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EXPLANATION OF PLATE XVIII,

HIS View represents the Engagement between the Nymphe, 32 guns, 250 men, and the Cleopatra French frigate, 40 guns and 320 men, at the time when the Cleopatra, being disabled and unmanageable by the loss of her tiller and mizen mast, fell on board La Nymphe. The Nymphe by this means falling athwart hawse of the Cleopatra, boarded her from the quarter-deck, and struck her colours. The view is supposed to be taken from the eastward, and on the Nymphe's larboard quarter. The wind was from the N. W. to N. N. W. and squally. A lugger happened to heave in sight at the close of the action, which is introduced.

We gave so ample an account of this spirited action in our Historical Memoir of Naval Transactions, that we refer our readers to it, as more explanatory of the annexed design; in which the situation of the respective ships is accurately described, from the report of officers then on board. The Nymphe, Captain Pellew, had the honour of taking the first frigate that was captured from the enemy, in the present war,

PHILOSOPHICAL PAPERS,

AND USEFUL NAVAL PROJECTS.

DESCRIPTION OF A MACHINE

OF

FOR PUMPING VESSELS AT SEA

WITHOUT THE LABOUR OF MEN.

F all the hydraulic machines invented by the ingenuity of man, the pump is the most useful, both on shore, and on board; and although, in appearance, the mechanism is simple, yet, on investigation, we find the principles abstruse and refined;-hence no wonder that its progress towards perfection should have been slow, and its improvement still occupying the attention of the ablest mechanics of the present day. The following contrivance, by Mr. Richard Wells, was communicated about two years ago to the American Philosophical Society; and probably some of our naval readers may suggest improvements to it, by means of applying to the apparatus a similar power, as the wind vanes

of a mill.

An Account of the Machine contrived by Mr. Wells. When a vessel at sea springs a leak which cannot be discovered, instead of exhausting the crew with continual working at the pumps,

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they may form, with very little trouble, a machine to discharge the water, which will work itself, without any assistance from the hands on board.

Let a spar, or spare top-mast, be cut to the length of eight or ten feet, or more, according to the size of the vessel; mortice four holes through the thickest end, through which run four oars, fixing them tight, exactly in the middle; to the four handles of the oars nail on four blades (made of staves), the size of the other ends, which will form a very good water-wheel, if the oars are strong. Then fix into the opposite ends what is commonly called a crank; the iron handle of a grindstone will suit extremely well; if that is not to be had, any strong bar of iron may be bent into that form, wedging it tight to prevent its twisting round. Then nail up a new pair of chaps on the fore part of the pump for a new handle to be fixed in, which will point with its outer end to the bow of the vessel; this handle will be short on the outside, but as long on the inside as the diameter of the bore of the pump will admit, in order that the spear may be plunged the deeper, and of course make the longer stroke. The handle must be long enough to have a slit sawed up it, sufficient to admit a stave edgeways, which must be fastened with a strong or iron pin, on which it may work; the lower end of the stave must be bored, to admit the round end of the crank. Then fix the shaft with the oars (or arms) over the gun-wale on two crotches; one spiked to the gun-wale, and the other near the pump; cutting in the shaft a circular notch, as well to make it run easier by lessening the friction, as to keep the whole steady. A bolt must be fixed in each crotch, close over the shaft, to keep it from rising; as soon as the wheel touches the water it will turn round, and the crank, by means of the stave fixed on its end, will work the handle of the pump. If the bore be four inches, and the piston or spear moves eighteen inches at a stroke, it will discharge 220 cubic inches of water; and, admitting the arms of the wheel to be six feet from the centre, it will turn round about 146 times in a mile, or 730 times in an hour, when the ship sails five knots, which is equal to nine hogsheads. If the surface of the water in the hold be fifteen feet from the nozzle of the pump, a man can raise in an hour, with common working, about thirty-eight hogsheads; this far exceeds the work performed by the wheel, but the calculation is made on pumps of the common size; I would therefore propose that all vessels should carry larger pumps, the advantage of which will appear from the following table:

A 4-inch bore will discharge per hour, sailing at the rate of five knots,

5-inch,

9 hogsheads

14 ditto

6 inch,
7-ditto,
8-ditto,

201 hogsheads,

28 ditto

37 ditto

Hence we find, that a pump of eight inches bore will discharge with the wheel nearly the same quantity that a man commonly raises. If both pumps be set to work by the crank, double the quantity, or 74 hogsheads, will be discharged; but if a cog wheel, of about three feet ten inches, with fifty-one cogs, be fixed on the end of the shaft or axis, and the crank be passed through a trundle or lantern wheel, of about two feet diameter, with thirteen rounds, to work with the axis parallel to the deck, and fixed to the pumps, in the manner used by brewers and distillers, the crank will make about four turns to one revolution of the great wheel, and of course deliver 296 hogsheads per hour; yet, as the resistance made by the pumps will in some measure impede the motion of the wheel, it will not turn at the rate of 730 times in an hour; for which suppose a deduction of onethird, which is certainly a great allowance, the quantity then discharged per hour is about 200 hogsheads, which is more than equal to the constant work of five men. Thus if a vessel, sailing at the rate of five knots, delivers 200 hogsheads per hour, equal to five men's work,

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I am aware of many objections that will be suggested. In the first place, it will be said, that pumps of eight inches bore will be too large to be worked by the strength of men, when the wheel cannot be applied. I answer, that no more force is required to discharge a gallon of water at a stroke from an eight-inch bore, than from a four-inch bore; as the short end of the lever or handle to the eight-inch bore need not be above a quarter part of the length of the four-inch, which will give a purchase to the sailor at the long end of the lever, sufficient to raise the piston or spear a quarter the height of what is required in a four-inch bore; for a piston moving three inches in an eight inch bore, and twelve inches in a four-inch bore, will deliver just about the same quantity of water. It will be farther objected, that in stormy weather, when vessels generally make the most water, the wheel could not be put overboard. I own there is some force in this objection; but if a remedy is beneficial in some cases, though not adequate in all, it ought not to be totally rejected. Many leaks happen at sea in moderate weather, and even those which are occasioned by damage in a storm, often continue when the waves are abated. Sailors are fre

quently unhappily washed overboard, and possibly those who may haye survived the storm are too few, and too weak, to keep the ship clear of water, and perform the other necessary duties on board; in such cases this machine would be evidently useful. It may also be urged, that the wind at such time may be so much a-head, that the ship cannot make way enough through the water to work the pumps: to which I reply, that when life is in danger, and death stares the affrighted crew in the face, the port of destination is not to be considered, but the vessel must be steered for that shore which best suits the working of the pumps, and keeping her above water.

I would therefore propose, that every vessel should not only have pumps of eight inches bore, but be provided with a shaft, crank, and proper wheels, which might easily be stowed away in little room, as the paddles of the water wheel may be unshipped; and the whole may be procured at a small expence.

A. top mast, or shaft of the wheel. B B oars, or arms of the wheel, C crank. D pump. EE props on the deck to support the shaft.

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CAL

TO THE EDITOR OF THE NAVAL CHRONICLE.

SIR, Naval Hospital, Yarmouth, Aug. 12, 1799. PERCEIVING that the plan of your laudable publication is to blend amusement with utility; that while it is open to every species of information, which it dispenses with the greatest liberality, it is more particularly adapted to the maritime; I shall, therefore, without further exordium, transmit the following copy of a letter, which I presume may be consistent with your design, and acceptable to many of your readers. I am, Sir,

"GENTLEMEN,

Your most obedient humble servant,

*

A. G. NAUTICUS.

Halifax Yard, Jan. 17, 1795.

SOME time since observing a hole in the remains of the Pembroke's bottom that resembled a shot hole, the water flowing into it being higher on the outside than within, I thought of an easy method for stopping it, supposing it to be a shot hole; for which I caused a bag to be made (a similar one is sent you purpose by this conveyance), which, by being forced through the hole from within, stuffed with oakum, and drawn tight into the hole, it totally prevented the water from finding a passage; this was performed in two minutes by one man. Admiral Murray, and all the captains, so readily adopting this mode after seeing it tried (in preference to any other) induces me to submit it to your consideration.

"A gunner's crow, or iron bolt, should first be forced through the hole to clear splinters, the bag can then be readily conveyed through; if the plank should be much shattered, the neck at the

awell of the bag may be thrumbed with long thrumbs to help to

fill up the rents. I am, &c. &c.

(Signed)

Principal Officers and Commissioners

of his Majesty's Navy.”

“HENRY DUNCAN.”

See the figure in the margin.

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