-At Hudson, N. Y., are two anthracite furnaces of 16 feet across the boshes, which make over 180 tons, each one, of pig-iron per week. The manager of these works, C. C. Alger, Esq., has probably produced the greatest results in proportion to their size with these furnaces of any in the world. His success with the Stockbridge charcoal blast furnace, of ten feet bosh, was almost as remarkable, running it repeatedly at the rate of 90 tons per week. The two furnaces of Messrs. Cooper & Hewitt, which are run with the Andover ores, are twenty feet across the boshes, and have produced about 220 tons each per week. These great results are ascribed mostly to a steady and efficient blast, of much greater pressure than has ever before been used. The machinery to obtain this requires a large outlay of capital. The two furnaces at Hudson complete cost about $175,000, and the other two somewhat over this sum.

Charcoal furnaces would be considerably less expensive, but though it might be expedient to begin with only one or two, an engine or blowing apparatus ought to be provided sufficient for a larger number. The cost of manufacture, supposing there are two furnaces of the most approved construction located at Detroit, should not vary materially from the following estimate, the company being supposed to own the mine, as in the former estimate of the cost of blooms:

Estimated cost of making Charcoal Pig Iron at Detroit, in large blast furnaces, railroad to the mines, and canal built.

Having written already much more than I intended, I will leave it for others to calculate the cost of puddling this iron and rolling it into bars, and to determine the extent and cost of refineries that should be added to the furnaces. One point only of interest I

would not fail to call attention to.

On the Island of Elba are found large bodies of ore similar to those of Lake Superior. The furnaces for smelting them are on the opposite shore of Tuscaney. They are small, and of very peculiar construction, different from any other furnaces, but by their extraordinary yield they have proved to be extremely well adapted for smelting this kind of ore.

ON THE USE OF BURNT LIMF INSTEAD OF LIMESTONE AS A FLUX IN BLAST-FURNACES. BY E. MONTEFIORE-LEVI AND DR. EMIL SCHMIDT.

The study of the gasses formed in blast-furnaces, with which these authors have been engaged for some years, has shown that the use of carbonate of lime as a flux is attended with great loss,

and likewise that this loss may be obviated by using burnt lime instead. The gases were taken from a blast-furnace, 54 feet high, at Ougrée, at thirty-two places, 1 foot apart, and the percentage of carbonic acid determined,

According to calculation, 8000 kilogrms. carbonic acid require for conversion into carbonic oxide 2173 kilogrms. of carbon, and the quantity of heat developed in the combination of this quantity of carbon with 1 equiv. of oxygen, is 2173·1386-3,011,778 heat units. At the same time, however, these 8000 kilogrms. of carbonic acid are reduced to 5092 kilogrms. of carbonic oxide by the action of the carbon, a change which is accompanied by the absorption of a quantity of heat equal to that developed by the combustion of the latter gas, i. e., 5092-2488-12,667,896 heat units. Consequently, deducting the 3,011,778 heat units developed in the oxidation of carbon from the total number of heat units absorbed in the reduction of carbonic acid to carbonic oxide, there still remains a loss of temperature equal to 9,656,118 heat units, equivalent to the heat developed by the combustion of 1609 kilogrms. of coke.

Subse.

These considerations led the authors to employ burnt lime in working blast-furnaces, and thus to obviate the loss of heat. The experiment was commenced at Ougrée in July, 1849. During the first few days the results were unsatisfactory, the management of the furnace was difficult, and the slags black and pasty. quently, when taking into account the impurities of ordinary limestone, 63 parts of burnt lime were substituted for 100 parts of limestone: the working of the furnace, until it was let out at the beginning of 1851, was continually regular and good; during these eighteen months the most satisfactory results were obtained. The saving of coke and increase of production were, as the experimenters anticipated, very evident; moreover, the raw iron was of better quality, and all the interior parts of the furnace, especially the tymp stone, remained in a much better state of preservation than when limestone was used. The following table gives the quantities of coke consumed, in the production of 100 kilogrms, raw iron, in the above-mentioned furnace, during the four months before and the four after the alteration of the charging, all other conditions remaining the same:

1849. March.

April
May.

With limestone.

......

......

June.....

150.0 kilogr.
.145.5
.156 5

.151.5

With burnt lime.

142 kilogr.

1849. July

......

66

66

August 138
September 133
October....139

66

Average quantity 153.2 kilogr. Average quantity 137-75 kilogr. Average quantity consumed with limestone 153-20 or 100 p. c. coke. Average quantity consumed with burnt lime 137.75 or 90 p. c. coke.

Difference

15.45 or 10 per cent. The practical saving is therefore 10 per cent., which corresponds tolerably well with the theoretical result.

The experiment was repeated in 1850, in a second blast-furnace, with the same favorable result of increased production, saving of fuel, and easier working. The following table shows the quantity of coke consumed for every 100 kilogrms. of raw iron, and the production during the first six months, (reckoned at twenty-eight days). The figures in the first column refer to the furnace in which limestone alone was used; the second column to the firstmentioned furnace, in which burnt lime alone was used; and the third column to the second furnace, in which limestone was used for three months, and burnt lime for the next three months. All three furnaces are constructed alike, smelt the same ore, and produce the same kind of iron :

The very regular and uniform results given in this table, show that by the use of burnt lime the consumption of coke for every 100 kilogrms. of raw iron was reduced by 14 to 15 kilogrms., while at the same time the production of iron increased within a certain period as much as 22 or 24 per cent.

Hitherto the opinion of metallurgists with regard to the use of burnt lime was rather unfavorable than otherwise; but since the above experiments were made at Ougrée, it has been employed with good results in England and Wales, among other places at Abershyne, where the results obtained were still more satisfactory than at Ougrée, inasmuch as the saving of coke affected by this means amounted to 13 kilogrms. for every 100 kilogrms, of limestone which was replaced by 63 kilogrms. of burnt lime.

New lime-kilns have recently been built at Ougrée; burnt lime has been employed there two years and a half, and with uniform results, for which reason the authors recommend its general application, from a thorough conviction of the advantage to be gained. The entire saving, inclusive of the expense of burning the limestone, is stated by them to amount to 30,000 francs annually for each furnace.-Zeitschrift des oesterr. Ingenieurvereines, 1852, p. 145-150. Translated for the Polytechnic Journal.

THE IRON MANUFACTURE OF GREAT BRITAIN.

The produce of the iron manufacture of Great Britain in 1750, was only about 30,000 tons; in 1800 it had increased to 180,000 tons; in 1825 to 600,000; and in 1832 the product of pig-iron was estimated at 2,701,000 tons. This estimate of the yield was made only upon those furnaces in blast, as follows:

The shipments of pig iron from Scotland to the United States for the last seven years, have been as follows:

The shipments of manufactured iron from Liverpool to NewYork, Boston and Philadelphia during the last seven years, have been as follows:

:

Of which during the year 1852, New York received 135,290 tons, Boston 24,414 tons, and Philadelphia the balance.

MANUFACTURE OF WROUGHT-IRON DIRECT FROM THE ORE.

A brief report was made in the last number of the Mining Magazine (Vol. I. No. 2) respecting the establishment of Messrs. Davis of Cincinnati, for the manufacture of wrought-iron direct from the ore. The process adopted is that of James Renton, of Newark, New Jersey. The ore is taken in its raw state, and after being stamped, and prepared by an admixture of carbon, it is put in a series of close tubes, placed in a chamber, the outer surface of the tubes being exposed to the waste heat of the furnace for several hours, when it is sufficiently deoxydized. It is then discharged, as required, into the furnace, where it is readily worked up into balls weighing about one hundred pounds, and taken to

the hammer, averaging two balls every hour. The process is continuous and uniform.

A company with a large capital has been successfully carrying on this process at Newark for a considerable time. Their iron has been introduced for manufactures, and with high commendation. We have seen their works in operation.

The cheapness of the process is worthy of attention. The following is a statement of the cost of a ton of blooms at Newark, with one furnace :

From two to two and a half tons of ore, at $4 ..$10 00
One and a half tons of coal, at $4,25...

Puddling and welding, per ton

Hammering

Labor.......

Coal for carbon......

6 38

5 00

1 50

3 00

1 25

2.00

Half ton of coal for engine. at $4.

Making the cost of a ton of blooms about........$29 63 Any description of fuel-wood or coal, both anthracite and bituminous, can be employed for heating the furnace, and with nearly equal advantage.

ARTICLE III.

Address of John H. Lathrop, LL. D., Chancellor of the University of Wisconsin, before the State Agricultural Society.

MR. PRESIDENT, AND GENTLEMEN OF THE STATE AGRICULTURAL SOCIETY: The extreme division of labor and of employments, concerned in the production of material wealth, by reason of which a greatly multiplied population is sustained at a far more elevated standard of enjoyment and of culture, both of body and of mind, is the distinction of modern civilization.

Indeed, all civilization implies a departure from the personal isolation and independence of the purely savage state-it implies social arrangement and classification, fitted more or less discreetly to the production of proposed social ends; be those ends political or economical-and the character as well as the permanence of the system, depends, ultimately and properly, on the adaptation of its arrangements to the real and permanent wants of men-on the wisdom of its means, and the benevolence of its ends.

In most of the ancient forms of civilization, the artificial arrangements of society were for the benefit of a governing body, who wielded the civil power, and directed the military arm of the State, while the LABOR which sustained the whole, was fixed in its position at the base of the social pyramid, by the hereditary disabilities of caste; or under the more crushing weight of territorial serfdom, or of domestic servitude.

Under social conditions like these, which divorced the intellect of the State from its productive arm, there is no ground for surprise at the brilliant results wrought out by the governing mind, in an Egyptian, a Greek, or a Roman civilization.