An Universal Dictionary of the Marine / Or, a Copious Explanation of the Technical Terms and Phrases Employed in the Construction, Equipment, Furniture, Machinery, Movements, and Military Operations of a Ship. Illustrated With Variety of Original Designs of Shipping, in Different Situations; Together With Separate Views of Their Masts, Sails, Yards, and Rigging. to Which Is Annexed, a Translation of the French Sea-terms and Phrases, Collected from the Works of Mess. Du Hamel, Aubin, Saverien, &c.

by William Falconer

The metal of cannon is not equally thick in all parts, but is in some measure proportioned to the force of the powder which it is to resist. At the breech, where the effort is strongest, the thickness of the metal is equal to the diameter of the corresponding shot. At the first reinforce, where this begins to slacken, the thickness is somewhat less than at the breech: at the second, where the force is still further diminished, the thickness is more reduced than at the first: and, by the same rule, the chace has less thickness than the second reinforce. The thickness of the chace gradually diminishes from the trunnions to the mouth of the piece; so that if a cannon was without cascabel, trunnion, and mouldings, it would exactly resemble the frustum of a cone, or a cone deprived of the small end.

In a vessel of war, cannon are placed on a sort of wheeled sledge, called the carriage, of which fig. 16. plate [VII]. is the plan, and fig. 17. the elevation. This carriage is composed of two large pieces of plank, called sides or cheeks, connected together by means of cross-pieces, which are either bolts, axle-trees, or transoms. The two axle-trees are fixed across under the fore and hinder parts of the carriage, being supported at their extremities by solid wooden wheels called trucks. The transom is placed directly over the fore axle-tree, and exactly in the middle of the height of the cheeks or side-pieces. The height of the transom is equal to two diameters of the shot, and the breadth to one diameter.

Explanation of the iron-work, and different parts of a sea-carriage, as exhibited in the plan and elevation of a thirty-two pounder, pl. VII. fig. 16. and 17.

a. The cap-squares, commonly called clamps in the sea-service.

b. Eye-bolts, by which one end of the clamp is fixed to the carriage.

c. Joint-bolts, upon which the other end of the clamp is fixed over the trunnions; after which it is fore-locked, to prevent the cannon from starting out of its carriage when fired.

b g. The cheeks or sides of the carriage.

d. The transom-bolt.

e. The bed bolt, upon which the bed rests to support the breech of the cannon. The bed is expressed by fig. 4.

f. Hind axle-tree bolts.