LAUNCH (OF. lanchicr, lancier, Fr. la nehcr, It. lanciare, to hurl as a lance, from Lat. lancea, lance). The largest boat carried by a man-of war; there are both steam launches and sailing launches. Large launches, 40 to 00 feet long. are carried by battle-ships and large armored cruisers. They are designed for use as picket or vedette boats, to guard against surprise by torpedo-boats when operating near the enemy's coast or fleet ; and they are as fast as strength and limited size permits, sonic. steaming eighteen or nineteen knots on trial. The sailing launch is a sloop-rigged boat, also intended for rowing.
The keel of a ship is laid upon a series of wooden blocks, placed 6 or 7 feet apart, and built up 3 or 4 feet from the ground. the tops of which lie in a line which slopes downward to the water at an angle of about five-eighths of an inch to the foot. The whole ship, therefore, when it is fin ished, slopes downward with this inclination, and rests upon the blocks just mentioned, and upon suitable timber shores. When the vessel is ready for launching, 'ways' of timber and phanking are laid down parallel to the keel, and at sonic little distance on each side of it, under the bilges of the ship; they extend into the water a consider able distance below high-water mark. A 'cradle'
is then built under the ship, of which the bottom is formed of smooth timbers resting upon the 1\ a y s. Before launching. the under sides of these timbers and the upper sides of the ways are well greased, and the weight of the ship is transferred from the keel-blocks to the cradle and ways. Timbers, called 'dog-shores; are placed so as to resist the tendency of the ship to slide down un til the right moment. When this arrives, at high water, the ceremony of launching and naming the ship takes place; the dog-shores are knocked away, and the vessel glides stern foremost into the water. As soon as the water removes the weight of the vessel from the cradle. the latter breaks up into pieces. Many large battle-ships and some other vessels have been built in dry docks and floated out when ready, instead of being launched. This system is economical, if the dry docks are not needed for other purposes. the Great Lakes the practice of launehing ships sidewise is very common.
She is a heavy boat, with good carrying ca pacity; is eoppered as a rule, and is generally used, when the battalion is sent away from the ship, as the artillery boat.