CONTEMPORARY PLAN OF LONDON OF 1570 EVOLUTION OF LONGBOW AND CROSSBOW. GENEALOGY OF LATER HOUSE OF LORRAINE.

THE LOUVRE MUSEUM

See London See London: 1666

ANCIENT AND MEDIEVAL

Introduction. "Man is sometimes distinguished as a tool-using animal. . . . [His] superiority as a tool-user... ultimately secured his position over the beasts of the world and enabled him to construct our material civilization. . . . His first tool might have been a stone. . . . A peaceful use of stones as agricultural tools may or may not have preceded their use as weapons. . . . Later some man may have broken a stone by throwing it against a rock, hoping to find among the pieces one suited to his needs [for digging, etc.]. In some such way there developed the idea of using tools and of forming them. Of course, it is only a small step from breaking the stone as just described and chipping off edges of the selected stone so as to form it more nearly to the desired shape. But this step may not have been taken for centuries. . . . Between the discovery of the method of conserving fire and its production by a simple machine many thousands of years must have intervened. A primitive method is that of rubbing a sharp stick back and forth in a groove cut in a block of wood. . . . This simple device is not, however, a machine. It is merely a special tool for rubbing and a block to be rubbed. When primitive man arranged a combination where the rubbing tool was actuated by another part of the device, which part in turn was controlled by the operator, then he had a machine. . . . [This] is of course a development of an earlier form . . . where a pointed stick or drill is twisted by the operator's hands. . . . From this primitive design we can obtain a concept of a machine as a device in which a motion communicated to one part results in a different motion of a second part."J. Mills, Realities of modern science, pp. 1, 4-8."Probably one of the most important steps ever taken by primitive man in his unconscious efforts to escape from savagery was the discovery of the wheel. The fact that rolling produced less friction than sliding was but dimly recognised: the mechanical principle involved was perhaps but vaguely distinguished, . . . [but the fact must soon have been grasped] that here was a contrivance that would facilitate locomotion and increase man's power over his surroundings. . . . This fortunate discoverer, together with him who first produced fire, were the forerunners of the engineers and manufacturers, the scientific discoverers and inventors of to-day. The wheel made it easy to move huge weights and to cover great distances, and when it was applied to spinning it transferred part of the burden of providing clothing from the animal to the vegetable kingdom. Rude skins gave place to finely woven fabrics, and the

tiller of the soil vied with the hunter and the shepherd in covering man's nakedness. At first the wheel was driven by manual toil or by the use of beasts, but when, after many centuries, wind and water were used, man saw opening up a wider vista which promised speed of production and more leisure to him who could harness the natural elements to his service. Was there joy when the first wheel turned in the wind, or a mad clapping of hands when one of these rough contrivances first creaked beneath the force of a mountain stream?-We shall never know. [The time is too far back to permit of anything beyond imagination upon the subject.]"-E. Cressy, Discoveries and inventions of the twentieth century, pp. 1-2.

Measurements: Time and space.-"The measurement of small portions of time was a very practical problem from the beginning. The first attempt to solve the problem consisted in observing shadows cast by the sun. The changing shadow of the human form was doubtless the first clock. . . . Observations of this kind led to the shadow clock or sun-dial. . . . Sun-dials have been used from the beginning of time and they have not yet passed out of use. They may still be seen in a few public places, but they are retained rather as curiosities than as real timekeepers. For the sun-dial is not a good timekeeper for three reasons: (1) it will not tell the time at night; (2) it fails in the daytime when the sun is not shining; (3) it can never be used inside of a house. The sun-dial can hardly be called an invention; it is rather an observation. There were, however, inventions for measuring time in the earliest period of man's history. Among the oldest of these was the fire-clock, which measured time by the burning away of a stick or a candle. The Pacific islanders still use a clock of this kind. 'On the midrib of the long palm-leaf they skewer a number of the oily nuts of a candle-nut-tree and light the upper one.' As the nuts burn off, one after another, they mark the passage of equal portions of time. . . . Fire-clocks of one kind or another have been used among primitive people in nearly all parts of the globe, and their use has continued far into civilized times. Alfred the Great (900) is said to have measured time in the following way: 'He procured as much wax as weighed seventy-two pennyweights, which he commanded to be made into six candles, each twelve inches in length with the divisions of inches distinctly marked upon it. These being lighted one after another, regularly burnt four hours each, at the rate of an inch for every twenty minutes. Thus the six candles lasted twenty-four hours.' .. If we could step on board a Malay proa we should see floating in a bucket of water

INVENTIONS

a cocoanut shell having a small perforation through which the water by slow degrees finds its way into the interior. This orifice is so perforated that the shell will fill and sink in an hour, when the man on watch calls the time and sets it to

O Brown and Dawson, Stamford, Conn. CHINESE WATER CLOCK (Built over 1300 years ago)

INVENTIONS

a copper bowl. At the moment the sinking occurs the attendant announces the hour by striking upon the bowl. The second step in the development of the water-clock was made in China several

thousand years ago. In the earlier Chinese clock the water, instead of finding its way into the vessel from the outside, was placed inside and allowed to trickle out through a hole in the bottom and fall into a vessel below. In the lower vessel was a float which rose with the water. To the float was attached an indicator which pointed out the hours as the water rose. By this arrangement, when the upper vessel was full, the water, by reason of greater pressure, ran out faster at first than at any other time. The indicator, therefore, at first rose faster than it ought, and after a while did not rise as fast as it ought to. After centuries of experience with the twovessel arrangement, a third vessel was [placed above so that] . . . as fast as water flowed from the middle vessel it was replaced by a stream flowing from the one above it. . . and the water flowed into the lowest vessel at a uniform rate. Finally a fourth vessel was brought into use. The Chinese water-clock has been running in the city of Canton for . . . six hundred years. Every afternoon at five, since 1321, the lowest jar has been emptied into the uppermost one and the clock thus wound up for another day. To follow the further development of the water-clock we must pass from China to Greece. In their early history the Greeks had nothing better than the sun-dial with which to measure time. About the middle of the fifth century B.C. there arose at Athens a need for a better timepiece [for use in the public assembly and in the courts of law]. . . . The sun-dial would not answer, for the sun did not always shine, even in sunny Greece; so the idea of the water-clock was borrowed. A certain amount of water was placed in an amphora (urn), in the bottom of which was a small hole through which the water might slowly flow. When the amphora was empty the speaker had to stop talking. The Greeks called the water-clock a clepsydra, which means 'the water steals away.' The orator whose time was limited by a certain amount of water would keep his eye on the clepsydra, just as a speaker in our time keeps his eye on the clock.... At first the Greeks used a simple form of the clepsydra, but they gradually adopted the improvements made by the Chinese, and finally added others. The great Plato is said to have turned his attention to commonplace things long enough to invent a clepsydra that would announce the hour by playing the flute. However this may have been, there was in use in the Greek world, about 300 B.C., a clepsydra something like .. a clock. As the water drops into the cylinder E the float F rises and turns G, which carries the hour hand around. Inside of the funnel A is a cone B which can be raised or lowered by the bar D. In this way the dropping of the water is regulated. Water runs to the funnel through H, and when the funnel is full the superfluous water runs off through the pipe I, and thus the depth of the water in the funnel remains the same and the pressure does not change. . . . When the hand in this old clock has indicated twelve hours it begins to count over again, just as it does on our clocks to-day.... If we pass from Greece to Rome, . . . we find that the Romans were slow to introduce new methods of timekeeping. The first public sun-dial in Rome was constructed about 200 B.C. . . . The water-clock was brought into Rome a little later than the sun-dial, and was used as a time-check upon speakers in

float again. This sinking cocoanut shell, the first form of the water-clock, is the clock from which has been developed the timepiece of to-day. With it, therefore, the story of the clock really begins. In Northern India the cocoanut shell is replaced by

the law courts, just as it had been in Athens. When the Romans first began to use the clepsydra it was already a very good clock. Whether it received any great improvements at their hands is not certain. Improvements must have been made somewhere, for early in the Middle Ages we find clepsydras in forms more highly developed than they were in ancient times. In the ninth century the Emperor Charlemagne received as gift from the King of Persia a most interesting timepiece which was worked by water. 'The dial was composed of twelve small doors which represented the divisions of the hours; each door opened at the hour it was intended to represent, and out of it came the same number of little balls, which fell, one by one at equal distances of time, on a brass drum. It might be told by the eye what hour it was by the number of doors that were open; and by the ear by the number of balls that fell. When it was twelve o'clock, twelve horsemen in miniature issued forth at the same time, and, marching round the dial, shut all the doors.' Less wonderful than the clock of the emperor, but more useful, as an object of study, is the medieval clepsydra. This looks more than ever like the clock we are accustomed to see. It has weights as well as wheels. As the float rises with the water it allows the weight to descend and turns the spindle on the end of which is the hand which marks the hours. This is partly a water-clock and partly a weight-clock. The weight in its descent turns the spindle; the water regulates the rate at which the weight may descend.

"The water-clock just described led easily and directly to the weight-clock. Clockmakers in the Middle Ages for centuries tried with more or less success to make clocks that would run by means of weights. In 1370, Henry De Vick, a German, succeeded in solving the problem. De Vick was brought to Paris to make a clock for the tower of the king's palace, and he made one that has become famous. In a somewhat improved form it can still be seen in Paris in the Palais de Justice. Let us remove the face of this celebrated timepiece and take a look at its works. It had a striking part, and a timekeeping part, each distinct from the other. . . . The weight, of 500 pounds, is wound up by a crank (the key). [There is also an].. hour hand. [If the weight] is allowed to descend, it is easily seen how the whole system of wheels will be moved-and that very rapidly. But if something does not prevent,... [the weight] will descend faster and faster, the hour-hand will run faster and faster and the clock will run down at once. If the clock is to run at a uniform rate and for any length of time, the power of the weight must escape gradually. In the clepsydra the descent of the weight was controlled by the size of the stream of flowing water. De Vick invented a substitute for the stream of flowing water. ... Fixed to the upper part of the [post]... is a beam or balance, at the ends of which are two small weights, and projecting from the posts in different directions are two pallets or lips. Now, as the top of the wheel turns toward you, one of its teeth catches the pallet and turns the post a part of the way round toward you. Just as the tooth escapes a tooth at the bottom of . . . [the wheel] (moving from you) catches the pallet and checks the revolving post and turns it from you. Thus as [the wheel] . . . turns, it gives a to-and-fro motion to the post and, consequently, a to-and-fro motion to the balance. ... [The wheel] is called the escapement because the power of the descending weight gradually escapes from its teeth. In the clepsydra the trickling

INVENTIONS

of water regulated the descent of the weight; in De Vick's clock the trickling of power or force from the escapement regulated the descent of the weight. The invention of this escapement is the greatest event in the history of the clock. De Vick's inven.. tion led rapidly to the excellent timepieces of today, to both our watches and our clocks. After the appearance of the weight-clock, the waterclock gradually fell into disuse, and all the ingenuity of the clockmaker was bestowed upon weights and wheels and escapements and balances. A century of experimenting resulted in a clock without a weight. In this timekeeper is recognized the beginnings of the modern watch. The uncoiling of a spring drove the machinery. Instead of the balancing beam with its weights as in De Vick's clock, a balance wheel is used. The escapement is the same as in the first weight-clock. The busy and delicately-hung little balance wheel

D

G

F

IMPROVED GREEK CLEPSYDRA

in your watch is a growth from De Vick's clumsy balance beam. The spring-clock would run in any position. Because it could be carried about it led almost at once to the watch. Many places claim the distinction of having made the first watch, but seems that the honor belongs to the city of Nuremberg. 'Nuremberg eggs,' as the first portable clocks were called were made as early as 1470. The first watches were large, uncouth affairs, resembling small table clocks but by the end of the sixteenth century small watches with works of brass and cases of gold or silver were manufactured."— S. E. Forman, Stories of useful inventions, pp. 188

200.

For space measurement, "the oldest known standard of length, the cubit, was the distance between the point of a man's elbow and the tip of his middle finger. In Egypt the ordinary cubit was 18.24 inches, and the royal cubit, 20.67 inches. A royal cubit in hard wood, perfectly preserved, was discovered among the ruins of Memphis early in the nineteenth century. It bears the date of the