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cesses which he will be called upon to perform. The student in civil engineering by his field-practice learns the use of his tools and the art of taking field-notes. The mechanical-engineering student is in the vicinity of machine-shops, which he can visit and at which he can work. The student in mining engineering has no such advantages. The mines are at a distance, and the railroad fare to get to them is oftentimes an insuperable difficulty.

The aim of these laboratories is essentially to give to the student in mining and metallurgy a chance to study on a small scale the practical parts of his profession. We cannot, in a small laboratory, build a mine to timber, to work, and to survey. We cannot make artificial quicksands and other impediments to mining. In short, we cannot study exploration; but we can study the mechanical preparation and the subsequent smelting of ores. Before presenting the plan of these laboratories, it may be interesting to indicate the progress of the idea from its beginning.

During the summer of 1870 President Runkle visited the mines of Colorado, and while there conceived the idea of making an expedition with the mining-students to some of the western mining-regions. He talked over the scheme with many railroad and mining-men, and everywhere received encouragement. In the summer of 1871 the institute party visited the mines of Colorado, and spent six weeks in taking notes of them. President Runkle here conceived the idea of building up a mining and metallurgical laboratory; and by the aid of Booth & Co., of San Francisco, a stamp-mill was obtained, with the Washoe silver-working apparatus. During the year 1872 the metallurgical laboratory was brought to its present state of advancement by Professor Ordway.

The two laboratories are intended to give students an opportunity to work on a small scale, with all the mining and smelting laboratory which can be used to advantage in a laboratory; and this apparatus has been chosen with the view to illustrate, as far as possible, the principles of all machines used in mining.

The mining laboratory now contains a 15 horse-power engine, a Blake crusher, a stamp-mill; a Washoe pan, settler, and concentrator; a Rittinger automatic shakingtable, a little hand-jigger, a rotary pulverizer, and a fan-blower. The metallurgical laboratory contains a blast-furnace, a roasting and smelting reverberatory furnace, a cupelling-furnace, assay-furnaces, and a forge. The laboratory is equipped for easy blast-furnace experiments, such as the smelting of copper and lead ores, for roastingoperations on gold, silver, lead, copper, and antimony ores, and for the Freiberg process for silver.

A student receives an ore for examination, and in the presence of his instructor selects specimens containing all its characteristic minerals, which he determines, and then selects the method of treatment. Specimens are saved; the ore is crushed and sampled; assays are made to determine its value. The ore undergoes the treatment which was chosen. Actual results are compared with the assay-value of the ore, aud, wherever practicable, the amount of fuel, power, labor, and water consumed is noted. But few experiments have as yet been tried, since the laboratories are scarcely yet completed. A gold-ore from Acworth, Ga., yielded the following results when treated by ba tery amalgamation:

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Apparatus for iron-working is not yet represented in the laboratories, partly for lack of space and partly because we have not yet decided what furnaces could be most usefully employed in a laboratory. A pair of crushing-rolls is now in course of manufacture.

The mining-schools of Prussia are owned and controlled by the government, as is the case also with most of the mines and metallurgical establishments. In consequence, students have great facilities afforded them for acquiring practical information. In this country no such bond of union exists between the mines and the schools. The schools must here depend on the generosity and sympathy of the public, and to obtain such help they must in some way reciprocate it.

It is fully expected that, by making students do systematic and careful work, results will be obtained which will be of such value to the donors of the ores that they will feel more than repaid for sending them. If this expectation fails, the alternative always remains that ores can be bought and shipped by the school.

The mutual interchange of ideas between the instructors of the institute and the miners which will grow out of such work is regarded as no mean part of the value of this laboratory to the school and to the public.

With regard to working ores for outside interest only, results being returned promptly and a fee received in compensation for work done, I can only say that we have not

force enough this school-year to make any promises whatever. I expect to be able to do prompt work in future years.

With reference to the students' work, the suggestion has been made that we shona hold a tournament, as it were, for a month, keeping all mining-students engaged st work in their regular shifts; that we should use all the apparatus during the month; have our regular break-downs, stoppages, and patchings up, and settle up accounts at the end of the month, making such assays and analyses as are needed.

At the meeting of the American Institute of Mining Engineers at which the foregoing paper was read the following remarks were made by Prof. W. P. Blake:

I have listened with great pleasure to the reading of this paper. I saw a part of the machinery described when it was set up in the Institute of Technology, and it gave me great pleasure, because I recognized in it a step in the right direction for the instruction of young men and scientific students who desire to apply directly the information they obtain in the laboratory, and to ascertain where they need the most light. and become familiar with those points in practical work which they require. Experience has shown this to be the case upon the western coast, where, after a long and expensive trial of the laboratories of the chemist, the mill-men-the men who were accustomed to do things by main strength-became satisfied that they needed some help from outside, and finding that they could not get it always satisfactory from the assayers and chemists, who did not know what they wanted, and did not care as long as they got their fee for the assays and analyses, they went to work and put up in San Francisco assay-laboratories upon a large scale. It grew first out of a demand, a commercial demand, to ascertain the value, in silver or in copper, of ores shipped to San Francisco. Large quantities of ore were sent by miners from down the coast-from Lower California and Mexico to San Francisco-to be assayed. The parties to wher these ores were sent wanted to know what they were worth. The parties to whom they proposed to sell them would not take the ores upon the ordinary assay of a fragment selected out of the mouth of the sack-would only take them after first getting the ores crushed and sampled in a proper manner to make the assays. The miners found on: how this was done, and they went to work and put up establishments of their o where loads of ore weighing perhaps a ton or even less-half a ton or 500 pounds—eezi be crushed up into small fragments, shoveled together over and over, and then, whee they got an honest admixture, they could send the sample to an assayer. After this experience it was very natural that they should desire to know how such ores could be worked; and that led them to try them in the various pans and machines for grinding that have been manufactured. Inasmuch as the samples of ore were not large is quantity, they commenced making small trial-pans-little working models sometimes would answer the purpose-into which they could put 10, 20, or 50 pounds of ore, and work a batch of it. The results were very satisfactory. They gave great satisfaction, not only to the miners who had ores to sell, but to the mill-men and to the mannfieturers of machinery, because the parties who were engaged in manufacturing machinery for the miners in the interior could, right in their own establishments, see the many difficulties which the mill-men had to encounter. They became aware of all the conditions connected with the erection and running of their mills and were enabled to provide for them. It has led to a succession of improvements, to the rejection of a great many worthless and useless machines, designed by parties who were not familar at all with the working of ores, but who had patents on peculiar shaped or formed machines for crushing or grinding, and desired to sell those machines in the marke's Most of these worthless machines have been eliminated from the practice on the Pacific coast; and now I think I may say, without danger, that we make a better staanp mill in the United States than is made in any part of the world, and we make better machinery for grinding and amalgamation, in pans, at any rate, than has ever bes made before. It is very gratifying to any one who has seen the progress of imp: ment on the western coast, and knows how much has been done there by the expertmental works of the mill-men and the mirers, to see here in Boston an establishect complete in all its parts and capable of not only educating persons who are so fortunate as to receive instruction here, but also to do a great deal of good, probably, in making ns aware of the value of the ores of this region, or any ores that come to this market, at? of introducing a better knowledge of mining er gineering to the manufacturers of this

coast.

Being on that occasion in the chair, as president of the Institute, I expressed substantially the following views on this subject, and quote them here, since I see no reason to change either the opinion or the form:

Besides the function of instruction of students which requires that such appartem should be of the received form, there is an important function which I think these

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practical laboratories will one day fulfill, and that is the carrying out of such experiments as will further improve the processes now in vogue. It is one thing to instruct our young men so that they can go West and handle the machinery now in use there; it is another thing, and an equally important one, to have machinery at our disposal somewhere where it can be run in a truly experimental manner, where truly scientific experiments can be made-by which I mean experiments so shielded from possible complexities and mistakes that the results shall be traceable to the proper causes. I may instance an investigation upon which I entered some years ago, in relation to the efficiency of stamps, calculated with regard to their speed, weight, and drop. Those three elements must have some definite relation to the efficiency of the stamp in the quantity it will crush. It does make some difference whether we drop a heavy stamp a certain distance or a light stamp, weighing half as much, twice as far. I have been for some time a partisan of lighter stamps and more rapid blows than have been the fashion in many parts of the country, and in investigating that question and developing results, although I was able to eliminate from the problem such disturbing elements as depended upon the generation and transmission of power, I was not able to eliminate or perfectly estimate the influence of the facility and area of discharge, which has a decided effect on the quantity crushed, nor, on the other hand, the character of the rock, since in comparing different stamp-mills in different localities you have always to bear in mind that you are comparing them by different standards. Some quartz may crush and does crush easier than others. We must throw out abnormal results on either hand. I have known 72 tons to be run in twenty-four hours through a 10-stamp mill. The average would be something like 124 to 15, and anything that varies far from that average in either direction might be fairly attributed to some abnormal quality in the rock. To make complete experiments of this kind you want to have all the conditions maintained except one. If you wish to test discharge, you want to use the same battery and the same quartz, and vary nothing but the discharge; if you wish to test the speed and the weight of the stamp, you must vary nothing but the speed or the weight. That is impossible when you come to collect the results of experiments in ordinary practice. You cannot ask the mill-man to vary the weight or speed of his stamps, or to keep taking different kinds of rock, and stop his running at short intervals and clean up with spasmodic frequency, just to suit your desires. Hence, it is almost impossible to get absolute results. I trust the creation of such laboratories as have been described to us in the paper just read will open the door to something like careful work of this character. A specimen of what I mean is furnished by the experimental investigation of the Washoe amalgamation, which was made under the charge of Professor Brush, Mr. Hague, and Mr. Daggett, on the ores of the Comstock lode, at the laboratory of the Sheffield Scientific School at New Haven. The results are published in the third volume of Clarence King's report. Another specimen of what I mean I have been fortunate enough to secure myself, through the assistance of Mr. G. F. Deetken, of Grass Valley, Cal., who has made a very thorough analysis at every stage of the California stamp-mill process.

I think it is a question worthy the consideration of the faculty of this school whether some of the peculiar amalgamating-machinery employed in California might not with advantage be substituted for the simple amalgamation in battery and on copper plates, which is recognized in practice now to be a wasteful method.

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