Page:A Dissertation on the Construction of Locks (1785).pdf/25

 to aſcertain the degree of force to be applied; for, it matters not how far the tumbler is lifted above the point, at which it ceaſes to controul the bolt. But in Mr. Baron’s Lock the caſe is otherwiſe. He hath not only improved upon the practiſed method of applying the tumbler, but hath given it an office which is perfectly new, and of more importance to its ſecurity, than any impediment which art can oppoſe to the introduction of a falſe key. Inſtead of leaving his tumblers liable to be forced to an indefinite diſtance from the point at which they ceaſe to controul the bolt; he hath confined their action within a circumſcribed ſpace, cut in the center of the bolt, of a dimenſion barely ſufficient to the purpoſe they are intended to anſwer. This ſpace or groove, is, in form, an oblong ſquare, and is not only furniſhed with niches on the under ſide, into which the hooks of the tumblers are forced by the ſpring as in other Locks, but is