FIG. 10.--MOUGIN'S HYDRAULIC GUN
CARRIAGE.
For high aiming, the gun and the movable part of its carriage are capable of revolving around a strong pin, c, so placed that the axis of the piece always passes very near the center of the embrasure, thus permitting of giving the latter minimum dimensions. The chamber of the 8 inch pump is provided with projections that slide between circular guides, and carries the strap of a small hydraulic piston, p, that suffices to move the entire affair in a vertical plane, the gun and movable carriage being balanced by a counterpoise, q.
The projectiles are hoisted to the breech of the gun by a crane.
Between the outer armor and turret sufficient space is left for a man to enter, in order to make repairs when necessary.
Each of the rolled iron plates of which the turret consists weighs 19 tons. The cupolas that we have examined in this article have been constructed on the hypothesis than an enemy will not be able to bring into the field guns of much greater caliber than 6 inches.--Le Genie Civil.
HIGH SPEED ON THE OCEAN.
To the Editor of the Scientific American: