The annexed engraving is a side elevation of an improvement inVastening the locks of doors, safes, vaults, &c, invented by William L. Bass, of Boston, Mass,, and which was patented in December, 1851. a a is the door ; c c isthelockor iron framework inside, in which the bolt, e, is moved jn and out by a pinion (not shown here.) In the bolt, c, is a notch, into which the pawl, h, of the lever, h i, fits, the said lever swinging freely on a bolt, k. The peculiar features of the invention consist in relieving the pawl from the bolt, and thus allow the unlocking of the door, which is effected by means of the movements of a clock. A A A is a frame of metal fastened to the partition; B is a screw to which is affixed a chain or cord, E, running on pulleys, F and H, and terminating with a weight, I. G is a lever, forked at one end, to which is suspended a loop, L (shown by the dotted lines), under the ratchet wheel, M. When the clock is in motion, the loop, instead oTJcatching in the teeth ol the ratchet wheel, drops from one tooth to another, but when the clock is stopped, it catches in the teeth of the latter, and holds the lever, G, in its place. At the end of the pawl, h i, is a hook, I, which fita over a projecting arm. m, in the hinged slotted plate, n, fitting against the weight-box, , and in any of the slots, can be fitted the stud, o. The weight, r, as it descends, strikes against the stud by means of a projection, v, and thus disengages the pawl from the bolt, e. P pis the back plate of the clock; q is the main wheel, to which the weight is attached ; s is the second wheel, and u the crown wheel, —the whole forming a time-piece with the exception ot the dial-work. The weight, r, being wound up on its axis, the escapement on the axis of the pendulum acts upon the crown wheel, , and the weight, r, gradually de-' scends as the gear wheels revolve. At the appointed hour, which is set by the stud or pin, o, in the selected slot, the knob, v, will strike it, and disengage the catch, m, thus allowing the bolt, e, to be withdrawn. It is evident from the above that the bolt of a lock, fastened in this manner, will be a safeguard against any burglarious attempts, and it will be efficient so long as the clock is running, the limit of which can be regulated at the will of the owner. If, however, the clock should be stopped by any accident, and it is required to open the door on the outside, it is Jone by applying a thumb-nut to an endless screw on the outside, which operates the ver-;ical screw, B, which will raise the cord, E, ind consequently the lever pawl, hi, from the jolt, e. The loop, L, (which' is a kind of :atch levlr), when the clock is stopped, catch-is in the teeth of the wheel, M, holds the orked lever, G, in its place, and thus the cord j s allowed to lift the pawl, but when the clock j s in motion, the ratchet wheel, M, moves the j oop, L, therefore the forked lever, G, is nutj leld firm, and the latch cannot then be lifted. More information may be obtained by let-er addressed to the patentee