442

ON LOCKS AND KEYS.

corresponding levers being stamped with the samenumbers. That part of the stem of the key whichcarries the bit is not cylindrical but wedge-shaped,

i 1 1 ! I 1

1 MltTT

lM5 1

ti\

13 I

1 It 1

a

Fig. 210.

as shewn at b (fig. 219), which is an end view of it,with the piece o in its place. The pieces composingthe bit are thus prevented from moving round onthe stem, and are still further secured from shakeby means of a pin fixed to the under side of a, asshewn by the dotted circle in fig. 219, b , and whichpasses through the lever-bits 5 to 1. The piece ais fixed in its place by a small screw, as shewn inthe cut b.

“ It is almost needless to remark, that if theowner changes the order of the pieces composing thebit, he must change also, in exact correspondence,the order of the levers within the lock. It maysometimes be advisable to do this, when suspicionexists that a copy of the key has been obtained ;and it might also in some circumstances be desirableto keep the key with its parts purposely misplaced,