Page:A Dissertation on the Construction of Locks (1815).pdf/37

 to effect it, otherwise than with the proper key, are the points to be ascertained, by a specification of the component parts of the movement, and an explanation of their respective offices.

I shall now, therefore, endeavour to illustrate in a familiar manner, the general principle of my invention, and then shew that method of applying it in the construction of Locks, which has appeared in practice, the simplest and most effectual for the purpose.

Fig. 1. G represents a sliding bar or bolt, prepared to move in the frame K, which frame has six notches cut on two of its sides, parallel to each other, across the direction of the bolt, to admit the six sliders a, b, c, d, e, f, to move freely therein. For the same purpose also, the bolt has six corresponding notches, and the sliders being dropped therein, it is retained in its place or prevented moving, until the obstruction thus formed by the sliders is removed. 1, 2, 3, 4, 5, 6, shew the six openings on the sliders made indiscriminately at different distances from the bolt, precisely fitted to its width, and which must be brought exactly in a line opposite thereto, before it can be moved. The ends of the sliders at o, o, are the only parts intended to be exposed, and are all