The powders that are sold for making soda-water, by mixing them together, consist of carbonate of soda and tartaric acid. When brought together in solution, a violent effervescence ensues, but the gas is not combined with the water in the same manner as when it is forced in and allowed to remain for some time with the liquid to be aerated. There is the further disadvantage attending such powders, that the tartrate of soda, formed by the tartaric acid and the carbonate of soda, employed to generate the gas, is drunk with the water.


[REVOLVERS AND MINIE RIFLES.]

"Is there anything whereof it may be said, See, this is new? it hath been already of old time, which was before us."[18] This observation of Solomon, the correctness of which we have often seen verified in this History of Inventions, is applicable even to that great apparent novelty the formidable "Revolver"—that death-dealing weapon, which will fire six shots in rapid succession by merely pulling the trigger so many times, as fast as it is possible.

The Revolver was almost unknown in this country until 1851, when it was brought prominently into notice at the Great Exhibition, by the specimens shown there by Colonel Colt, of the United States. Pistols with six barrels, which might be fired successively with the same lock, by turning them round, were, indeed, previously seen in gun-shops; but their clumsy form and their great weight prevented them from being used. Nor was Colonel Colt much more successful in his earlier attempts to bring his Revolver into public notice. He obtained his first patent in America in 1835, and established a manufactory for the pistols at Paterson, United States, where he expended £35,000 in attempting to bring the fire-arm to perfection, but with no beneficial result to himself beyond gaining costly experience. He made further improvements in 1849, and so far perfected the weapon that it had been used extensively in America before it was brought into notice in this country.

When Colonel Colt came to England, he undertook to investigate the origin of repeating fire-arms, with a view to ascertain how far he had been anticipated; and the result of his researches was, that repeating fire-arms, similar in principle to his own Revolver, had been invented four centuries before.

He found in the Armoury of the Tower of London a matchlock gun, supposed to have been made as early as the fifteenth century, which very closely resembles, in the principle of its construction, the Revolver of the present day. It has a revolving breech with four chambers, mounted on an axis fixed parallel to the barrel, and on that axis it may be turned round, to bring any one of the four loaded chambers in succession in a line with the barrel, to be discharged through it. There are notches in a flange at the fore end of the revolving breech to receive the end of a spring, which is fixed to the stock of the gun, for the purpose of locking the breech when a chamber is brought round into the proper position. The hammer is split at the end, so as to clasp a match, and to carry its ignited end down to the priming powder when the trigger is pulled. Each chamber is provided with a priming pan that is covered by a swing lid, and, before firing, the lid is pushed aside by the finger, to expose the priming powder to the action of the lighted match. If the date of this gun be correctly stated, a very rapid advance in the art of gunnery must have been made after the invention of gunpowder, which took place only one hundred years previously. The want of a better mode of discharging the gun than a lighted match was one of the chief obstacles to the introduction of the Revolver four centuries ago.

There is also in the Tower Armoury a specimen of a repeating fire-arm of a more recent date, though still very ancient, that presents considerable improvement on the preceding one. It has six chambers in the rotating breech, and is furnished with a barytes lock and one priming pan, to fire all the chambers. The priming pan is fitted with a sliding cover, and a vertical wheel with a serrated edge projects into it, nearly in contact with the powder in the pan. To this wheel a rapid motion is given by means of a trigger-spring, acting upon a lever attached to the axis of the wheel; and the teeth of the wheel strike against the barytes, which is brought down, previously to firing, into contact with it, and the sparks thus emitted set fire to the powder in the priming pan, and discharge the piece. In this instance, also, the breech is rotated by hand.

A still further advance towards perfection in repeating fire-arms is to be seen in the United Service Museum, where there is a pistol, supposed to have been made in the time of Charles I., with the breech rotated by mechanical means. In this pistol, the act of pulling back the hammer turns the breech, containing six chambers, one-sixth part of a revolution, and the priming powder is ignited by a flint hammer striking against steel.