Engineering, but neither then nor ever considered that such a ship could be of any use for our purpose; because from that sketch it was at once evident that such ships had not enough displacement, and would draw too much water.

Admiral Popoff never knew of Mr. Elder's idea as to the flat-bottomed ships, and has never known about his specification, drawn for a patent, before it was published in the Times a few weeks ago, by Messrs. Elder and Co. If Mr. John Elder really had entertained any idea of building such ships for Russia, as stated in the Times, then surely he would have shown the model of her to Admiral Popoff. As it is, we never could have wanted a ship of 16,000 tons, because the largest then existing Black Sea dock could only have lifted a vessel of 2,400 tons, with a width of 120 feet.

The following is the translation from Herodotus, Book I., chap. 194, laid on the table by Mr. J. Scott Russell:"The boats which come down the river to Babylon are circular and made of skins. The frames, which are "of willow, are cut in the country of the Armenians, above Assyria, and on these which serve for hulls, a "covering of skins is stretched outside, and thus the boats are made, without either stem or stern, quite round "like a shield. They are then entirely filled with straw, and their cargo is put on board, after which they 66 are suffered to float down the stream. Their chief freight is wine, stored in casks made of the wood of the palm tree. They are managed by two men, who stand upright in them, each plying an oar, one pulling and the "other pushing. The boats are of various sizes. Each vessel has a live ass on board; those of the "larger size have more than one. When they reach Babylon, the cargo is landed and offered for sale, after which "the men break up their boats, sell the straw and the frames, and, loading their asses with the skins, set off on their way back to Armenia. The current is too strong to allow a boat to return up stream, for which reason they "make their boats of skins rather than wood. On their return to Armenia they build fresh boats for the next

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" voyage."

The date of Herodotus' visit would be about B.C. 450 or 460, i.e., not less than 2,300 years ago.

NOTE.-See various annotations in Rawlinson's edition of Herodotus translated. The modern boats of this description are navigated in the same way, but are said to be coated with bitumen instead of skin. They are called "kufa." The accompanying sketch shows the shape of the kufa, and the attitude of men in her.

ON A PROPOSED CELLULAR SYSTEM OF BUILDING FOR SHIPS OF WAR.*

By H. J. BOOLDS, Esq., Surveyor, Lloyd's Registry of British and Foreign Shipping.

[Read at the Seventeenth Session of the Institution of Naval Architects, 6th April, 1876; the Right Hon. LORD HAMPTON, G.C.B., D.C.L., President, in the Chair.]

ELEVEN years ago, in February, 1865, I read a Paper before the Scottish Shipbuilders' Association on "Cellular Ships of War," in which I advocated the sub-division of such ships into a greater number of water-tight compartments or "cells" than was then usual, or, so far as I was aware, had ever been contemplated in naval construction in this or any other country.

My object was to make the ships of our Navy unsinkable either by shot, ram, or torpedo; and, considering the excessively expensive character of a modern war ship, and what I may call the excessive facility with which ships could be sunk by either means, I believed I was doing the country some service by offering to our naval constructors a cheap and simple solution of the difficulty of keeping an iron-clad afloat and efficient in spite of all the accidents of naval warfare.

Notwithstanding the important changes that have taken place since then, in the power and size of guns, thickness of armour, and the science, if not the practice, of torpedo warfare, no attempt has been made, either on my plan or any other, to give our ships of war greater safeguards from sinking; and the internal hold arrangements of the war ships of this country are still-like merchant ships, which are intended only for facility in stowing and discharging cargo-constructed in compartments large enough singly to sink any ship, in the event of perforation from any cause. This has long appeared to me an anomalous state of matters for which there is no accounting.

As a matter of calculation and fact the whole business of a war ship is to keep herself afloat while she sinks or otherwise destroys her antagonist; but, while the science of naval warfare has been directed to destruction by every means, and protection only from

*Received 15th January, 1876.

gun

shot and shell, nothing whatever has been done for protection from the ram or torpedo. The power of the has been so much increased that the thickest armour that can be made and carried afloat is comparatively valueless for protection from shot, and worse than valueless for protection from sinking.

If, therefore, a ship, even without armour, could carry her guns and fight without risk of being sunk, she would be a much more formidable antagonist than any ship of war now in existence. There is no reason that I am aware of why all our ships of war should not be of that character. All are now built chiefly of iron and propelled by steam; their stores of every description are calculated in proportion to their armament and steam power; and the spaces in the hold are allotted and partitioned in some irregular way for the respective details of the equipment.

Now, with the exception of the machinery, which necessarily occupies large spaces, and perhaps of coals, which may require to be frequently taken in and consumed in large quantities, there is no part of the stores of a ship of war that may not be stowed in the smallest separate compartments into which I propose to divide such ships, without being in any way inconvenient to get at in emergency; even the machinery may be so divided that it may be in several water-tight compartments instead of as at present usually all in one, and there is no particular reason why coals may not be stowed in smaller separate compartments than customary, which may be emptied in detail, and closed water-tight when empty.

The recent sinking of the Vanguard by the ram of the Iron Duke has induced me to call public attention again to the system of cellular sub-division, which I believe to be the only adequate safeguard against underwater damage.

All iron ships have some bulkheads, usually limited in sailing ships to one collision bulkhead at the bow; screw steamers have, in addition, one or two whole or partial bulkheads at the stern to protect the body of the ship from danger through accidents to the screw, shaft, or pipe; and two bulkheads generally enclosing the machinery, boilers, and coals. These are all that are considered absolutely necessary against usual sea risks; the holds being required to be as large free spaces as possible for general cargo purposes.

In large and long vessels the two principal holds may be again divided by bulkheads into two spaces before and two abaft the engine room; thus separating the largest ships into seven, or, at most, eight water-tight compartments, injury in any one of which is usually sufficient to cause a total loss.

For the necessities of cargo and trade smaller sub-divisions would be seriously inconvenient, and are, therefore, not desirable nor recommended. But although ships of war are not generally divided into a greater number of water-tight compartments than merchant steamers, there are no considerations of cargo or stowage, or of dispatch in loading and discharging, to weigh for a moment against the dangers which a ship of war—from the very "reasons for her existence"-is bound to encounter, and which she ought, therefore, to be guarded against.

In the larger iron-clads, partial protection from bottom injuries is obtained by an inner skin of iron riveted and made water-tight upon the inner edge of the floors and frames to the height of the upper part of bilge or lowest deck. The value of this inner skin has been proved in the cases of the Great Eastern and the Agamemnon; but beyond this the holds of a man-of-war, though usually as large and open as the holds of a merchant ship, are not required for any purpose but the stowage of her own consumable stores-coals, water, provisions and ammunition. Some bunker divisions have to be made for coals. Fresh water for the use of a large crew, though required in large quantity, amounting to several hundred tons, is not generally carried in tanks exceeding ten tons capacity each, which occupy a considerable space of the hold of every man-ofProvisions have to be stored in barrels, and store rooms built for the purpose; while magazines for ammunition, shot and shell, and other necessaries, are all divided into quantities and spaces, limited for convenience and safety into the smallest manageable proportions.

war.

It therefore appears to me self-evident, that it would be an immense practical advantage to the ship, if the spaces into which it is absolutely necessary to separate the stores of every kind by divisions, which are now of no other use than simply as partitions, and which only add their own weight to the weight of the stores for no benefit to the ship, were enclosed by regularly-divided and permanent water-tight partitions, which would serve all the purposes for which tanks, store rooms and magazines are now required, and contribute, in proportion to their number and arrangement, to the strength and safety of the ship, instead of being, as at present, merely dead weight, increasing the risk of her destruction.

In the accompanying drawings I have shown, firstly, the composite cruiser, designed to illustrate my Paper of eleven years ago on "Cellular Ships of War;" and, secondly, the Vanguard, enlarged from drawings which appeared in the Engineer of 10th September, 1875, but with the lower holds altered and divided on the cellular system, to show how easy it would have been to have rendered that ship unsinkable, and how easy it would still be to make the rest of our ships of war much stronger and unsinkable, without

impairing their efficiency otherwise in any respect. In the Vanguard plan I have shown. the orlop beams lifted about 2 feet to bring this deck about 1 foot above the load line, and made a complete iron deck. The inner skin is carried up the inside of the frames and attached to this iron deck, making a complete inner ship. A longitudinal bulkhead is run through the centre line of ship from the keel to the gun deck, or deck next above the load line. All the principal transverse bulkheads are carried up to this deck, and additional bulkheads are put in, dividing the holds into spaces 24 feet long, making the spaces between the gun and orlop decks about 24 feet square.

Below the orlop deck the holds are again sub-divided by longitudinal and transverse bulkheads into spaces about 12 feet square, all fitted and caulked water-tight between the deck and the inner bottom, and from each other, there being no openings into these cells except by an iron water-tight door on the orlop deck, each space between the gun and orlop decks opening into four cells.

In an original design it would be intended to carry each of these 24-feet cellular spaces to the outer skin, thereby confining the water between the two skins to that space, with one water-tight opening in the inner skin for access to the frame spaces for cleaning and painting.

The engine room-from the design as a twin screw steamer-occupies one 24-feet space each side of central line, the next space before that being four coal cells, each 12 feet square; then a 24-feet boiler space, then four coal cells, then 24-feet boiler space, and then 12-feet cells from that to the bow-those next the forward boilers being used for coals; each cell will hold 50 tons of coals, and each group of four will hold 200 tons. Three groups on each side will hold 600 tons, or 1,200 tons of coal in all, with very little more inconvenience in trimming than ordinary bunker arrangement for such ships.

The after-end of the ship would be sub-divided in the same way, the cells through which the screw shafts pass being made tight around the shafts by stuffing boxes; the lower part of the cells through which the shafts pass can also be floored over the shaft, with access from the cells. All the cellular divisions are large enough for store rooms for all purposes, and being water-tight, will serve as tanks for water, and can be filled in groups wherever required for that purpose.

The whole of the bulkhead cellular divisions in such a ship as the Vanguard would not exceed 500 tons weight, and as the weight of armour above necessitates as large an amount of ballast in such ships, the whole of this ballast would be saved, and the strength and safety of the ship would be immensely increased, without adding anything to the draught of water or displacement.