fluids is mainly influenced by the forms of those
bodies. There seems no reason why the forms which
are best adapted to cleave water, should not be best
to cleave air, the difference being only in density.
The longer the vessel, the less is the tendency to
go to leeward. The cylinder or conical form is never
used for cleaving water, but in preference the
section of a bayonet is used. This, therefore, is
the true form of a powder-propelled projectile.
If we wished to run a man through the body, the last instrument we should use would be a spherical bullet on the end of a stick. This is precisely
the kind of thing we put on to a bull's horns to
prevent penetration. The most effective instruments yet known for piercing flesh are the small
sword and the bayonet — a three-edged section
forming three hollows. And the metal most
effective for constructing such weapons is steel.
We have hardness for penetration, strength for
resistance, and facility for form, maximum result,
and minimum resistance to the atmosphere. Where
the ordinary leaden shot would pierce through one
enemy, this projectile would pierce through half-
a-dozen. It would inflict a disabling wound, but
not a cruel wound, lacerating and tearing open like
a “ragged bullet.”
We have hitherto aimed at constructing pro- jectiles necessary to be carried on the shoulder or to be drawn by horses. We have never made wheel guns to be drawn by men. For this reason our range is limited by size and weight, or our difficulties are greatly increased by the various contingencies attached to the use of horses in battle. Wheel guns, drawn and managed by men, would obviate all the difficulties. A gun twelve feet in length, and with an inch and a- quarter bore, would weigh about two hundred weight, and would throw a shot from three to four pounds weight a distance of two miles.
This gun, placed upon a pair of high and light wheels, such as are used by the Americans for their travelling gigs, could be drawn by men with the utmost facility, and would easily pass through and over hedges, or be lifted over low walls. The length of these guns pre-supposes that they must be breech-loading, and with such an arrangement of breech, that in case of abandoning them, a small part could be taken away, so as to render them useless — a far more efficient process than what is called “spiking.” There are yet more advantages.
A soldier going into battle has a knapsack on his shoulders, a gun in his hand, and his ammunition slung about him. Now, it would be a great advantage that his body should be as unencumbered as possible. With this wheel-gun, in charge, say of three men, three knapsacks could all be slung to it as well as all the ammunition, three hand-guns, and three twelve- feet pikes, without perceptibly increasing the re- sistance to draught. If cavalry were sent against a body of men so provided, the guns and the pikes would form a most effectual barricade. If artillery were sent, the long-range would enable them to shoot both horses and gunners, and disable their approach. And in all transit the same advantage that a railway-navvy gets by using a wheelbarrow, instead of carrying his load on his back, would be obtainable by the use of this armed wheel-carriage. The men would get over more ground with less fatigue in the course of a day than with all their baggage strapped to their persons. This would be “flying artillery.” The particular modes of constructing such guns, and the analysis of the improved guns that have been constructed of late, must be left for a further number.
W. Bridges Adams.
THE SPIDER-CRAB.
I delight in watching the habits of fish, insects, &c. in a good Aquarium. We are indebted to these inventions of more modern times for some curious discoveries in natural history, especially those which refer to the hitherto unknown habits of marine animals. Let me here mention one instance of a peculiar instinct in a small crab, which may interest the reader, and which afforded me much pleasure, especially as I believe the facts I am about to relate are not generally known, or if known, only to a very few persons, and those few not of the scientific world. At the same time, I am unwilling to claim any credit for the discovery. It was first communicated to me through an amiable clergyman and his wife residing in Scotland, who, having an aquarium, and living close to the sea, had frequent opportunities of ascertaining the facts I am about to relate, and which I was able myself to verify during a recent sojourn I made at Bognor in Sussex. The facts are these.
There is a very small species of crab, called by the fishermen at Bognor the spider-crab, and which has its body and claws covered with numerous very minute hooks, scarcely perceptible to the naked eye, but perfectly so with the help of a magnifying-glass. It may be asked, “What can be the use of these hooks?” You shall hear. This crab is a prodigious coxcomb, and very careful of its own precious person. Either then for the purpose of concealing itself from its enemies, or from an innate love of finery, it selects a quantity of seaweed, always preferring the most gaudy colours, those chiefly red. Having selected them, he cuts them into fine thread-like slips, and runs them through the hooks. When he has completed his toilette, he appears one mass of seaweed, thus not only disguising himself from those enemies which might otherwise make him their prey, but perhaps feeling himself the best dressed crab in the neighbourhood. It is also remarkable that this labour for making his toilette is renewed every morning, so that the quantity of seaweed consumed is very great. This may be observed by any one who has the opportunity of keeping these comical little crabs in an aquarium, although I regret to add, that they do not live long in a state of confinement.
They are caught in considerable numbers in the lobster and prawn baskets at Bognor, together with another crab, about the same size as the spider-crab, but which is not furnished with hooks. On speaking to the Bognor fishermen respecting the latter, I found they all entertained the idea that the seaweed grew on them.