of battery, and traversing and operating guns in turrets, see patent of Ericsson, 1866, 1870; Perley, 1865, 1867; Eads, 1864, 1865; Bartol, 1863.
Training twin guns in parallelism in turrets, Eads, 1866.
Eads, 1864, 1865, has a means for training the gun upon an imaginary center, which is the center of the exterior opening of the port or embrasure, so as to reduce the opening to the smallest size.
The first notice of the discovery of gun-cotton was made by Braconnet, in 1833, who detailed the action of nitric acid on starch, sawdust, linen, and cotton.
He called it xyloidine.
Pelouse, in 1838, called attention to this compound.
Dumas, in 1843, again cited a mode of preparing, and made suggestions for the application.
Schonbein, in 1846, brought forward his plan of using nitric and sulphuric acids.
It was described by W. H. Ellet of Columbia, S. C., in 1846.
Baron Von Lenk, 1864, used cotton skeins instead of employing the wool in masses, thus render