Page images


(See page 412)

The Technical World Magazine

Volume 1

Volume IV


No. 4

Story of the Iron Industry
How Lake Superior Ore is Turned into Most

Valuable of Pigs

Iron and Steel Expert

In the last twenty-five years the production of iron in the United States has increased eighteenfold. This industry and those growing out of it have made more men millionaires than any other single line of business. The following article describes accurately and simply the processes which follow the digging of iron ore from the great Lake Superior mines-richer, they are, than any diamond or gold mines-until it is turned into the pig iron of commerce. Mr. Blackiston, the author, is one of the leading authorities on the subject. See back of frontispiece. - The Editors.

UT of the world's annual produc- pig or cast iron. The yearly valuation

tion of forty to fifty million of this product is over two hundred and tons of pig iron, the United fifty million dollars.

States alone furnishes about The ever - increasing consumptive eighteen million tons, or two-fifths power of the United States for iron and of the entire output. This, if steel products has caused a phenomenal loaded into ordinary freight cars, growth in this branch during the last would make a train extending over ten twenty-five years. During this period it thousand miles, or two-fifths around the has risen from a little over one million to globe. If made into telegraph wire eighteen million tons. Of this tonnage three-sixteenths of an inch thick, it would Pennsylvania contributes about fortyextend from the earth to the sun, a dis- seven per cent, while Ohio produces seventance of almost one hundred million teen per cent, and Illinois about ten per miles. Although the great bulk of this cent. The growth of iron manufacture in vast production is consumed in the these three states has been one of the most United States, three to four hundred notable features of the industrial growth thousand tons are annually exported. of the United States. The production

Over forty million dollars are annually of Pennsylvania alone to-day is seven paid in wages to the eighty thousand men times greater than the entire production and boys employed in the production of of this country in 1870. Copyright, 1905, by The Technical World Company


[graphic][merged small][ocr errors]

United States in Lead

transported and sold in foreign countries In 1870, when railroad construction at a large profit. was most active in this country, England, The channels of consumption of this which produced three times as much iron enormous tonnage are numerous and exas did this country, furnished us with tensive, affecting almost every walk of all of our rails and other material. After life. Five million tons is of grades suitthat, Germany took the lead, but only to able for foundries, for the production of be surpassed by the United States, which iron castings for machinery, railroad to-day has an output almost equal to rolling stock, cast-iron pipes, and a varithat of England, Germany, and France ety of small uses. About half a million combined.

tons is converted into wrought iron, while The great and rapid advancement of another half million is used for steel castthe United States in this branch of in- ings. The remainder, amounting to dustry is due, to a great extent, to its about eleven million tons, is utilized as rich, reliable, and easily obtained iron ore the basis of steel manufacture. and its unsurpassed coking coal, the two forming the most essential ingredi

Iron a Prehistoric Product ents used in iron making. These, aided The actual manufacture of iron dates by the modern and inexpensive handling back almost to the prehistoric era, but it and by splendid transportation facilities, was not until 1620 that it was introduced reduce the cost of manufacture to such into the United States. From that time a low figure that American iron can be on the improvements were rapid and

wonderful, the foremost of which were the introduction of coke in the eighteenth century, the steam engine in 1769, and the hot blast of J. B. Neilson in 1828.

A splendid example of one of these antiquated furnaces can still be seen near Lakeville, Conn. It was built in 1762; and so excellent was its product that cannon, cannon balls,

shells, etc., were used UNLOADING A VESSEL.

therefrom, as also the large The modern method of uploading the huge ore-carriers at the rate of six to seven thousand tons every ten hours.

chains which were stretched across the mouth of the Hudson during that exciting period.


Pig or cast iron is not pure iron, but an alloy of which iron is the most important ingredient. Unlike many of the common alloys, such as bell metal or brass, which are composed of a mechanical mixture, it consists of a large, complex union of many and differ ent elements, such as carbon, manganese, silicon, sulphur, phosphorus, etc. The most important of these is carbon, which gives fluidity to the metal when molten and hardness when


The three principal ingredients used per cent of iron, and the low ores, thirty in its manufacture are iron ore, coke, and to fifty. limestone. In a few cases, charcoal, an- Although small quantities of ore are thracite, and bituminous coal are used, found in Alabama, New York, Pennsylalone or mixed, in place of the coke. All vania, New Jersey, Wisconsin, Minneof these are plentiful in this country and sota, Michigan, Virginia, and West Virof most excellent quality.

ginia, about eighty per cent of the total The iron ores of this country are di is mined in the famous Lake Superior vided into four general classes, the high- region, of which the following are the grade ores containing about fifty to sixty principal ranges: The Vasaba in Minn

[graphic][merged small]
[graphic][ocr errors]

MODERN BLAST FURNACE, THE RECORD-BREAKER OF THE WORLD. The photo shows the skipway, up which the material is carried to the top of the furnace. The down

he downcomers, or pipes down which the gas travels, are also very plainly illustrated.

« PreviousContinue »