s on the wall show the general construction of the modern German, French, and English heavy breech-loading guns. The Germans have a tube, a jacket, and hoops. The French, a thick tube or body, and hoops. The English, a tube, a jacket, and an overcoat, as it may be called. In each system of construction, the whole of the wall of the gun comes into play to resist the transverse bursting strain of the charge.
The longitudinal or end strength varies: thus, in the German guns, the tube and hoops do nothing--the jacket is considered sufficient. The French construction relies entirely on the thick body, while the English method aims at utilizing the whole section of the gun, both ways. Of course, if the others are strong enough, there is no particular advantage in this; and it is by no means improbable that eventually we shall find it cheaper, and equally good, to substitute hoops for the "overcoat."
I fear I have detained you a long time over construction, but it is both instructive and interesting to note th