Part 18

It is a very useful contrivance for tired shoppers needing to make their way from floor to floor in the great department stores, for travelers on subway or elevated railways, for large mills, theaters, or other places where easy getting up and down stairs is necessary. The escalator is a simple device. No intricate machinery is needed. It is so arranged as to be always going, traveling upwards or downwards, and returning out of sight below. It has been called “an elevator with the doors always open.” It is capable of carrying all the passengers who can crowd upon it, stepping on or off at the bottom or top, it being estimated that more than 10,000 people an hour can be thus moved.

[Illustration: BATTERY OF ELEVATORS IN A DEPARTMENT STORE]

[Illustration: ELECTRIC DUMBWAITER INSTALLATION WITH MACHINE IN BASEMENT SHOWING CALL BUTTONS]

[Illustration: A COMPLETE INSTALLATION OF A 2 : 1 ELECTRIC TRACTION PASSENGER ELEVATOR, SHOWING MACHINE AND CONTROLLER AT TOP OF HATCHWAY

This elevator is used where the slower speeds are required as in department stores.]

[Illustration: ESCALATOR OR MOVING STAIRWAY AT SIXTH AVENUE AND THIRTY-THIRD STREET STATION OF ELEVATED RAILWAY, NEW YORK CITY]

[Illustration: A DUPLEX ESCALATOR OF THE CLEAT TYPE IN A DEPARTMENT STORE

This type of escalator makes use of hard wood cleats in place of steps.]

[Illustration: AN ESCALATOR OR MOVING STAIRWAY FOR THE USE OF EMPLOYEES IN A LARGE WORSTED MILL]

The Cleat Escalator.

In the original type of escalator the steps flatten out into a level platform at top and bottom, easy to step on and off, and divide into regular steps as they climb upward, passengers in a hurry being able to hasten their speed by walking at the same time that they are carried. Another type is that known as the cleat escalator. In this there are no steps, it being composed of hardwood cleats moving in longitudinal ridges and grooves, there being a handrail on either side moving at the same speed. The platform glides through the prongs of a comb at the lower level and journeys upward at a moderate speed. At the upper level it disappears through a similar comb and returns out of sight. The passengers slide off upon the prongs of the comb at the top and land without jar or shock. Both these types of escalators can be made to move up or down by aid of a swinging switch, or two of them can be placed side by side, one moving upward and the other downward.

[Illustration: A CLEAT TYPE ESCALATOR, SHOWING THE HARDWOOD CLEATS USED IN PLACE OF STEPS]

The Moving Platform.

A device acting on the same principle is the moving platform, with the difference that this may be of indefinite length and act as a sort of railway for carrying passengers from place to place. The passenger steps from a sideway at rest to one in moderate motion, and from this to a second one moving more rapidly, and in this way can be carried horizontally at a fair rate of speed. On reaching his station he has but to step back on the slower platform and from this to the moveless sideway. The pioneer example of this contrivance was installed on a long pier leading into Lake Michigan at the Chicago Exposition of 1893, and plans for putting it into practical use in various cities have been entertained. None of these, however, have yet been put into effect. Certain drawbacks, possibly that of cost of installation and operation, has served as a hindrance.

[Illustration: A GRAVITY CONVEYOR OF THE SINGLE SPIRAL OPEN TYPE

For the quick and safe conveyance of heavy goods from upper to lower levels.]

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What Happens when Animals Hibernate?

We have all heard of certain animals sleeping through the long winter months and most of us have probably wondered what happens to them when they do this.

This hiding away for a long sleep, or hibernation, as it is called, commences when the food of the animal begins to get scarce, and the length and depth of the sleep depends on the habit and constitution of the animal.

Bats, bears, some animals of the rodent order, such as the porcupine, the dormouse, some squirrels, etc., all the animals belonging to the classes of _Amphibia_ and _Reptilia_, such as tortoises, lizards, snakes, frogs, etc., and many species of mollusks and insects, hibernate more or less completely, retiring to suitable places of concealment--the bat to dark caves, the hedgehog to fern-brakes, snakes to holes in trees, etc.

During hibernation there is a great decrease of heat in the bodies of the animals, the temperature sometimes sinking to 40° or even 20° F., or in general to a point a little above that of the surrounding atmosphere. The respiration as well as the pulsation of the heart is exceedingly slow, and the irritability of the animal often so low that in some cases it can be awakened only by strong electric shocks.

With frogs and amphibious reptiles the dormant state is very common, and if the temperature is kept low by artificial means they may remain dormant for years.

The term “æstivation” has been used to describe a similar condition into which certain animals, such as serpents and crocodiles, in tropical countries pass during the hottest months of the year.

How do Peanuts Get in the Ground?

Peanuts are really the seeds or pods of a plant belonging to the family called the earthnut in Great Britain, the nuts there being used chiefly to fatten swine. The peanut-stand so commonly seen on street corners here is kept well supplied by the extensive cultivation of peanuts in the United States, mainly in the South, and in several tropical countries.

As most people have discovered, the nuts have a much more agreeable taste after being roasted. They also yield an oil which is often used for olive oil, and very good “peanut butter” is now made by grinding them up and mixing them with oil.

The peanut plant, or groundnut as it is also called, has a hairy stem and the leaves usually grow in sets of two pairs each, on the extreme end of each little branch-stem. The pod or nut is situated at the end of a separate stalk, which is longer than the leaf-stems, this stalk having the peculiarity, after flowering, of bending down and pushing the fruit into the earth. After the peanuts have reached their full growth, they are dug up very much in the same way as potatoes, a machine potato digger now being extensively used for this purpose.

[Illustration: MACHINE POTATO DIGGER DIGGING PEANUTS]

[Illustration: PICKING PEANUTS BY HAND]

How did Your State Get Its Name?

Alabama is named after the Indian word which means “Here we rest;” Alaska comes from the Eskimo word “Alakshak” or “Alayeska” and means “The main land;” Arizona is the result of the Indian word “Arizonac,” meaning “small springs” or “few springs;” and Arkansas is sort of a mixture of the Indian “Kansas,” which means “smoky water,” and the French prefix “arc,” meaning “bow” or “bend.”

California comes from the Spanish words “Caliente Fornalla,” or “hot furnace;” Colorado, also from the Spanish “colored,” from the red color of the Colorado River; and Connecticut, in Indian, means “long river.”

Delaware was named after Lord De la Warr; Florida originated from the Spanish “Pascua de Flores,” which means “Feast of Flowers,” because it was discovered on Easter Day; Georgia was called after King George II of England; and Hawaii is a native name peculiar to the natives there, although Captain Cook called it part of the “Sandwich Islands” after Lord Sandwich.

Idaho is Indian, meaning “Gem of the Mountains;” Illinois is another mixture of Indian and French, the Indian word “illini” and the French suffix “ois” meaning “tribe of men;” and Indiana and Iowa are both plain Indian, the former standing for “Indians’ land,” and the latter, “beautiful land.”

Kansas and Kentucky are Indian, too, Kansas meaning “smoky water” and Kentucky “at the head of the river,” or “the dark and bloody ground;” and Louisiana is named after Louis XIV of France.

Maine and Maryland each come from abroad, Maine being called after the Province of the same name in France, and Maryland after Queen Henrietta Maria of England, consort of Charles I; while Massachusetts, Michigan, Minnesota, Mississippi and Missouri are all from the native Indian language, meaning, in the order in which they are given, “place of great hills,” “fish weir,” “sky-tinted water,” “great father of waters” and “muddy;” and Montana traces back to the Latin word “montanus,” meaning “mountainous.”

Nebraska is another Indian name, and means “water valley;” while Nevada is Spanish, meaning “snow covered;” New Hampshire and New Jersey are both from across the water, the former after Hampshire County in England, and New Jersey after the Island of Jersey at the time when Sir George Carteret was its Governor; New York and both North and South Carolina were also named after monarchs abroad, New York after the Duke of York in England, and the Carolinas after Charles IX of France; while North and South Dakota bring us back to the Indian language again, meaning “allies.”

Ohio and Oklahoma are both Indian, too, Ohio meaning “beautiful river,” and the latter, “Home of the red men;” while Oregon is from the Spanish word “oregano,” which stands for the wild marjoram, a plant abundant on the coast; Pennsylvania traces back to the Latin, meaning “Penn’s woody land;” the Philippine Islands come from the Spanish words “Islas Filipinas,” after King Philip; and Porto Rico is also Spanish, from “Puerto Rico,” meaning “rich port.”

Rhode Island is called after the Island of Rhodes; Tennessee, Texas and Utah are all Indian, Tennessee meaning “river with the great bend,” Texas coming from several different forms of very old Indian language, meaning “friends,” and Utah after the tribe by that name, also called the “Utes;” Vermont is from the French, meaning “green mountains,” and Virginia is called after Elizabeth, the “Virgin Queen” of England.

Washington gets its name from a good, straight American source--George Washington; West Virginia is so called because it was formerly the western part of Virginia; and Wisconsin and Wyoming are both Indian, the former meaning “gathering of the waters,” and the latter, “great plains.”

The Story of Coal Mining

An interesting story is told in an English book by Edward Cressy, of the great coal strike in 1912. Many factories and workshops had to close for want of fuel. A workman from one of these, on reaching home, purchased a sack of coal and set it up against the back door. Then he sat in the kitchen, in which there was no fire. From time to time, when he felt chilly he got up, flung the sack of coal across his shoulders and ran around the yard until he became warm. That was his way of saving fuel. He was only doing in his own fashion what all engineers and manufacturers are trying to do in other ways all the year round.

The extent to which all manufacture and transport, all industry there, was paralyzed during the strike, shows the complete dependence of modern life upon fuel. In spite of the fact that in Great Britain nearly 240,000,000 tons of coal are raised annually, a temporary stoppage of supply threw all the ordinary machinery of existence out of action and revealed the magnitude of the debt that the world owes to those who win precious stores of fuel from the depths of the earth.

Probably no industrial operation excites more widespread interest, when accorded publicity, than the mining of coal, and that because of the dangers which attend it. The annual list of victims buried beneath a falling roof, or mangled by runaway cars, causes little comment, but every now and then the world is startled by an appalling catastrophe in which hundreds of men lose their lives. From the early days when growing industry demanded more coal, inventors have been busy devising all sorts of safety appliances for the miner.

The original safety-lamp, with which practically everyone is familiar, is the parent of scores of others, each claiming to offer some special advantage. All sorts of mechanical devices to prevent overwinding--an accident which would fling the cage with its coal or human freight out of the pit mouth--have been invented, and every section of the work has been made as safe as human ingenuity and human skill have been able to make it. But the number of disastrous explosions has not been materially reduced.

Many varieties of coal give off a gas known as marsh-gas or fire-damp. This is inflammable and, when mixed with air, violently explosive. It is the presence of this gas that necessitates the safety-lamp. There are a few kinds of mines which evolve no gas, and in these naked lights are used. But all mines must be ventilated by forcing air through them with a fan, and this air must be in sufficient quantity to keep the percentage of gas below a dangerous standard. Most mines are examined at regular intervals by a “fireman” who can estimate approximately the percentage of gas present by the size of the faintly luminous “cap” which hovers above the flame of his lamp.

Explosions have occurred, however, in cases where it is extremely doubtful whether gas has been present in dangerous quantity, and attention has been drawn to the possible causes. Many varieties of coal produce a quantity of fine dust which settles in the roadways, on roof, and sides, and floor. For many years there has been a controversy as to the relative importance of gas and dust in producing explosions, and the question is still one which gives rise to a lively difference of opinion. But there is no doubt that a mixture of coal-dust and air is explosive, and that even if an explosion is started by gas the disturbance creates clouds of dust which gives rise to secondary explosions and spread the disaster over a wider field than was originally affected.

[Illustration: _Courtesy of the Link-Belt Co., Chicago._

HANDLING COAL

Four-ton grab buckets operating on the four bridge-tramways pick up the coal from the hold of lake steamers and deposit it either on the dock or in cars. The four machines can be moved to any part of the dock to which steamers are moored and four ships can be unloaded rapidly at one time. The motive power is electricity.]

[Illustration: _Courtesy of the J. M. Dodge Co._

STORING COAL

A 480,000-ton anthracite coal storage plant. Coal cars are dumped into hoppers under the tracks and the coal carried to the top of the piles by conveyors. It is reloaded into cars by other conveyors operating at the base of each pile. This system has been of great value in preventing a shortage of coal during strikes.]

Consequently a plan has been evolved for the ventilating current to be reversed periodically, in order to remove dust which has settled on the side of timbering and crevices, and the roadways to be watered in order to allay the dust. A plan has also been tried of spreading fine stone-dust in the roadways. This mixes with the coal-dust and renders it less inflammable.

Unfortunately the disastrous effects of an explosion do not end with the explosion itself. The main products of combustion, whether of fire-damp or coal-dust, are carbon monoxide and carbon dioxide. The latter causes suffocation and the former is a dangerous poison. It is the dreaded “after-damp” of the miner. Those who survive an explosion are therefore in danger of suffocation or poisoning, and it becomes imperative to restore the circulation of the air with the least possible delay. For even if the fan has escaped injury, fallen portions of the roof may have choked up some of the roadways, or the explosion may have torn down doorways and provided a short cut for the air. But if the atmosphere is dangerous for men in the pit at the time, it is equally dangerous for others to go down and effect repairs or render first aid.

The work of the rescue party is therefore a labor of desperate heroism and often attended by additional loss of life. It has recently been found possible to reduce the dangers of after-damp by providing rescue parties with respirators fitting over the mouth and nose, and supplied with oxygen from two steel bottles of the compressed gas strapped across the back. An effective apparatus of this kind, such as has been adopted by the United States Government for the use of the Bureau of Mines Rescue Crew, is shown in the accompanying illustration. The bag in front is known as a “breathing bag” and has separate compartments for the inhaling and exhaling, the tube at the right leading to the former and that at the left to the exhaling compartment, which usually contains sticks of caustic soda to absorb the carbon dioxide exhaled by the wearer.

Coal is largely formed from vast masses of vegetable matter deposited through the luxuriant growth of plants in former epochs of the earth’s history. In the varieties of coal in common use the combined effects of pressure, heat and chemical action upon the substance have left few traces of its vegetable origin; but in the sandstones, clays and shales accompanying the coal the plants to which it principally owes its origin are presented in a fossil state in great profusion and frequently with their structure so distinctly retained, although replaced by mineral substances, as to enable the microscopist to determine their botanical affinities with existing species. Trees of considerable magnitude have also been brought to light.

[Illustration: SECTION OF PART OF A COAL-FIELD, SHOWING A SUCCESSION OF BURIED TREES AND LAND SURFACE

_a_, sandstones. _b_, shales. _c_, coal-seams. _d_, under-clays or soils.]

The animal remains found in the coal-measures indicate that some of the rocks have been deposited in fresh water, probably in lakes, while others are obviously of estuarine origin, or have been deposited at the mouths of rivers alternately occupied by fresh and salt water. The great system of strata in which coal is chiefly found is known as the carboniferous.

[Illustration: MINE SAFETY CREW]

[Illustration: MINE RESCUE WORK

Upper view, Bureau of Mines Rescue Crew in safety helmets, ready to enter a gas-filled mine. Lower view, resuscitating a victim overcome by gas by means of the oxygen reviving apparatus.]

[Illustration: BRIQUETTING MACHINE

Enormous quantities of coal are lost at the mines in coal dust. By adding a binding material, such as pitch, and pressing the mixture into briquettes or small bricks, an excellent fuel is made.]

[Illustration: MINE RESCUE WORK

The mine rescue crew is using the canary-bird test for poisonous gas. The bird succumbs to gas earlier than a man and thus indicates a dangerous condition of the atmosphere. The canary is revived by oxygen and the crew puts on safety helmets before proceeding.]

There are many varieties of coal, varying considerably in their composition, as anthracite, nearly pure carbon, and burning with little flame, much used for furnaces and malt kilns; bituminous, a softer and more free-burning variety; and cannel or “gas-coal,” which burns readily like a candle, and is much used in gasmaking. The terms semi-anthracite, semi-bituminous, coking coal, splint coal, etc., are also applied according to peculiarities.

All varieties agree in containing from 60 to over 90 per cent of carbon, the other elements being chiefly oxygen and hydrogen, and frequently a small portion of nitrogen. Lignite or brown coal may contain only 50 per cent of carbon. For manufacturing purposes coals are generally considered to consist of two parts, the volatile or bituminous portion, which yields the gas used for lighting, and the substance, comparatively fixed, usually known as coke, which is obtained by heating the coals in ovens or other close arrangements.

About 260,000,000 tons of coal are annually mined in Britain, the value being over $300,000,000. Large quantities are exported. The British coal-fields, though comparatively extensive (covering about 9,000 square miles), are far surpassed by those of several other countries, as the United States and China, the former having coal-fields estimated to cover about 451,000 square miles; the latter over 200,000 square miles. Britain no longer mines the largest quantity, having been far surpassed by the United States. Other countries in which coal is worked are Belgium, France, Germany, Russia, India, New South Wales and Canada. China has hitherto mined only on a small scale.

The annual production of anthracite coal in Pennsylvania is more than 86,000,000 tons of 2,240 pounds, valued at the mines at $198,000,000. In 1910 there were produced of bituminous coal 388,222,868 tons, valued at $463,654,776; amount of coke manufactured, 37,000,000 tons. This was distributed widely over the country, the greatest producers, after Pennsylvania, being Illinois, West Virginia, Ohio, Alabama and Colorado.

Recently a very large output of coal has been discovered in Alaska, the value of which is as yet undetermined, though it is believed to hold a vast quantity of coal. The value of the western coal-fields also is far from known, and since 1906 very extensive tracts of coal-bearing lands have been withdrawn from settlement, principally in Wyoming, Montana, Colorado, Utah and New Mexico, their beds being largely of lignite. These cover about 50,000,000 acres, and, with those of Alaska, are held by the government as national assets. The mines of Alaska are claimed to be exceedingly rich, both in bituminous and anthracite coal, the beds examined being estimated to contain 15,000,000,000 tons, while there are large districts unexamined. They have not yet been worked, the government keeping them back for public ownership.

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How can We Hear through the Walls of a Room?

We are able to hear easily through the walls of many rooms because the material used in those walls are good conductors of sound. We know that some things are better conductors of heat than others, and just in that same way, some things conduct sound better than others. Wood has been shown to be an even better conductor of sound than air. Most of us have stood at the foot of an overhead trolley pole to see if we could hear a car coming, and we know that the reason we did this was because we could hear the wire humming, when we put our ears against the pole, even though we could not hear any sound in the air.

When we are in a room that has wooden walls we can hear sounds in the next room very plainly, not because the wall is thin, but because the wood in the wall is a good conductor of sound. Other walls made of different kinds of material, are not as good conductors of sound. While you may hear through them, you cannot hear as plainly as you can through a wooden wall.

What is a Diesel Engine Like?

The Diesel engine has caused a great deal of comment of late years because of the spectacular uses to which it has been successfully applied. A specially constructed Diesel engine was probably the chief aid in the accomplishment of the first submarine trans-Atlantic voyage by the German submarine “Deutschland.”

It is an oil engine which was invented by Rudolph Diesel in 1893.

The engine operates at compression pressures very much higher than those used in any other internal combustion engines, and it dispenses with the usual igniting devices by rendering the air charge incandescent by compression.

[Illustration: THE DIESEL ENGINE]

The efficiency of the Diesel engine is high, and it can use low grades of fuel, but it has the disadvantage of greater weight per horse-power than other engines.

It has found increasing favor for use in marine propulsion, and in 1913 was adapted to high-speed railway service, and put into use in Germany.