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SAN FRANCISCO SECTION T. A. RICKARD, Chairman W. H. SHOCKLEY, Vice-Chairman C. E. GRUNSKY, JR., Secretary-Treasurer, 57 Post St., San Francisco, Cal. E. A. HERSAM H. W. YOUNG. A meeting of the San Francisco Section was held at the Engineers' Club of San Francisco on Mar. 28, 1916. Dr. Bailey Willis, Head of the Geological Department of Stanford University, read a paper on The Relation of the Major Structural . Features of the South American Continent to the Mineral Districts. Vice-Chairman Shockley interested the Section with an account of his experiences in South America. Discussion was participated in by C. F. Tolman, Jr., A. C. Lawson, Frank Probert, and E. A. Hersam. C. E. GRUNSKY, JR., Secretary.

Jan 5, 1916

Jan 1, 1955

By AIME

VERSATILITY is perhaps the outstanding characteristic of the subject of this sketch. He is author, golf-player, musician, public speaker, philatelist, German scholar, and has been a school teacher; but these are incidental. Oliver Ralston's professional forte might be described as beneficiating solid minerals and he has dealt in an important way with practically all of them. To this work he has brought a fertile mind stimulated by keen imagination but kept on the track by a sense of economic balance. An indication of his versatility is evidenced by his career with the Bureau of Mines, which he first joined in 1912, when the Bureau was just one year old. Except for two excursions into industry-Hooker Electro Chemical Co. (1917-20) and United Verde Copper Co. (1928 to 1935)-his entire professional career has been with the Bureau.

Jan 1, 1946

By AIME AIME

CHARLIE WARNER, Chairman of the Petroleum Division, is no stranger to the problems of the oil industry or to those of the Petroleum Division, after more than 25 years of experience in locating and producing oil and more than 22 years of membership in the Institute. He was born at Jefferson, N. Y.. April 27, 1894, and educated in the public schools of New York State and at Cornell University where he studied geology and allied sciences from 1913 to 1917 and received a B.A. degree. Immediately upon completion of this training, he was employed by the Empire Gas & Fuel Co. as a field geologist in Oklahoma and Kansas. Two years later he became district geologist for the Emerald Oil Co. in Oklahoma and Kansas, and in 1920 he rejoined the Empire Gas & Fuel Co. in the capacity of district geologist in Oklahoma. In September of 1921 he began his association with the Houston Oil Co. of Texas. He was district manager for the company in the Mid-Continent area until 1932 when he was transferred to the head office at Houston, where he became superintendent of the land and lease department in 1934 and was elected a director of the company in 1941. In these capacities, and also as petroleum engineer for the company, he keeps in intimate touch with all phases of field activity and with the regulation of the industry by State and Federal agencies.

Jan 1, 1943

By John M. Dale

As much as half of the world's known reserves of elemental sulfur occur at or near the earth's surface in natural or native sulfur deposits of volcanic or sedimentary origin. Yet these reserves constitute only a small percentage of the world's supply. Looked on as marginal materials, they remain relatively untouched despite the current demand and improved prices for sulfur. There are two main reasons for this. The first is the nature and occurrence of the deposits. They are generally small and widely scattered in remote and often arid locations, and the gangue constituents of the ore are apt to vary considerably-not only between deposits but also within deposits. The second reason is the lack of workable and economically feasible processes for recovering sulfur from the ores in such deposits. Historically, the older thermal processes in which the sulfur is vaporized away from the gangue were probably the most successful, but they were inefficient and created pollution problems. A few of the historical processes remain in operation today. Recently, however, an improved thermal process to handle all sulfur-containing surface ores has been designed under sponsorship of the Pan American Sulfur Co. A schematic diagram of this process is shown in Fig. 1. The process equipment consists of a paddle trough conveyor retort which is operated as a closed unit to prevent any air or oxygen from entering the system. Ground surface sulfur ore and heated pebbles are fed to this unit simultaneously. The ore and heated pebbles are slowly conveyed and continuously mixed down the conveyor retort. Heat from the pebbles and heat supplied to the outside walls of the trough conveyor retort raise the ore temperature above the boiling point of sulfur. Sulfur vapors and steam originating from moisture in the ore are ducted to a condenser, and the sulfur is recovered as a liquid. The gangue and the pebbles are discharged from the trough conveyor and separated-the gangue being discarded, and the pebbles being conveyed to a direct-fired rotary pebble heater where they are reheated before they are again charged into the rotary trough conveyor retort. The hot gases which pass countercurrent to the pebbles are ducted to the outside of the rotary trough conveyor where they pass countercurrent to the flow of the ore in order to maximize heat recovery and utilization.

Jan 4, 1969

Jan 1, 1939

Jan 1, 1939

Jan 1, 1903

By AIME AIME

MECHANIZATION of operations and the development of much more refined preparation practices have been conspicuous achievements in coal-mine engineering in the last two decades. To both, Paul Weir was an outstanding contributor during his seventeen years' service with the Bell & Zoller Coal & Mining Co. and its aliates, the Centralia Coal Co. and the Crescent Mining Co. From 1920 to the end of 1936, when he resigned to go into consulting work in Chicago, he was successively chief engineer, general superintendent, and vice-president of Bell & Zoller. He changed its Zeigler mines from hand to mechanical loading, and planned and built a central mechanical cleaning plant.

Jan 1, 1939

By Thomas H. Sheehan

The purpose of this paper is to present an application of computer technology to assist the mineral company financial executive in assessing exchange risks. The paper is divided into five parts: Background, Translation Approaches, Theory, Empirical Validation, and Conclusion. BACKGROUND Exchange risk results from a change in the rate of exchange between a host and a home country's currencies. Legitimate reasons exist for changes in the currency exchange rates among countries in a world with over a hundred different currencies. These reasons include: different economic growth rates, social factors, cultural heritages, and political motivations. The problem of exchange rate changes are perennial and exist whether the world operates on exchange rates or floating exchange rate practices. The cause of the problem is trade and international payment imbalances. If one accepts the premise that exchange rates fluctuate over time, then the mineral company financial executive faces a continual process of reassessment of the impact of exchange rate changes on the financial worth of his company. (1) The mineral company financial executive prepares balance sheets and income statements that are audited by certified public account- ants annually for shareholders, bankers, and tax authorities. The financial executive translates assets and equities denominated in foreign currencies into domestic dollars, e.g., Japanese firms convert to Yen, French firms convert to Francs, and so on. When figures from foreign subsidiary operations are consolidated into the balance sheets of the parent corporation, estimates of the company's finan-

Jan 1, 1977

By B.S. Butler

If geology is to continue to serve the mineral industry with increasing effectiveness as it has done in the past, there must be a steady output of better and better trained geologists and engineers with broader geological background. It may seem that the education and technical training of geologists belong entirely to the universities and colleges and has nothing to do with either Government surveys or the mining industry, outside of these activities furnishing a field for future work for the geological student. It will take but the most casual look, however, to see the large influence of Government surveys in education. Geological Maps Geological maps are essential tools in teaching geology, without which the instructor would be lost. Maps are produced by mining and oil companies, by university workers and by other individuals and institutions, but nearly all of the comprehensive maps, and most of the maps of small areas that are available, are directly or indirectly the work of public surveys. Such surveys in the past have been the only organizations with the continuity of effort and funds necessary to carry out projects that must combine the work of many individual geologists over long periods. Have we all the maps we need and of the quality we need? I believe that all who have used general maps, like the geological maps of the world, the maps of 'North America and the United States, maps of the several states and of smaller areas, appreciate fully the value of the maps as they are but realize also the value of greater accuracy, which can come only by more detailed work; and there are many areas of which we have no adequate maps. Other Helps I have chosen to emphasize maps as a help in preparing the young geologist to go out from the schools with some background of what has been accomplished and some outlook of what is yet to be done. Maps, however, are scarcely more essential to the teacher than many allied helps. What would the teacher of economic geology do if the work by Government surveys along that line were to be blotted out? We may

Jan 1, 1935

By B. S. Butler

If geology is to continue to serve the mineral industry with increasing effectiveness as it has done in the past, there must be a steady output of better and better trained geologists and engineers with broader geological background. It may seem that the education and technical training of geologists belong entirely to the universities and colleges and has nothing to do with either Government surveys or the mining industry, outside of these activities furnishing a field for future work for the geological student. It will take but the most casual look, however, to see the large influence of Government surveys in education. Geological Maps Geological maps are essential tools in teaching geology, without which the instructor would be lost. Maps are produced by mining and oil companies, by university workers and by other individuals and institutions, but nearly all of the comprehensive maps, and most of the maps of small areas that are available, are directly or indirectly the work of public surveys. Such surveys in the past have been the only organizations with the continuity of effort and funds necessary to carry out projects that must combine the work of many individual geologists over long periods. Have we all the maps we need and of the quality we need? I believe that all who have used general maps, like the geological maps of the world, the maps of 'North America and the United States, maps of the several states and of smaller areas, appreciate fully the value of the maps as they are but realize also the value of greater accuracy, which can come only by more detailed work; and there are many areas of which we have no adequate maps. Other Helps I have chosen to emphasize maps as a help in preparing the young geologist to go out from the schools with some background of what has been accomplished and some outlook of what is yet to be done. Maps, however, are scarcely more essential to the teacher than many allied helps. What would the teacher of economic geology do if the work by Government surveys along that line were to be blotted out? We may

Jan 1, 1935

The Year Book of the Institute is mailed with this Bulletin. Its membership lists, both alphabetic and geographic, are corrected to Jan. 1, 1918, but its list of officers is revised inn accordance with the elections in February, 1918. The amendment to the Constitution, relating, to qualifications for membership, adopted at the same time, is also inserted in its proper place. We would call attention to the Honor Roll, heading the list of membership. This includes the names of those whom we know (in February, 1918) to be on active military duty, as well as those who are rendering emergency service to the Government in other branches. We are aware that the list is not complete, and shall be grateful for information as to any omissions or corrections. Because of the rapid movement of the military members, their addresses have been omitted from the alphabetic list. Mail addressed to such members, and sent to the office of the Institute, will be forwarded to the best of our information at the time.

Jan 3, 1918

Jan 1, 1884

Jan 1, 1939

By AIME AIME

Jan 1, 1939

Jan 1, 1942

By John S. Rinehart, Norman Ahlquist

The model which Birkimer has developed to explain the increase in fracture strength of brittle, rock-like materials with increasing rate of loading may have some applicability. It should be noted that since his analysis presupposes elastic behavior he could equally well express his result as an increase of stress to fracture with increasing strain rate, a fact which is well known. Certainly his experimental results do not contradict his strain rate to the one third power law. On the other hand, we do feel that the data are insufficient and inadequate to establish the relation- ship definitely. 'In metals, the whole fracture picture is greatly complicated by concomitant plastic flow and, in rocks, by the presence of macroscopic flaws and inhomogeneties. Both lead to uncertainties as to the state of stress during the fracture process. He quotes in support of his theory Rinehartfs results on rock in which the latter found that under impulsive loading by explosives, rocks appear to be many times stronger than under static loading. We suspect that the observed increase has little specific relevance to the theory which Birkimer puts forward. Rinehart's measurements were made by spalling rocks using a sawtooth shaped stress wave of known intensity and duration. The rise time of such a pulse is essentially zero, certainly less than 0.1 microseconds, so that it is not possible to apply Birkimerfs theory quantitatively. We favor attributing the increase in fracture strength to two factors. First, the action takes place very quickly in an exceedingly thin region so that statistically the probability is small of encountering one or more of the large flaws that contribute so significantly to the reduction of strength of most rocks under tension. It is also conceivable that the compressive wave that has just passed by the region of fracture has strengthened the rock by collapsing some of the larger flaws. Second, the state of stress obtaining at the time of fracture is not all that existing when the

Jan 1, 1971

By Eldred D. Wilson

Apropos of metals low in the series illustrated by Dr. Butler's Table II, it is interesting to note that Cress and Feldman reported traces of platinum metals in several samples of alunite. They found, chemically and spectrographically, several traces of platinum, palladium, and rhodium in alunite from Sugar Loaf Peak, near Quartzite, Ariz.; silver, platinum, and rhodium in alunite from Rio Grande County, Colorado; and traces of rubidium and gallium in various samples of alunite. These authors stated that the platinum metals appear to be present as oxides and suggested deposition by hydrothermal solutions under near-surface conditions.

Dec 1, 1956

ONE of the perplexing problems that face the translator of an old technical treatise is the question of terms for units of weight and measure. We have used an English word only when it is linguistically equivalent to the Italian one and is a unit of approximately the same size. Libbra and oncia thus become pound and ounce, for the actual weights were within 10 per cent of the modem Troy weights. On, the other hand, the length measures braccio, palmo, and dito, which could be rendered literally as arm, palm, and finger or digit, respectively, have no good English metrological equivalents and it has seemed best to retain the Italian words. The exact transfer of Biringuccio's weights and measures into modern terms is impossible because of the uncertainty as to his standards. Even as late as 1803, when the metric system was first introduced into Italy, practically every city had its own standards. There were, for example, at least eight different palmi, varying from 22.3 to 29.2 centimeters. The values listed below for the various units mentioned by Biringuccio are the Florentine ones, which were also used in Siena and Tuscany: [ ]

Jan 1, 1942