History of Locks

The following is an extract from our Encyclopaedia of Locks and Builders Hardware. First published in 1958.

The History of Locks Old locks and their  keys together form a subject which has received considerable attention. There is a great deal of information about them in the works by John Chubb (1850) George Price (1856), Commissioners of Patents (1873), Pitt-Rivers (1883) and H. W. Chubb (1893) which are named in the Bibliography. These are the outstanding studies in the English language and together they have provided much of the material for the present account.

Of earlier and other means than locks and keys to protect valuables it must suffice to mention only a few. Primitive man's treasures were often buried or hidden in caverns, the hollow trunks of trees or elsewhere. Cords and ropers were used in various ways to fasten doors and for other measures of security. The Gordian knot comes to mind. Then there was the wooden latch on the inside face of a door which would be lifted or drawn back from the outside by a cord passing through a hole in the door. To prevent opening from outside no more was needed than pulling in the cord.

In a history of locks it is interesting and important to trace the means adopted to make the lock secure, as age succeeded age. There are and have been throughout the centuries, only two mechanical principles by which security in key operated locks is obtained. One is by means of fixed obstructions to prevent wrong keys from entering or turning in the locks. The other, which is superior, employs one or more movable detainers which must be arranged in pre-selected positions by the key before the bolt will move. The earliest locks, although crude, ungainly and inartistic, demand notice for the admirable means adopted by their makers to provide the security. After these, through another long period, appeared locks which, according to present ideas, were inferior in respect of security to the primitive forms. On the other hand, many of these later locks were so beautifully fashioned that the work of the artist overlaid and sometimes obscured the mechanical intention. This is true no less of Roman times than when French and German smiths of the Middle Ages encrusted their lock plates with Gothic mouldings and carved their delicately shaped keybows. As the styles of architecture and its kindred arts succeeded one another, the decoration and treatment of locks and keys were affected by the same changes. Mechanically they altered also, if not always for the better. In a much later age, which showed itself more utilitarian than artistic, the mechanical features of locks and the need to provide greater security gained a new importance.

It is quite reasonable to suppose that the first barring of a door was done by means of a cross beam, either dropped into sockets of sliding in staples fixed on the door; and it is equally reasonable to suppose that if it slid, a vertical pin dropping into a hole through the staple and beam together, kept the beam in place. If the beam was on the outside of the door, the locking pin must be hidden, and reached either through a hole in the beam, or else through a hole in the staple. This is the kind of primitive lock as made by the Egyptians.

They shortened the beam in a long bolt, and made it hollow for part of its length, so as to reach the pin hidden in beam and staple through the beam itself. The key, which was pushed up the hollow, had pegs on it to match the pins which held the bolt - for the one pin was now multiplied. When the key was well home it was raised, and so its pegs lifted up the pins out of the way, leaving the bolt free. Then the bolt was drawn back by the key; the pegs are the latter filling up and engaging with the holes until then filled by the pins. It will be noticed that the shank of the key is the arm and the pegs are the fingers of the hand. The dropping pins are the true tumblers. The Egyptian lock was first described by Eton in his Survey of the Turkish Empire, 1798. Further information about it was given early in the 19^th century by Denon, the Frenchman, who said that he had found the locks sculptured in one of the grand old temples of Karnac, which shows that the same kind of lock has served Egypt for 40 centuries. Locks almost identical or with very little difference and still made of wood have been seen recently in Iraq and Zanzibar. In another class of primitive locks, the pins were reached through a hole in the staple and not through the bolt. There is good reason to believe they were once remarkably widespread. They have seen comparatively recently in some parts of Scandinavia, in the Hebrides and Faroe Islands. They have been observed also upon the West Coast of Africa and in the less frequented parts of certain Balkan States. The hole in the staple by which to get at the pins is a horizontal one above the bolt. The pins are square in section, and are notched on their sides for the key to pass and get into position before being lifted. The key is usually flattish, with little side projections which engage the pins. After they are lifted, it is necessary to pull back the bolt by hand, thus making a marked and essential difference between this and that of Egypt, in which the bolt is withdrawn by the key itself. These locks vary in detail, some having two sets of pins, the key passing between the sets, in others the pins have holes right through them for the key, not merely side notches.

The next two classes of primitive locks are those in which the beam or bolt was mounted on the inside surface of the door. In this case, if fastened by the tumbler pin, it would not be so necessary to conceal it as when bolt and pin were outside the door. There are some curious sickle-shaped pieces of iron found now and again - as illustrated - which look as if they were made for the purpose of putting through a hole in the door and pulling up or pushing up the pin. Perhaps they simply engaged the bolt in a direct fashion, and, being turned from the outside, move it to and fro, but they vary in their outlines too much for this supposition to be probable, some being full sickle-shackle and other only slightly cranked or bent, and in some well-preserved specimens their ends have been carefully shaped, as it to fit a hole exactly. They have been found at many places in France and Germany. General Pitt-Rivers ascribes some which he himself found near Lewes, to the late Celtic period. At last we come to the fourth primitive type of lock, the bolt or beam being still inside the door. In this type the bolt was kept out by the projection of a spring or springs, which spread out against the sides of the staple in the same way that an unwilling boy spreads out his arms and legs against the jambs of a doorway through which his school fellows try to push him. The first function of the key is to compress the springs. It is a flattish one, with return prongs or hooks on its end. It is first passed through a horizontal slit in the door and bolt; then turned a quarter circle, and pulled. The pull brings the prongs to bear upon the springs of the bolt making them lie flat, and so clear of the fixed obstructions at theirs ends. The bolt is then free to slide back, and this is effected by simply sliding back the key, for its prongs are now embedded in the bolt. The keys of these locks have been numerously found among Roman remains, and not long ago it was stated that locks of this kind were still in use in Norway.

Some references and quotations from ancient and other writers concerning primitive locks and their keys are of interest. Aratus in his description of the constellation Cassiopeia says that in shape it resembles a key. Huetius agrees, adding that the stars to the North compose the curved part and those to the South the handle of the crooked or curvey keys belonging to those early days. According to Parkhurst's Hebrew Lexicon (1807) keys of this kind with handles of wood or ivory were put through holes in the doors and turned one way or the other to move the bolt. Homer in the Odyssey says that Penelope wishing to open a storeroom picked up a well made copper key which had an ivory handle. That is the translation by a modern scholar. Pope's version is:-

A brazen key she held, the handle turn'd, With steel and polish'd elephant adorn'd;

The poet Arison in the Anthologia applies to a key an epithet meaning on that is much bent. Eustathius, a Greek commentator on Homer about AD 1170, says that keys of this kind were very ancient but still in use in his time. As they were in the shape of a sickle and awkward to carry otherwise, they were tied together and carried on the shoulder. This custom is confirmed by Callimachus in his Hymn to Ceres. Eustathius attributes the invention of keys to the Lacedemonians while Pliny and Polydore Virgil give credit to Theodorus of Samos. This, however, is disproved by other authors who hold that keys were in use before the Siege of Troy.

It has been said that the most ancient lock every discovered is that described by Mr Joseph Bonomi in Nineveh and its Palaces as having secured the gate of an apartment in one of the palaces of Khorsabad. He says that the gate was fastened by a large wooden lock like those still used in the East, the wooden key with iron pegs at one end to lift the iron pins in the lock, being as much as a man can carry. Mr Bonomi adds that the length of such keys ranged from thirteen to fourteen inches to two feet or more. In a letter which appeared in a trade journal in 1850 Mr W C Trevelyan said that it was remarkable that the locks which had been in use in the Faroe Islands, probably for centuries, were identical in their constructions with those of the Egyptians. They were, lock and key, in all their parts made of wood; of which material, he believed, were others which had been found in Egyptian Catacombs, thus making the Egyptian so like the Faroese in structure and appearance, that it would not be easy to distinguish one from the other.

The frequent mention of locks and keys in the Old Testament is further evidence of their great antiquity. In the book of Judges (Chapter iii), it is recorded that after Ehud had stabbed Eglon, King of Moab, he shut the doors of the parlour upon him, and locked them, and when the servants came and found the doors locked, they took a key, and opened them. This would probably be in the twelfth or thirteenth century B.C., and there is no reason to doubt that by that time locks and keys were in use in Palestine. In the Song of Songs (Chapter, v, v. 5) there is a poetical reference to hands dropping with Myrrh on the handles of the lock. Then in the book of Nehemiah (Chapter iii, v.6) 445 B.C., it is stated that at the time of repairing the old gate of Jerusalem, they set up the doors thereof, and the locks thereof, and the bars thereof. In confirmation of other records that keys in the early days were very large, there is in the prophecy of Isaiah (Chapter. xxii, v.22) circa 712 BC, this passage: And the key of the house of David will I lay upon his shoulder. (See illustration).

Roman padlocks in metal were constructed very much after the fashion of the fourth primitive type of lock for doors mentioned earlier. The shackle or hasp, which was separate from the body, carried on its lower side a pair of spreading springs, which entered a hole in the end of the body when the two pieces were being put together. When the shackle was pressed in fully, the springs which during the operation had been gradually closed up, spread out inside the body and so held the two pieces together. To take them apart, the springs, which were simply flexible barbs, had to be compressed. This was done in some locks by a key which was turned after being pushed through a hole in the body.

Illustration (A) shows a lock in the Roman style which was operated in that manner. Another lock illustrated (B) though German of the 18^th century has similar mechanism. Its keyhole is concealed by a secret hinged cover which is released by using the projection on the bow of the key to press the end of a spring that is reached through the hole in the side of the shackle. In locks such as that at (C) the key when inserted merely slides along the springs to compress them and then drives the shackle outwards. This style of padlock is found to be the almost universal native type in China at this day, so one wonders who was the first and true inventor, Roman or Celestial. Being loose portable locks of a kind convenient to secure baggage of all sorts in transit, they might easily become well known, especially along the ancient trade routes. These padlocks, whether Roman or Chinese in origin, are seen all over the East, shaped and decorated in ways peculiar to their own countries. Some are shaped like dragons, others like horses or dogs, the tails forming the hasps. The Romans had other kinds of padlocks as well, in which the security parts were made like those of their fixed locks. The padlock has always been in favour as a fastening with the Greeks and Romans, and the natives of the East. In all probability the movable lock succeeded the primitive. It seems to form the connecting link between the earliest locks and those of more recent date.

Roman keys have been found also in various parts of England, and specimens are to be seen in the British Museum, some being rigidly attached to finger rings. Mr Price declares that the holes and cuts in the keys discovered at Herculaneum and Pompeii, of which three are illustrated, are distinct from the old Roman keys found in this country, and indicate that they did not perform a complete revolution in the locks, which, in consequence, were the equivalent of the spring locks of modern days. Roman keys are found much more frequently than Roman locks, some being of such shapes that it is not always easy to say what their locks were like. One kind of key has its bit angle shape; one angle is cut to operated bolt pins in the way already described, the other being pierced with holes as if to pass fixed obstructions or wards. Many of the keys were undoubtedly made to turn, their stems being pin or pipe, after the manner of modern keys. Some of the pipes were drilled right up so that any dirt or other obstructions could be pushed through. This old idea is from time to time brought forward as a novelty by one or another in these days. A great many of the keys of olden times have been found at different periods; most of them are of bronze, but some are made of iron; many of these keys have numerous wards peculiarly shaped, extending considerably up the shank and belonging without doubt to warded locks, which, judging from the intricate arrangement of the ward-bits of their keys, must have been elaborately contrived. Lipsius, in his comments on the second book of Tacitus, is the first to allude to the ancient usage's respecting keys, which in some cases, he states, had a ring adapted in size for the purpose of being worn on the little finger, and engraved to answer the purpose of a seal. From the evidence of various early writers is seems safe to conclude that the Greeks and Romans learned the use and construction of locks from the Egyptians. From the beginning of the mediaeval period, the shapes of keys are more like our own, and working more like them than the preceding types. The sliding and pushing have given place entirely to turning movements, the keys being either made pipe-fashion to slide onto a fixed pin in the lock, or else made solid, and terminating in a projecting pin, which fitted a socket or hole in the back plate of the lock. Later on, the section of the pipe was not always circular; sometimes it was triangular, and the pin on which it was pushed was shaped to fit it. Of course, provision was then made for the pin itself to turn with the key. The outside of the key, too was fluted in the Renaissance period and the lock pin then became a barrel as well, revolving in bearings at both ends. Some of the most beautiful specimens of keys are those belonging to the 15^th and early 16^th centuries which can be seen in various museums. They are represented by the illustration. For perfect proportion in all their details and minute workmanship, they have never been excelled. Their four-sidedness and breadth gives them a strong sturdy look, but this is lightened by the gracefulness of their pierced tops and sides. Flat pictures along do not show their beauty.

From Roman times until the end of the seventeenth century reliance for security in the great majority of locks was placed upon fixed obstructions. The falling pins had gone almost into disuse. To this end, wards and keyholes of peculiar shapes were extensively used. Wards became progressively intricate so that in the best locks the fashioning of them and keys to suit, with numerous fine slits and perforations, was truly a craft that required a long apprenticeship. The exterior of such locks was in keeping with the interior and as a result very many beautiful specimens with delicate forging, open work and fine traceries were produced, especially in the fifteenth, sixteenth and seventeenth centuries. The skill and imagination of the smiths who made them, as a branch of the blacksmith's art, were apparent in these locks of which many good examples are preserved in the museums and other buildings of this country, France, Germany, Italy and elsewhere. They were often very large and expensive locks which in the making must have taken as many weeks as minutes are now required for the manufacture of some locks. To keep the dead bolt of these early locks in the locked or unlocked position, a spring was commonly fitted or, alternatively, a single acting tumbler which was no more than a simple catch or hook, without any security value, to be lifted by the key as it was turned. In warded locks with spring bolts the tumbler was not necessary. The wide diversity of design of the mediaeval locks, with never a repetition as it seems, is one of their striking features. Dozens of pages could be covered with illustrations and accounts of these locks but here a few only must suffice.

One interesting lock, known as the Beddington lock, is illustrated. It is a wrought iron gilt rim lock measuring about 14 x 8 inches with the Royal Arms and supporters used by Henry VII and Henry VIII. It is said that Henry VIII took it with him when he travelled and had it screwed to his bedroom door wherever he stayed. A seventeenth century lock with its key is shown below. This was formerly on the iron door of the Treasury at Aix-la-Chapelle, but now is at South Kensington. The lock, which was five bolts, measures 171/4 x 91/2 inches and the key is 73/4 inches long. Among mediaeval locks we find chest locks occupying an important place. Wooden chests, often strengthened with iron bands, were the safes in which our forefathers kept their treasures. The locks of some of these had an elaborate system of bolts arranged round the lid of the chest. Two varieties of comparatively simple chest locks are illustrated below.

It has been said that keyless combination locks were common in China in remote antiquity. Others ascribe the invention to the Dutch but the history of these locks remain obscure. It is clear from two quotations given here in Modern English that they were in use at the beginning of the 17^th Century, probably in the form of letter padlocks. In Beaumont and Fletcher's play The Noble Gentleman written before 1615, were the lines:

A cap case for your linen, and your plate,
With a strange lock that opens with A.M.E.N.

Improvements were made later by M Regnier, Director of the Musee d'Artillerie, in Paris, who was a man of considerable ingenuity. He produced some keyless combination locks which were held in high regard at the time. There were of excellent workmanship and so constructed that the combination could be changed. In some verses by Carew addressed to Thomas May on his Comedy of The Heir, acted in 1620, there is the following passage:

As doth a lock,
That goes with letters; for, till every one be known
The lock's as fast, as if you had found none.

Robert Barron, who was British born, made a valuable contribution to the development of locks by his invention in 1778. He recognised the weak points of wards and the insecurity of locks which depended on them. Barron devised a lock with two pivoted tumblers described as double acting, both of which had to be lifted correctly, neither too much nor too little, before the bolt could move. Six years later, Joseph Bramah, a Yorkshire man, patented the famous lock which is known by his name. This is technically very important though as a commercial product the lock to a large extent has fallen in disuse. It is believed to be the first lock having the security mechanism in a nozzle or cylinder and a small key which did not reach the bolt but acted through intervening members. The mechanism comprised a set of sliding plates to be pushed inwards differently by the key to certain positions to allow movement of the bolt.

The name of Chubb is famous in the lock world for the invention of the detector lock and for the production of high quality lever locks of outstanding security during a period of 140 years. The detector lock, which is described elsewhere in this work, was patented in 1818 by Jeremiah Chubb of Portsmouth, England, who gained the reward offered by the Government for a lock which could not be opened by any but its own key. It is recorded that, after the appearance of this detector lock, a convict on board one of the prison ships at Portsmouth Dockyard, who was by profession a lockmaker, ad had been employed in London in making and repairing locks, asserted that he had picked with ease some of the best locks, and that he could pick Chubb's lock with equal facility. One of these was given to the convict together with all the tools which he stated to be necessary, as well as blank keys fitted to the drill pin of the lock and a lock made on exactly the same principle, so that he might make himself master of the construction. Promises of a reward of £100 from Mr Chubb, and a free pardon by the Government were made to him in the event of his success. After trying for two or three months to pick the lock, during which time he repeated overlifted the detector, which was as often undetected or readjusted for his subsequent attempts, he gave up, saying that Chubb's were the most secure locks he had ever met with, and that it was impossible for any man to pick or to open them with false instruments. Improvements in the lock were subsequently made under various patents by Jeremiah Chubb and his brother Charles.

From the Barron and Chubb locks, which demonstrated the protective values of their double acting detainers, whether tumblers or levers, it was a logical process to develop a lever lock in its simplest form, that is to say, without detectors or other additional feature. Thus came into being what is known as the English lever lock. Notwithstanding its long history, which extends over nearly 150 years, and the advent of other mechanisms, it still remains the best type for locks which are operated by a key with a projecting bit designed to act directly on the bolt. Levers, in essence, are thin metal plates of which any reasonable number may be superimposed to swing on the same pivot. Collectively and simultaneously they must be lifted correctly to pre-selected positions, which may be different for each lever, before the key, as it turns, can move the bolt. Lever lock with these fundamental characteristics, if different in detail, are now made in all parts of the world. The interest aroused by the Barron, Bramah and Chubb inventions, all for the sake of giving more security in locks, and their claims to high achievement, created a desire in other lock people to devise something as good or better. So during the first half and middle of the 19^th century very many fine locks were cleverly contrived. Most of them were costly to produce and for that and other reasons have fallen into the limbo of oblivion.

The rivalry between some of the manufacturers was acute and faith in their own inventions strong. Challenges were thrown out and offers of reward to the would-be pickers of locks, if successful. It is believed that Bramah began it in 1817 or earlier by offering £200 to anyone who could make an instrument to pick a padlock which was exhibited in Bramah's shop window in Piccadilly. It is said that an ingenious mechanic after spending a week in the attempt gave it up in despair. In 1832 Mr Chubb challenged a Mr Hart to pick a Chubb lock. More of this kind of thing continued on and off, frequently before panels of judges and witnesses, until the year 1851 of the Great Exhibition. The whole affair was known as the lock controversy for there was a good deal of interchange of correspondence and letters to the press. In 1851 Alfred Charles Hobbs came from America to sell locks in this country. He first gained fame here by picking some of the best locks of the day having previously mastered all American locks which he head been challenged to pick. This Mr Hobbs, who invented the protector lock, was one of the founders of the firm of Hobbs Hart & Co Ltd.

The credit of producing pin tumbler locks, as we know them, belongs to the Yales, father and son. In 1848 Linus Yale senior, who was born in Middleton, Conn. for a time devoted his attention to bank locks and later applied the pin tumbler mechanism of the ancient Egyptian lock to modern conditions. The first models had the tumblers built into the case of the lock, which had a round fluted key. Linus Yale junior developed the pin tumbler cylinder, reducing it to its present dimensions, with different kinds of keys, these being at one time flat and later corrugated, which eventually gave place to the paracentric pattern now used. Pin tumbler locks very much alike in size and construction are now made in great quantities in many countries throughout the world.

Thomas Parson's lock of 1833 was the first change key lock patented in England but old locks embodying the same idea have been seen, showing that Parsons was not the original inventor. For one of these early locks the key bit was made of a number of pieces which could be threaded on the stem in any order and there secured by a nut and a pin. The levers in the lock were rearranged to suit. A keyless combination lock superior to any so far named, is the kind made for safes and strong rooms. This was developed in the United States of America during the second half of the 19^th century, so it is believed. Such locks are widely used in the States and to a smaller extent in this and other countries. Some of them are capable of one hundred million changes of combination. Keyless locks of a simpler construction, though they are manipulated similarly to the one just names, are made for drawers, boxes and other receptacles.

As far as is known, the lock patented in 1831 by Williams Rutherford, a bank agent, of Jedburgh in Scotland, was the first time-lock made. This was a lock requiring a key to open it after a given period of time. The inventor introduced at the rear end of the bolt a circular stop plate, which prevented the withdrawal of the bolt by the key until the plate had rotated a definite amount in order to bring a notch in it opposite the end of the bolt. The rotation of the circular plate was caused by clockwork. As the notch could be set at pleasure any distance from the end of the bolt, the time could be varied, but the lock could not be opened by its own or any other key until the appointed number of hours had elapsed. The modern time-lock as used for safes and strong rooms is a much more elaborate piece of mechanism than Rutherford's. It may be used as the sole fastening of the bolts of the door, or in conjunction with locks of other kinds. It is believed that Mr James Sargent, of Rochester, NY made the fist model of this variety about 1865 and subsequently improved it. Great numbers of these locks are now in use in different parts of the world. The need for time locks arose in America when masked burglary increased to such an alarming degree. Finding that forcibly opening or attempting to open safes and strong rooms was too slow and too dangerous, burglars adopted another plan. A gang of masked and armed men in the night would seize an official of the bank and compel him by torture, if necessary, to disclose the combinations of the locks or give up his keys. Such success followed this procedure that the method soon became prevalent, and bankers were told that neither the bank officials themselves nor anyone else could open the safe doors before a determined time.

In 1890 an early model of the flat or disc tumbler lock, of which enormous quantities are made these days, was patented in Great Britain.

During the first quarter of this century early models of knobsets or cylindrical locksets were produced in America. In 1919 a British patent and a few years later other British patents applying to knobsets were taken out by W R Schlage whose name in the United States is famous in this connection. Though gaining favour slowly at first, knobsets had a rapid increase of popularity later and now many manufacturers in America and a few in other parts of the world producing great numbers. It is believed that in England only the firm of Josiah Parkes & Sons Ltd, is making them.