Such are a few of tho principal American locks. Long before the date of the Great Exhibition, the makers of those locks maintained an animated controversy respecting the merits of their several inventions, accompanied by challenges and prizes fur the picking of the locks. Nowell not only picked Andrews's unpick:able lock, but picked his own also ; and then set about devising new means of security—just as Vauban, having invented a particular system of fortification (his "first ''), found out moans of capturing fortresses constructed on that system, and then devised another system (his " second ") to remedy the defecta of the first. When similar lock-picking challenges and con troversies took place, at a meeting of the Institute of Civil Engineers in 1850, the American exploits in this art were mentioned ; but it was not till the following year that the matter acquired public) notoriety. During the Great Exhibition in 1851, Mr. Hobbs made known his opinion that all English locks could bo picked; ho picked one mado by Messrs. Chubb, to justify his belief ; and then arose a warm con troversy as to the question whether the operation was, under all the circumstances, fairly conducted. 3lesars. Bramoh had fur many years had a most complicated lock, for the picking of which a prize of two hundred guineas was offered ; Mr. Hobbs undertook this task, asked for thirty days to do it in, succeeded, and obtained tho prize. But hero agam a discussion arose as to the fairness or unfairness of the process. And so it has been in other cans. Mr. Smith picked a Newell lock ; but in a way which (it was contended), amounted only to a "ringing of the changes " among a certain number of combinations, and not a real pickins. Messrs. Puckezedge and Parnell invented a lock, the picking of which was to be rewarded with a prize; the lock was placed, or at least opened, and tho prize claimed ; but a court of Law decided against the claimant. If it would answer any useful purpose to notice other lock-picking exploits, there are ample materials for duiug so ; but it is obvious that all the challenges on this subject are likely to be vitiated by various circumstances, and the results con tested with angry feelings; for a man whose trade is that of making safety-locks would not be very ready to acknowledge the vulnerability of his own productions. The best result of these contests has been, that all the best locks have been made still better than before, by' additional securities suggested by the contests themselves. Mr. Hobbs
in 1853, picked a lock in a few minutes which had just won a prize from the Society of Arts—since which event it has been deemed better to let the lock-makers fight their own battles, without any testimonials or sanction from learned bodies. Mr. Denison has devised a lock in which a handle suffices to shoot or lock the bolt, but the unloCking cannot be effected except by the previous use of a very small key— an arrangement which he thinks likely to be useful in giving an employer much control over his clerks and others in the use of the lock.
The of this series of controversies has also been shown in the improvement of the manufacture of locks generally, both in efficiency and cheapness. Messrs. Hobbs and Ashley have introduced the American plan of manufacturing by machinery. ensuring both rapidity and exactness to a degree not attainable by mere hand-work ; and it can hardly be doubted that English manufacturers must ultimately follow the same course. Mr. Price, of Wolverhampton, living in the very centre of the lock-making district, states that down to 1356, there was scarcely a machine of any kind used in the manufacture of locks and keys throughout the whole district. Wolverhampton makes most of the good locks, Willenhall nearly the whole of the common kinds ; but in the one place, as in the other, the operations are almost wholly hand-work. The manufacture is mostly in the hands of small masters, each of whom works at the bench himself and employs a small number of men and apprentices. The produce is sold to the Wolverhampton factors or merchants; and many of the small masters depend on the weekly receipts from the factors for the means of carrying on the next week's operations. There are very few lock manufactories where the trade is conducted on anything like a large scale.
The principle and detail of modern lock-construction will be found fully treated in Tomlinson's • Cyclopedia of Arts ;' in the 'Rudimentary Treatise,' forming a part of Weale's Series ; and in Denison's Essay, reprinted from the new edition of the ' Eucyclopcdia Britannica ;' while Price's bulky volume (nearly 1000 pp.) on safes, locks, and keys, is a storehouse of gossip on all parts of the subject.