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By T. A. Rickard

Our Transactions contain two notable papers descriptive of the stamp-milling practice of the Black Hills and of Grass Valley, namely, the elaborate and complete treatise of Prof. H. 0. Hofman, on " Gold-Milling in the Black Hills,"" and the paper describing the North Star mill, by E. R. Abadie, its superintendent. Having visited and examined the stampmills of both localities, I venture to offer here such comment as more recent information or a different point of view has suggested.†

Jan 1, 1896

By R. W. Raymond

The " law of the apex," with its vague and impracticable " extra-lateral rights," is defended—if it is defended at all— on the ground that it is required by the peculiar conditions of the mineral deposits or of the mining industry in those States and Territories in which it is operative. As I have repeatedly attempted to show, in papers read before the Institute, and most recently in an article on " The Relation of the Mining Law of the United States to the Davelopment of its Mineral Resources," published in Mr. Rothwell's Mineral Industry for 1894, there is now (whatever may have been the case formerly) no peculiarity of conditions in the regions referred to which warrants the subjection of their mining industry to a burden so vexatious and injurious as this law imposes. I have called attention to the absolute freedom from expensive litigations over mining titles enjoyed by all other States in the Union and all other regions in the world where the absurd extra-lateral right does not exist.

Jan 1, 1896

By F. C. Holman

It is desired in these notes to record a vein-phenomenon certainly unique in the writer's limited experience, and, as it seems to him, sufficiently rare to be worthy of mention. In the little mining camp of Forbestown, situated in the Sierra Nevada of California, it was announced one day, when the miners of the Cold Banks mine came off shift, that "washed gravel" had been struck on the 265-foot level. To those acquainted with that section and the character of the mine (a gold-bearing quartz-vein) this was a somewhat startling announcement; for, prolific as the State is, we are not in the habit of mixing up promiscuously our vein- and placer-deposits. However, the statement proved to have some foundation. The mine is located at an altitude of about 2700 feet, on the brink of one of the great canyons of erosion characteristic of the drainage of this range. A lateral ravine cuts the vein at right angles, thus making its general strike approximately parallel to the canyon at this point, and with a variable dip of from 20 to 40 degrees towards the canyon. The strong, well-defined vein, often 20 feet wide and more, presents nothing to distinguish it particularly from scores of others in the State, unless if be considered peculiar in the highly crystalline character of its quartz and the nature of the enclosing country-rock, which is metamorphic in the extreme, very hard, devoid of lamination, and in bedding so obscure that it might easily pass—at least on superficial examination—for one of the basic eruptives. Near by in the district can be found a series of slates common to the gold-belt of this range, and within the limit of the company's property is an intrusion of an acid eruptive. On an adjoining claim a granite shows itself. The mine is opened through an inclined shaft sunk on the vein. The ore carries both free gold and sulphurets, the greater part of its value

Jan 1, 1896

By William P. Blake

In view of the present exposition at Atlanta, and the timely meeting of the Institute in that city, and the expressed desire of the Council for contributions to the knowledge of the mineral resources of the Southern States, I may be permitted to offer some desultory notes upon the subject, chiefly in the form

Jan 1, 1896

By J. A. Holmes

As the Appalachian mountains reach their maximum development in western North Carolina, we find also in that region indications of extensive dynamic disturbances and alterations undergone by the rocks in' connection with these mountain uplifts. Among the minor results of these changes have been the formation of numerous dikes or a veins " of exceedingly coarse granitic materials, which in some places are mined for the mica which they contain, and in other places are quarried for kaolin. These dikes are filled with quartz, feldspar, and mica, in varying proportions, very coarsely crystallized. Sometimes the mica (generally muscovite), sometimes the feldspar (generally albite or orthoclase) predominates. When the mica is present in considerable quantity, and in large crystals, the dike is usually spoken of as a mica-vein, and is often worked for mica. Sometimes these crystals of mica occur on one side or the other; sometimes on both sides; and sometimes they are largely concentrated toward the middle of the vein, or, it may be, distributed throughout the dike with a considerable degree of uniformity. In many cases the crystals of mica are too small and few to permit the working of the vein as a micamine ; in other cases, very little mica is present, and the feldspar constitutes the larger part of the material. This feldspar of the dikes undergoes, through the weathering action of the atmosphere, certain chemical changes, resulting in its alteration from feldspar into kaolinite—the kaolin of commerce. These dikes vary considerably in size, ranging from a few inches to several hundred feet in thickness, and up to many hundred yards in length. They are generally parallel to the schistosity of the crystalline rocks, which, however, in some cases, they cross at varying angles. The kaolin in those dikes which occur in the Unaka or

Jan 1, 1896

By William B. Phillips

The concentration of natural magnetites has been carried on in this country for several years, and more or less information has been collected on the subject. Various inventors, availing themselves of the magnetism which is inherent in such ores, have devised machines for separating the impurities from the ore by means of the electric current; and a greater or less degree of success has rewarded their painstaking and persevering efforts. We are now fairly in position to judge of the value of the process as applied to such material. It is not my purpose to speak of this matter further than may be required by the emergencies of the case. I shall assume that most engineers and metallurgical chemists are already acquainted with what has been done at the Chateaugay mines, at Mineville, at the Benson mines, at the Weldon and Ogdensburgh mines, and at Cranberry; although, at this latter place, there has not been so much done as we could wish. I shall not now speak of the various types of separators. From the time of William Fullarton, to whom was granted an English patent, in 1792, for separating iron-ore by the application of magnetic attraction, down to the present time, a great. many devices have been suggested, and a great many patents taken out for this purpose; but it is not necessary now to enter upon a discussion of their merits. Perhaps, at some future meeting of the Institute, after we shall have experimented further with some of the machines on the market, there may be an opportunity to contribute something to the current knowledge of the efficiency and economy of separating-machines. In this paper I propose to give, as briefly as possible, the results already reached in converting a non-magnetic ore into magnetic ore, and then concentrating it over a magnetic separator of the alternate-polarity type. I am aware of the work

Jan 1, 1896

By J. A. Holmes

It is a fact that is coming to be more widely recognized by the general public, as well as by members of the medical fraternity, that the health of persons living in our hill-country depends in no small degree upon the drinking water obtained, just as it has been found that the* use of pure water in the lowlands and swamp-areas of the Southern States results in practical immunity from malarial diseases. Hence the problem, how to obtain supplies of wholesome water for the towns and manufacturing establishments in the hill-country or Piedmont plateau-region of the Southeastern States, becomes one of considerable interest, the importance of which will continue to increase, as the favorable conditions for manufactures and agriculture in this region will make it, in the near future, the most thickly populated portion of the South Atlantic States. Water-supplies from Surface-streams are unquestionably of the first importance; and in the mountain counties, where the region is still largely forest-covered and the streams are swift and continually aerated by rapids and cascades, the water is of superior purity and clearness. This statement is also applicable to the more elevated and sparsely settled portions of the Piedmont plateau; but in the less hilly and more thickly settled portions of this region the streams are more sluggish, and the waters more muddy and less pure, owing to the fact that a much larger proportion of the surface is under cultivation.

Jan 1, 1896

By Courtenay de Kalb

The following observations upon onyx-marbles are fragmentary, and may shortly be rendered superfluous by the appearance of a work upon these interesting stones by Prof. George

Jan 1, 1896

In reply to inquiries and comments which have reached me since the publication of this paper, and in explanation of some seeming discrepancies between my statements in the text concerning the amount of displacement of the faults, on one hand, and certain figures in the plates on the other hand, I give here, with some additional remarks, my measurements of the displacements in the different sections, which it originally seemed unnecessary to print : By displacement, I mean neither the throw, i.e., the vertical distance apart of the two edges of a faulted bed (what Mr.

Jan 1, 1896

By Joseph D. Weeks

The primary problems of civilization are material ones; their answers are writ in fire. When these problems in their higher aspects have pressed for solution, it has been out of the burning bush that the Divine voice has spoken, or in the cloud and smoke that the Divine finger has traced the rules by which these problems shall be solved. It is with the material problems, however, that we, as engineers, have to deal.

Jan 1, 1896

By Harvey S. Chase

During the recent great depression in iron, little has been done in the magnetic separation of iron-ores; and previous to the present decade the art was in its infancy, so that there were few, if any, successful separators on the market, and but scanty practical data could be obtained as to the industry itself. Moreover, the recent development of the great Mesabi Bessemer beds, coincident with the intense depression in business, has discouraged active attempts to solve the problems presented in the crushing and separation of the refractory magnetites of the South. Experiments have been carried on, however, upon a practical scale in separating these ores magnetically, at the well-known Cranberry mines, in Mitchell county, N. C., with results which are encouraging. The magnetites of the Blue Ridge, in the South, have been known, and the soft ores of the region have been used in Catalan forges, since very early times. The original settlements in East Tennessee were made along the Watauga river by Daniel Boone, William Bean, John Sevier, and other stalwart pioneers; and this valley lies parallel with the " Cranberry " lead, which is undoubtedly the most celebrated and the most extensive deposit of workable magnetic ore in the Southern States. This lead I have personally traced along the outcrop, be-

Jan 1, 1896

By Robert W. Hunt

In 1888 the writer had the honor of submitting to the Institute a paper on " Steel Rails and Specifications for their Manufacture."* In his judgment the specifications were sufficient for "that day and generation." In that paper I said: '' The first duty falls upon the railroad engineer in designing his section. If that is bad, the steel-maker will be heavily handicapped in trying to furnish a satisfactory rail. I suppose it is hopeless to expect the adoption of standard sections."

Jan 1, 1896

By P. W. Shimer

The purpose of this note is to call attention to a source of error in the determination of graphitic carbon, made by the usual method of solution in hydrochloric acid. Although the method is tedious, because of the necessary treatment of the separated carbon with caustic potassa, alcohol and ether, the text-books seem to give it preference; and it is, perhaps, used more generally than the method of solution in dilute nitric acid. Solution in hydrochloric acid usually gives higher graphitic-carbon results than solution in nitric acid, and many, therefore, consider it more trustworthy, the inference being that the lower results obtained by nitric acid are due to the loss of some of the finely-divided graphite by reason of the oxi-

Jan 1, 1896

By Graham MacFarlane

The eastern coal-field of Kentucky covers about 11,000 square miles of territory. On the east and south it extends to the State lines of West Virginia, Virginia and Tennessee. Its western boundary may be roughly described as an irregular line beginning at the Ohio river, in Greenup county, thence through the counties of Carter, Menifee, Wolfe, Estill, Jackson, Rockcastle, Pulaski and Wayne, to the Tennessee line. The changes in the rock-intervals and in the coal-seams from the northeastern end of the field to the south and southeastern end are so great that no satisfactory identification of the coals has yet been made, and the correlation of the Kentucky coals

Jan 1, 1896

By William Glenn

The Ritchie vein, of Ritchie county, W. Va.,* was a straight fissure, about 3600 feet in length, which cut vertically downward across the horizontal beds of shale and of sandstone to a depth not ascertained. It might be described as lying in a. Vertical plane, bearing 12 degrees north of west. The geological horizon is that of the " upper barren coal measures'" of the Appalachian coal-field, being a part of the strata lying above the Pittsburgh bed. The vein matter was declared by Prof.

Jan 1, 1896

By Henry Lloyd Smyth, J. Ralph Finlay

The most important area of the so-called Keewatin rocks of northern Minnesota is that which runs westerly from Lake Saganaga, near the national boundary, and finally disappears beneath the drift (or has not been farther traced), in the neighborhood of Vermilion Lake. With this belt we have a general acquaintance, extending back some four years. During the past year we have had the opportunity of studying in considerable detail a small part of it, embracing an area of about 12 square miles on the south and east shores of Vermilion Lake. In this paper we desire to record our observations and conclusions, which seem to us important. II.—Literature. Outside the Minnesota Geological Survey, the list of the investigators who have studied the geology of the Vermilion Lake area is not long. Whittlesey, in 1876,* mentioned the occurrence, in the area about Vermilion Lake, of rocks resembling the Canadian Laurentian. Chester,? in 1884, described the iron-ore at Vermilion Lake as occurring in connection with jasper and quartzite, intimately bedded with the country-rock, chiefly sericite schist, and standing in a nearly vertical attitude. The Vermilion iron-bearing rocks, and those of the Mesabi range, he says, are of the same age.

Jan 1, 1896

By William M. Brewer

History.—The history of gold-mining in Georgia and Alabama antedates the discovery of gold in California. A very large proportion of the gold used in the United States previous to 1849 was produced by these States. A great deal of this history is merely tradition, and no reliable statistics can be obtained ; yet a personal examination of the gold-fields of Georgia and Alabama indicates that tradition is as fairly reliable, with regard to the history of these gold-regions, as it is in any similar cases throughout the world. In Georgia, the history of gold-mining dates back to 1829, when the first gold-mining excitement in the United States occurred. In Alabama, the discovery of gold was made some years later through the work of prospectors, incited by the rich finds in the Georgia mining camps. The greatest product of gold in these States was between the years 1840 and 1849. In Lumpkin county, Ga., and Cleburne county, Ala., the districts from which the most of this gold was taken, the tailing-dumps are silent witnesses of the extensive operations which were carried on by the primitive and crude methods then known. It is no rare thing to see trees 12 to 15 inches in diameter, and even

Jan 1, 1896

By Clinton M. Ball

Magnetic iron-ore is found in many localities throughout this and other countries, in large bodies and in convenient proximity to other materials required for its conversion into iron and steel; and these bodies of ore would have great commercial value on account of their nearness to consuming markets if they were generally suitable in their natural state for use in the larger operations of steel-making. In the manufacture of iron and steel it has been found, however, that not all ores are equally valuable as sources of raw material for the finished products of furnace, forge and foundry; and, as is now well understood, this is because of the intrusion, in the process of formation of the ore-bodies, of substances which can enter into deleterious combinations with the iron itself, or form compounds associated with the iron oxide which will hinder, if they do not altogether prevent, the production therefrom of the higher grades of finished metal. It is only since the development of the modern method of steel-making by the Bessemer process that the art of the chemist has been called to a critical study of the nature and effect produced by the presence of these pernicious substances in the furnace while the iron is undergoing reduction to the metallic state. Phosphorus and sulphur are the most common and obnoxious elements, and the admixture of one or the other, or both of these, in small percentages and varying proportions, will greatly modify the final results of manufacture. It so happens that generally, although not always, these hurtful elements are found in compounds in the ore which are not magnetic, and this circumstance has led to the expenditure of much ingenuity and money over a long period of time, in attempts to utilize the attractive power of magnets to separate the magnetic oxide of iron out of its crushed ores and from sands, in

Jan 1, 1896

By C. A. Mezger

These districts are limited approximately on the north by the railroad from Salisbury to Ashville, and comprises the counties of Alexander, Catawba, Burke, Rutherford, McDowell, Cleveland, Lincoln, Polk and Henderson in North Carolina, and Greenville, Spartanburg, Union and York in South Carolina. The occurrence of monazite at Amelia Court House, in Virginia, belongs evidently to the same geological system, as its distance from the Alleghenies corresponds with that of the above-mentioned districts, and all the stratification runs parallel with those mountains.

Jan 1, 1896

By Eugene A. Smith

Geological Relations. In his second report upon the Geology of Alabama, Prof. M. Tuomey calls attention to a rock occurring near Florence, in the Tennessee valley, the composition of which is as follows: Per cent. Carbonate of lime,.. .. .. ..16.41 Phosphate of lime,.. .. .. ..14.19 Peroxide of iron,.. .. .. .. .36 Quartz and other insoluble matters,. .. ..68.72 99.68 This rock was referred by Prof. Tuomey to the Carboniferous, because he found the Carboniferous limestones always resting conformably upon it, whilst both rest uncomformably upon the underlying Silurian or Devonian rocks. The recent discovery in Tennessee of phosphate-rock of this age (or approximately so) has stimulated the search in Alabama for similar rich material; but our search has been, up to this time, unrewarded by the finding in quantity of anything of better quality than the rock whose analysis is given above. It is, however, in high degree probable .that the rich phosphaterock of Tennessee will at some time be found to have its counterpart in Alabama. Materials of several kinds, containing a notable quantity of phosphoric acid, have been found in Alabama in both the Cretaceous and the Tertiary formations, and for our present purpose they may be most conveniently considered in their geological relations.

Jan 1, 1896