554

ON LOCKS AND KEYS.

trial has taken place between them to establish thefact, but it nevertheless remains undoubted, andthe sooner Mr. Chubb improves his patent, so as toset Mr. Hobbs at defiance, the better for his owninterests.”

Mr. Hobbs has stated that the principle on whichthe picking of locks depends to be, that “ wheneverthe parts of a lock which come in contact with thekey are affected by any pressure applied to the bolt,or to that portion of the lock by which the bolt iswithdrawn, in such a manner as to indicate thepoints of resistance to the withdrawal of the bolt,such a lock can be picked.” The first step is toproduce the requisite pressure.

We may observe that during the present year Mr.Hobbs fully demonstrated to us the easy manner inwhich the above principle can be successfully applied,by operating upon an improved patent lock in ourpresence, which he picked in a few minutes.

The following diagrams, with the explanation,are copied from the work edited by Mr. Tomlinson,before referred to, which, added to the remarksmade at page 306, it is hoped will enable ourreaders to fully comprehend and understand theprinciple of “ picking by pressure ”* as distin-

* We believe the method of picking locks with moveable obstructionsto the passage of the bolt by the tentative process was first made publiclyknown in this country at a special general meeting of the Society of Arts ,on the 30th of June, 1851, when a paper was read by Mr. Paul R. Hodge“ On the progress of improvements in locks in the United States ofAmerica. ”