|Birmingham made 'detector' lock, John Wilkes, c. 1680. V&A.|
This lock is from about 1680 and is one of three Birmingham locks made by John Wilkes at the V&A. The working of the lock is described: 'The master of the house could select, by turning the small knob at the top of the lock, the number of bolts (1 to 4) that he wished to put into operation. When set at number four, which is maximum for locking the top four bolts are locked out by just turn of the key, but four turns of the key are required to withdraw these, i.e. one at a time. There is however literally a "sting in the tail" of the top bolt, the one last withdrawn, for it triggers off the twin anti-burglar bottom bolts, and these can only be unlocked by a reverse action of the correct key.'*
Similar locks (or at least parts of them) are held at Birmingham Museum and Art Gallery and the MET Museum in New York [below]. The layout and workings are slightly different, but overall the designs are very similar.
|Lock, John Wilkes (of Birmingham), c. 1680. BMAG.|
|Birmingham lock, c. 1680. MET Museum.|
Attributed to John Wilkes as the lock is unsigned.
*From V&A website.