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By C. A. Mezger

DURING my stay at Raposos, State of Minas Geraes, Brdzil, I had the opportunity of making some observations, which, in the shape in which I am able to lay them before the Institute, are only to be considered as an experience which may possibly have important consequences. The ore-bodies worked there for gold are exclusively chimneys, mostly cylindrical, following the dip of the argillaceous slates (about 45° E.), without any visible connection with each other, without veins, and only exceptionally with some small stringers along the stratification, pinching out at short distances from the chimneys. They are composed of quartz with about 8 to 10 per cent. of pyrite and pyrrhotite, and different iron oxides.

Jan 1, 1895

By Arthur W. Sheafer

MR. ECKLEY B. COXE, in his able and interesting paper on " The Preparation of Small Sizes of Anthracite,"* read and discussed at the Glen Summit Meeting, October, 1891, refers to the reputed immense amount of coal contained in the culm-banks, which are the unsightly accompaniment of every mining operation in the anthracite coal-regions. Mr. Coxe thinks the available amount and value greatly exaggerated, giving among his reasons (1) the spoiling of the culm by mixing with other refuse; (2) its deterioration; (3) its destruction by fire ; and (4) frequent failures to realize expectations as to the size of the banks. These points are undoubtedly important factors in determining the advisability of working any individual bank, but they have a varying influence in the several regions, some prevailing more in one than in another. Although the amount of fuel lying waste in these banks is still an uncertain and undetermined quantity, yet no one can visit the Schuylkill region without being impressed with the fact that a considerable amount of culm, too valuable to be left merely to the mercy of the elements, surrounds and encumbers each site of an old or present colliery operation. The rapid increase in the number of washeries, and the demand for leases on old culm-banks, shows that, in the Schuylkill region at least, the question of deterioration doès not play an important part. The proportion of coal to refuse, the relative percentage of the sev-

Jan 1, 1895

By Beverley S. Randolph

The coal-measures of George's Creek coal-region, in Maryland, lie in a comparatively flat synclinal basin, about 4 miles wide. The dip of the measures is, in places near the edge of the basin, as much as 20 feet in 100. The Pittsburgh seam, known locally as the " Big Vein," is the only seam worked at the present time. Ocean No. 3, one of the large mines of the Consolidation Coal Company, has its opening on the outcrop of the Pittsburgh seam, in a ravine which cuts into this seam to such an extent as to bring this opening to within a mile of the axis of the basin. After working all the coal to the rise of this point, the mine was further developed by extending a slope down the dip of the seam, making such an angle with the line of greatest dip as to give a grade varying from 1 to 10 per cent., down which the empty cars carry a rope from a single-drum winding-engine. The coal was worked from each side of this slope in successive Iifts during its progress. From the top of the slope, for a distance of 4000 feet to the fourth lift, the " make " of water is drained by gravity through a heading into the adjoining mine. Below this point the water was pumped into this same heading, at the fourth lift, from which point, as before mentioned, it flowed by gravity.

Jan 1, 1895

By Guy R. Johnson

Like many other similar plants the ore-washer of the Longdale Iron Company has been a growth of years. In its principal features there is probably nothing new, as the type is that of the well-known " log-washer." Some of its minor details may, however, be of interest to those members who have to deal with the washing of large quantities of brown iron-ores, the principal gangue of which is clay. * Until 1883, the ore at Longdale, being of unusual purity, needed no washing, and was charged to the furnaces as it came from the mines—both lump and fine—the only attempt at cleaning being the' picking over a screen of 1½-inch iron bars, 3½ inches from center to center, set in the top of the bins through which the cars for the furnaces were loaded." In 1883 it was no longer possible to win the ore by open cuts, and regular underground work became necessary. It was very

Jan 1, 1895

Since this paper was written, some changes have taken place, materially reducing the cost of iron-making as estimated in the text. These are chiefly reductions in the prices of ore and fuel. The charcoal used is now made in bee-hive ovens, and the price is con-

Jan 1, 1895

By C. A. Stetefeldt

In a former paper (Runs., xxi., 286) I described the plant of the Marsac Refinery, and the manipulations of the process, but cou1d not, at the time, give reliable statistical results. To supply the latter is the object of the present paper. I shall give actual facts as correctly as possible, without any bias one way or the other. For all statistics I am indebted to Mr. W. G. Lamb, who has charge of the Marsac lixiviation-plant and refinery; to Mr. A. Luebeck, assayer at the Ontario mill; and to the Daly Office, Salt Lake City.* Before starting on the work of the year 1892, a most careful clean-up was made, and any remnants were charged to the refinery. During 1892 the Marsac lixiviation-works produced 48.8 tons of so-called "regular" sulphides, which contained, on an average, 11,449 ounces of silver per ton; 11.77 ounces of gold per ton; and 569.8 pounds of copper per ton. To this must be added, 266 pounds of sulphides and by-products left over from the product of 1891, which contained 1380 ounces of silver, 1.41 ounces of gold, and 63 pounds of copper. Before giving the results of the clean-up, a general discussion of the items of expense, methods of assaying, etc., is desirable.

Jan 1, 1895

By Henry M. Howe

I NOW call your attention to two directions in which very important progress may be confidently hoped for—pyrometry and the heat-treatment of steel. We already find in the market more than one pyrometer which, in spite of serious defects, may lie used advantageously for determining and controlling the temperature of many of our metallurgical processes. It is to be hoped, and with much confidence, that by the rapid extension of the use of such instruments, the economy and efficiency of these processes may undergo an increase which, in the aggregate, will be of the greatest importance. In this connection, the lucid paper of Prof. Roberts-Austen," and the learned bulletin of Mr. Barus, are most welcome. But much remains to be done in the way of devising pyrometers suitable for manufacturing purposes. While some of the present pyrometers are most convenient and accurate in the laboratory, serious difficulties attend the use, in factories, of those which I have

Jan 1, 1895

By F. M. F. Cazin

Some twenty years ago the author of a book,* by which, for the first time, molecular action was made to account for nearly all phenomena in hydrodynamics, began his preface as follows: " It is contrary to all experience, that any branch of science should suddenly cut short its own line of reasoning, and drop all connection with its past, and yet as quickly re-establish itself on an entirely new basis. It is, therefore, not without justification that this book should be met with caution and even distrust." When the newly-discovered natural facts and laws presented in this paper were, in 1891, first laid before the officers of the American Institute of Mining Engineers, they might have been preceded by a preface to the same effect; and the expression would have found its justification by the actual experience these facts and laws met with. Since then, as the result of their publication in one of the most prominent

Jan 1, 1895

By H. O. Hoffman, C. D. Demond

There are two methods of determining the fusibility or refractoriness of fire-clays, the theoretical and the experimental. In the former, conclusions are drawn from the chemical composition; in the latter, from the changes which the clay undergoes when subjeoted to intense heat. It is well to use both methods, beginning with the actual heat-test and explaining the results obtained from this by the help of the chemical analysis. In discussing the subject, however, it is better to reverse this order. I. The Theoretical Method.* Leaving out the hygroscopic and combined waters and any organic matter, as not directly affecting the fire-resisting property, the refractory constituents of fire-clay are alumina and silica, and the fluxing constituents magnesia, lime, soda, potash and ferric oxide. According to Bischof,† alumina is the least fusible component, and silica follows close upon it. If, however, a mixture of the two be heated, it will be found that its melting-point is much lower than that of alumina, as a silicate will then have been formed. The way in which silica affects the refractoriness of alumina has been strikingly presented by Seger 1 in a diagram reproduced in Fig. 1. The abscissæ represent the melting-points of Seger cones Nos. 26 to 36 (see p. 55); the ordinates, the relative amounts of alumina and

Jan 1, 1895

By Edwin A. Sperry

At the request of some of my engineering acquaintances, to whom the results became known, I submit the following description of the survey made by me for the underground tunnel-connection between the Riverside and Home coal-shafts, at Leavenworth, Kansas. The State law requires an escape-shaft; and as neither of the shafts had one, the two companies decided to make this connection in order to comply with the law and still escape the great expense of sinking

Jan 1, 1895

By Henry Louis

It can scarcely be considered a matter of doubt, in the present state of our knowledge, that the existence of, at any rate, two wellmarked allotropic modifications of gold can be recognized, namely

Jan 1, 1895

By Francis Laur

BAUXITE, at first considered as a mineralogical curiosity without importance, now attracts daily increased attention from mineralogists, geologists, and manufacturers. The metallurgy of aluminum, which has entered with the advent of electrolysis upon a new phase within the last few years, requires every day larger quantities of pure alumina, and this can only be obtained from bauxite, which is, of known substances, the richest in free alumina. Bauxite has been mined since 1872 in France, whereabout 200,000 tons have been produced, and where, as a natural consequence, its deposits, qualities, and applications have become known. Within a few years past, discoveries of important deposits of bauxite have been made in the United States and Canada, and this almost entirely new subject has thus acquired an additional interest for the mining engineers and metallurgists of the American continent. A brief summary of the available data concerning it appears likely, therefore, to be appropriate and valuable.* I.—HISTORICAL. It was in 1821 that the famous chemist Berthier discovered at Baux (Bouches du Rhône) a hydrate of alumina (varying from 66 to 79 per cent. in its contents of the oxide) mixed with silica and

Jan 1, 1895

By Otto F. Pfordte

The silver-ore-deposits of the famous district of Cerro de Pasco were discovered in 1630 by Huari-Capcha, an Indian shepherd. In the early part of its history, the district yielded enormous riches. The records from 1784 to 1846 (excluding five years, 1821-25, during which civil war prevailed) show a product of 2,323,526 lbs. of silver; and the value of the total product since the discovery may be estimated at about $565,000,000. The town of Cerro de Pasco is situated in the province of the same name, department of Junin, Peru, 14,250 feet above sea-level. The nearest railway station is on the line of the Callao and Cerro de Pasco R.R., at a distance of about three days' travel on horseback. The population of the town numbers about 6000, mostly native Indians. Mines.—The mines are mainly located in the immediate neighborhood of the town and partly even under the principal streets, being distributed in several very large open cuts 250 to 350 feet deep called tajos, which extend in a nearly direct north and south line west of the town and are known as Tajo de Santa Rosa, Tajo Tingo or Portachuelo, Cajac Graude, Cajac Chico, Salsipuedes, Avella Fuerte, and several smaller ones. Tajo de Santa Rosa, the largest and most southerly, is closely connected on its north side with Tajo Tingo; while the others are entirely separate and lie northward in the order given ; the extreme ends of the series being about a mile apart. Besides these, there are Tajo Descubridora a short distance east of Sta. Rosa and Tajo Matagente, about half a mile north of the main plaza in the town of Cerro de Pasco. The argentiferous deposit consists mainly of a ferruginous sandstone, while the neighboring country-rock is limestone, conglomerate and slate. The judicial fixed point from which all mining claims are measured, is a cross erected on a small elevation east of, and between tajos Sta. Rosa and Tingo, called Santa Catalina. This important

Jan 1, 1895

By Jacob Lychenheim

IN connection with the manufacture of special Beseemer pig, containing .030 per Cent. or less of phosphorus, it was found that the phosphorus in anthracite varied so greatly that it was necessary to sample and analyze each car-load. This, of course, in addition to our routine work, involved a considerable amount of extra trouble, and some experiments were made, with the view of cutting down the time and labor of the determination to a minimum.

Jan 1, 1895

By Jos D. Weeks

On the extreme fringe of' the great Appalachian coal-basin is a long narrow detached coal-field, which is, in some respects, one of the most important in the United States. This field, about 90 miles long by 2½ to 16 miles wide, extends from the southwest corner of Somerset county, Pennsylvania, through Allegany and Garrett counties, Maryland, Mineral, Grant and Tucker counties, West Virginia, into Randolph county, West Virginia. In this distance four distinct sub-districts are recognized, the Wellersburg in Pennsylvania, the Cumberland-Georges creek in Maryland, and the Elk Garden and the Upper Potomac in West Virginia. The output of coal from the whole field including steam, domestic, smithing and coking-coal of the best quality, is about 4,500,000 tons annually. It is the nearest to tide-water of all the bituminous coal-fields which supply the great coal-markets of the Northern Atlantic seaboard ;

Jan 1, 1895

By Frank L. Nason

RECENT explorations with a diamond-drill, originated and conducted by Mr. J. A. Van Mater, Superintendent of the Lehigh Zinc and Iron Company, have revealed some very important geological facts, which, it is believed, will be of special practical interest to mining engineers. During these explorations the writer was frequently called in consultation, and hence the facts here recorded are almost entirely the results of personal observation. The franklinite-deposit upon which the explorations were conducted has a long continuous outcrop. Figs. 1, 2 and 3 give a map and sections. Beginning at the extreme southern point,

Jan 1, 1895

By C. Willard Hayes

Introduction.—The recent developments in the metallurgy of aluminum and its consequent rapidly growing use in the arts are at present attracting considerable attention to its ores. The success of the Hall electrolytic process, by which the metal is obtained directly from the oxide, has removed bauxite from the position of a rather uninteresting mineral to that of an important ore. Its production on a commercial scale is so recent, particularly in this country, that little attention has yet been paid to its mode of occurrence and origin.. Any investigation, therefore, which throws light upon these points should be of interest to mining engineers- at the present time, especially if the conclusions afford a basis for estimating the probable extent and value of deposits already known and a mane of directing search for others. Two localities in the United States have so far yielded bauxite in commercial quantities. These are in Arkansas and in the Coosa valley of Georgia and Alabama. According to descriptions of the Arkansas deposits by Branner, they bear little resemblance to those in the Southern Appalachians and their geological relations appear to be entirely different. Only the latter deposits are considered in the following paper. These have been briefly described by McCalley† and Spencer.† They were visited by the writer during the past summer and somewhat carefully examined, in connection with the study of the areal geology of the region. Location of the Deposits.—The ore is found irregularly distributed within. a narrow belt of country extending from' Adairsville, Ga.,

Jan 1, 1895

By Erik G:Son Odelstjerna

ALTHOUGH the Swedes have not taken as prominent a position in the open-hearth as in the Ressemer industry, the successful development of which in Sweden has been described by Prof. Åkerman, in a paper read before the Institute,? nevertheless our work with the Siemens-Martin method may possess some interest, even for countries outside our own, and especially for the United States, where the charcoaliron industry competes with that of Sweden for the first rank in extent and importance. I take the liberty therefore of giving in

Jan 1, 1895

By Werner Langguth

SINCE the introduction of the improved method of precipitating gold from chlorine solution by SO2 and H2S at the Golden Reward chlorination-works, Deadwood, S. D.,* this modern method has been further adopted in the chlorination-works of the Portland Consolidated Company at Deadwood, and in those of the Black Hills Milling and Smelting Company at Rapid City, S. D. It has proved practically most successful in the handling of large quantities of gold solution, and constitutes up to date, with Mr. John E. Rothwell's most important improvement, namely, barrel-leaching under hydraulic pressure, the principal progress made in gold chlorination. The method of refining the gold sulphides which result from this method of precipitation, was introduced by me in 1890 at the Golden Reward works, and in 1892 at those of the Black Hills Company. It has not suffered any changes during the last three years, and is substantially as described below:

Jan 1, 1895

By Ellis Clark

These mines were discovered by George W. Lufkin in August, 1878, and mere worked almost continuously until August, 1893, a period of fifteen years. The ore-deposits in this locality lie close to the surface, and it is strange that the Spaniards, passing and repassing for nearly three centuries, did not discover them, particularly as they are marked in several places by large outcrops of black flint and iron, which would lead even a casual observer in a mineral country to suspect the proximity of ore. The mines are situated about six miles from the old Santa Fé trail, and fifteen miles from the Rio Grande. The geology is such that a skilled geologist passing over the ground would probably suspect, from the peculiar arrangement of the formations, the occurrence of ore. The formations in the district, eruptive and sedimentary, are nine in number; and of these eight are to be found within one thousand feet of the Grande workings. Topography. The topography of the Lake Valley district shows its dependence on the surface and underground geology, in a degree more marked

Jan 1, 1895