Speaker 1: Section nineteen of Birds and All Nature, Volume seven, number two,
Speaker 1: February nineteen hundred. This is a LibriVox recording. All LibriVox
Speaker 1: recordings are in the public domain. For more information or
Speaker 1: to volunteer, please visit LibriVox dot org. Common Minerals and
Speaker 1: Valuable Ores three minerals containing carbon Theodore F. Brooken's b
Speaker 1: S Principal O Sable Fork's Union, Free School and Academy,
Speaker 1: New York. Among minerals of economic importance, carbon minerals hold
Speaker 1: the unique position of being at the same time of
Speaker 1: the most common and the most rare occurrence. As far
Speaker 1: as external appearance indicates, a piece of common coal and
Speaker 1: the most brilliant diamond are widely separated with regard to
Speaker 1: chemical composition, they are closely related. Intermediate between the coal
Speaker 1: of the stoke furnace and the brilliant of the jewelry
Speaker 1: shop is still another well known form of carbon, the
Speaker 1: graphite of the lead pencil. These three substances comprise the
Speaker 1: far greater part of carbon containing minerals. In so far
Speaker 1: as our mind's picture of a mineral is that of
Speaker 1: an aggregation of crystals of fairly perfect form, our consideration
Speaker 1: of coal as a mineral is erroneous. We must yield
Speaker 1: to a broader interpretation of the essential characteristics of a
Speaker 1: mineral and modify our idea so as to include any
Speaker 1: homogeneous substance solid with the exception of mercury, of fairly
Speaker 1: definite chemical composition quote occurring in nature, but not of
Speaker 1: apparent organic origin unquote. Organic substances are those that are
Speaker 1: alive or have lived. Vegetation is undoubtedly the origin of
Speaker 1: all coal, but often much more than a cursory examination
Speaker 1: is necessary to prove such origin. In the less altered coals,
Speaker 1: the vegetable origin is readily proved by the actual presence
Speaker 1: of seeds, plant fibers, and other equally apparent organic remains.
Speaker 1: A microscopic stud is necessary for finding the presence of
Speaker 1: woody fiber in the more metamorphosed form. The word metamorphose
Speaker 1: comes from the Greek meta means after or over morphi
Speaker 1: is form. A metamorphosis is a change of form or
Speaker 1: a forming over. The history of the discovery of the
Speaker 1: value of coal as a means of producing heat and
Speaker 1: of the development of the coal mining industry covers a
Speaker 1: comparatively recent period. Coal occurs in such quantities near the
Speaker 1: surface of the Earth's crust, and its outcrops are so
Speaker 1: numerous that it cannot have failed to attract the attention
Speaker 1: of the most ancient of peoples. Indeed, that coal could
Speaker 1: be used as a fuel is mentioned by a writer, Theophrastus,
Speaker 1: who lived three hundred years BC. The ancient Celts of
Speaker 1: Britain are repeated to have evidence knowledge of the industrial
Speaker 1: value of coal. It was not until near the middle
Speaker 1: of the thirteenth century, however, that coal became so important
Speaker 1: an economic product as to result in statutes granting to
Speaker 1: certain places the privilege of mining it. After a long
Speaker 1: period of trial in England, the superiority of coal over
Speaker 1: other fuels was recognized, and stone coal, as the harder
Speaker 1: form was commonly known, came into general use. In America,
Speaker 1: bituminous or soft coal was mined to a slight extent
Speaker 1: in the latter half of the eighteenth century. The form
Speaker 1: now commonly used in house heating furnaces. Anthracite for a
Speaker 1: long time baffled the colonists in their efforts to make
Speaker 1: it burn. The knowledge that an anthracite fire is most
Speaker 1: effective if not continually poked is said to have been
Speaker 1: acquired generally by accident. Europe and the United States today
Speaker 1: produce practically all the coal of the world. In Europe,
Speaker 1: Great Britain, Germany, France, Austria, Hungary and Belgium are the
Speaker 1: main sources of supply. Several important coal areas exist in
Speaker 1: our own country, notably that of the New England Basin
Speaker 1: with an area of five hundred square miles, the Appalachian
Speaker 1: District with an area of sixty five thousand square miles,
Speaker 1: the Northern Area in Michigan covering seven thousand square miles,
Speaker 1: the Central Area, comprising parts of Illinois, Indiana, and Kentucky
Speaker 1: and including forty eight thousand square miles, the scattered Western
Speaker 1: Area with a total of ninety eight thousand square miles,
Speaker 1: the indefinite Rocky Mountain Area, and the Pacific Coast region
Speaker 1: including parts of California, Oregon, and Washington. Coal mining is
Speaker 1: yet an undeveloped industry in our territorial possessions. Alaska has
Speaker 1: an abundant supply of coal, and lesser quantities are found
Speaker 1: in Cuba and Puerto Rico. Mention has already been made
Speaker 1: of the two common kinds of coal, bituminous and anthracite.
Speaker 1: These two kinds mark different stages in the transformation from
Speaker 1: plant organism to mineral product. As the biologist traces the
Speaker 1: successive steps in the evolution of an individual of a
Speaker 1: species from germ to adult, so the geologist unfolds before
Speaker 1: us the wonderful history of a piece of coal, from
Speaker 1: its firm dis appearance on the Earth to the time
Speaker 1: when it is thrown into our fire grate as fuel.
Speaker 1: Coal is the metamorphosed product of vegetable growths, changed by
Speaker 1: atmospheric agencies and the internal forces of the Earth, acting
Speaker 1: through a total period of perhaps millions of years. In
Speaker 1: the remote past, ages before man had appeared on the Earth,
Speaker 1: the atmosphere of our globe was highly charged with carbon gases.
Speaker 1: Vegetation flourished in luxuriance. Great swamps were common. The ocean
Speaker 1: alternately covered and receded from verdure clothed land areas. Ponds
Speaker 1: were transformed to morasses, and swamps in the swamps thus formed.
Speaker 1: The accumulated sediment of centuries upon centuries covered alternate layers
Speaker 1: of decayed plant organisms, until finally beds of peat were formed.
Speaker 1: Great masses above pressed on those underneath. The internal heat
Speaker 1: of the earth reached up and transformed the densely packed
Speaker 1: masses of peat, until the beds became hard and brown,
Speaker 1: the product of the partial metamorphism being what we know
Speaker 1: as lignite or brown coal. With the continued action of
Speaker 1: the forces of metamorphism, the lignite turned still darker, and
Speaker 1: as more gases were driven off, became heavier, until the
Speaker 1: bituminous stage was reached, which in turn was succeeded by
Speaker 1: the anthracite stage. Graphite or black lead, is a mineral
Speaker 1: containing not more than five per cent of impurities, and
Speaker 1: is generally supposed to have originated as did mineral coal,
Speaker 1: and to represent a still more advanced stage of development.
Speaker 1: It occurs in various localities, both in the vicinity of
Speaker 1: coal measures and far removed from them. The chief part
Speaker 1: of the world's supply comes from Ceylon, though Germany and
Speaker 1: the United States produce quantities of graphite of excellent quality.
Speaker 1: In the Laurentian rocks of Canada, and of course, with
Speaker 1: as ancient origin, extensive deposits are found. This presence of
Speaker 1: graphite and strata in which as yet no certain traces
Speaker 1: of organic life have been found, has led some to
Speaker 1: believe that this form of carbon mineral may have another
Speaker 1: than organic origin. Various uses are served by graphite. The
Speaker 1: chemist finds it of great value in making his crucibles.
Speaker 1: The engineer uses it finally powdered as a lubricant. The
Speaker 1: housekeeper polishes stoves with it. The electrician uses it in
Speaker 1: his arc lights. All civilized nations use it in the
Speaker 1: lead of lead pencils. The stem grapho to write on
Speaker 1: which so many of our words as geography, telegraph, graphophone,
Speaker 1: et cetera, are formed, suggests also the origin of the
Speaker 1: name graphite. The finest quality lead pencils are those made
Speaker 1: from graphite occurring in a state sufficiently pure to allow
Speaker 1: the cutting and grinding of pieces to the size needed
Speaker 1: in the case of the medium. In poorer grade pencils,
Speaker 1: the graphite has first been finely powdered and then pressed
Speaker 1: into the requisite shape and size. The purest form of
Speaker 1: carbon found in nature is the diamond. The rare their
Speaker 1: occurrence of diamonds indicates that the essential conditions in nature
Speaker 1: for causing the transformation of some less pure form of
Speaker 1: carbon into diamond are seldom present. While diamonds have actually
Speaker 1: been produced in the laboratory by far seeing and indefagable chemists,
Speaker 1: yet the cost of such products is so great as
Speaker 1: to preclude the possibility of the most precious of gems
Speaker 1: becoming at all common. The diamond is the hardest of
Speaker 1: all known substances, and will scratch any other mineral across
Speaker 1: which it may be drawn. Three localities have successively furnished
Speaker 1: the main part of the world's stock of diamonds. A
Speaker 1: century and a half ago, practically all the diamonds came
Speaker 1: from India, where at one time sixty thousand persons were
Speaker 1: employed in diamond digging. Toward the middle of the eighteenth century,
Speaker 1: when the diamond differous districts of India were becoming exhausted,
Speaker 1: the discovery of the precious gem in Brazilian deposits was made.
Speaker 1: At present, the supply of diamonds from Brazil has much diminished,
Speaker 1: and the diamond fields of South Africa Africa, whereas located
Speaker 1: the famous Kimberly Mine, produced a larger part of the
Speaker 1: world's output of diamonds. Among famous diamonds of the world
Speaker 1: should be mentioned the co enore of the British crown,
Speaker 1: which Hindu legend relates was worn five thousand years ago
Speaker 1: by one of their national heroes. The largest known diamond
Speaker 1: weighing three hundred sixty seven carrots was found in Borneo
Speaker 1: and is now owned by the Rajah of Matan end
Speaker 1: of section nineteen