In 1805, Mr. Stansbury, an American, came over to this country with a new lock, which he patented, and was very assiduous in endeavouring to get it intro duced; in which attempt, however, he met with so little encouragement, that it might be deemed a failure. Nevertheless, there was sufficient originality in his contrivance to merit a notice in this place : the key was of the ordinary shape of those with a pipe, but longer and narrower in the bit, on the lower side of which were a number of pins projecting from its surface ; the key had no wards, and the lock, consequently, none; the bolt was not moved by the key immediately, but through the instrumentality of a revolving circular plate, attached to, and underneath which, was a fixed pin, that took into a notch in the bolt ; it was therefore the office of the key to remove the impediments to the motion of the revolving plate, which impediments consisted in a number of pins passing through it and another fixed circular plate or bridge underneath, the said pins being pressed through both, and made flush with the surface of the upper by the action of springs rivetted to the bridge. The two plates thus locked together were separated by the projecting pins upon the key, which, entering the holes in the upper plate, pressed the spring pins out of them and turned the plate round. The pin-holes in the circular plates were not opposite to the key-hole, but on one side leading towards the bolt, so that to find them out it was necessary to push the key slightly against the plate whilst turning it round.
Mr. Lawson subsequently took out a patent for a lock, the additional security in which consisted in the employment of a sliding curtain, which is drawn before the key-hole in the act of unlocking, thus rendering it impossible to move the bolt whilst a pick remained in the aperture.
In 1816 a lock was invented by Mr. Kemp, of Cork, the security of which consisted in the adaptation of tumblers or sliders, operated upon by two, three, or more small concentric tubes, of different lengths, placed inside the barrel of the key. These tubes were made of such a length as to push back the pins or sliders that detain the bolt, to the required positions, until each one corresponds with the notch that is cut in it for the projecting part of the bolt. Mr. Kemp calls his invention the union lock, from the circumstance that it unites the qualities of Barron's and Bramah's locks ; and from the manner in which the combination is effected, it affords, according to the inventor, a greater degree of security than either of the former, or than both of them together, supposing a lock of each kind was placed on the same door; and that a dishonest servant, who does not possess any particular ingenuity, may be instructed by a lock smith how to take the requisite impressions of either Barron's or Bramab's keys, even if he could be intrusted with them only for a few minutes : but this cannot be done with the key of the union lock, as it would require the locksmith to examine it himself, and to make several tools to ascertain its dif ferent dimensions, which he could not do without having it in his possession for some considerable time, with leisure to make repeated trials. In this remark of'
Mr. Kemp's we entirely coincide ; and it still applies to all locks hitherto made (1834), that the keys, when in the possession of s workman, may be copied; and, in many, without possession. Mr. Kemp'a invention may supply • partial remedy for this defect; but until a complete one is provided, the art of lock making is imperfect, and no locks are inviolable.
Viewing the subject in this light, it affords the editor of this work much satisfaction to state, that he has in his possession a lock, the key of which cannot be copied; a locksmith possessing no tools by which an exactly similar one can be made; and the machine by which the original one was made, is so arranged as to be deprived of the power of producing another like it. The lock is very simple, very strong, and can be very cheaply made. The cost of a com plete machine to make them would be about one hundred pounds ; with that they might be manufactured at one-half the expense of any patent lock. The inventor is desirous to have the subject brought before the public under a patent, but want of time to devote himself to such an object at present obliges him to lay it aside.
Locks have been made which required that the key should be a powerful magnet ; others, in which an unusual and complicated motion must be given to the key ; and others, in which an improper key or instrument would fire a pistol, or ring an as proposed by the Marquis of Worcester.
Of all the various locks that have of late years been introduced to the notice of the public, Mr. Chubb's has obtained the greatest celebrity. Although it possesses but small claims to novelty, it cannot be denied that it combines, in an eminent degree, the qualities of security, simplicity, strength, and durability ; and we think that the persevering and business-like manner in which the inge nious inventor has contrived to fix it before the public eye, has contributed in no small degree to the successful "-run" it has had. The chief characteristic in this lock, and that which marks it as Chubb's, is the employment of • lever called a detector, which locks the bolt fast upon any of the tumblers being beyond its assigned range, and shows that some person has been attempting to unlock it by a false instrument. In other respects the lock resembles Barron's and Bramah's ; and we are disposed to question its boasted superiority over those admirable inventions for a reason which now forces itself upon our atten tion. In Barron's and Bramah's the picker has no means of knowing whether the tumblers are lifted too high or not ; but in Chubb's he has only to put the detector hors de combat in the first instance, by a correct thrust from the out side of the door (which might be accurately measured) so as toilx it fast in its place; the detector then becomes a stopper to the undue ascent of the turn ers, and the extent of their range is thereby correctly ascertained : thus it appears to us, the detector might be converted into a director of the means of opening the lock.