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By Joshua E. Clayton

THIS remarkable gold and silver bearing district is situated on the middle fork of Boise River, in Alturas County, Idaho Territory, about eighteen miles north of Rocky Bar, and sixty-five to seventy miles, as the crow flies, east of Boise City, the capital of the Territory. This district lies in the very heart of one of the most wild and mountainous regions of Idaho. For many miles in every direction nothing can be seen but bold granite mountains, with deep narrow gorges cutting into their sides in every direction, rendering them almost inaccessible except to the hardy mountaineer and adventurous prospector. The mountain sides are covered, in most part, by dense forests of pine, fir, and spruce timber. In every canon there are clear streams of pure running water that empty into the principal forks of Boise River. The only line of approach to this mountainous region at present is from the southwest, by way of Rocky Bar, the county seat of Alturas County, to which place there is a good wagon-road. From thence to Atlanta City, eighteen miles, the road, or pack-trail, passes over the high, steep range that separates the south and middle forks of Boise River. During severe winters this line of approach is closed up by deep snows for months at a time, thus leaving the district isolated, in the bosom of the grand old mountains. The geological formation is granite, of a coarse, friable texture, and in many places is traversed by numerous dikes of syenite, and three or four varieties of porphyry, which cut through the granite in easterly and westerly directions. The metal-bearing veins also have an easterly and westerly trend, but are occasionally intersected by the dikes. The largest number of the gold and silver lodes are confined to a

Jan 1, 1877

By Samer Sadek

The Georgia Department of Transportation (GDOT) undertook an exploratory feasibility study to one of the most ambitious tunneling projects in the United States. HNTB Corporation was retained to perform the study, deemed the Atlanta North-South Tunnel, which is approximately 7 miles long and consisting of four lanes (or six lanes) starting at the southern terminus of SR 400 extending to the south connecting with the northern terminus of I-675, providing substantial relief to the Downtown Connector (I-75/I-85), the most congested portion of Atlanta?s freeway system. This paper summarizes the analysis performed during the first phase of this challenging assignment which, if constructed, would be one of the longest roadway tunnels ever built in the United States.

Jan 1, 1896

By George E. Thackray

In December, 1894, the Cambria Iron Company made a number of heats of Bessemer steel to be used in structures by one of its customers, subject to inspection and tests by a firm of consulting engineers, one of the requirements being that the material should riot exceed .08 per cent. of phosphorus. In other respects the requirements were such that they could only be met by material of good quality; but the general spe cification is not introduced here, as it is not the purpose of this paper to deal with anything except certain difficulties encoun tered in determining the phosphorus-content of the material in a manner satisfactory to both seller and buyer. Preliminary determinations of phosphorus were made in sample-ingots from each of the heats from which material was rolled for the order in question, and these preliminary chemical tests, made in the laboratory of the Cambria Iron Company, showed that, with very few exceptions, every heat was within the prescribed limit of phosphorus. After the material had been rolled, sample-drilling8 of finished material were taken from the various heats in the regular manner in use at the works, these samples being thoroughly mixed and divided into two parts, one of which was analyzed at the works' laboratory and the other sent to the inspecting engineer. Several hundred determinations were made from this mate rial without reaching an agreement between the work of the inspector's chemist and that of the works' chemist; but as it is not the object of this memorandum to treat of this part of the subject at length, it is considered sufficient to present herewith only a few of these first determinations. The analyses given in Table I. are those of the original series made on the heats which were afterwards resampled for final determination by an arbitrator; and they are selected for this reason, as the entire " comparison is thus rendered more complete.

Jan 1, 1896

By E. J. Schmitz

This section was obtained last year during an examination of the iron-ore resources of the Rich Patch Mountain region and along Craig's creek valley. The geological members below the Oriskany and Lower Helderberg are exposed along the gap in a beautiful arch, while the higher formations appear in a more or less disturbed state on both sides of this arch, and are partly covered by dèbris. I have thought it of interest to the Institute to reproduce the drawing of this section at the gap which I made in my note-book at the time of my examination; those parts of the section, which lie at both sides of the arch, are only approximated. I give also a number of notes and measurements, referring to the Clinton formation and especially to the characteristics of the fossiliferous ore-seam opened in the various tunnels along the arch (see section). I. In Tunnel C: For the first 110 to 120 feet to second shute, we find the ore only here and there in small deposits, and interchanging with, or changing into, either a very siliceous limestone or a sandstone. About 10 feet beyond shute we have : Sandstone roof. Clay-slate, 211/2 inches Brown lean ore, 1 inch. Sandy clay, 3 to 31/4 inches. 1. Dark .brown ore, 3 inches. 2. Fossil-ore, changing into sandstone or very siliceous limestone, 2 inches. 3. Brown lean ore, 6 inches. Clay and slate below, 1 foot. 194 feet from entrance : Sandstone roof. Clay-slate, 4 inches. Clay 15 inches. Fossil-ore, 63 to 7 inches. Clay and ore, If inches. Lean brown ore, 2 inchea. Clay to bottom, 2 feet.

Jan 1, 1896

By W. S. Ayres

The protractor here to be described embodies several important improvements that have been suggested by the use of other protractors and by observing the errors occurring in practice with them. It is more particularly an improvement

Jan 1, 1896

By R. W. Leonard

A method of accurately determining the value of gold-bearing ores and gravels with a compact field-outfit is much desired by prospectors, especially when the work lies in a district far removed from railways or good wagon-roads. We are all familiar with the fire-assay of gold-ores, and fully recognize its accuracy and value; but only those who have tried to determine the value of a gold-bearing vein as a commercial venture, from fire-assays of selected samples, know how misleading is the information thus obtained, however carefully and honestly the samples may be selected. The reasons are that, for the fire-assay a very small portion of ore is treated (rarely more than six assay-tons, or a little over one-third of a pound), and a minute particle of the precious

Jan 1, 1896

By R. W. Raymond

The relations of Eckley B. Coxe to the Institute, as one of its founders and early Presidents, and, throughout its history, an enthusiastic supporter and a valued contributor, would alone

Jan 1, 1896

By William Glenn

In their account of chromium, Roscoe and Schorlemmer (Treatise on Chemistry, London, 1879) state that "In 1762 Lehmann, in a letter to Buffon, de nova minerœ plumbi specie crystalline rubra, described a new mineral from Siberia, now termed crocoisite." In 1786 Lehmann analyzed it (Nicholson's Jour., Dee., 1798) and found that it contained chiefly lead, and that the " mineralizers " were arsenic and sulphur. It was next examined in 1189 by Macquart and Vauquelin, who stated that it contained an intimate mixture of iron, alumina, and lead peroxide. The account of their work was published over the name of Macquart. Vauquelin (Louis-Nicolas) was a Norman peasant, who had studied in the village school, and at the age of fourteen was a laboratory-boy in a pharmacy at Rouen. Later, he found his way to Paris, and in 1789 was assistant to Fourcroy, a pharmacist and a teacher of note. It was here that he met Macquart, with whom he did the work on Siberian red lead, and at this time his friend Cheradame taught him his Latin.

Jan 1, 1896

By J. Volney Lewis

The following paper is based chiefly on work done for the North Carolina Geological Survey, and is presented here by permission of Professor J. A. Holmes, State Geologist. It represents, in a very general way, the field-results obtained during the summer months of 1893, and 1894, and part of 1895; and the portions pertaining to North Carolina are, to a certain extent, abstracts of a report shortly to be published as Bulletin No. 11 of the State Survey. Less emphasis, however, is here laid on the petrographic descriptions of the peridotites, and more detailed treatment is given to subjects pertaining to methods of mining, cleaning, and utilization of the commercial product, corundum. Some of the most extensive fields for investigation which this subject presents have been scarcely more than suggested.

Jan 1, 1896

W. M. Courtis, Detroit, Mich.: Except for free-gold ores, I have always believed in scorification. I think the crucibleassay gives silver low. We found this out at the Wyandotte works in assaying Silver Islet ore. The mine-managers made us, and also the check-assayera, run one of the duplicates by

Jan 1, 1896

E. C. Pechin, Buchanan, Va.: I am sorry to see the table appended to Mr. Chase's excellent paper. In the discussion at the same meeting, on "Notes on a Southern Coal-Washing Plant," Prof. Phillips very properly says: " There is no use in giving an analysis as representing a coal when it does not do so. It gives a wrong impression of the conditions under which business is conducted." The same may be said about ores. I have no personal knowledge of the ores in many of the localities given in Mr. Chase's table; but if these are to be judged by what is positively known of the Cranberry ores, the analyses are grossly misleading. The furnace-shipments from Cranberry have rarely reached 44 per cent. of iron, and any such percentage as 58 or 66 or 68 can only have come from hand-picked specimens. Indeed, with any such percentages, Mr. Chase's paper would have been superfluous, because concentration would be unnecessary. Besides, the paper itself (page 553) gives the fact that the Cranberry average is 42 to 43 per cent. Why should a table be appended, contradicting this statement of the text ? Let us always have the exact conditions under which business may be conducted. "Boom" and business analyses are widely different.

Jan 1, 1896

Albert Arents, Alameda, Cal.: From Mr. Furman's description of his crucible-assays I infer that he regards iron nails as a necessary or advisable adjunct. Against such a notion I must beg leave to protest. Nails should not be used in

Jan 1, 1896

William Clinton Brown, Brooklyn, N. Y.: The demand for an apparatus for cooling water for condensers, refrigeratingmachinery and air-compressors, as well as water-jacketed furnaces, has led manufacturers to put such an apparatus on the market, so that it is now possible to purchase a cooling-tower, properly designed and constructed, by simply stating the amount of water to be cooled and the temperatures of the hot and the cold water. The principle is similar to that described by Mr. Henrich, but wood is not used in the best apparatus. There are two great objections to wood: First, it cannot last long under the very trying conditions to which it is subjected; and second, it absorbs the organic matter with which water in constant use becomes impregnated, and the resulting odor is very disagreeable. A few days ago I saw a cooling-tower and condenser, built by the Henry R. Worthington Co., in operation at the Edison electric-lighting station in Brooklyn, N. Y., cooling the water for a 700 horse-power condenser. It consisted of a large stack of iron, about 15 feet in diameter by about 30 feet high. This stack was filled with tiling through which the water falls. A whirligig distributes the water evenly over the top, and a large fan, about 6 feet in diameter, driven by a 10 horse-power electric motor, blows air into the bottom, thus giving a positive circulation. The water, in running down the sides of the tiling, is met by the blast of air, and enough is evaporated to cool the rest. The vacuum-gauge on the condenser showed 26 inches; so the condenser was undoubtedly getting sufficient cool water.

Jan 1, 1896

Jan 1, 1896

R. W. Raymond, New Pork City: It seems questionable to me whether Mr. Mezger's identification of the rock-structure he describes, as the Augengneiss of previous authors, is warranted by the definitions given by them. Naumann (1854)t describes Augengneiss as a porphyry-like variety, " which has assumed, by reason of single large kernels or granular concre-

Jan 1, 1896

I;. D. Godshall, Everett, Wash. (communication to the Secretary) : In Mr. Morse's interesting paper several statements occur which seem to require correction and comment. This is the more appropriate, since Mr. Morse has mentioned me by name, and has cited my "Review of the Russell Process,"* so that silence on my part might be taken as indicating an assent which I cannot give. On the first page of his paper Mr. Morse says that the " goingback " of chlorination was " the only difficulty encountered at Aspen," and adds that he has " never seen any explanation " of the cause. The plain inference is that he now fills this complete

Jan 1, 1896

T. M. Drown, South Bethlehem, Pa.: Mr. Thackray's paper shows in a striking way the high degree of rapidity and ac curacy exhibited by the chemists of our steel-works in ordinary everyday practice. That determinations made in an hour should present only slight differences in the third place of deci male is certainly matter for surprise and congratulation. This remarkable result has been due, perhaps, in part, to a remark able cause. The managers of works, ignorant of all the diffi culties of the laboratory, have demanded "the impossible " of their chemists—and the chemists have done it! Andrew A. Blair, Philadelphia, Pa.: Mr. Thackray's paper is extremely interesting, especially in its bearing on the question of a standard method for the rapid determination of phosphorus in the laboratories of steel-works. Before discussing the re sults in general, I desire to explain the results obtained by me under method A'. This is the method which I have used in the work of the sub-committee on Methods of the Interna tional Steel Standards Committee. It may be described briefly as follows: Solution in nitric acid; oxidation of carbonaceous matter by permanganate; precipitation of phosphoric acid by molybdate solution; reduction of molybdic acid in the reductor, and titra tion by permanganate. This method was used apparently by only three chemists, Dr. Dudley, Mr. Crowell, and myself. In determining phosphorus by this method, among the most essential points to be considered are the ratio of iron to molyb dic acid, or the reducing action of zinc on molybdic acid as compared to its reducing action on iron, and the ratio of molyb dic acid to phosphorus in the ammonium phospho-molybdate obtained by precipitation from the solution of the steel. In regard to the first point, the usually accepted ratio is 1 to 0.90756, or, as it is roughly stated, 0.9076, which is based on the assumed reduction of the molybdic acid to Mo12019,. This

Jan 1, 1896

F. E. Thompson, Pottstown, Pa.: If Mr. Webster's endeavor to open up the subject of cast-iron should prove as prolific of results as did the discussion on " The Physics of Steel," he must certainly feel richly repaid. His remarks concerning the secretiveness and conservatism of the average foundry-man recall to my mind an instance of a blast-furnace which, for the last year, has been producing much foundry-iron. The manager, believing that much more of his product could be used in the foundry than the foundry-men were will-

Jan 1, 1896

Adolph Thies, Haile Gold-Mine, S. C.: I have little to add to what my friends Messrs. Nitze and Wilkens have said on this subject. What I have done in mining during the last fortyone years, partly in this country and partly in South Africa (though not, as to Africa, in the diamond- or the gold-fields,

Jan 1, 1896