the only chance of safety in a small boat; but if the shore be flat, and the broken water extend to a great distance from it, this will often be impossible.

From a pamphlet of the National Life-boat Institution.

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