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By R. W. Raymond

Recent literary labors have led me to the compilation of the following tables and estimates, which may possess interest for my colleagues in the Institute, and which are here submitted without comment.

By F. P. Dewey

THE Falling Cliff Mine adjoins on the west the Bertha Mine, from which a large amount of first-class ore has been taken, producing the purest zinc known to commerce. The two mines are in the same hill, Bertha being on the northern 'slope and Falling Cliff on the top and opposite slope. The formation is No. 2 limestone. Although considerable exploration has been done by numerous shafts and' tunnels (there being over six hundred feet of the latter), no satisfactory determination of the dip and strike of the .vein could be made on account of its contortions, the ore descending from the top to the. bottom of the tunnels and rising again in very short distances; but enough has been done to indicate a very large mass of

Jan 1, 1882

By Bland Z. Richardson

Jan 1, 1985

By James E. McNulty

Coal reserve estimates are prepared using a simple equation: the product of area, bed thickness, density and recovery factors. Each of these elements involves a degree of risk based on certain assumptions. Reserve area, thickness and density rely on certain physical data whose accuracy, reliability and sufficiency may be problematical. Estimates of recovery factors for mining and coal preparation are often subjective. Most reserve estimates assume, sometimes incorrectly, that the subject reserves will be completely extracted. The principle that certain coal resources are reserves, if they can be considered economically recoverable at the time of determination, needs to be reexamined in the light of recent market cycles. Reserve estimating requires the exercise of judgments, the validity of which reflect the qualifications, experience and objectivity of the estimator.

Jan 1, 1985

By Dodge, C. E.

ONE of the first mining areas to be developed in Arizona was that in the district centering about Clifton and Morenci. Traces of metals were first noticed by Henry Clifton on an expedition in 1864. Definite copper outcroppings were also reported in the following year by General J. H. Carleton when he led his troops into the district on an Indian raid. Actual mining operations were started in the early seventies. and the first smelter was finished in 1873. Two adequately financed companies acquired most of the property, and both commenced production about 1882. These were the Arizona Copper Co.. owned by a group of Scotch investors, and the Detroit Copper Mining Co., afterwards purchased by the firm of Phelps, Dodge & Co. Later the Shannon Copper Co. acquired and operated a number of claims in the northern part of the district. These three companies all operated underground, mines independently for many years.

Jan 1, 1942

By Zay Jeffries

Discussion of the paper of ZAY JEFFRIES, A. H. KLINE and E. B. ZIMMER, presented at the New York meeting, February, 1916, and printed in Bulletin No. 108, December, 1915, pp. 2359 to 2369. ZAY JEFFRIES, Cleveland, Ohio.-The original portion of this paper represents a laboratory method for determining grain size in metals. It was developed not so much to find a quick method as it was to facilitate certain work which I was carrying on a couple of years ago. I had a great many determinations to make and the planimeter method was very slow, as was the Heyn method, and both of them were laborious, so I tried to shorten the time of the determinations. Since preparing the present paper, Dr. T. M. Focke, Professor of Mathematics at Case School of Applied Science has called my attention to the fact that both the Heyn and Intercept methods are mathematically

Jan 5, 1916

By E. H. Tenney

A DISCUSSION of the probable future use of coal for power develop-ment involves the study of several basic factors, such as future demand for power, the quantity and availability of fuels in direct competition with coal, the price of coal, and a closely related factor-the efficiency and cost of fuel utilization. Predictions based on purely statistical analyses of past coal con-sumption have definite limitations. For example, statistics showing the relation between coal utilization and total energy consumption from all sources between the years 1890 to 1930 indicate that during that period, the energy consumption per person in the United States increased five times, while the coal consumption per person increased only twice1, and there has been an actual decrease in per capita coal consumption since 1920. Figures such as these, compiled by authentic agencies, emphasize the need for caution in attempting estimates as to the future use of coal, and, incidentally, would seem to offer little basis for optimism in the coal industry. They also suggest the value of analyzing broadly the part played in the past by the related factors of power consumption, competitive fuels, coal prices and the efficiency of utilization. Proper weight must also be given in such a study to the present status and limitations of power-plant developments, and to the question of what the coal industry itself can do to further its own interests and influence the consumption of its product.

Jan 1, 1935

By Persifor Frazer

From the easternmost point reached by the Ural excursion of the VIIth International Geological Congress (the city of Tschéliabinsk, a little more than 30' of longitude east of St.

Jan 1, 1899

By James T. B. Ives

The variety of copper-ore to which these notes refer is cornparatively rare, and, so far as I am aware, has not been recorded hitherto as occurring in Ontario. Moreover, the rocks of this locality differ so much in nature and mode of occurrence from the orebearing rocks of the western United States, that a description of them may be interesting. A line drawn upon a map of the region of the great lakes from the mouth of the Severn river at the Southern end of Georgian Bay, following the Canadian shore northwestward, and leaving Manitoulin island to the south, will describe the boundary between the Archaean rocks lying north of it and the Silurian rocks southward.

Jan 1, 1890

By AIME AIME

Council.* PRESIDENT OF THE COUNCIL. JOHN HAYS HAMMOND* New York, N. Y. (Term expires February, 1909.) VICE-PRESIDENTS OF THE COUNCIL. SAMUEL B. CHRISTY BERKELEY, CAL. JOHN A. CHURCH NEW YORK, N. Y. PERSIFOR FRAZER PHILADELPHIA, PA. (Term expires February, 1909.) J. PARKE CHANNING NEW YORK, N. Y. FREDERICK 1V. DENTON PAINESDALE, MICH. JOHN B. FARISH DENVER, COLO. (Term expires February, 1910.)

Mar 1, 1908

By John M. Hancock

IN beginning my remarks, may I make it entirely clear that since January 4, 1947, I have not been a member of the United States Delegation to-the United Nations Atomic Energy Commission I am speaking, therefore, in purely a personal capacity. Because of the interest of the engineering profession with reference to uranium, and because of the title assigned me for this talk, I am going to assume that you know what the United States Plan is for the control of atomic energy. At best, in the limited time, I could only summarize, at the risk of giving undue emphasis to the items mentioned, and at the risk of omitting many important parts of what seems so far to be a complete and well-rounded Plan for meeting the problem. I will aim to comment upon those aspects of the Plan that continue as problems and involve apparent, or obvious, misunderstandings and contrary views The control of atomic energy represents not only a problem but a challenge-both faced by- all the peoples of the world It involves a new approach to the problems of the kinds that arise between nations, problems that have not ever been solved even by international treaties in their efforts to outlaw weapons of war. These efforts range from the Kellogg-Briand treaty to outlaw war, and its obvious failure to prevent World War II, to the interdiction by the Pope of the use of the crossbow in the days of the Crusades. All previous plans have been failures-that makes

Jan 1, 1947

One-half fare return rate again available to members of the Institute and dependent members of their families. DON'T FORGET YOUR RAILROAD CERTIFICATE Over 300 members of the A. I. M. E. and dependent mem-bers of their families attending the last annual meeting se-cured return railroad tickets at half price by means of the railroad certificate, thereby saving several thousand dollars. DIRECTIONS 1. Be sure to obtain your railroad certificate when pur-chasing your railroad tickets for the meeting or you will lose money. 2. Purchase your tickets at regular one-way adult tariff fare between the dates specified for your territory in the accom-panying table. 3. Present your certificate for valida-tion at Institute headquarters in New York immediately after registration. Certificates will be validated on Feb. 21 and 22 between 9 a. m. and 5.30 p. in. 4. You must use your return half-rate tickets not later than Feb. 27. 5. Use the same route for both going and return trip. PLEASE REMEMBER THIS 1. Unless-250 certificates are validated at headquarters it will be impossible for anyone to secure the reduced rate. 2. Unless you secure a certificate you cannot take advantage. of the half-rate return fare, even if the necessary 250 certificates are validated.

Jan 2, 1928

By Oberlin Smith

The experiments described in this paper are very incomplete and only preliminary to those I hope to make in the future. Having had a good deal of experience in cutting, forming and drawing sheet-metals, and feeling a great interest in the commercially new and wonderful metal, aluminum, I applied to my friend, Mr. A. E. Hunt, for some specimens in sheet-form, that I might, from time to time, test its working-properties in presses with which we happened to be experimenting at the works of the Ferracute Machine Company. The chances for such trials being accidental only, and the time having been limited to the last few weeks, no crucial experiments have been tried, and no exact data have been obtained for a rigid comparison with other metals. The results of what little we have done, however, are shown in the articles exhibited in connection with the reading of this paper, which comprise various cups, plates, boxes, bells and cartridge-cup and shells. For the latter I am indebted to my friend, Mr. Hobbs, of the Union Metallic Cartridge Co., who, at my request, ran several pieces of sheet-aluminum through the dies with which he was making brass cartridges. The specimens are rougher than they would be had the metal not been a little too thin for the particular dies which he happened to be running.

Jan 1, 1890

By I. R. Kramer, L. J. Demer

T. H. Alden and R. L. Fleischer (General Electric Research Laboratory)— The authors' results indicate clearly and, we believe, significantly that during tensile deformation the surface layers of an aluminum crystal are hardened more severely than the interior of the crystal. A probable explanation of this effect, as the authors indicate, is that dislocations in the primary slip system may be obstructed at the surface or, it should be added, near the surface. The intent of this discussion is to show that the oxide film on aluminum is not likely to be responsible for this effect, but that the results can be understood if it is assumed the secondary slip is more active in the surface layers than in the interior. Prior study has shown that the principal mechanical effect of an oxide film on a single crystal is to raise the yield stress while leaving the rate of strain hardening during the initial deformation relatively unaffected.33 Since the yield stress is unchanged during polishing in the present case, we conclude that continual removal of the oxide film exerts a small effect on the plastic hardening.* It appears that the hardening interactions are occurring not only at the immediate surface, but to an appreciable depth below it, although with decreasing severity. For example, Kramer and Demer found that with removal of 0.004 in. from a specimen, the easy glide region was extended somewhat; but the yield stress did not decrease. The initial yield stress was recovered only after 0.041 in. was removed. Since a very brief polish would permit dislocations trapped behind a surface film to run out,34 extra dislocations must, instead, be trapped to a considerable depth below the surface. The same conclusion is drawn from the observation of decreasing hardening slope with increasing surface removal rates. If the hardening interactions were only at the immediate surface, a full softening effect would be observed at some small removal rate. The view is taken here that strain hardening is principally caused by small amounts of secondary slip.35 The secondary dislocations will interact in various ways with the primaries, interfering with their motion and causing them to accumulate in the crystal. Prior studies of easy glide have shown Diehl's model of hardening to be qualitatively consistent with the effects of impurities,36 of temperature,36 and of crystal size.37 On this basis the enhanced hardening of the surface layers in aluminum arises from increased secondary slip at and to some depth below the surface. Selective removal of this hardened layer is expected to decrease the measurable "bulk" hardening, the effect increasing with the removal rate and decreasing with the applied strain rate. We suggest that the stress on secondary systems is raised by the bending moments arising from interactions with the grips during the deformation. This stress from the grips has been shown to be a maximum37 near the surface, and hence, increased secondary slip should result. Prior investigations of grip effect:; indicate that as the grip stresses are raised by changing the crystal shape, the easy glide slope increases while the extent of easy glide decreases.38-40 It has been shown also that bending moments superimposed during tensile testing may either decrease easy glide, when supporting the moments caused by gripping, or increase it, when cancelling the gripping moments.38 This interpretation of the authors' results, emphasizing the special importance of secondary slip near the surface, is also consistent with the earlier results of Rosi.41 Copper crystals alloyed with silver in the surface layer show greatly increased easy glide compared with pure copper. In addition, the easy glide slope is reduced. The effect of bulk alloying in extending easy glide has been well established and has been interpreted as indicating the relative difficulty of secondary slip in alloy crystals. Since non-basal glide is difficult in zinc crystals, the effects of surface removal during deformation may be less important. Experiments to test this idea are in progress. I. R. Kramer and L. J. Demer (authors' reply)—The authors wish to thank Dr. Alden and Dr. Fleischer for their discussion. Our interpretation of the data in the paper is that dislocation motion is obstructed by "debris" which starts to form at the surface and extends towards the interior of the crystal with further plastic deformation. The fact that we did not find a reversion from Stage II to Stage I by surface removal shows that in Stage II the "debris" fills the entire cross-section of the specimen. Drs. Alden and Fleischer take the view that bending stresses due to the grips are responsible for the

Jan 1, 1962

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 Lloyal O. Bacon

In the spring of 1952 Calumet and Hecla Inc. began a geophysical program near Shullsburg, Wis., in the Wisconsin-Illinois lead-zinc district, to assist the geological and drilling exploration programs. Sphalerite, the ore mineral in this area, occurs with a considerable amount of marcasite. In general the higher the percentage of sphalerite in the ore, the higher the percentage of marcasite; however, there may be mineralized zones high in marcasite but low in sphalerite. Orebodies in general are relatively narrow and elongated.

Feb 1, 1956

By George Rice

SINCE my earliest recollection, the coal business has been in a state of unrest. It has always been a matter of bewilderment to the serious thinking, the instability of this most important industry; second only to agriculture in its effect on the great development of this country, and even more important in certain aspects, because without fuel railroads could not run, agriculture could not get its products to market, nor would the great manufacturing enterprises have been possible. I will not attempt to discuss the present serious -labor dispute or similar disagreements of the past; in the settlement of which more or less successful attempts have been made to equalize, temporarily at least, natural conditions through "joint agreement" as to prices paid labor; but will confine my views to the general underlying conditions of which the disputes are symptoms, and try to show how these must be remedied before there can be any hope of stabilizing conditions.

Jan 5, 1922

By J. B. Rather

THE use of sulfuric acid in refining illuminating oils antedates the beginning of the petroleum industry in America by many years. It was used as early as 1792 by Tower in refining "coal oil" in the British Isles, and by 1860 there were 53 refineries in the United States manufacturing "coal oil," most of them using sulfuric acid as a refining agent. Following the completion of the Drake well in 1859, many of the "coal oil" refiners began to use petroleum for manufacturing illuminating oil, and their methods and equipment were adapted so far as possible to this new raw material. The value of sulfuric acid in refining "coal oil" having been established, this reagent was immediately tried and found to be satisfactory in refining petroleum. Notwithstanding the tremendous advances in petroleum technology since that time, sulfuric acid remains today the most valuable and most widely used means for refining petroleum products. EARLY METHODS OF DISPOSAL OF ACID SLUDGE With the almost immediate expansion of the petroleum industry came the problem of disposing of the acid sludge produced in the refining operations. While in 1859, the year of the discovery of the Drake well, a patent was granted for sludge separation and separated acid concentration, most of the earlier refiners, and many of their successors, felt that separation and recovery of spent acid was uneconomical. Accordingly, many of them disposed of the sludge in any way that seemed expedient at the time. It was buried in the refinery grounds, barged and dumped at sea, run into neighboring streams, or dumped into sewers. Some optimists carted it to open pits in the hope that it would either sink into the ground or evaporate. Not so many years ago, the superintendent of an eastern refinery, who was using the open-pit method of disposal, lost a sludge cart, with horse attached, in such a pit. The horse was recovered almost immediately, but its availability for further use was reduced to zero by the loss of its hair.

Jan 1, 1928

By J. Blodget Britton

To the question, "Do the Pennsylvania anthracites contain phosphorus ?" asked at the last meeting of the Institute during the discussion on the metallurgical value of Western lignites, I can now give a definite answer. Through the kindness of a gentleman connected with the Philadelphia and Reading Railroad, and another connected with one of the principal ironworks on the Lehigh, there was sent to the Iron-masters' Laboratory a number of samples of the coals now largely shipped from the Schuylkill and Lehigh regions. Seventeen of these I examined for their contents of ash and phosphorus, and obtained results as follows

Jan 1, 1873

By Bernard Lallement

INTRODUCTION Geostatistics have been used for five years at the B. R. G. M. to compute the ore reserve estimation. At present this technic is also used at the beginning of the exploration project to determine the best way to prove the orebody. The best way is a compromise between the cost of the exploration and the precision of the estimation. It is clear that geostatistics cannot be used without any data, but very often an exploration project is decided on an orebody which has already been drilled. Old data can therefore be used. This was the case this year for two orebodies: an iron deposit and a lead deposit. The iron deposit was explored by drifts and has now to be proved. We used geostatistics to determine the best drilling pattern. The variograms computed with these old data showed that an anisotropy existed between the two directions of the orebody, which meant that the drill pattern had to be rectangular. The lead deposit was explored by drill holes and a short drift in part of the orebcdy. The problem was to choose between a regular pattern of drill holes or a long drift and some added drill holes. The case of this study will be exposed afterwards. On the other hand, if the orebody is completely unknown, the exploration project generally forecasts two exploration steps (the first step

Jan 1, 1977