It was near the close of the sixteenth or the beginning of the seventeenth century, that the heavy and ill-shaped artillery began to give place to more wieldy and useful pieces. A certain M. de Linar demonstrated, in the latter part of the sixteenth century, that cannon twelve feet in length would give a greater range than those seventeen feet in length, the calibre being the same; but some years elapsed before advantage was taken of this discovery. In 1624, Gustavus Adolphus caused experiments to be made to verify this point, and, on being convinced of its truth, caused his batteries to be furnished with shorter and lighter pieces. This great king introduced, about the same time, a new and lighter kind of artillery, made of sheet iron and leather. Each piece had its chamber formed of thin metal and embraced by strong iron rings; over these was placed a form of hardened leather, which was again encircled with rings and held compactly together. These pieces were mounted on light carriages, so that two men could easily manoeuvre them. It was said that they would fire from eight to ten rounds without requiring repairs. Gustavus made use of them in all his military operations from 1628 to the time of his death. They did him excellent service on numerous occasions; being so very light they could be easily transported, and, on the field of battle, their movements could be made to conform to the movements of his troops. As cannon and small arms were gradually introduced into general use, various inventions and improvements were proposed and introduced from time to time. Cannon were constructed with two or more barrels; some were arranged for being loaded in the breech, and others at the mouth of the piece; two pieces were sometimes connected by horizontal timbers, which revolved about a vertical axis, so that the recoil of one piece would bring the other into battery; and various other arrangements of this description, which have recently been revived and some of them patented as new inventions. The small arms employed at this period were much the same as those used at the present day, except the matchlock, which afterwards gave place to flint-locks. Arms of this description were sometimes made to be loaded at the breach, and guns with two, three, and even as many as eight barrels, were at one time in fashion. In the _Musee de l'Artillerie_ at Paris may be found many arms of this kind, which have been reproduced in this country and England as new inventions. In this Museum are two ancient pieces, invented near the end of the sixteenth or the beginning of the seventeenth century, which very nearly correspond with _Colt's patent_, with the single exception of the lock![33]