With what ease a large log of timber, or other heavy body, may be floated along the surface of water, by only a moderate-sized cord attached to it, is well known.
Could means once be contrived of conveying such a cord to or from a ship in distress, to form a line of communication between the mast and a fixed point on shore, one grand difficulty would be surmounted. For to this line of communication might be fixed collateral cords, which being conveyed to the sufferers, grasping the broken planks, or struggling in the waves, many lives might probably be saved.
Now, were the line sufficiently strong, and made to pass through a metallic cylinder, in form of a sliding hoop, the ship’s crew might, one by one, if placed thereon, slide along the rope from the mast to the shore, as on an inclined plane. The ship’s stores, buckled to the sliding hoop, might be conveyed in the same manner; nay, even the ship itself, drifted on a neighbouring sand bank, or ledge of rocks, might, by men properly stationed on the beach, be thus towed safely to shore.
That this might be safely accomplished during a calm, can scarcely be doubted: but how to convey a line to or from the ship when all communication is cut off by a boisterous sea, and “when not even a boat dare venture out,” must give us pause, and at first view appear impracticable.—Dangerous as such an enterprize may seem, yet we now know, that a life-boat built on scientific principles, and manned with a few resolute tars, is fully adequate to the task; such a boat, however, being yet little known, and no where to be met with, except at Shields, recourse must be had to other measures. Those who have duly considered the theory of projectiles, will be best qualified to judge how far the following conjectures, when matured by experience, may bring to light new modes of deliverance.
1st, Suppose the distance not to exceed two hundred yards, might not a small cord of that length be transmitted from the ship to the shore by a powerful sky-rocket properly directed?
2d, By an arrow shot from a large bow of superior force?
3d, By a cord fixed to a perforated bullet, and discharged from a musket or small piece of ordnance, taking care to first wet the cord to prevent its being fired by the explosion? To the end of the small cord thus conveyed to the shore, might be fixed a larger one, or even a rope, which, by means of the small cord, might be drawn on board the ship.
4. Might not the conveyance of one or more cords be accomplished, with still more certainty, from the people on shore to the distressed ship, by means of a stout water-spaniel, or rather by a well-trained Newfoundland-dog? These sagacious animals are known to delight in enterprize, and in rescuing persons in the act of drowning. Were they once brought to encounter a rough sea, and, with cords fastened to their collars, taught to plunge-in at the word of command, making regular excursions to and from the wreck, many valuable lives might probably thus be preserved.
5. In such disasters, not only the sufferers, but spectators, are apt to lose all presence of mind; otherwise expedients might often be contrived for rescuing helpless mariners in their distress.
6. Might not Dr. Franklin’s experiment, with a large paper-kite, deserve a trial, especially in the direction of a fair wind and lee-shore?
7. Might not a courageous rider, mounted on a steady well-trained horse, sometimes be very useful on these trying occasions? The horse, it ought to be remembered, swims with his nose and eyes just above water; but, if imprudently checked by the bridle, it proves fatal both to him and the rider. The heroic conduct of Cornelius Voltimed, a Dutchman, at the Cape of Good Hope, can never be sufficiently admired, nor his unhappy fate too sincerely deplored. In order to assist fourteen persons belonging to a vessel stranded near the coast, his intrepid philanthropy impelled him to ride his horse repeatedly into the sea; having at length happily succeeded in saving all but one, his strength failed, and in his last generous attempt to rescue that one unfortunately lost his own life!
The Dutch, in order to prevent plunder, ordain that no person shall approach the ship on pain of death; but this excessive zeal for the protection of property, so truly characteristic of the nation, generally damps every zealous effort for rescuing the forlorn sufferers. Had, therefore, the virtuous, the humane Voltimed even escaped the perils of the sea, he would, nevertheless, have been tried for his life by his unfeeling countrymen!
8. Vessels being most frequently cast away on a lee-shore, the difficulty of sending out assistance is greatly increased by that circumstance; but, were the sailors to fix a line to an empty cask, or buoy, the direction of the wind and tide, being favourable, would forcibly impel it from the wreck towards the beach, where assistance would be ready to fasten the line to some neighbouring tree or post.
9. But what seems to bid fairest for establishing a line of communication with the shore, is a late contrivance invented by Mr. Bell, of the Royal Artillery, which, on reading the account, I am glad to find, coincides with my own proposal, respecting the transmission of a cord with a bullet by gun-shot. Concerning the result of the Experiment, the Society of Arts have published the following favourable report:
“To ascertain the merit of Mr. Bell’s invention, his Grace the Duke of Richmond having given directions, proper trials were accordingly made, by throwing a loaded shell[12] on shore from a small mortar fixed in a boat, moored in the river Thames, above two hundred yards from the shore. To the shell was attached a rope, one end of which remained on board the boat. The shell, falling about a hundred yards within land, buried itself full eighteen inches in the gravel; when Mr. Bell and another person, on a raft floated by casks properly ballasted, hauled themselves on shore in a few minutes, by means of the rope above mentioned.
12. By which is meant a shell filled with lead, to which, a staple or ring being fixed, the rope is to be made fast. The shell thus loaded weighed about seventy pounds, being eight inches in diameter.
“These trials, having been repeated three times successively with the desired success, and it appearing that the method, proposed by Mr. Bell, of throwing a line on shore from a ship in distress, either stranded, or in danger of being so, promises to be of very important advantage to the maritime world; as by means thereof such vessel may obtain relief, any person, when landed, being enabled to secure ropes from the ship; or additional hands may thereby be conveyed from the shore to assist those on board. In cases of imminent danger, moreover, where all hopes of saving the vessel may be lost, Mr. Bell’s method offers the most probable means of saving the crew.
“The Society therefore voted to Mr. Bell a bounty of fifty guineas, on his leaving with the Society a complete model of his contrivance; which model is reserved in their Repository, for the inspection and use of the Public[13].”
13. Transactions of the Society of Arts, &c. Vol. X. p. 203. See also Raccolta di salvar, l’equipaggio d’un Bastimento, &c. by Count Berchtold, with an elegant engraving, descriptive of the entire apparatus.
That this, or other similar inventions may prove useful in time of need, the apparatus must be provided beforehand; and ought to constitute a part of the ship’s equipment previous to the voyage.
A Philosophical Correspondent has favoured me with the following communication, which displays much ingenuity, and seems worthy of further inquiry.
“As you wish, my dear Sir, for further intelligence, respecting the means I should propose for preventing ships from sinking, I will endeavour to give you some idea of the power of the apparatus. Its constituent parts are these:
“A pair of cylindrical flexible vessels, rendered impervious both to air and water by means of elastic resin, and a four-barrelled pump for inflating them. As the contents of cylinders increase in proportion to the squares of their diameters, such may be enlarged or diminished to equal the power in request; consequently both the pumps and air-vessels may be readily apportioned to the duty they have to perform. From the diameter of the cylinders of the pump, to judge of their discharge, we must consider the length of the stroke within the reach of middle-sized men, and the number of discharges which may be made in a given time. With the aid of simple mechanism, I have accomplished a perpendicular stroke of two feet, capable of being repeated from sixty to seventy times with ease, and from eighty to an hundred, if requested, in a minute.
“Air is a fluid of so volatile a nature, that the slightest pressure impels it forward; four men, therefore, can pump in more air than four hundred men can pump out water.
“That vessels of canvas may be made, at the same time, both flexible and air-tight, hath been demonstratively proved already. Such vessels, in their flaccid state, occupy little more space than a folded sail, and consequently are stowable in a narrow compass, till wanted. When immersed and inflated, they remove a quantity of water adequate to the air which they contain, and, if fixed to a ponderous body, give it a degree of buoyancy proportionate to the water they displace. If this be equal to the difference in weight between that body and an equal bulk of the fluid which surrounds it, the whole will rest suspended even with or near the surface of the fluid. Enlarge their contents, and turn the balance in favour of the sinking body, it will rise and float. Fix sufficient buoyant powers, therefore, to the sides of a ship, in such manner that they cannot break loose; though a plank should start in her bottom, she still would float.
“One method, then, of preventing a ship from sinking may be by a brace of air-vessels occasionally lashed to her sides. Another is, that of inflating a brace within her. To bring the former to effect requires a more perfect knowledge of the strength of cordage than the most experienced rope-maker can boast. Our best calculators egregiously err in this particular; for, instead of its increasing in proportion to the square[14] of the diameter of the cordage, it comes far nearer to the proportion of the simple diameter only, as numerous experiments with the best new town-made ropes of various sizes have convinced me. In the first mode, therefore, several difficulties remain to be overcome. The other is easy, consisting only in the simple operation of inflating air-vessels within her. Let such be placed in confinement either in the hold, between the decks, or under lashings in small open sloops (to which your attention, Sir, seems chiefly paid), and they will operate with the most certain and powerful effect. For, though water, through its density, will expel air when at liberty, it can never incroach upon it when properly confined. Secure, then, but a due portion of the lighter fluid in eligible situations, and the ingress of the grosser will be prevented. Consequently, though the sea run mountains high, and break over the sloop with the most tremendous surge, if the crew can secure themselves by lashing to the mast or rigging, and can at times have opportunity to supply the loss of air (which, through the inaccuracy of valves, air-cocks, &c. will sometimes happen), by a few additional strokes at the pumps, she will continue buoyant, in spight of elements, and be safe from the danger of sinking. Small vessels, under such circumstances, are liable, however, to be driven on shore; but, as they draw little water, their crews would probably be preserved.
14. See Falconer’s Marine Dictionary, article Cable.
“As yours, Sir, is the cause of humanity, I have troubled you with these particulars; and hope, that, as a possibility of relief appears, some Philanthropic Society or other will be induced to exert their endeavours for the preservation of the glorious tars of Britain.”
As the preceding scheme is supported, by its ingenious author, on true philosophical principles, and seems well calculated to keep a packet boat, or vessel of small size, buoyant, as some successful trials on the model seem to evince; yet, as the apparatus rests on the instable basis of air and water, might not some difficulty arise, during a sea storm, particularly in securing the air-cylinders, when destined to act externally on a large scale? It ought, therefore, to be subjected to the test of further experiment, both internally and externally, on vessels of different rates, as the invention certainly merits the attention of those who preside over maritime affairs. For, what keeps afloat a first-rate ship of war, with its immense freight of guns, stores, ammunition, and men, but the difference of specific gravity between air and water? What causes the ship to founder, but the accidental ingress of water, with a proportionate egress of air? Impervious air-vessels, therefore, properly placed, and inflated within the ship, would prevent the spaces thus occupied from being filled with water, and consequently bid fair to keep her buoyant, even though her upper deck became level with the surface of the sea. It was thus that the ship Guardian was prevented from foundering, whose packages and stores containing lighter fluids, such as spirits and air, which the water being unable to expel, alone kept the vessel afloat. Hence appears the utility even of empty casks if rendered impervious and immoveably fixed between the decks of a ship in distress.