Читать книгу Rudimentary Treatise on the Construction of Locks - Dodd George - Страница 6

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Locks and door-fastenings have not, until modern times, been susceptible of any classified arrangement according to their principles of construction. They have been too simple to require it, and too little varied to permit it. That some such fastenings must be employed wherever doors of any kind are used is sufficiently apparent; and there is a little (though only a little) information obtainable, which shews the nature of the fastenings adopted in early times. The bolt, the hasp, the chain, the bar, the latch, the lock, all were known, in one or other of their various forms, in those ages which we are accustomed to consider classical. Travellers, generally speaking, do not descend to locks, or rather they do not think about them; otherwise they might have collected much that would have been novel and applicable to the present work; and, indeed, there is some ground for the assertion, that a notice of the door-fastenings of all nations would reveal to us something of the social and domestic habits of various members of the great human family. Be this as it may, however, we may profitably make a little inquiry into the locks of ancient times.

In the volumes of Lardner’s Cyclopædia relating to the “Manners and Customs of the ancient Greeks and Romans,” we do not find any mention of the kinds of locks used by those nations; but the author, while describing the houses, says:—“Doors turned anciently upon large pivots in the centre, let into sockets in the lintel and threshold, so that one of the sides opened inwards, the other outwards; and Plutarch gives the following curious reason why persons were to knock and alarm the porter, viz. lest the visitor entering unawares should surprise the mistress or daughter of the family busy or undressed, or servants under correction, or the maids quarreling.” As the visitors had thus the power (if permitted so to do) to open the outer door of a house, it would appear that very little in the nature of a lock was employed under ordinary circumstances, unless indeed it were a mere latch. In respect to Roman houses it is stated, that “the doors revolved upon pivots, which worked in a socket below, and were fastened by bolts which hung from chains.” There is no mention of locks here. Mr. St. John, in his work on the same subject, says: “The street-door of a Grecian house, usually, when single, opened outwards; but when there were folding-doors they opened inwards, as with us. In the former case it was customary, when any one happened to be going forth, to knock, or call, or ring a bell, in order to warn passengers to make way.” After describing the various kinds of wood of which the doors were made, he proceeds: “The doors at first were fastened by long bars passing into the wall on both sides; and by degrees smaller bolts, hasps, latches, and locks and keys, succeeded. For example, the outer door of the thalamos in Homer was secured by a silver hasp, and a leathern thong passed round the handle, and tied, perhaps, in a curious knot.”

Mr. Yates, in a learned article on this subject in Smith’s Dictionary of Greek and Roman Antiquities, collects numerous details scattered through various early writers. We will string together a few of these details, so far as they have any relation to the fastenings of doors. The outer door of a Roman house was generally called janua; whereas the inner doors were called ostia. The doorway, when complete, consisted of four indispensable parts—the threshold or sill, the lintel, and the two jambs. The threshold, on which the feet trod, was often regarded with a kind of superstitious reverence; the lintel, which crossed the doorway at the top, having a considerable superincumbent weight to bear, was usually made of one piece of timber or stone of great strength; the jambs, or side uprights, were also made in one piece each. The doorway, in every building of the least importance, contained two doors folding together; even the internal doors had their bivalve construction. But in every case each of the two valves was wide enough to allow persons to pass through without opening the other; in some cases even each valve was double, so as to fold like our window-shutters. These doors, or valves, were not hinged to the side-posts, as with us, but were, as has already been stated, pivoted to the lintel above and the threshold below. The fastening usually consisted of a bolt placed at the base of each valve or half-door, so as to admit of being pushed into a socket made in the sill to receive it. The doorways in some of the houses at Pompeii still shew two holes in the sill, corresponding to the bolts in the two valves. At night, the front door of the house was further secured by means of a wooden and sometimes an iron bar placed across it, and inserted into sockets on each side of the doorway; hence it was necessary to remove the bar in order to open the door. Chamber-doors were often secured in the same manner. In the Odyssey there is mention of a contrivance (adverted to by Mr. St. John) for bolting or unbolting a door from the outside; it consisted of a leather thong inserted through a hole in the door, and by means of a loop, ring, or hook, capable of taking hold of the bolt so as to move it in the manner required. We have here evidently the elements of a more complete mechanism; for the bolt was a rude lock in the same degree that the thong was a rude key. That the Romans afterwards had real locks and keys is clear; for the keys found at Herculaneum and Pompeii, and those attached to rings, prove that a kind of warded lock must have been well known.[2] There are the remains of a tomb at Pompeii, the door of which is made of a single piece of marble, including the pivots, which were encased in bronze, and turned in sockets of the same metal; it is three feet high, two feet nine inches wide, and four and a quarter inches thick; it is cut in front to resemble panels, and thus approaches nearer in appearance to a modern wooden door; and it was fastened by some kind of lock, traces of which still remain.

[2] An examination of the Roman keys in the British Museum sufficiently attests this fact.

The same facts frequently become more clear when described in different words by different writers. We shall make use of this circumstance. Mr. Donaldson, in his Essay on Ancient Doorways, presents us with details which illustrate many of the foregoing remarks. “Homer describes the treasures and other valuable objects (mentioned in the Odyssey) as being kept in the citadel, secured merely by a cord intricately knotted. This, of course, was soon found to be a very insufficient protection, and therefore a wooden bar was adopted inside the doors of houses, to which it was attached by an iron latch, fastened or removed by a key adapted to it; this key was easily applied from within; but in order to get at it from without, a large hole was made in the door, allowing the introduction of the hand, so as to reach the latch and apply the key. The lock called the Lacedæmonian, much celebrated by ancient writers, was invented subsequently; it was especially fitted for the inner chambers of houses, the bar fastenings continuing to be employed for closing the outer doors of dwellings and the entrance-gates to cities. The Lacedæmonian lock did not require a hole to be made in the door, for it consisted of a bolt placed on that side of the entrance-door which opened, and on the inside of a chamber-door. When a person who was outside wished to enter, it was necessary for him to insert the key in a little hole and to raise the bolt; and in time this species of fastening was improved by the insertion of the bolt in an iron frame or rim permanently attached to the door by a chain, and fastening the door by the insertion of the hasp, through the eye of which was forced the bolt inside the lock by applying the key.” After quoting a Latin sentence from Varro in elucidation of his subject, Mr. Donaldson proceeds to observe, that for the most part the locks of the ancients were different in principle from those of modern days, not being inserted or mortised into the doors, nor even attached except by a chain; they were, in fact, padlocks.

One of the passages in the Odyssey alluding to the primitive mode of fastening the valves or folding-doors of a house runs thus:—

“Whilst to his couch himself the prince addressed,

The duteous nurse received the purple vest:

The purple vest with decent care disposed,

The silver ring she pulled, the door reclosed;

The bolt, obedient to the silken cord,

To the strong staple’s inmost depth restored,

Secured the valves.”

Most of the other great nations of antiquity resembled either the Egyptians or the Greeks and Romans, more or less closely, in their domestic and domiciliary arrangements; or, at any rate, so far as such humble matters as locks and keys are concerned, we need not seek far from those nations for examples. The Nineveh and other Assyrian explorations have, however, revealed many curious and unexpected facts; from the temples and the palaces we may by and by penetrate into the houses and rooms of the citizens sufficiently to know how their doors were fastened. In the mean time ancient Egypt awaits our notice.

Sir J. Gardner Wilkinson, in his Manners and Customs of the Ancient Egyptians, gives the following information concerning the doors and door-fastenings of that remarkable people, on the authority of models, sculptures, and paintings, still existing. The doors were frequently stained so as to imitate foreign and rare woods. They were either of one or two valves, turning on pieces of metal, and were secured within by a bar or by bolts. Some of these bronze pins have been discovered in the tombs of Thebes; they were fastened to the wood with nails of the same metal, the round heads of which served also as ornaments. In the stone lintels and floors behind the thresholds of the tombs and temples are still frequently to be seen the holes in which the pivot-pins turned, as well as those of the bolts and bars, and the recess for receiving the opened valves. The folding-doors had bolts in the centre, sometimes above as well as below; a bar was placed across from one wall to the other.

In many of the ancient Egyptian doors there were wooden locks fixed so as to fasten across the centre at the junction where the two folds of the door met. It is difficult, by mere inspection of the bas-reliefs and paintings, to decide whether these locks were opened by a key, or were merely drawn backwards and forwards like a bolt; but if they were really locks, it is probable that they were on the same principle as the Egyptian lock still in use. For greater security, these modern locks are occasionally sealed with a mass of clay; and there is satisfactory evidence that the same custom was frequently observed among the ancient inhabitants of that country. Sir J. G. Wilkinson gives a representation of an iron key, now in his possession, which he procured among the tombs at Thebes, and which looks very much like a modern burglar’s picklock. In relation to keys generally, and after mentioning the use of bronze for their manufacture, he says: “At a later period, when iron came into general use, keys were made of that metal, and consisted of a straight shank about five inches in length, and a bar at right angles with it, on which were three or more projecting teeth. The ring at the upper extremity was intended for the same purpose as that of our modern keys; but we are ignorant of the exact time when they were brought into use; and the first invention of locks distinct from both is equally uncertain; nor do I know of any positive mention of a key, which, like our own, could be taken out of the lock, previous to the year 1336 before our era; and this is stated to have been used to fasten the door of the summer parlour of Eglon, the king of Moab. The description here adverted to is that contained in Judges iii. 23-25: ‘Ehud went forth through the porch, and shut the doors of the parlour upon him, and locked them ... his servants ... took a key, and opened them.’”

The curious and ingenious wooden lock of ancient Egypt is still in use in Egypt and Turkey. In Eton’s Survey of the Turkish Empire, published towards the close of the last century, the locks then and there in use are thus described: “Nothing can be more clumsy than the door-locks in Turkey; but their mechanism to prevent picking is admirable. It is a curious thing to see wooden locks upon iron doors, particularly in Asia, and on their caravanserais and other great buildings, as well as upon house-doors. The key goes into the back part of the bolt, and is composed of a square stick with five or six iron or wooden pins, about half an inch long, towards the end of it, placed at irregular distances, and answering to holes in the upper part of the bolt, which is pierced with a square hole to receive the key. The key being put in as far as it will go, is then lifted up; and the pins, entering the corresponding holes, raise other pins which had dropped into these holes from the part of the lock immediately above, and which have heads to prevent them falling lower than is necessary. The bolt, being thus freed from the upper pins, is drawn back by means of the key; the key is then lowered, and may be drawn out of the bolt. To lock it again, the bolt is only pushed in, and the upper pins fall into the holes in the bolt by their own weight.” Mr. Eton, probably seeing how well the tumbler-principle is here understood, says: “This idea might be improved on; but the Turks never think of improving.” The locks on the doors of modern houses in Cairo seem to be of this long-established form, except where iron locks have been imported from Europe.

A letter was inserted in the Journal of Design for July 1850 from Mr. W. C. Trevelyan; in which, after adverting to the Egyptian lock, he says: “It is remarkable that the locks which have been in use in the Faröe Islands, probably for centuries, are identical in their construction with the Egyptian. They are, lock and key, in all their parts made of wood; of which material, if I mistake not, they have also been found in Egyptian catacombs; and so identical with the Faröese in structure and appearance, that it would not be easy to distinguish one from the other.”

fig. 1.

fig. 2.

fig. 3.

fig. 4.

The construction of this remarkable Egyptian or pin-lock will be understood from the accompanying engravings. The quadrangular portion, a a fig. 1, is the case of the lock, screwed or otherwise fastened to the door, having a wooden bolt, b b, passing horizontally through a cavity in it. In the part of the case above the bolt are several small cells containing headed pins, arranged in any desired form; and in the top of the bolt itself are an equal number of holes similarly arranged. The effect of this arrangement is such that, when brought into the right positions, the lower ends of the headed pins drop into the corresponding holes in the bolt, thereby fastening the bolt in the lock-case. A large hollow, or cavity, is made at the exposed end of the bolt, the cavity extending as far as and beyond the holes occupied by the pins. The key consists of a piece of wood (shewn in two positions, figs. 3 and 4,) having pins arranged like those in the lock, and projecting upwards just to a sufficient distance to reach the upper surface of the bolt. This being the arrangement, whenever the key is introduced and pressed upwards, its pins exactly fill the holes in the bolt, and by so doing dislodge those which had fallen from the upper part of the case. The bolt may, under these circumstances, be withdrawn (as shewn in fig. 2), leaving the headed pins elevated in their cells, instead of occupying the position shewn by the dotted lines in fig. 1. The cavity in the bolt must of course be high enough to receive the thickness of the key, and also the length of the pins protruding from the key.

This primitive lock comprises many of the best features of the tumbler or lever-locks of later days, as will be seen in a future chapter. There will also be opportunities of shewing how the pin-action has been applied in other ways in some of the modern locks.