Part 18

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.]

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.

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.

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.

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.

What does the Sheep-Grower Get for the Wool in a Suit of Clothes?

A man’s ordinary three-piece fall suit has about nine pounds of wool in it. Such a suit might cost somewhere between twenty and forty dollars, depending on whether it was bought ready made or whether it was made to order. If the price was questioned, the retailer would probably explain that it was all wool and that the wool cost was the reason it was expensive, and still the sheep-man who raised the wool only received an average of about eighteen cents a pound, or $1.62, for all the wool used on the suit.

Of course, the largest part of the cost of a suit of clothes is really accounted for by the cost of transportation, weaving, tailoring and selling, but we must all agree that the sheep-man who tends the flock all winter and cuts the wool in the spring is not to blame for high prices.

The Story in a Silver Teaspoon[16]

The spoon is older than history. There is, perhaps, no article or utensil of common use today that can trace an earlier origin. The evolution and development of the spoon into the graceful and beautiful forms in use on our tables is fascinating and instructive.

Primitive men of the Stone Age used an implement that might by courtesy be called a spoon. From then on down through the Egyptian, Greek and Roman civilizations it can be clearly traced in varying forms and substances--wood, shell, flint, bone, ivory, bronze and the precious metals, gold and silver.

A witty Frenchman has said that spoons, if not as old as the world, are certainly as old as soup.

In the Bible is the first recorded mention of the use of spoons made of precious metal. This reference is the twenty-fifth chapter of the Book of Exodus, wherein the Lord commanded Moses to make golden spoons for the Tabernacle.

Excavations in Egypt have brought to light early examples of spoons of various materials, and it is certain that the early Greeks and Romans used gold and silver spoons, both at the table and in the Temple. Early specimens of spoons made of wood, ivory, bronze, silver and gold are preserved in the museums of Europe and Egypt.

During the early Christian and medieval eras spoons were in common use. Saxon and Early English examples are to be seen in the English museums today.

The medieval spoon was of silver, horn or wood, etc. On the Continent, silver spoons were made much earlier than in England. In Italy they were in use probably long before 1000 A. D.

During the Tudor and Stuart reigns a fashionable gift at christenings was the apostle, so called because at the end of the handle was the figure of an apostle. Sometimes a thirteenth spoon was added, called the “Master” spoon, because it bore the figure of Christ. A complete set was a very valuable gift, and could only be afforded by the rich.

Folks of limited means used copper, pewter, latten or alchemy spoons; the latter two materials being somewhat like brass, examples of which are sometimes found in this country in the graves of Indians of the sixteenth and seventeenth centuries, showing their intercourse with early English traders.

At this period the stems were hexagonal, ending in an acorn, a bird or a ball, while the bowls were fig shape. Later the stems were baluster shape with a seal top, and at the time of the Commonwealth the stem became flat and perfectly plain. These latter are called “Puritan” spoons.

Naturally, the early New England colonists brought with them the spoons they had used at home, and the early Colonial silversmiths followed closely the designs which they found at hand or which were later imported from England. In fact, within a few years after a certain type had become popular in the mother country, it was adopted in this country as the fashionable style. It is, therefore, easy to date, approximately, an American-made spoon, because it follows so closely in style the dated or hall-marked English spoon.

During the last quarter of the seventeenth century, both in England and America, spoons were generally of a style now known as rat-tail. From the end of the handle, down the back of the bowl to about the middle, ran a ridge shaped like a rat-tail. This is sometimes thought to have been an attempt to strengthen the spoon, but its use must have been purely ornamental, for it adds little strength to these strongly made spoons. Sometimes the rat-tail was shaped like a long V and grooved, while on each side were elaborate scrolls. The bowl was perfectly oval in shape, while the end of the handle was notched or trifid.

This style of spoon was continued, with modifications, through the first third of the eighteenth century. Then the bowl became ovoid, or egg-shaped, and the end of the handle was rounded, without the notch.

The rat-tail was gradually replaced by what is known as the drop, or double drop, frequently terminating in a conventionalized flower or shell, or anthemion, while down the front of the handle ran a rib.

Later, the bowl became more pointed, the drop was replaced by a tongue, and the handle, after 1760, instead of slightly curving to the front at the end, reversed the position. Somewhat later, the handle became pointed, and was engraved with bright, cut ornaments and a cartouch at the end in which were engraved the initials of the owner.

During the first ten years of the nineteenth century a popular style was the so-called coffin-shaped handle, succeeded, probably about 1810, by a handle with a shoulder just above the junction with the bowl, while the end became fiddle-shaped or of a style now known as tipped, shapes produced to this day.

Until about 1770, spoons were of three sizes: the teaspoon, as small as an after-dinner coffee spoon; the porringer spoon, a little smaller than our present dessert size; and the tablespoon, with a handle somewhat shorter than that of today.

So few silver forks have been found in collections of old silver that it forces the belief that they were generally made of steel, with bone handles. There seems no reason why, if in general use, silver forks should not now be as common as spoons.

In the great silver exhibition recently held in the Museum of Fine Arts, Boston, of more than one thousand pieces, there were only two forks to be found.

Great skill was developed by the early silversmiths of England and America. The purity and gracefulness of design in many cases remain as standards for our best craftsmen today. It is, however, erroneous to suppose that all of the ornamentation was done by hand.

Ornaments on the back of spoon bowls and handles were impressed by dies forced together by drop presses or under screw pressure. This is absolutely proven by the exact duplication of the pattern on sets of spoons. Accurate measurements show that these ornaments were not handwork, for there is not the slightest deviation in dimensions.

But, however beautiful the silver of our forbears and however valuable now, from a historic standpoint, there are few of us who, if given the choice, would not decide in favor of the product of the twentieth century silversmith, who brings to his creations all of the good of the old masters, and who has the facilities for turning out work more perfect in line and detail and uniformity than was ever dreamed of by the silver worker of old.

We admire the beautiful silverware that we see in the shop windows, we derive satisfaction and pleasure from the daily use of silver on our tables, but few people have any understanding how silver plate is made; and there is, perhaps, still less knowledge of its interesting history.

The combining of two separate metals--that is, the plating of a base metal with a finer one--was, until the eighteenth century, a lost art of the ancients.

The application of one metal upon another was practiced by the Assyrians, who overlapped iron with bronze; copper implements and ornaments coated with silver have been found at Herculaneum, while many ancient Roman specimens of harness and armor are found to be ornamented with silver on copper. The Aztecs of Mexico and the Incas of Peru used the process of fixing two metals together by the action of heat, before making up. The method was also known to the old Celts, as shown by specimens found in Iceland. It seems, however, to have been a lost art in Europe, probably because up to the thirteenth century the Church had control of the arts and crafts in England, and the finer metal work was used only for church vessels, the household implements being very simple and mostly of wood and cheap metal.

Horace Walpole, writing in 1760, states: “I passed through Sheffield, a business town in a charming situation, with 22,000 inhabitants, and they remit £11,000 a week to London. One man there has discovered the art of plating copper with silver.”

The inventor to whom the quotation refers was Thomas Bolsover, a skilled silversmith, who, in the year 1742, it is traditionally reported, while repairing a thin layer of silver on the copper handle of a knife, evolved the idea of combining copper with silver in layers ready for manufacture into any desired form.

Bolsover himself apparently did not appreciate the importance of this invention, and it remained for Joseph Hancock, one of his apprentices, to develop the idea to a commercial success. He vigorously encouraged the trade in Sheffield, Birmingham and other manufacturing centers, and finally constructed a rolling-mill and made his fortune by supplying the plate to the silversmiths.

The earlier specimens of this Sheffield plate, as it came to be known, had the silver on one side of the copper only, but later attempts were made to improve the appearance of finer pieces by covering the underside of the copper with tin.

Crude as this idea and the old methods of manufacture may seem, compared with modern processes, this old plate found a ready sale. It replaced in many households pewter ware which, until the introduction of Sheffield plate, was the best substitute for sterling silver. It became fashionable for everyday use by the nobility and wealthier families, who put aside their solid silverware to be used on state occasions only. The name “plate,” which is from the Spanish word _platte_, came to be used generally to designate the imitation of solid silver.

This plate, being such a close imitation of solid silver, was not permitted by the laws of England to bear any stamp whatever prior to 1773, when the town of Sheffield was specially privileged to put upon its product the marks of the makers. These marks, however, were not to bear any resemblance of the lion or leopard’s head, these being the hall-marks of England.

It was not until 1785 that this privilege was extended to the town of Birmingham and other manufacturing centers.

It is curious to note that this law against the imitation of silver, which really dated from the fifteenth century, made a special exception to articles made for the Church.

Sometimes this old Sheffield plate, in addition to bearing the maker’s name, bore the name of the lord or earl for whom it was made, and today these old pieces are more highly valued by their owners than silver which is intrinsically more valuable.

Much of the charm of old plate was in its beauty of form and design, for the work attracted the best of English artisans. It would appear, too, that they were fairly well paid for their labor, as Pepys, in his “Diary,” refers to a present made him of a pair of flagons which cost £100. “They are said to be worth five shillings, some say ten shillings, an ounce for the fashion.”

The first notable improvement over the Sheffield work came toward the middle of the nineteenth century, when electro-silver plating was first practiced and, in 1847, commercially perfected, by Rogers Brothers of Hartford, Conn.

The marvelous force of electricity was brought to bear on the making of silver-plated knives, forks, spoons, etc., as well as hollow-ware articles, such as coffee and tea pots, water pitchers, sugar bowls and platters. Instead of these articles being made of sheets of rolled copper and silver, a silver plate of any desired thickness is applied to the base metal by electricity.

This quick and less expensive method of manufacture rendered silver plate available to all classes, and the Sheffield plate was quickly superseded, the old method of manufacture becoming obsolete.

While the process of manufacture was cheapened, the newer craftsmen wisely held to the art standards of the old masters. With the new process came the perfection of modern construction, and the cost is so much less than in the old days that a perfect table service of authentic design, of quality beyond question and guaranteed in every respect, is within the reach of any well-to-do family. Many of the old family pieces of Sheffield have found their way into the melting pot in exchange for the modern electro-plated silverware.

The making of silver-plated flatware is an interesting process and one that requires a great amount of skill and care. The finished teaspoon, as it lies in the show-case or chest, is the result of over thirty distinct operations, while a plain silver-plated steel knife has passed through thirty-six stages in its evolution from the bit of steel rod, in which shape it begins its journey. Some of the more important steps in the making of a spoon are briefly described below:

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