the act of shifting any boom-fall from one side of the mast to the other.

In order to understand this operation more clearly, it is necessary to remark, that by a boom-fall is meant any fall whose bottom is extended by a boom, the fore-end of which is hooked to its respective mast; so as to swing occasionally on either side of the vessel, describing an arch, of which the mast will be the centre. As the wind or the course changes, it also becomes frequently necessary to change the position of the boom, together with its fall, which is accordingly shifted to the other side of the vessel as a door turns upon its hinges. The boom is pushed out by the effort of the wind upon the fall, and is restrained in a proper situation by a strong tackle communicating with the vessel's stern, and called the fleet. It is also confined on the fore part by another tackle called the guy.

GYGEUS, in Ancient Geography; called also Co-

lous; a lake of Lydia, distant 40 stadia, or five miles, from Sardis.