Page:EB1911 - Volume 16.djvu/863

 introduced by Queen Mary. It is captured by the sweep-net in August, and is esteemed as a delicacy. The lakes adjoining the town afford the inhabitants exceptional advantages for the game of curling. There was once a team of Lochmaben Curlers entirely composed of shoemakers (souters) who held their own against all comers, and their prowess added the phrase “to souter” to the vocabulary of the sport, the word indicating a match in which the winners scored “game” to their opponents’ “love.” Lochmaben unites with Annan, Dumfries, Kirkcudbright and Sanquhar (the Dumfries burghs) in returning one member to parliament.

LOCK, MATTHIAS, English 18th-century furniture designer and cabinet-maker. The dates of his birth and death are unknown; but he was a disciple of Chippendale, and subsequently of the Adams, and was possibly in partnership with (q.v.). During the greater part of his life he belonged to that flamboyant school which derived its inspiration from Louis XV. models; but when he fell under the influence of Robert Adam he absorbed his manner so completely that it is often difficult to distinguish between them, just as it is sometimes easy to confound Lock’s work with the weaker efforts of Chippendale. Thus from being extravagantly rococo he progressed to a simple ordered classicism. His published designs are not equal to his original drawings, many of which are preserved in the Victoria and Albert Museum, South Kensington, while the pieces themselves are often bolder and more solid than is suggested by the author’s representations of them. He was a clever craftsman and holds a distinct place among the minor furniture designers of the second half of the 18th century.

Among his works, some of which were issued in conjunction with Copeland, are: A New Drawing Book of Ornaments (n. d.); A New Book of Ornaments (1768); A New Book of Pier Frames, Ovals, Girandoles, Tables, &c. (1769); and A New Book of Foliage (1769).

LOCK (from the O. Eng. loc.; the word appears, in different forms, in many Teutonic languages, but with such various meanings as “hole,” Ger. Loch, “lid,” Swed. lock, &c.; probably the original was a root meaning “to enclose”), a fastening, particularly one which consists of a bolt held in a certain position by one or more movable parts which require to be placed in definite positions by the aid of a key or of a secret arrangement of letters, figures or signs, before the bolt can be moved. It is with such fastenings that the present article chiefly deals.

The word is also used, in the original sense of an enclosure or barrier, for a length of water in a river or canal, or at the entrance of a dock, enclosed at both ends by gates, the “lock-gates,” and fitted with sluices, to enable vessels to be raised from a lower to a higher level or vice versa (see and ). In guns and rifles the lock is the mechanism which effects the firing of the charge; it thus appears in the names of old types of weapons, such as wheel-lock, match-lock, flint-lock (see, § Firearms; also and ). Lock (Ger. Locke) in the sense of a curl or tuft of hair, the separate groups in which the hair naturally grows, may be, in ultimate origin, connected with the root of the main word. Lockjaw is the popular name of the disease known as (q.v.). The name “Lock Hospital” is frequently used in English for a hospital for patients suffering from venereal diseases. According to the New English Dictionary there was in Southwark as early as 1453 a leper-hospital, known as the Lock Lazar House, which later was used for the treatment of venereal diseases. The name appears to have become used in the present sense as early as the end of the 17th century. Lock hospitals were established in London in 1745–1747 and in Dublin in 1754–1755.

The forms in which locks are manufactured, such as padlock, rim-lock, mortise-lock, one-sided or two-sided, &c., are necessarily extremely numerous; and the variations in the details of construction of any one of these forms are still more numerous, so that it is impossible to do more here than describe the main types which have been or are in common use. Probably the earliest locks were of Chinese origin. Specimens of these still extant are quite as secure as any locks manufactured in Europe up to the 18th century, but it is impossible to ascertain the date of their manufacture. With the exception, in all probability, of these Chinese examples, the earliest lock of which the construction is known is the Egyptian, which was used four thousand years ago. In fig. 1, aa is the body of the lock, bb the bolt and cc the key. The three pins p, p, p drop into three holes in the bolt when it is pushed in, and so hold it fast; and they are raised again by putting in the key through the large hole in the bolt and raising it a little, so that the pins in the key push the locking pins up out of the way of the bolt. It was evidently to locks and keys of this nature that the prophet alluded: “And the key of the house of David will I lay upon his shoulder” (Isaiah xxii. 22), the word muftah used in this passage being the common word for key to this day.

In the 18th century the European lock was nothing better than a mere bolt, held in its place, either shut or open, by a spring b (fig. 2), which pressed it down, and so held it at either one end or the other of the convex notch aa; and the only impediment to opening it was the wards which the key had to pass before it could turn in the keyhole. But it was always possible to find the shape of the wards by merely putting in a blank key covered with wax, and pressing it against them; and when this had been done it was unnecessary to cut out the key into the complicated form of the wards (such as fig. 3), because no part of that key does any work except the edge bc farthest from the pipe a; and so a key of the form fig. 4 would do just as well. Thus a small collection of skeleton keys, as they are called, of a few different patterns, was all the stock in trade that a lock-picker required.

The common single-tumbler lock (fig. 5) requires two operations instead of one to open it. The tumbler at turns on a pivot at t, and has a square pin at a, which drops into a notch in the bolt bb, when it is either quite open or quite shut, and the tumbler must be lifted by the key before the bolt can be moved again. The tumbler offered little resistance to picking, as the height to which it might be lifted was not limited and the bolt would operate provided only that this height was sufficient; the improvement which formed the foundation of the modern key lock was the substitution of what is known as the “lever” for the tumbler, the difference being that the lever must be lifted to exactly the right height to allow the bolt to pass. This improvement,

together with the obvious one of using more than one lever, was introduced in 1778 by Robert Barron, and is illustrated in figs. 6 and 7. Unless the square pin a (fig. 6) is lifted by the key to the proper height and no higher, the bolt cannot move. Fig. 8 illustrates the key of such a lock with four levers, the different distances between the centre of the key barrel and the edge of the bit being adapted to lift the levers to the respective heights required. This lock differs from the