Part 25

Famous reproduction of the Cliff-dwellers’ Ruins, near Colorado Springs, Col. The cliff-dwellers of early America built their habitations in the canyons of the Colorado and Rio Grande, where the action of the elements had worn away a layer of soft rock, leaving layers of hard rock above and below as roof and floor for the dwelling.]

What were the First Apartment Houses in this Country?

A great many years ago, long before the white men came to America, there was a race of Indians called “cliff-dwellers,” because they built their dwelling places far up on the sides of steep cliffs. They probably made their homes so hard to reach in order that they might be safe from visits of their enemies. While many of their homes were small single-family houses, there were also a number of large two and three-story dwellings with many rooms in which different families lived.

Some of these cliff dwellings may still be seen in the valleys of the Rio Grande and the Rio Colorado and its tributaries. Close examination shows that many of them were very skilfully built, every advantage being taken of the natural rock formations, and the stones being dressed and laid in clay mortar, very much as the bricklayer does his work on an up-to-date apartment house today. The outsides of the buildings somewhat resembled the cement houses which have been put up in later days, a coat of clay being spread on the outside walls and carefully smoothed off. Oftentimes the inner walls were plastered too.

Many relics of the inhabitants have been found in these cliff dwellings, although we cannot tell how they lived, for the region is now rainless and therefore destitute of food plants. Conditions must have been different then and the ground less barren.

Why do We Call 32° Above Zero “Freezing”?

We know that freezing is the transformation of a liquid into solid under the influence of cold. Each liquid always solidifies at some fixed temperature, which is called its freezing point, and the solid melts again at the same temperature. Thus the freezing point and the melting point, or point of fusion, are the same, and the point is always the same for the same substance.

Consequently the freezing point of water, or the melting point of ice (32° F.), is taken for one of the fixed points in thermometry. The freezing point of mercury is 39° below zero, of sulphuric ether 46° below zero, of alcohol 203° below zero F.

How is Fresco Painting Done?

In producing fresco paintings, a finished drawing on paper, called a cartoon, exactly the size of the intended picture, is first made, to serve as a model.

The artist then has a limited portion of the wall covered over with a fine sort of plaster, and upon this he traces from his cartoon the part of the design suited for the space. As it is necessary to the success and permanency of his work that the colors should be applied while the plaster is yet damp, no more of the surface is plastered at one time than what the artist can finish in one day. A portion of the picture once commenced, needs to be completely finished before leaving it, as fresco does not admit of retouching after the plaster has become dry. On completing a day’s work, any unpainted part of the plaster is removed, cutting it neatly along the outline of a figure or other definite form, so that the joining of the plaster for the next day’s work may be concealed.

The art is very ancient, remains of it being found in India, Egypt, Mexico, etc. Examples of Roman frescoes are found in Pompeii and other places. After the beginning of the fifteenth century fresco painting became the favorite process of the greatest Italian masters, and many of their noblest pictorial efforts are frescoes on the walls of palaces and churches.

Some ancient wall paintings are executed in what is called “Fresco Secco,” which is distinguished from true fresco by being executed on dry plaster, which is moistened with lime water before the colors are applied.

Fresco painting has in recent years again been revived, and works of this kind have been executed in the British Houses of Parliament and other public and private buildings, more especially in Germany.

The Story of a Piece of Chewing Gum[26]

The original “chewing gum” was spruce gum, the exudation of the cut branches of the spruce or fir tree. Later, pure white paraffin wax, variously flavored, took its place, but only in its turn to give way to the “chicle” now almost exclusively employed.

Though its employment in the manufacture of chewing gum is of comparatively recent date, chicle was used by the Indians prior to the days of Columbus as a means of quenching their thirst. It was first commercially imported as a substitute for rubber, but its peculiar suitability for chewing gum has resulted in the entire product being consumed by that industry. In 1885 the United States imported 929,959 pounds of chicle. The growth of the chewing gum industry is shown by the importation of nearly 5,500,000 pounds for the year ending with June 30, 1910.

The trees are “tapped” during the rainy season. The sap, or juice, as it exudes has the appearance of milk, but gradually changes to a yellow color and is about the thickness of treacle. The tree drains rapidly, the full supply of “milk” being generally obtained within a few hours, but an interval of several years usually elapses before it will yield a fresh supply. The milk differs from the juice obtained from the sugar maple, for example, in that it is not the life sap of the tree, and the flow varies greatly, some trees which show full life yielding much less than apparently poorer specimens. “Crude chicle” is obtained by simple boiling and evaporation of the milk, accompanied by frequent kneading. The product, as pressed in rough molds, is of a light gray color.

The bulk of the crude chicle manufactured is shipped in blocks to Canada, where it is further evaporated and carefully refined prior to importation into the United States. When the chicle arrives at one of the chewing-gum factories it is immediately turned over to the grinding department. It comes from Mexico in cakes, varying in size from twelve- to eighteen-inch cubes; these are a putty color, but in composition chicle is porous and brittle, particularly after it is thoroughly dried. In the cubical form it is said to contain from twenty-five to thirty per cent moisture. After it is ground and dried it is practically free of moisture, but one of the most difficult problems which the manufacturer faces is to thoroughly dry chicle before he proceeds to treat it for its introduction as the base of chewing gum.

The cubes are broken by a large steam hammer into irregular-shaped pieces weighing from a few ounces to a pound. These chunks are then run through grinding machines, which reduce the chicle to a coarse meal. Sometimes this breaking and grinding is done in Mexico, but the duty on ground dried chicle is five cents per pound more than upon cube chicle.

Chicle meal is dried upon frames in a special drying room, which is kept at a temperature of 80° F. An electric blower exhausts all of the moisture from the air. The pure meal is then transformed into a thick syrup under intense heat and passed through a filtering machine, one of the latest and most expensive pieces of machinery employed in the entire manufacture of chewing gum. This machine has practically solved the perplexing problem of separating impurities and foreign substances from chicle. Before the filterer was invented it was almost impossible for the manufacturer of chewing gum to produce gum entirely free from particles of grit.

During the process of filtration the chicle is also sterilized, and comes from the machine as pure as distilled water.

It is next passed to the cooking department and placed in huge steam-jacketed kettles, which revolve continually and thus keep the chicle from scorching. While it is being cooked in these large kettles sugar is added, and as soon as the gum is done it is placed in a kneading machine. It is now about the consistency of bread or cake dough, and after being kneaded and cooled, flavor is added.

Peppermint, spearmint and other oils used are triply distilled and absolutely free of all impurities. The orange oil comes from Messina and is always the product of the very latest orange crop.

From the kneading machine it reaches a sizing table, to which are attached heavy rollers for reducing the mass of gum to a strip about a quarter of an inch in thickness and twelve inches wide.

At this stage it will be seen the gum begins to take on a ribbon shape. As it comes from the first series of rollers, it is cut into short lengths sprinkled with powdered sugar, and these short lengths are passed in sticks about two feet high on to a second series of rollers. Under the second rollers each short length of gum is once more reduced in thickness and extended in length.

The surfaces of the second rollers contain knives running lengthwise and around. These knives partially cut the gum to its final size. The thin sheets are then sent to another drying room. They remain in this room from twelve to forty-eight hours, according to the season of the year, and are then ready for the wrapping machines.

Machines have also been invented which stamp out little nuggets of gum. To be finished these pieces are sent to a long room containing a line of twelve large white kettles, each on a separate base. It is these machines which coat the nuggets with snowy sugar. The kettles revolve until a sufficient coating of the liquid sugar has adhered.

The chewing gum wrapping machine is considered by machinery builders to be one of the most ingenious automatic manufacturing machines in use. It is about the size of an ordinary typewriter desk and is operated by one girl. She receives the thin sheet of partially cut gum from the last drying room. The machine operator drops the slabs of gum into a feeding chute. Each slab is here automatically wrapped in wax and silver-foil papers. These papers are fed from rolls, as printing paper is fed to a newspaper press.

As the slabs are wrapped they slide into a pocket. When five of them are finished, two steel fingers remove them and put on the final outside wrapper. The complete, wrapped packages of five slabs slide along a little runway into boxes.

The same girl who feeds the gum into the wrapping machine closes the lids of the boxes and places them on a packing table by her side. When the packing table is filled with boxes a boy removes it to the shipping room, where it is crated and forwarded to the wholesale dealers.

* * * * *

Where did the Ferris Wheel get Its Name?

The Ferris wheel was named after its builder, George W. Ferris, an able engineer, now dead.

The original Ferris wheel was exhibited at the Chicago World’s Fair. It was a remarkable engineering feature.

Its diameter was 270 feet and its circumference 825 feet. Its highest point was 280 feet. The axle was a steel bar, 45 feet long and 32 inches thick. Fastened to each of the twin wheels was a steel hub 16 feet in diameter. The two towers at the axis supporting the wheel were 140 feet high, and the motive power was secured from a 1,000 horse-power steam engine under the wheel.

The thirty-six cars on the wheel each comfortably seated forty persons. The wheel and passengers weighed 12,000 tons.

By the Ferris wheel the almost indefinite application of the tension spoke to wheels of large dimensions has been vindicated, the expense being far smaller than that of the stiff spoke.

What is Done to Keep Railroad Rails from Breaking?

The breaking of rails has been the cause of much attention on the part of railroad and steel engineering experts ever since the tendency toward the construction of heavy locomotives and greater train loads became evident.

The report of the Interstate Commerce Commission for 1915 gave broken rails as the cause of 3,345 accidents, in which 205 people were killed and 7,341 were injured, with a property loss of $3,967,188. A steel man is authority for the statement that one cold winter day in 1913, a single locomotive, making excessive speed, broke about a hundred rails in the distance of a mile on one of the leading railroad systems.

Both steel and railroad men were, therefore, much interested in the announcement made by the New York Central Railroad, in August, 1916, to the effect that the road’s staff of specialists had discovered the cause and remedy for the hidden flaws in steel rails. It was said that no rails produced under the specifications provided by them had yet developed any fissures.

The process by which those rails were prevented from developing fissures consisted mainly of rolling them from reheated blooms, and although that method is said to have been used in a number of rail mills for many years, no mention had previously been recorded of the prevention of breakage in that way. The experiments are, therefore, sure to be watched with a great deal of interest, and it is probable that fewer accidents will occur from broken rails in the near future.

The technical man will be interested in an outline printed in the _Iron Age_, which said: “Induced interior transverse fissures in basic open-hearth rails are due in part to an occasional hot rail being cooled so rapidly by the rolls or so chilled by the gusts of air before recalescence on the hot beds as to cause a log of some of the transformations of the metal in the interior of the rail head. Induced interior transverse fissures can only develop in the track from the effects of preceding causes, either of which is no longer a mystery.”

The report of the railroad experts also laid stress on the theory that “gagging” rails--subjecting them to blows for the purpose of straightening them--was also likely to cause faults by injuring the metal.

How does a “Master Clock” Control Others by Electricity?

With the aid of electric currents, one clock can be made to control other clocks, so as to make them keep accurate time.

By means of this method one high-class clock, usually in an astronomical observatory, compels a number of other clocks at considerable distances to keep time with it.

The clocks thus controlled ought to be so regulated that if left to themselves they would always gain a little, but not more than a few minutes per day.

The pendulum of the controlling clock, in swinging to either side, makes a brief contact, which completes the circuit of a galvanic battery, and thus sends a current to the controlled clock. The currents pass through a coil in the bob of the pendulum of the controlled clock, and the action between these currents and a pair of fixed magnets urges the pendulum to one side and to the other alternately. The effect is that, though the controlled clock may permanently continue to be a fraction of a second in advance of the controlling clock, it can never be so much as half a second in advance.

An electrically controlled clock usually contains a small magnetic needle, which shows from which direction the currents are coming. The arrangements are usually such that at every sixtieth second no current is sent, and the needle stands still. Any small error is thus at once detected.

The Story of the Calculating Machine

How did Men Learn to Count?

Historians tell us that man was able to count long before he was able to write. Of course, he could not count very far, but it was enough for his needs at that time. He had no money and very few possessions of any kind, so that he did not have much occasion to use arithmetic.

It was fairly simple for prehistoric men to distinguish one from two, and to distinguish a few from a great number, but it was more difficult for him to learn to think of a definite number of objects between these extremes. Those who have studied the evolution of figures say that man found it hard to think of a number of objects without using a mark or a finger or something to stand for each object. That is how the first method of counting came into use.

Because man had ten fingers and thumbs, he learned to count in tens. When he had counted ten, he could make a mark to remind him of the fact, and then count them over again. Some of the early races learned to designate units from tens and tens from hundreds by working their fingers in various ways. Other peoples also made use of their toes in counting, so that they could count up to twenty without getting bothered.

Cantor, the historian, tells of a South African tribe which employed an unusual system of finger counting. Three men sat together facing a fourth who did the counting. Each of the three held up his fingers for the fourth man to count. The first man’s ten fingers and thumbs represented units; the second man represented tens, and the third hundreds. By this means, it was possible to count up to 999.

Who Invented the First Adding Machine?

Early cuneiform inscriptions, made about 2200 B. C., show that the Babylonians had developed a fairly extensive system of figuring. This was in the days of the patriarch Abraham. When men’s minds were overtaxed with the strain of counting into the hundreds and thousands, the Babylonians invented the first adding machine, a “pebble board,” a ruled surface on which pebbles were shifted about to represent different values.

The next adding and calculating machine was an evolution from the digits of the human hand and is known as the abacus in China, and the soroban in Japan.

The abacus may be defined as an arrangement of movable beads which slip along fixed rods, indicating by their arrangement some definite numerical quantity. Its most familiar form is in a boxlike arrangement, divided longitudinally by a narrow ridge of two compartments, one of which is roughly some three times larger than the other. Cylindrical rods placed at equal intervals apart pass through the framework and are fixed firmly into the sides. On these rods the counters are beaded. Each counter slides along the rod easily and on each rod there are six tamas or beads. Five of these slide on the longest segment of the rod and the remaining one on the shorter. Addition, subtraction, multiplication, division, and even square and cube root can be performed on the abacus, and in the hands of a skilled operator considerable speed can be obtained.

The Oriental tradesman does not deign to perplex himself by a process of mental arithmetic; he seizes his abacus, prepares it by a tilt, makes a few rapid, clicking movements and his calculations are completed. We always look with some slight contempt upon this method of calculation, but a little experience and investigation would tend to transform this contempt into admiration, for it may be safely asserted that even the simplest of all arithmetical operations, the abacus, possesses distinctive advantages over the mental or figuring process. In competition in simple addition between a “lightning calculator” and an ordinary Japanese small tradesman, the Japanese would easily win the contest.

Blaise Pascal, the wonderful Frenchman, who discovered the theorem in conic sections, or Pascal’s hexogram, was not only one of the foremost mathematicians of his day but also excelled in mechanics; when he was nineteen years old he produced the first machine for the carrying of tens and the first arithmetical machine, as we know it, was invented by him about 1641. This was the first calculating machine made with dials. The same principle, that of using discs with figures on their peripheries, is employed in present-day calculating machines. Among these are numbering machines of all kinds, speedometers, cyclometers and counters used on printing presses.

Who Discovered the Slide Rule Principle?

It was early in the seventeenth century that Napier, a native of Naples, invented the first actual mechanical means of calculating. He arranged strips of bone, on which were figures, so that they could be brought into various fixed combinations. The instrument was called “Napier’s rod” or “Napier’s bones.” It was the beginning of the slide rule, which has been found of invaluable aid to accountants and engineers.

One trouble with all these contrivances was that, although they aided man to figure, they offered no means of making a record of the work. The man who used these machines had no way of checking his work to know if it was right unless he did it all over again.

The first machine to perform multiplication by means of successive additions was invented by Leibnitz in the year 1671 and completed in 1694. It employed the principle of the “stepped reckoner.” This model was kept first at Göttingen and afterward at Hanover, but it did not act efficiently, as the gears were not cut with sufficient accuracy. This was long before the days of accurate machine tools.

The first satisfactory calculating machine of this nature was that of C. X. Thomas, which was brought out about 1820. It is usually called the Thomas de Colmar Arithmometer. This Thomas type of machine, which is commonly known as the beveled gear type, is still in use today in modern business.

The “Difference Engine.”

In the year 1822 a very ambitious project was conceived by Charles Babbage. He commenced to construct an automatic calculating machine, which he called a “difference engine.” The work was continued during the following twenty years, the English government contributing about $85,000 to defray its cost. Babbage himself spent a further sum of about $30,000. At the end of that time the construction of the engine, though nearly finished, was unfortunately abandoned, owing to some misunderstanding with the government. A portion of this engine is exhibited in South Kensington Museum, London, along with other examples of Babbage’s work. If the engine had been finished it would have contained seven columns of wheels, twenty wheels in each column, and also a contrivance for stereotyping the tables calculated by it. It was intended to perform the most extended calculations required in astronomy and navigation, and to stamp a record of its work into plates of copper or other material.