A. A luff-tackle on the fall of another luff. (See Fig. 49.)

Q. Describe the single Burton.

A. A rope rove through two single blocks, with a hook in the bight of the running part.

Q. What is the power gained?

A. Treble. Quadruple if both blocks move.

Q. How is power determined when one tackle is applied to the fall of another?

A. It is equal to the product of their respective powers.

Q. What is mousing, and what is its purpose?

A. A seizing around a hook to prevent it from spreading or unhooking. (See Fig. 49.)

Q. What is a bight of a hook?