Chapter XVI: The Message 222 (4)

Inventors everywhere put their wits together to construct an engine that would draw a load. The great Watt tried to make one, but having failed, he came to the conclusion that the steam-engine could do good work only when standing still. Among those who entered the contest was Richard Trevithick, a Cornish miner, born in 1771. Trevithick when a lad at school was able to work six examples in arithmetic while his teacher worked one. He proved to be as quick in mechanics as he was in mathematics. He began his experiments with steam when a mere boy, and as early as 1796 he had built a steam-locomotive which would run on a table. By 1801 he had constructed a steam-carriage (Fig. 7). Three years later (1804) Trevithick exhibited a locomotive which carried ten tons of iron, seventy men, and five wagons a distance of nine and one-half miles at the rate of five miles an hour. This was the first steam carriage that actually performed useful work. The honor of inventing the first successful locomotive, therefore, belongs to Richard Trevithick, although he never received the honor that was due him.

The honor went to George Stephenson, of Wylam, near Newcastle, England. Stephenson's parents were so poor that they could not afford to send him to school long enough for him to learn to read and write. In his eighteenth year, however, he attended a night school and learned something of the common branches. In his childhood Stephenson lived among steam-engines. He began as an engine boy in a colliery and was soon promoted to the position of fireman. At an early age he was trying to build the locomotive that the world needed so badly, one that would do good work at a small cost. Trevithick's locomotive was too expensive. Stephenson wanted a locomotive that would pay its owner a profit. At the age of thirty-three he had solved his problem. In 1814 he exhibited a locomotive that would run ten or twelve miles an hour and carry passengers and freight cheaper than horses could carry them. Eleven years later he was operating a railroad between Stockton and Darlington, England. The steam carriage was now a success (Fig. 3). The iron horse was soon transporting passengers and freight in all the civilized countries of the world (Fig. 4). Observe that the first passenger car was simply the old coach joined to a locomotive.

The locomotive worked wonders in travel and in carrying loads, yet men were not satisfied with it. We never are satisfied with our means of transportation. No matter how comfortably or cheaply or fast we may travel we always want something better. In the latter part of the nineteenth century the great cities of the world were becoming over-crowded. The people could not be carried from one part of a city to another without great discomfort. The street cars drawn by horses could not carry the crowds and the elevated steam cars were not satisfactory. Wits were set to work to relieve the situation and about thirty years ago the _electric car_ (Fig. 5) was invented. Without horse or locomotive this quick-moving car not only successfully handles the crowds which move about the city but it also relieves over-crowding by enabling thousands to reach conveniently and cheaply their suburban homes. It also does the work of the steam car and carries passengers long distances from city to city.

A late development in carriage making is seen in the automobile. As far back as the sixteenth century a horseless carriage was invented (Fig. 6) and was operated on the streets of a German city. But here the power was furnished by human muscle. The first real automobile (Fig. 7) was invented in 1801, by the man who invented the first successful locomotive. Trevithick's road locomotive--for that is what an automobile really is--did not work well because the roads upon which he tried it were in very bad condition. Inventors after Trevithick for a long time paid but little attention to the road locomotive; they bestowed their best thought upon the locomotive that was to be run upon rails--the railroad locomotive. In recent years, however, they have been working on the so-called automobile and they have already given us a horseless carriage that can run on a railless road at a rate as great as that of the fastest railroad locomotives. To what extent is this newest of carriages likely to be used? It is already driving out the horse. Will it also drive out the electric car and the railroad locomotive? Are we coming to the time when the railroad will be no more and when all travel and all hauling of freight will be done by carriages and wagons without horses on roads without rails? The answers to these questions can of course only be guessed.

The last and latest form of the carriage is seen in the _flying-machine_, the automobile of the air. In all ages men have watched with envy the movements of birds and have dreamed of flying-machines, but only in modern times has man dared to take wings and glide in bird-like fashion through the air. The first actual flying by a human being was done by a Frenchman named Bresnier, who, in 1675, constructed a machine similar to that shown in the right hand picture at the top of Figure 9. Bresnier worked his wings with his feet and hands. Once he jumped from a second story window and flew over the roof of a cottage. From the days of Bresnier on to the present time man has taxed his wits to the utmost to conquer the air, and in his efforts to do this he has invented almost every conceivable kind of machine. About the middle of the nineteenth century inventors began to apply steam to the flying-machine, and it is said that in 1842 a man named Philips was able, by the aid of revolving fans driven by steam, to elevate a machine to a considerable distance and fly across two fields. In 1896 Professor Langley, with a flying-machine driven by a small steam-engine, made three flights of about three-fourths of a mile each over the Potomac River, near Washington. This was the first time a flying-machine was propelled a long distance by its own power; it was the first aerial automobile. But the aerial steam carriage was never a success; the steam engine was too heavy. In the early years of the twentieth century inventors began to use the light gasoline engine to drive their flying-machines and then real progress in the art of flying began, and so great has been that progress that the automobiles of the air are becoming rivals of those on the land.

THE BOAT

At first, when a man wanted to cross a deep stream, he was compelled to swim across. But man at his best is a poor swimmer, and it was not long before he invented a better method of traveling on water. A log drifting in a stream furnished the hint. By resting his body upon the log and plashing with his hands and feet he found he could move along faster and easier. Thus the log was the first boat and the human arm was the first oar. Experience soon taught our primitive boatman to get on top of the log and paddle along, using the limb of a tree for an oar (Fig. 1). But the round log would turn with the least provocation and its passenger suffered many unceremonious duckings. So the boatman made his log flat on top. It now floated better and did not turn over so easily. Then the log was made hollow, either by burning (Fig. 2), or by means of a cutting instrument. Thus the canoe was invented. Very often if the nature of the tree permitted it, the log was stripped of its bark, and this bark was used as a canoe.

The canoe was one of the earliest of boats, but it is not in line with the later growth. The ancestry of the modern boat begins with the log and is traced through the raft rather than through the canoe. By lashing together several logs it was found that larger burdens could be carried. Therefore the boat of a single log grew into one of several logs--a raft (Fig. 3). By the time man had learned to make a raft he had learned something else: he had learned to row his boat along by pulling at an oar instead of pushing it along with a paddle. But in order to row there must be something against which the oar may rest; so the oarlock (Fig. 4) was invented. Rafts were used by nearly all the nations of antiquity. Herodotus, the father of history, tells us that they were in use in ancient Chaldea. In Figure 3 we have a kind of raft that may still be seen on some of the rivers of South America. Here a most important step in boat-building has been taken. A _sail_ has been hoisted and one of the forces of nature has been bidden to assist man in moving his boat along.

The raft was bound to develop into the large boat. The central log was used as a keel and about this was built a boat of the desired shape and size. Stout timbers, called ribs, slanted from the keel, and on the ribs were fastened planks running lengthwise with the vessel. To keep out the water the seams between the planks were filled with pitch or wax. Thus the raft grew into a large spoon-shaped vessel (Fig. 5). The early boat was usually propelled by oars, although a single sail sometimes invoked the assistance of the wind. It had no rudder and no deck, and if there was an anchor it was only a heavy stone.

In the early history of the boat there was no such thing as a rudder. The oarsman had to steer his craft as best he could. With the appearance of larger boats, however, a steersman comes into view. He steers by means of a paddle held over the stern of the boat. Within historic times, probably about the time of Homer (1100 B. C.), the rudder appears as an oar with a broad blade protruding through a hole in the side of the boat well to the stern (Fig. 6). Throughout the whole period of ancient history boats were steered by rudders of this kind.

The anchor came later than the rudder. Of course even in primitive times there were methods of securing the vessel to the ground under water but they were very crude. Sometimes a sack of sand was used as an anchor, sometimes a log of wood covered with lead was thrown overboard to hold the boat in its place. In Homer's time the anchor was a bent rod with a single fluke. About 600 B. C. Anacharsis, one of the seven wise men of Greece, gave a practical turn to his wisdom and invented an anchor with two flukes (Fig. 7). The invention received the name of "anchor" from the name of the inventor.

It was in the Mediterranean Sea that the boat had its most rapid development. As early as we can get a glimpse of that wonderful body of water it was alive with boats (called galleys) that had well-laid keels and lofty sides, and rudders, and sails. The greatest of the earlier navigators were the Phoenicians whose boats had traversed 5,000 years ago the whole course of the Mediterranean and had even ventured beyond the Straits of Gibraltar. The ancient Greeks also were a great sea-going people, and their merchantmen or trading boats visited every part of the known world. But it was the Romans who at last became masters of the ancient seas. The Roman galley, therefore, may be taken as the representative boat of ancient times. What kind of a boat was the Roman galley? It was propelled chiefly by oars, just as nearly all the boats of antiquity were. Occasionally a sail was hoisted when the wind was favorable but the main reliance was the rower's arm. Men had not yet learned to use the sail to the best advantage. The older galleys had one row of oarsmen (Fig. 8), but as the struggle for the mastery of the sea became keener the boats were made larger and more rowers were necessary. Galleys with two and three, and even four rows of oarsmen were built by the Roman navy. When there was more than one row of oars the rowers sat on benches one above another. The oarsmen were slaves or prisoners captured in war, and their life was most wretched.[18] They were chained to the benches on which they sat, and were compelled to row as long as a spark of life was left. Sometimes they dipped their oars to the music of the flute, but more often it was to the crack of the lash. Figure 9 shows us how the Roman galley looked when Rome was at the height of her power (100 A. D.). Here is a vessel about 400 feet long and about 50 feet across its _deck_, a part of the boat, by the by, which was not to be seen in the earlier galleys. The boat is a trireme, that is, it has openings for three tiers of oars, and it is propelled by several hundred oarsmen. For steering purposes it has four stout paddles, two on each side near the stern. Two masts instead of one carry the sail which, considering the size of the boat, would seem to be insufficient. This galley of the first century of our era represents the full development of the boat in ancient times.

After the downfall of Rome (476 A. D.) it was a long time before there was any real progress in boat-making. The glimpses we get now and then of vessels in the Middle Ages almost make us feel that boat-building was going backward rather than forward. But such was not the case. The ship in which William of Normandy sailed (Fig. 10) when he crossed over the Channel to give battle to Harold (1066 A. D.) was not so impressive as a Roman galley, yet it was, nevertheless, a better boat. In the first place William's boat was a better sailer; it relied more upon the force of the wind and less upon the oar. In the second place, it could be steered better, for the rudder had found its way to its proper place and was worked by a tiller. Finally, the shape of the Norman boat fitted it for fiercer battles with the waves.

If we should pass from the English Channel to the Adriatic we should find that boat-making had undergone the same changes. A Mediterranean galley of the fourteenth century (Fig. 11) shows fewer oars and more sails. Instead of three rows of oars and two sails as on the Roman galley, there are three sails and one row of oars. This was the tendency of the boat-builder in the Middle Ages; he crowded on the sail and took off the rowers. A war-boat of the sixteenth century (Fig. 12) shows that the last row of oarsmen has disappeared.

About the middle of the thirteenth century there began to appear on the decks of vessels almost everywhere in Europe, a little instrument that is of the greatest importance in the history of the boat. This was the _mariner's compass_. The use of the magnetic needle was known in China (Fig. 13) a thousand years before it was known to the Europeans, but in this, as in many other instances, the Chinese did not profit by their knowledge. Sailors have always sailed at night by the North star; but before the use of the compass was understood they could little more than guess their way when the night was dark and the stars could not be seen. With a mariner's needle on board they can tell the direction they are going no matter how dark the night. We can easily understand that sailors prized very highly the discovery of the compass. With the appearance of this faithful guide they became bolder and bolder and were soon venturing out upon the trackless expanse of the ocean. It was the compass that led to the discovery of the new world, for without it no sailor could have held his course due west long enough to reach the American coast.

After men had learned to carry their burdens on the broad back of the ocean, boat-building took on new life. All the great nations of Europe wanted a share in the new world that had just been found; but no nation could hope to profit greatly by the discovery of Columbus if its vessels were not swift and strong. So there arose a grim contest for the mastery of the Atlantic, just as in ancient times there had been a struggle for the mastery of the Mediterranean. Spain, France, Portugal, Holland and England all joined in the battle. When we see the kind of boats she sent out upon the oceans we are not surprised that England won. Compare the heavy, angular galley of the first century with the graceful ship of the sixteenth century and we see at once the progress the boat made in the Middle Ages (Fig. 14).

The log, the raft, the galley, the sailing-ship, these were the steps in the development of the boat up to the end of the seventeenth century. In the eighteenth century another step was taken. You remember that in that century inventors were everywhere trying to make a steam carriage. They were at the same time trying to make a steam boat. Their efforts to use steam to drive boats were rewarded with success earlier than were their efforts to use it to draw carriages. This was to be expected. Boat-building has always moved along faster than carriage-building. Men were gliding about in well-built canoes before they had even the clumsiest of carts. The Londoners who gazed with admiration upon the _Great Harry_ as it sailed on the Thames, had never seen as much as a lumbering coach. And so with the steamboat; it had crossed the Atlantic before the locomotive could carry passengers from one town to the next.

France, England, Germany and America were all eager to have the first steamboat. In this race America won, although France and England came out with their colors flying. As far back as 1663 the Marquis of Worcester, of whom we have heard before (p. 59), described a vessel that could be moved by steam: "It roweth," he said, "it draweth, it driveth (if needs be) to pass London bridge against the stream at low water." It was one thing, however, to describe a steamboat, and quite another thing to make one. Worcester's steam-vessel existed only in the imagination of the inventor. Denys Papin, who did so much for the steam-engine, fitted out a boat with revolving paddles which were turned by horses. This was nothing new. The ancient Roman galley was sometimes propelled by paddle-wheels turned by horses or oxen. It is sometimes claimed that Papin turned the paddle-wheels of his boat by means of steam, but there are no grounds for the claim. If France wants the honor of having made the first steamboat she would do better to turn from Papin and look to Marquis of Jouffroy of Lyons, This nobleman, it is claimed, built a steamboat (Fig. 15) which made a successful trip on the river Soane, in the year 1783, before a multitude of witnesses. This claim may or may not be just. It may be as the French say: the boat after the trial trip may have been taken to pieces, the model may have been lost and the French Revolution may have swallowed up those who witnessed the trip.

About the time the Frenchman is said to have been experimenting with his steamboat on the Soane similar experiments were being tried in many other places. In the latter part of the eighteenth century the idea of a steam-propelled boat seemed to be in the air. An English poet of the time was bold enough to prophesy:

Soon shall thy arm, Unconquered Steam, afar
Drag the slow barge and draw the rapid car,
Or on wide, waving wings, expanded bear
The flying chariot through the fields of air.

For the most part the prophesy has been fulfilled, although the steam flying-machine is not yet an accomplished fact. Among those who helped to make good the words of the poet was James Rumsey, of Sheppardtown, Virginia. Rumsey in 1786 propelled, by means of steam, a boat on the Potomac River moving at the rate of five miles an hour. It is almost certain that this was the first boat ever drawn by steam. How did Rumsey drive his boat? A piston in a cylinder was worked by a steam-engine. When the piston was raised it brought water in and when it was pushed down it forced the water out behind and the reaction of the jet pushed the boat along. A remarkable revival of a very ancient idea! Just as Hero turned his globe by reaction, just as Newton pushed the first steam carriage along by reaction, so Rumsey pushed the first steamboat along by reaction.

If you will look on a map of the United States and observe the vast network of waterways which come to the different parts of the country you will understand how important a subject steam navigation must have been to the people of America in the latter part of the eighteenth century. Here was a tract of land containing millions upon millions of fertile acres, but it lacked good roads, and without roads it could not be developed. It was, however, traversed by thousands of miles of excellent water-roads and it was plain that if steamboats could be put upon these rivers the gain would be incalculable. The most pressing need of the time, therefore, was a steamboat. No one saw this more clearly than John Fitch. This talented but eccentric man served his country in the Revolution, and after the war was over roamed hither and thither for several years as a soldier of fortune. About 1785 he went to Philadelphia with a plan for a steamboat. He organized a company, and secured enough money to enable him to carry out his plans. His boat was ready by August, 1787, and he made his trial trip in Philadelphia when the Constitutional Convention was in session. Many of the members of that distinguished body went down to the river to see how the new invention worked. It worked fairly well, but did not arouse much enthusiasm. Its speed was only three or four miles an hour and its movement was exceedingly awkward. It was pushed along by two sets of oars, one set entering into the water as the other came out. The steam rowboat of 1787 proved at least to be a failure, and was abandoned as worthless. Fitch afterward built another steamboat, but it also met with accident and came to naught. Heartbroken by his many failures the poor fellow at last ended his life with his own hand. He deserved a better fate, for his experiments taught the world a great deal about the steamboat.

While Rumsey and Fitch were making their boats in America, European inventors were not idle. On the contrary they were so very active that they almost won the honor of making the first successful boat. One of these, William Symington, an Englishman, built a boat that may, with much justice, be called the first practical steamboat that was ever launched. This was the _Charlotte Dundas_ (Fig. 16) which made its trial trip on the Clyde and Firth Canal in 1802. On the _Charlotte_ was a _paddle-wheel_ instead of Fitch's two sets of paddles. The wheel was placed at the rear of the boat and was drawn by means of a crank which was turned by a rod attached to the piston-rod. Watt and his co-workers, a few years before, had shown how the steam-engine could be made to turn a wheel and Symington in the construction of his boat put this principle to good use. The _Charlotte_ did so well that the Duke of Bridgewater ordered eight more boats like her to be built for use on the canal. Symington was elated for he thought he had at last made a successful steamboat, that is, a steamboat that would give to its owner a profit; but he was doomed to disappointment for the owners of the canal refused to allow steamboats to be employed upon it, and worse than this the duke soon died and the inventor's financial support was gone. The _Charlotte_ was taken off the canal and laid in a creek where she fell to pieces. The really successful steamboat had not yet been built.

It was to be built first where it was needed most, and that was in America. It was built by a man who kept his eyes on Rumsey and Fitch and Symington, and made the best of what he saw. As all the world knows, this was Robert Fulton. In August of 1807 Fulton's steamboat the _Clermont_ (Fig. 17) made a trip on the Hudson River from New York to Albany, a distance of 150 miles, in thirty-two hours, and returned in thirty hours. Fulton advertised for passengers, and his boat was soon crowded. "The _Clermont_," says an English writer, "was the steamboat that commenced and continued to run for practical purposes, and for the remuneration of her owners." Here was the boat that was wanted--one that was financially profitable.

The paddle-wheels of the _Clermont_ were on the sides of the boat about midship. As the wheel turned, about half of it was in the water and about half was out. There were engineers, even in Fulton's day who did not believe the wheels ought to be on the sides of the boat. Look at waterfowl, they said, look at the graceful swan; its feet do not work at its sides, half under the water and half out. Every animal that swims propels itself from behind, and its propellers are entirely under the water. So, thought these engineers, the paddle-wheel of a boat should be placed behind, and should be entirely covered by the water. John Stevens, an engineer of Hoboken, New Jersey, in 1805 built a steamboat according to this notion (Fig. 18). A close inspection of the wheel of the boat would show that it is spiral- or screw-like in shape. Stevens' boat made a trial trip on the Hudson and worked well; but after Fulton's great success the little steamer with its spiral-shaped wheel in the rear was soon forgotten. The idea of a screw-propeller, however, was not lost. It was taken up by John Ericsson, a Swedish engineer, who, in 1839, built, in an English shipyard for an American captain, the first screw-propeller that crossed the Atlantic--the _Robert F. Stockton_. This was the last step in the development of the boat. Since 1839 there has been marvelous progress in ship-building, but the progress has consisted in improving upon the invention of Ericsson rather than in making new discoveries. With the screw-propeller in its present form we may close our story of the boat. The homely log propelled by rude paddles has become the magnificent floating palace.

FOOTNOTE:

[18] A spirited account of life on a Roman galley is found in Wallace's "Ben Hur."

THE CLOCK

"Tic-tac! tic-tac! go the wheels of time. We cannot stop them; they will not stop themselves." Time passing is life passing and the measurement of time is the measurement of life itself. How important then that our chronometers, or time measures, be accurate and faithful! It is said that a slight error in a general's watch caused the overthrow of Napoleon at Waterloo and thus changed the history of the world. Because of its great importance the measurement of time has always been a subject of deep human interest and the story of the clock begins with the history of primeval man.

The larger periods of time are measured by the motion of the heavenly bodies. The year and the four seasons are marked off by the motion of the earth in its long journey around the sun; the months and the weeks are told by the changing moon; sunrise and sunset announce the coming and the going of day. The year and the seasons and the day were measured for primeval man by the great clock in the heavens, but how were smaller periods of time to be measured? How was the passing of fractional parts of a day, an hour or a minute or a second to be noted? An egg was to be boiled; how could the cook tell when it had been in the water long enough? A man out hunting wished to get back to his family before dark: how was he to tell when it was time to start homeward?

Plainly, 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. As the shadow grew shorter the observer knew that noon was approaching; when he could reach out one foot and step on the shadow of his head he knew it was time for dinner; when his shadow began to lengthen he knew that evening was coming on. Observations of this kind led to the _shadow clock_ or _sun-dial_ (Fig. 1). You can make one for yourself. On a perfectly level surface exposed all day to the sun, place in an upright position (Fig. 1) a stick about three feet long, and trace on the surface the shadows as they appear at different times of the day. A little study will enable you to use the shadows for telling the time. 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 (Fig. 2), 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 the 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. Here is a clock that can be used at night as well as in the daytime, in the house as well as out of doors. Mr. Walter Hough tells us that Chinese messengers who have but a short period to sleep place a lighted piece of joss-stick between their toes when they go to bed. The burning stick serves both as a timepiece and as an alarm-clock.

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 A. D.) 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."[19]

We all remember Irving's account of time-measurement in early New York: "The first settlers did not regulate their time by hours, but pipes, in the same manner as they measure distance in Holland at this very time; an admirably exact measurement, as the pipe in the mouth of a true-born Dutchman is never liable to those accidents and irregularities that are continually putting our clocks out of order." This, of course, is not serious, yet it is an account of a kind of fire-clock that has been widely used. Even to-day the Koreans reckon time by the number of pipes smoked.

If we could step on board a Malay proa we should see floating in a bucket of water 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 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 a copper bowl (Fig. 3). 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 two-vessel arrangement, a third vessel was brought upon the scene. This was placed above the upper vessel, which now became the middle vessel. As fast as water flowed from the middle vessel it was replaced by a stream flowing from the one above it. The depth of the water in the middle vessel did not change, and the water flowed into the lowest vessel at a uniform rate. Finally a fourth vessel was brought into use. The Chinese water-clock shown in (Fig. 4) has been running in the city of Canton for nearly 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. In the public assembly the orators were consuming too much time, and in the courts of law the speeches of the lawyers were too long. It was a common thing for a lawyer to harangue his audience for seven or eight hours. To save the city from being talked to death a time-check of some kind became necessary. 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 (Fig. 5). 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, and if he were interrupted he would shout to the attendant, "You there, stop the water," or would say to the one who interrupted him, "Remember, sir, you are in my water." The story goes that upon one occasion the speaker stopped every now and then to take a drink; the orator's speech, it seems, was as dry as his throat, and a bystander cried out: "Drink out of the clepsydra, and then you will give pleasure both to yourself and to your audience."

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 the one shown in Fig. 6. This begins to look 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. Notice that 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. How easily it would have been to have continued the numbers on to twenty-four, as they do in Italy, and on the railroads in parts of Canada, to-day.

If we pass from Greece to Rome, our usual route when we are tracing a feature of our civilization, 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., an event which the poet Plautus bewailed:

Confound the man who first found out
How to distinguish hours! Confound them, too
Who in this place set up a sun-dial
To cut and hack my days so wretchedly
Into small portions! When I was a boy
My stomach was my sun-dial, one more sure,
Truer, and more exact than any of them,
This dial told me when 'twas the proper time
To go to dinner.

The water-clock was brought into Rome a little later than the sun-dial, and was used as a time-check upon speakers in 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 shown in Figure 7. This looks more than ever like the clock we are accustomed to see. It has weights as well as wheels. As the float _A_ rises with the water it allows the weight _C_ to descend and turns the spindle _B_ on the end of which is the hand which marks the hours. Notice carefully that 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 (Fig. 8). It had a striking part, and a timekeeping part, each distinct from the other. The figure shows only the timekeeping part. The weight (A), of 500 pounds, is wound up by a crank (the key) at _P_. _O_ is the hour-hand. If _A_ is allowed to descend, you can easily see how the whole system of wheels will be moved--and that very rapidly. But if something does not prevent, _A_ 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 (Fig. 1) 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. Fasten your attention upon the workings of the saw-toothed wheel _II_ and the upright post _K_, which moves on the pivots _l_ and _k_, and you may learn what he did. Fixed to the upper part of the post _K_ is a beam or balance _LL_, at the ends of which are two small weights _m_ and _m_, and projecting from the post in different directions are two pallets or lips _i_ and _h_. Now, as the top of the wheel _II_ turns toward you, one of its teeth catches the pallet _i_ and turns the post _K_ a part of the way round _toward_ you. Just as the tooth _escapes_ from _i_ a tooth at the bottom of _II_ (moving from you) catches the pallet _h_ and checks the revolving post and turns it _from_ you. Thus as _II_ turns, it gives a to-and-fro motion to the post _K_ and, consequently, a to-and-fro motion to the balance _LL_. _II_ is called the _escapement_ because the power of the descending weight gradually _escapes_ from its teeth. In the clepsydra the trickling 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. The king was much pleased with De Vick's invention. He gave the clockmaker three shillings a day, and allowed him to sleep in the clock tower; a scanty reward indeed for one who had done so much for the world, for De Vick's invention led rapidly to the excellent timepieces of to-day, to both our watches and our clocks. After the appearance of the weight-clock, the water-clock 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 (Fig. 9). In this timekeeper you recognize 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 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 it seems that the honor belongs to the city of Nürenburg. "Nürenburg 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 (Fig. 10).

The last important step in the development of the clock was taken when the _pendulum_ was brought into use. The history of the pendulum will always include a story told by Galileo. This great astronomer, the story runs, while worshiping in the cathedral at Pisa one day, found the service dull, and began to observe the swinging of the lamps which were suspended from the ceiling. Using his pulse as a timekeeper he learned that where the chains were of the same length the lamp swayed to and fro in equal length of time, whether they traveled through a short space or a long space. This observation set the philosopher to experimenting with pendulums of different lengths. Among the many things he learned one of the most important was this: a pendulum thirty-nine inches in length will make one vibration in just one second of time. Now, if the pendulum could only be kept swinging and its vibrations counted it would serve as a clock. Galileo, of course, saw this, and he caused to be made a machine for keeping the pendulum in motion (Fig. 11), but he did not make a clock; he did not connect his pendulum with the works of a clock. This, however, was done about the middle of the seventeenth century, although it is somewhat difficult to tell who was the first to do it. The honor is claimed by an Englishman, a Frenchman, and a Dutchman. The truth is, clockmakers throughout Europe were trying at the same time to make the best of the discoveries of Galileo, and several of them about the same time constructed clocks with pendulums. The one who seems to have succeeded first was Christian Huygens, a Dutch astronomer, who, in 1656, constructed a clock, the motions of which were regulated by the swinging of a pendulum (Fig. 12). The weight was attached to a cord passing over a pulley and gave motion to all the wheels, as in De Vick's clock. Like De Vick's clock also Huygens's clock had its escapement wheel acting upon two pallets. In the Dutchman's clock, however, the escapement, instead of turning a balance beam to and fro, acted upon the pendulum, giving it enough motion to keep it from stopping.

We need not carry our story further than the invention of Huygens. Timepieces are cheaper and better made and more accurate than they were two hundred years ago, but no really important discovery has been made since the pendulum was introduced.

FOOTNOTE:

[19] Wood, "Curiosities of Clocks and Watches."

THE BOOK

What is a book? It is an invention by means of which _thought_ is recorded, and carried about in the world, and handed down from one age to another. Almost as soon as men began to think they began to make books and they will probably continue to make them as long as they continue to think. The story of the Book, therefore, takes us back to the very beginning of human existence.

At first thought was recorded and preserved by _tradition_. An account of a nation's deeds, its laws, the precepts of its religion were stamped, printed, on the memory of persons specially trained to memorize these things and hand them down by word of mouth from generation to generation (Fig. 1). These persons were usually priests, who underwent long years of daily and hourly training in memorizing what was to be handed down. The Sanskrit Vedas, the sacred scripture of the Hindoos, were for many centuries transmitted by tradition, and it is said it took forty years to memorize them. It is a wonder it did not take longer, for the Vedas make a volume as large as our Bible. It is believed that primitive people everywhere first adopted the method of tradition to record and preserve the thought which they did not wish to perish. We may say, then, that the first book was written on the tablet of the human memory.

A Mural Decoration in the Library of Congress.]

The first step in the growth of the book was taken when _memory aids_ were invented. Sometimes we tie a knot in a handkerchief to help us to remember something. Now, it was just by tying knots that primitive man first lent assistance to the memory. The first material book was doubtless a series of _knots_ well represented by the _quipu_ (Fig. 2) of the ancient Peruvians. This curious-looking book was written (tied) by one known as the officer of the knots. It contains an account of the strength of the Peruvian army, although it is confessed that its exact meaning cannot be made out. It was not intended to be read by any one who was not a keeper of the knots. Books made of knots were used by nearly all the ancient peoples of South America and by some of those of Asia. Akin to the knotted cord is the _notched stick_, which is still used in Australia by the savages to assist the memory of one who has a message to carry. Figure 3 shows a variety of such message-sticks. The lowest one--a crooked branch of a tree--contains an invitation to a dancing party. The notches are read by the messenger. The notched stick as an aid to memory is not confined to savage races. Many a highly civilized baker has kept his accounts by making notches in sticks and so has many a modern dairyman, as he has delivered milk from door to door.

Memory aids were followed by _picture-writing_. To express thought by means of pictures is an instinct shared alike by the lowest savage and the most enlightened people. All over the earth we find examples of early picture-writing. A beloved chief had died, a fierce battle had been fought, an exciting chase had occurred: promptly the event was pictured on a stone or on the skin of some animal. Pages might be filled with illustrations of these primitive picture-books, but we must be content with a single specimen (Fig. 4). This was found painted on a rock in California: "_We selected this as a camping place, but we have found nothing_," say the human figures _f_, _g_, _h_, _i_. The upturned palms say plainly, "nothing, nothing." "_One of our comrades_ (_d_) _has died of starvation_," say the three lank figures at _c_ pointing to their own lean bodies. "_We deeply mourn his loss_," says the sorrow-stricken _a_. "_We have gone northward_," says _j_, his distinguished arm extended to the north.

Practice in picture-making was bound to lead to shorter methods of expressing ideas. It was soon found that reduced pictures, or _picture-signs_, would suffice to express ideas. Thus, if the idea of sorrow was to be expressed it was not necessary to draw an elaborate picture of a sorrowful looking man like _a_ in Figure 4; a weeping eye would express the idea just as well. Instead of numerous figures (_e_, _f_, _g_, _h_, _i_) weeping and saying, "nothing here," a single pair of empty palms would say the same thing just as clearly. In this way a pair of clasped hands came to mean "friendship"; two trees meant "a forest"; a calf running toward water meant "thirst." These picture-signs, of course, assumed the form in which they could be most easily and rapidly drawn. The weeping eye became [symbol: eye]; the pair of extended palms [symbol: palms]; the forest [symbol: trees]; thirst [symbol: dog walking on water]. A simple picture of this kind became a fixed conventional sign for certain ideas; it was always drawn in the same way and it always stood for the same idea.

Picture-signs (ideographs) followed picture-writing in almost every country where the people were progressive. China was writing its books with picture-signs many thousands of years ago, and it is writing them in the same clumsy way still. Even in highly civilized countries picture-signs have not been entirely abandoned. Examine the advertising page of a newspaper or observe the business signs on the street and you will find picture-signs--pictures that are always made in the same way and that always stand for the same thing.