Wheel-lock.
1. (Fire-arms.) A form of lock for fire-arms which superseded the old matchlock, whereby the piece was touched off by a match or portfire. The wheel-lock was invented in Italy early in the sixteenth century; it was moved by a chain and wound up like a watch to prepare it for use. The wheel, originally, was not fixed in the gun, but was fitted in a groove when ready for firing; at other times being carried in a bag. It consisted of a furrowed wheel of steel, whose friction against a piece of sulphuret of iron was made to communicate fire by sparks to the priming. See gun-lock.
2. (Locksmithing.) A form of lock having a series of wheels or disks with letters around their edges. The interior arrangements of the lock were such as to prevent the bolt being shot until a series of letters were in line, forming a combination known only to the owner and maker. See letter-lock. 3. A wagon-lock, to retard the revolution of the wheels in descending a hill.
