The Annals of the Civil War Written by Leading Participants North and South
Alexander Kelly McClure, Ed.

With such a result I did not attempt, of course, to mount and use the other, but assembled a board of officers to study the principle that might be involved in the peculiar construction, and to make experiments generally with ordnance. The happy results of the extensive experiments made by this board with many guns of different calibre, including muskets, and last of all with the other Blakely, was that if the cartridge were not pressed down to the bottom of the bore of a gun, and a space were thus left in rear of the charge, as great a velocity could be imparted to the projectile with a much smaller charge, and the gun was subject to less abrupt strain from the explosion, because this air-chamber, affording certain room for the expansion of the gases, gave time for the inertia of the heavy mass of the projectile to be overcome before the full explosion of the charge, and opportunity was also given for the ignition of the entire charge, so that no powder was wasted as in ordinary gunnery.

When this was discovered the remaining Blakely was tried from a skid, without any cartridge in the rear chamber. It fired both projectiles, shell and solid shot, with complete success, notwithstanding the small amount of metal at the extremity of the breech. I at once utilized this discovery. We had a number of eight-inch columbiads (remaining in Charleston after the capture of Sumter in 1861), which contained a powder-chamber of smaller diameter than the calibre of the gun. The vent in rear of this powder-chamber was plugged, and a new vent opened in advance of the powder-chamber, leaving the latter to serve as an air-chamber, as in our use of the Blakely gun. They were then rifled and banded, and thus turned into admirable guns, which were effectively employed against the Federal iron-clads. I am surprised that the new principle adapted to these guns has not been used for the heavy ordnance of the present day, as it would secure great economy in weight and cost. The injured Blakely gun was subsequently thoroughly repaired, and made as efficient as when first received.

In the year 1854, while in charge as engineer of the fortifications of Louisiana, I attended a target practice with heavy guns by the garrison of Fort Jackson, on the Mississippi river, the object fired at being a hogshead floating with the current at the rate of about four and a half miles an hour. I was struck with the difficulties of trailing or traversing the guns-forty-two pounders and eight-inch columbiads-and with the consequent inaccuracy of the firing. Reflecting upon the matter, I devised soon afterward a simple method of overcoming the difficulty by the application of a “rack and lever” to the wheels of the chassis of the guns; and I sent