Gun-lift

The gun-lift recently devised by Col. Laidley, of the U. S. Ordnance Corps, is a most complete and rapid means for moving and dismounting heavy guns. In it the hydraulic jack is placed upon a stand over the gun, whereby the building-up of the crib-work of blocks, which serves as a base for the jack to stand on, is dispensed with, and the position of the jack has not to be changed during the operation of raising or lowering a gun. The ordinary carpenter’s horse or trestle is taken as the basis of the hoisting apparatus. The cap of the trestle, having to sustain the weight of the gun suspended at a distance of more than 2 feet from the points of support, is a large, strong, and heavy piece of timber, and the legs of the trestle have to be strongly braced. The bolster, a strong piece of oak on top of the cap of the trestle, has two mortices cut in it, one for a hoisting-bar to pa through , and the other for the fulcrum-post to rest in . The fulcrum-post has a rece cut on the top to receive the end of a lever and keep it in place. The lever has a mortice through which the hoisting-bar, already mentioned, pa es; the latter is perforated with a series of holes through which a pin pa es, by which the end of the lever, under which the hydraulic jack works, can be fastened to the hoisting-bar. The hoisting-bar has a hook on its lower end to which the weight to be raised is fastened by means of a sling.