A. Front pintle is where the gun traverses about a point in the front part of the carriage; center pintle where it traverses about a point in the center of the carriage.

Q. What is a rack?

A. A bar or arc having teeth that engage in a gear-wheel or worm. (See Fig. 7.)

Q. What is a gear-wheel?

A. A wheel with teeth on the circumference.

Q. What is a bevel-gear?

A. Two wheels whose axles are at an angle to each other and whose teeth engage. (Fig. 8.)

Q. What is a miter-gear?

A. A bevel-gear with axles of equal-sized wheels at right angles. (Fig. 9.)

Q. What is a worm?