406

ON LOCKS AND KEYS.

that this “ swivel” is of no benefit whatever, whilethe reversal of the Barron’s tumbler affords noimprovement in security, and we should think wasnot quicker made. The improvements were appli-cable to all kinds of locks. Another improvementconsists in a peculiar mode of cutting out the woodin stock locks. Previous to this period the oblong-shaped cavity in the stock for the works of thelock to occupy was sawn out ; but by this improve-ment the chamber is formed of a circular shape,which is cut out by a tool in a lathe ; and this givesthe lock a much neater appearance.

Friend’s Secret Lock, invented about 1825.

This is a dial lock, which requires the aid of akey to lock and unlock. The inventor states that“ Keys or picklocks are of no use in opening it.The key which belongs to it is of no use to anyperson without the guide, which is so portable asto be put into a pocket-book, &c., and can bevaried in such a manner in a few seconds, by suchan indefinite number of movements, as to put itout of the power of any person to open it, evenif he is in possession of the guide , unless he isacquainted with the numbers to which it is set.This renders it safe, strong, compact, and secure.To open the lock you will observe on the guide twocircles, with the numbers 1, 2, 3, 4, 5, 6, 7, 8, 9,10, on each, and the stops are now set at 2, 6.Put on the guide to the front of the lock, with the