Obtain specimens of crude petroleum, naphtha, refined oil, aniline dye, paraffine, and carbolic acid; note the properties of each. Throw away the naphtha after using.

Read Mineral Resources of the United States on the foregoing subjects.

CHAPTER XIII

METALS OF THE ARTS AND SCIENCES

The development of modern civilization is directly connected with the mining and manufacture of the useful metals. Their effect on the affairs of mankind can be rightly understood only when they are studied in their relations to one another, as well as to the people who used them. Next to the discovery of the use of fire, an appreciation of the use of metals has been the chief thing to develop the intellect of mankind.

When human beings discarded natural caves for artificially constructed dwellings--when they began to cook their food and clothe their bodies, they required tools. These, in the main, consisted of the spears and arrow-heads used as weapons of the chase, and the axes and knives used as constructive tools.

Rough stone gave place to flint because the latter would take a better edge. For the same reason the people of central Europe sent to the deserts of central Asia for jade wherewith to make axes and knives.

Again, for the same reason, jade was discarded, because an alloy of copper and tin produced a bronze that would not only take a sharper edge than stone, but it was hard enough to cut and dress the latter. Egypt rose to a commanding position because of her control of the copper mines in the Sinaitic peninsula, and subsequently of the gold products coming from the upper Nile.

A meridian drawn through Cairo, Egypt, practically divides the world into two kinds of civilization. East of this meridian the population is almost wholly agricultural and, excepting j.a.pan and India, the character of the civilization has changed but little in the past 2,000 years. West of the line the population is essentially characterized as metal-workers. It controls the world--not especially by virtue of a high degree of intellectual development, but because it has availed itself of the properties and characteristics of metals and their applications to commerce.

The four metals that have had the greatest influence on western civilization are gold, silver, iron, and copper. The discovery of gold and silver has always resulted in a rapid settlement of the regions in which the discoveries were made, and usually in the building of great industrial centres. Thus, the discovery of gold in California was the first step in making the United States a world power. The acquisition of so large an amount of gold caused an industrial expansion that hurried the Civil War, and led to the manufacture of iron and steel both for agricultural machinery and railroad transportation. This, in turn, brought the country so closely in touch with the affairs of China and j.a.pan, that European and American diplomacy in eastern Asia are a common concern. The commercial position of Great Britain is very largely due to her iron mines.

The production of Bessemer steel at a price far less than that of iron at the beginning of the nineteenth century lowered the cost of transporting commodities to the extent that large areas, once of necessity very moderately productive of food-stuffs, are now densely peopled because food-stuffs can be transported to these regions more economically than they can be grown there. Thus, owing to the improvements in iron and steel manufacture, the farmer of Minnesota, the planter of Louisiana, the miner of Colorado, and the factory operative of Ma.s.sachusetts have each the same comforts of living that are enjoyed by all the others, and have them at scarcely more than half the cost of fifty years ago.

[Ill.u.s.tration: STEEL MANUFACTURE--THE NATIONAL STEEL COMPANY'S SMELTERY AND ROLLING-MILLS, MINGO JUNCTION, OHIO]

The gradual decrease in the production of the silver mines near the present site of Ergasteria proved a beginning of the fall of Athens; and when gold was discovered in the Perim Mountains of Macedonia, the seat of Greek power moved thither. Philip of Macedon h.o.a.rded the treasure from the mines of Pangaeus, and with the capital thus acquired his son, Alexander the Great, conquered the East, implanted h.e.l.lenic business methods there, and drew the various trade routes between Europe and Asia under one control.

In the fifteenth century copper from the mines near Budapest and silver from the Schwarz Mountains of Germany were the resources that made Germanic Europe pre-eminent. The wresting of the trade in these two metals from Venice caused the rise of Antwerp and brought immense gains to Lubeck, London, Brussels, Augsburg, and Nuremberg. In the latter part of the nineteenth century copper again reached a high position of importance from the fact that upon it largely depends electric motive power and transportation.

=Iron.=--Iron is one of the most widely diffused of metals. It is abundant in the sun; meteorites contain from more than ten to eighty or ninety per cent. of it; all earths and rocks contain at least traces of it; and in various places the deposits of ore in nearly pure form aggregate cubic miles in extent.

In only a few localities is iron ore found in a metallic or "native"

form. Many meteorites consist of metallic iron mixed with nickel and manganese, and in Greenland a volcanic d.y.k.e or ledge of metallic iron is known to exist. The iron of commerce is derived from "ores," or chemical compounds of iron and oxygen, or iron and carbon. The cheapness of the product depends upon the ease with which the ore may be quarried, transported to coal, and smelted. The following are the ores commonly employed in the production of iron:

_Red hemat.i.te_ has a reddish metallic l.u.s.tre and when pure contains seventy per cent. of iron.[42] It is the most abundant of the workable ores, and certainly the best for the manufacture of Bessemer steel. The ores of the Lake Superior region are mainly red hemat.i.te, and the latter const.i.tutes more than four-fifths of the output of the United States.

[Ill.u.s.tration: THE COMPARATIVE PRODUCTION OF IRON AND STEEL]

_Brown hemat.i.te_, or limonite, has a chestnut brown color and contains very nearly sixty per cent. of iron[43]; it includes the "bog" ores, and is very abundant. Not far from one-quarter of the Appalachian ores are brown hemat.i.te; it const.i.tutes about one-eighth of the output of the United States.

_Magnetic_ iron ore, or magnet.i.te, of which loadstone, a natural magnet, is an example, has a metallic, steel l.u.s.tre and contains 72.4 per cent.

of iron.[44] Most of the ores obtained in Pennsylvania and New York are magnet.i.te. The magnet.i.tes furnish about one-sixteenth of the output of the United States.

_Carbonate of Iron_, or siderite, occurs in a few localities, the ore produced in Ohio being almost wholly of this kind. It contains when pure about forty-eight per cent. of iron.[45] It const.i.tutes less than one per cent. of the output of the United States.

_Iron pyrites_, or sulphide of iron, sometimes called "fools' gold," is a very common mineral. It is used in the manufacture of sulphuric acid, but is worthless for the production of iron; indeed, the presence of a very small percentage of sulphur in iron renders the latter worthless for many purposes.

Extensive deposits of iron are known to exist in very nearly every country in the world, but those which can be advantageously worked are few in number. In order to be available, the deposits must be within easy transporting distance of the people who use it, and likewise within a short distance of the coal used to manufacture it.

For these reasons most of the workable deposits of ore are in or near the great centres of population in western Europe and the eastern part of the United States; as a matter of fact, practically all the iron and steel of the latter country is produced in the populous centres of the Atlantic slopes. In most great steel-making districts it is essential to mix the native ores with special ores brought from a distance, the latter being used to give strength and hardness to the resulting metal.

Ores from Sweden, and from Juragua, Cuba, are employed for this purpose in the steel-making establishments of the United States.

In the past few years the United States has jumped from an insignificant position in the production of iron and steel to the first rank among the iron-producing countries. This great advance is due to the fortunate geographic position of the iron ore and the coal, and also to the discovery of the Bessemer process of making steel.

In general it is more economical to ship the ore to the coal than _vice versa_. The position of the steel-making plant is largely determined by the cost of moving the c.o.ke and ore, together with that of getting the steel to the place of use. Formerly, iron manufacture in the United States was not profitable unless the coal, ore, and limestone[46] were very near to one another.

These conditions still obtain in the southern Appalachian mineral fields; the ore and the coal are at no great distance apart, and a great iron-making industry, in which Birmingham and Bessemer form the princ.i.p.al centre, has grown into existence. For the greater part the coal is c.o.ked; and in this form less than a ton[47] is sufficient to make a ton of pig-iron. The smelteries and rolling-mills are built at places where the materials are most conveniently hauled.

In the past few years the iron and steel industry which formerly centred about the navigable waters at the head of the Ohio River, has undergone a readjustment. Rolling-mills and smelteries exist at Pittsburg and vicinity, and at Youngstown, New Castle, and other nearby localities, but greater steel-making plants have been built along the south sh.o.r.es of Lakes Michigan and Erie, all of which have come about because of reasons that are purely geographic.

Immense deposits of excellent hemat.i.te ore in the old mountain-ranges near Lake Superior have recently become available. For the greater part the ore is very easily quarried. In many instances it is taken out of the quarry or pit by steam-shovels which dump it into self-discharging hopper-cars. Thence the ore is carried on a down grade to the nearest shipping-port on the lake. There it is dumped into huge bunkers built at the docks, and from these it slides down chutes into the holds of the steam-barges. A 6,000-ton barge is loaded in less than two hours; a car is unloaded in a few seconds.

[Ill.u.s.tration: MOVEMENT OF IRON ORE]

Water transportation is very cheap compared with railway transportation, even when the road is built and equipped as an ore-hauling road. The ore is therefore carried a distance varying from one thousand to one thousand five hundred miles for less than it could be loaded, on cars hauled one-tenth that distance by rail, and unloaded.

[Ill.u.s.tration: STEEL MANUFACTURE--ORE DOCKS]

At the south sh.o.r.e of Lake Erie, the ore meets the c.o.ke from western Pennsylvania and coal from the Ohio coal-fields, and as a result new centres of iron and steel manufacture have grown up along this line of "least resistance." The ore is unloaded at the docks by means of mechanical scoops and shovels. So cheaply and quickly is it mined and transported that it is delivered to the smelteries at a cost varying from $1.75 to $3.25 per ton.

[Ill.u.s.tration: LAKE SUPERIOR IRON ORE FIELDS]

There are three forms in which iron is used--cast iron, wrought iron, and steel. Cast iron is crystalline and brittle. The product as it comes from the blast furnace is called pig-iron. In making such commodities as stoves, and articles that do not require great strength, the pig-iron is again melted and cast into moulds which give them the required shape.

Cast iron contains from one to five per cent. of carbon.

Wrought iron is malleable, ductile, and very flexible; when pure it is also very soft. It is prepared by melting pig-iron in furnaces having such a shape that the molten metal can be stirred or "puddled" in contact with the air. By this means the carbon is burnt out, and while still at a white heat the pasty iron is kneaded or "wrought," in order to expel other impurities.

Steel is a form of iron which is thought to contain a chemical compound of iron with carbon. It is stronger than iron and finer in grain.

Formerly, steel was made by packing bars of pure iron in charcoal powder, the whole being enclosed in clay retorts that were heated to whiteness for about three days. The product obtained by this method is known as cementation steel. It is still used in the manufacture of cutlery, tools, and fine machinery; it is likewise very expensive. In smelting certain ores it is easy to burn out the carbon in open furnaces, and "open-hearth" steel is an important factor.

Just about the beginning of the Civil War, when the railways of the United States were taxed beyond their capacity to carry the produce of the country, it became apparent that something more durable than iron must be used for rails. The locomotives, then weighing from twenty-five to thirty-five tons each, were too light to haul the freight offered the roads; they were also too heavy for the rails, which split at the ends and frayed at the edges.

[Ill.u.s.tration: IRON AND STEEL]

The Bessemer process of making steel was the result of the demand for a better and a cheaper method. By this process, the iron is put into a "converter" along with certain Swedish or Cuban ores to give the product hardness. A hot blast is then forced into the converter which not only melts the ma.s.s but burns out the excess of carbon as well. The color of the flame indicates the moment when the conversion to steel is accomplished.

In 1860, before the establishment of the Bessemer process, steel commanded a price of about one hundred and twenty-five dollars per ton; at the beginning of the twentieth century steel billets were about eighteen dollars per ton. In western Europe and the United States there are used about three hundred pounds of iron and steel per capita; in South America the rate of consumption is about fifteen pounds; in Asia (j.a.pan excepted) it is probably less than three pounds.

The economic results of low-priced steel are very far-reaching. Steam boilers of steel carry a pressure of more than two hundred and fifty pounds to each square inch of surface--about four times as great as in the iron boilers formerly used. Locomotives of eighty tons draw the fast pa.s.senger trains at a speed of sixty miles an hour. Ponderous compounding engines weighing one hundred and twenty tons haul ninety or more steel freight cars that carry each a load of 100,000 pounds. The iron rails formerly in use weighed about forty pounds per yard; now steel rails of one hundred pounds per yard are employed on most trunk lines.

In the large commercial buildings steel girders have entirely supplanted timber, while in nearly all modern buildings of more than six stories in height, the frame is constructed of Bessemer steel. Indeed, a steel-framed building of twenty-five stories has greater stability than a brick or stone building of six. Such a structure as the "Flatiron Building" in New York or the Masonic Temple in Chicago would have been impossible without Bessemer steel.

In ocean commerce cheap steel has worked even a greater revolution. In 1860, a vessel of 4,000 tons displacement was thought to be almost up to the limit. The Oceanic of the White Star Line has a displacement of about twenty-eight thousand five hundred tons. This is nearly equalled by the measurement of half a dozen other liners, and is exceeded by the freighters built by Mr. J.J. Hill for the China trade.

[Ill.u.s.tration: _From a copyrighted photograph by C.L. Ritzmann, N.Y._

STEEL MANUFACTURE

THE FULLER (FLATIRON) BUILDING, NEW YORK CITY]