Page:A Dissertation on the Construction of Locks (1815).pdf/50

 4th. The Lock, in principle, is capable of infinite variation, so that Locks may be made with component parts of precisely the same dimensions to the most remote period of futurity, without a duplicate of any former one, and arranged for one key to pass the whole. This property of transposition which supercedes all apprehension from false keys and the property of motion upon which the complete security of the Lock depends, are illustrated by the subjoined Table, in which the first column shews the number of sliders in each Lock. Column 2nd., the number of transpositions. Column 3rd., the variations which may be made in any Lock, supposing the projected surface of each slider to admit of only six different situations for the notch, by which the actual sum of security compared with unity is demonstrated for any given number of sliders, from 4 to 18.