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On the Construction of Locks and Keys by John Chubb
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CONSTRUCTION OF LOCKS AND KEYS. 33
directed to the subject of secure locks, and he produced specimens of those in use at the Millbank and Pentonville Prisons, which, though not of first-rate workmanship, were tolerably safe, strong, and cheap ; most important considerations, when from seven hundred to eight hundred locks had to be provided.
The lock from the Millbank Prison was a good common tumbler lock, with a bolt and a brass guard, in which there was a slot for a pin to slide in, to keep the bolt in its place ; it only locked singly, but as yet it had defied ordinary attempts to pick it.
That from the Pentonville Prison was of a better description ; it was the invention of Mr. Thomas, of Birmingham, and consisted of a common tumbler, a bolt, and a brass guard flap, retained in position by a spring inserted at the back of the lock. The key, in its revolution, lifted the guard flap, at the same time acting upon the tumbler, which threw the bolt. The lock had also a handle on the outside attached to a trigger, which caught the bolt, when shot back by the key in opening the door, and retained it until the handle was touched, which put the bolt on half lock. This contrivance, the object of which was to save the time of the turnkeys, placed the bolt in such a position, that on closing the door from the inside, the lock could only be opened by the application of the key from the outside, and every prisoner was obliged, by the rules, to touch the handle of the trigger, and thus shut himself into the cell. These locks had been in use eight years, during which period not one had required to be replaced, and any trifling derangements had been made good whilst the prisoners were at exercise. They only cost ten shillings each, notwithstanding that the offers, in the first instance, ranged from twenty-five shillings to forty shillings.
Mr. CHUBB said, he was prepared to produce a workman who would pick any number of Davis' cabinet locks, of different combinations, which he had never seen before, taking only half an hour for each lock.
He was willing to make the same offer with respect to the locks from the Pentonville Prison ; and he might state, that in point of security, he considered them absolutely worthless: in proof of which he exhibited one of them, and a common burglar's tool, by which the lock could be opened with the greatest ease.
Mr. CHARLES HART said, he had some experience in locks, and was conversant with the merits of all the different kinds. From his experience, he considered Chubb's locks were the most secure, and were generally made better than any others. Many inferior locks, made on the same principle, were commonly sold, but he had never yet met with a man who could pick a lock of Mr. Chubb's own manufacture.
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On the Construction of Locks and Keys by John Chubb