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By William P. Blake

Travelers in the desert regions of the southwestern portion of United States, especially along the valley of the Colorado of the West, can hardly fail to note that most of the rocky outcrope of the harder rocks have a uniform prevailing blackness of the surface, in strong contrast with the normal color of the interior of the rock when freshly broken. For example, the granitic or gneissic rocks of Pilot Knob, below Yuma, are blackened beyond easy recognition. So also rocks upon the lower Mojave in California are so thoroughly blackened, as if painted, that ordinary gneiss can scarcely be recognized without breaking it so as to show the interior color and structure. The discoloration is not confined to the rocky outcrops in place, but is found upon boulders and upon the loose rounded pebbles which strew the surface of the mesas along the Colorado river. These fragmentary rocks partake of the general blackening.

Jan 1, 1905

By Henry M. Howe

A discussion of the paper published in Bi-Monthly Bulletin, No. 20, March, 1908, pp. 227 to 237, and No. 22, July, 1908, pp. 615 to 620. PROF. HENRY M. HOWE, New York, N. Y. (communication to the Secretary *) :-Mr. Hibbard's definition of steel would be the best yet offered were it not for its one defect, the vagueness or equivocalness of "fusion-process." Puddling is surely in one sense a fusion-process, and so are the charcoal-hearth or knobbling-processes. But what he says suggests the following definition, which seems to me a good one: " Steel: any variety of iron which is usefully malleable at least at some one temperature, and is either cast when molten into a malleable mass, or if not so cast can be much hardened by sudden cooling." It is not necessary in a definition that quantitative bounds should be set up, for instance, that the exact height at which dwarf apple-trees cease and standards begin, or at which hills cease and mountains begin, should be stated. These quantitative measures are proper for specifications and contracts, but are not necessary for purposes such as the present. HENRY D. HIBBARD, Plainfield, N. J. (communication to the Secretary t) :-Professor Howe's criticisms of my definition of steel are not, it seems to me, well founded, for the . following reasons: The term "fusion-process" has been used during the past quarter or half century to distinguish the crucible, Bessemer and Siemens-Martin processes from the puddling- and cementation-processes, and probably no one at all conversant with the art of iron-metallurgy would now mistake its meaning. Moreover, no steel-metallurgist is in doubt of the meaning of the term "hardened? as applied to steel. If it were really necessary to describe what is meant by the term then it would

Nov 1, 1908

By Donald B. Gillies

TO me a graduating class of engineers constitutes one ' of the finest inspirations I can imagine. You have finished your four- year scholastic career and are starting out in competition with thou- sands of other young men from other universities to make your mark. Be- cause of your training you men are such an essential part of our present- day civilization that a great weight of responsibility rests on your shoulders, especially at this time, for this is an engineering era. Today, it is the engineer who dreams the dreams and makes our civilization better. It's the engineer who carries those dreams into realization and fulfillment. No matter where we go in business and industry, we find- engineers in key positions, charged with great responsibilities.

Jan 1, 1939

By N. S. Wagner

The production of lightweight aggregates in Oregon is a new industry, and, like all new enterprises, it is suffering from growing pains characterized by numerous, small operations some of which flourish for a short time and then cease altogether. Normally all industrial mineral products are produced in a highly competitive atmosphere. At the present time this condition does not exist to a very marked degree in the state because as yet producers have not saturated the constantly expanding market. This paper has been prepared with the intention of outlining very briefly the current status of the various products now being used as lightweight aggregates in Oregon. The present picture will surely change, perhaps quite radically within even a short space of time.

Jan 1, 1949

By Norman Brown, J. V. Rinnovatore

It was found that a shear stress applied during the recovery had no effect on the amount of recovery if the stress was less than the instantaneous yield point irrespective of the direction of the stress. Large ajplied stresses during recovery had a marked effect, which depended on the direction of stressing. Single strain reversals at -72°C not only produced the Bausch-inger effect but also increased the flow stress. The increase inflow stress was attributed to vacancies, which have appreciable mobility at -72 °C. THEORIES I-' of recovery suggest that the internal stress field of the dislocations plays an essential role. Most investigations of recovery use time and temperature as the independent variables; however, here stress has been introduced as a variable in two ways: 1) by varying the internal stress field according to the amount of strain prior to recovery and 2) by applying an external stress during recovery. Tannen- baum and Kauzrnann studied the effect of applying a stress during recovery by measuring the change in creep rate after recovery; they found that stresses as high as 95 pct of the creep stress had no effect on recovery. Earlier, Wood and scrutton6 showed that an applied stress during creep increased the rate of poly-gonization. The experiment by Wood involved poly-crystalline aluminum whereas Tannenbaum and Kauzmann used a single crystal of zinc. In this investigation, zinc single crystals were used and deformed in a manner to prevent polygonization. Thus, the main difference between this investigation and that of Tannenbaum and Kauzmann is the use of the stress-strain curve instead of creep rate as the index of recovery. In addition, the applied stress during recovery varied

Jan 1, 1961

By Robert F. Love

Deep under the hills of southwestern Wyoming lies a nonmetallic mineral deposit of incredible dimensions and value. This nearly pure, horizontal bed of the mineral trona, a sodium sesquicarbonate (Na2HC0,.NaHC08.H20), is found in the Green River formation some 1500 ft below surface. It is believed that evaporation of an ancient saline lake left this sodium carbonate as the evaporite and mysteriously left practically no sodium chloride, which is the common constituent of an evaporated saline lake. The trona bed averages 10 ft in thickness and extends over an area of several hundred square miles. In 1938 a geologist with the U. S. Geological Survey identified the trona in the core from a former oil exploration drillhole. By so doing, he initiated the developments of a chemical industry of impressive growth in the area, an industry on the threshold of further and much more spectacular growth. A drilling program by the Union Pacific Rd. and Intermountain Chemical Co. in the early 1940's succeeded in blocking out mineable reserves of several hundred million tons. Development of the deposit started in 1946 with the sinking of a 12-ft diam, concrete-lined shaft 1500 ft deep-followed by construction of a small pilot calcining plant. Actual mining of the trona started in 1947 and continued on a limited scale until 1953, when the $15 million surface facilities were completed, along with the second shaft and other expanded underground facilities. Since April 1953 the mine has been producing more than half a million tons per year, from which the refining plant has produced more than 300,000 tons per year of high quality soda ash.

Dec 1, 1956

By Carle R. Hayward

The growing importance of metallography has caused a corresponding interest in the improvement of apparatus for preparing specimens of metals and alloys for microscopic examination. The purpose of this paper is to describe an electric heating-furnace, a grinding- and polishing-machine, and a device for mounting specimens, which are used in the metallographical work at the Massachusetts Institute of Technology. These three pieces of apparatus were designed and made in the laboratory of the Institute, and each possesses some original features which may be of interest. Electric Heating-Furnace. The accurate control of heat necessary for metallographic work is best obtained by the electric-resistance furnace. Uufortunately, however, even the platinum-wound furnaces cleteriorate with use and ultimately burn out, while the cheaper resistance-materials are often short-lived. Since the resistance-coil must be replaced from time to time, it is of advantage to be able to make this change with as little trouble as possible, and this is an important feature in the furnace shown in Fig. 1. A is a cylindrical galvanized-iron can, with two handles, B. A porcelain tube, C, passes through the central hole in the cover of the can and rests upon the asbestos disk, D; the bottom of the tube is held in place by the asbestos ring, 3. The space, F, around the tube is filled with powdered magnesia. G is an ordinary assay-crucible, with the cover inverted so as to present a smooth top for supporting a second porcelain tube, H. The latter is wound with " Excello " resistance-tape, 0.014

Jan 1, 1912

Levi Holbrook was born in Westboro, Mass., March 7, 1836. He was a descendant of John Holbrook, who came from England in 1660 and settled in the Massachusetts Bay Colony. Mr. Holbrook was prepared for college at Williston Seminary, East-hampton, Mass., and after one year spent in the West, he entered Yale. He was a, member of Phi Beta Kappa and of Linonia. During the six months following his graduation he was in Boston, under medical treatment for his cyes; then he took a horseback trip across the Rocky Mountains to the Columbia River and back, and resided in Danville, Va., for a time. From 1860 to 1863, as his eyes permitted, he was a student of modern languages and literature in Cambridge, Mass., part of the time being a resident graduate at Harvard University. Finally, however, he was obliged to abandon the idea of a literary life and from 1864 to 1867 he was engaged in financial business in Boston. The following year, he spent in New York, and then traveled for a year in Europe, Egypt and Asia Minor. In 1871, he returned to New York City. Mr. Holbrook was a member of the New England Historic Gcncalogical Society, the Society of Colonial Wars, and the Sons of the Revolution, was registrar general of the Order of the Founders and Patriots of America from 1915 to 1920, and had been governor of the New York society of that order. He was also a member of the American Fine Arts Society, the Order of the Cincinnati, the American Geographical Society (of which he was a councillor and secretary). and the Geographical Society of America. He joined the American Institute of Mining Engineers in 1878, and served as manager from 1895 to 1897. Mr. Holbrook died on July 26, 1922, from organic heart trouble, at his residence in Center Harbor, N. H. He was married Dec. 27, 1871, in Newark, N. Y., to Viola, daughter of John A, and Elizabeth (Failing)Vowers, who died on Sept. 10, less than six weeks after her husband. His two children, Clark Holbrook of Red Bank, N. J., and Mrs. Julian P. Smith, survive him

Jan 1, 1923

Levi Holbrook was born in Westboro, Mass., March 7, 1836. He was a descendant of John Holbrook, who came from England in 1660 and settled in the Massachusetts Bay Colony. Mr. Holbrook was prepared for college at Williston Seminary, East-hampton, Mass., and after one year spent in the West, he entered Yale. He was a, member of Phi Beta Kappa and of Linonia. During the six months following his graduation he was in Boston, under medical treatment for his cyes; then he took a horseback trip across the Rocky Mountains to the Columbia River and back, and resided in Danville, Va., for a time. From 1860 to 1863, as his eyes permitted, he was a student of modern languages and literature in Cambridge, Mass., part of the time being a resident graduate at Harvard University. Finally, however, he was obliged to abandon the idea of a literary life and from 1864 to 1867 he was engaged in financial business in Boston. The following year, he spent in New York, and then traveled for a year in Europe, Egypt and Asia Minor. In 1871, he returned to New York City. Mr. Holbrook was a member of the New England Historic Gcncalogical Society, the Society of Colonial Wars, and the Sons of the Revolution, was registrar general of the Order of the Founders and Patriots of America from 1915 to 1920, and had been governor of the New York society of that order. He was also a member of the American Fine Arts Society, the Order of the Cincinnati, the American Geographical Society (of which he was a councillor and secretary). and the Geographical Society of America. He joined the American Institute of Mining Engineers in 1878, and served as manager from 1895 to 1897. Mr. Holbrook died on July 26, 1922, from organic heart trouble, at his residence in Center Harbor, N. H. He was married Dec. 27, 1871, in Newark, N. Y., to Viola, daughter of John A, and Elizabeth (Failing)Vowers, who died on Sept. 10, less than six weeks after her husband. His two children, Clark Holbrook of Red Bank, N. J., and Mrs. Julian P. Smith, survive him

Jan 1, 1923

By S. H. Ash

THE increasing need for the products of our mines, mills, and processing plants, the loss of mine manpower to plants other than those concerned with the mineral industry, and the drafting of our younger men into military service have created an acute situation in many places as to workers and production. This, in turn, has focused attention on the need for conserving manpower by conserving the health and life of our mining people. Health A world-wide tendency is noticeable in the mineral industry toward protecting the health of workmen,-particularly younger workers, as well as older workers who can continue to produce in many places where manpower is lacking. This matter was emphasized at the Geneva Labor Conference for Coal Mines at the Committee's fourth session, held in Geneva, Switzerland, May 7 through 19, 1951. Papers concerning the health of workers were presented at the annual meetings of the mining sections of the National Safety Council, the Coal Mine Inspectors' Institute of America, the American Public Health Association, and other organizations. Safety Conferences Without exception, the attendance at mining-safety conferences in widely separated places throughout the country during the year was the largest to date. What is needed at the safety meetings throughout the country is more-widespread attendance by those who can sell the idea to the workers that they are the focal point in accident prevention and that safety is not going to be achieved alone or even in part by laws, decrees, or commands, but by quiet influence, unconscious suggestion, and personal' guidance. If these are acquired by the workmen, a safe environment and ample, capable supervision supplied by management, accidents will be fewer and less severe. Many safety conferences attempt to develop the foregoing idea by enumerating and describing training programs for supervisors and workers alike. Nothing can replace a course in first aid for all persons employed at any mine or plant as an introductory and basic step to a successful safety program. Even in this, the shoe must fit the foot, rather than applying the order do this or else. In first-aid

Jan 1, 1952

By P. H. Dudley

In giving a brief account of the experiments in progress to inquire into some of the facts in regard to "railway resistances," recently commenced upon the Lake Shore and Michigan Southern Railway, with the dynagraph (which is essentially an instrument recording upon paper the force required to draw a train, at all speeds, marking the time in short intervals, so that the force absorbed due to any

By Emil Schroedter

The death, on May 6,1908, of Dr. Hermarnn Wedding, Privy Mining Councilor of the Kingdom of Prussia, and Professor of the Metallurgy of Iron and Steel at the Royal Mining Academy of Berlin, was a loss keenly felt by the whole metallurgical world. Not alone in his native land, but also in foreign countries, did he enjoy an esteem of which the title of honorary membership in the American Institute of Mining Engineers, the United States Association of Charcoal Iron-Workers, and the (British) Iron and Steel Institute bears eloquent testimony.

Jan 1, 1910

By George Wolff

To THE average person, the purport of the items and figures on the balance sheet of a mining company are hazy and the real financial condition of the company is cloaked in obscurity. It is also likely that the satisfaction of the stockholder in his investment, as well as the determination of the prospective investor, rests more on the reputation of the company, his confidence in the management, the stated earnings per share and the dividends paid, than on a comprehension of the information contained in the balance sheet. The balance sheet of any company at best can only closely approximate the true financial condition as of a given date. Any item of asset, except cash, can probably be altered if another's viewpoint is applied. It is difficult and expensive to drill and explore an orebody to determine the entire tonnage of ore therein. Those inherent difficulties render it practically impossible to prepare an absolutely correct balance sheet of a mining company. It is possible, however, to present the facts of a mining company more intelligently and comprehensively than is usually done. With this, in mind, a balance sheet of an imaginary mining company is submitted, with supporting schedules. The same fundamental principles hold true whether we consider a large or a small company. Less complexity is involved in dealing with the affairs of a smaller company. Therefore, for this purpose, the assumed company operates but two mines and a smelting plant. It has been deemed advisable to introduce the features of the operation of a mine acquired prior to March 1, 1913 and one after that date. The presentation therefore is concerned in one mine with the appraisement as of March 1, 1913 and in the other with the appraisement by reason of discovery. A consequential factor pertains to dividends paid from depletion reserves and therefore free of surtax to the stockholders. While supporting schedules, when necessary, give details of certain items on the balance sheet, it seems desirable to give further explanations with respect to some of them. This seems to be important because some mining companies do not treat the items as indicated on the statements submitted.

Jan 1, 1928

By Lewis Stockett

During the year 1903, a building having machinery corresponding to ail anthracite-coal breaker was erected at the town of Stockett, Cascade county, Mont., for the purpose of breaking-up and cleaning bituminous coal. The coal is mined from a vein of the Kootenai group of the Lower Cretaceous measures having the following section: The vein is nearly horizontal in position, and each bench differs in quality as shown in Table I.

Jan 1, 1905

Some years ago it was my good fortune to inspect some coal properties in Germany, and the most striking impression I received on my trip was that in that country every one in the coal industry, miners and operators, was proud of the fact-not apologetic about it-and that industrially coal was looked upon as a King. The explanation, of course, was that at least 90 per cent of the entire mineral value produced in Germany was from coal, and that it was the very foundation of the nation's industrial life. The feeling was so different from that existing in the United States among those engaged in producing coal that it made a profound impression on me, and many times since then I have speculated about the reasons for the difference in opinion in the two countries. Here, of course, our units are much smaller and more numerous, there is not so large a proportion of technically trained men, and we have the American trait of depreciating the things we do at home; but among those not actively

Jan 1, 1939

By C. E. Lesher

Two processes for agglomerating fine sized ores with low temperature coke are described. One process (Orcarb) agglomerates ores with limited amounts of carbon; the other (ore-carbon pellets) pelletizes fine sized ores, using low temperature cokes as the binder. Data are presented on the products obtained when taconite, magnetite, and hematite concentrates and several titanium oxide ores were used. REDUCTION of finely divided oxide ores has long been a major metallurgical problem. Various methods of agglomerating, notably briquetting, sintering, nodulizing, and pelletizing, have been developed and are in industrial use. Carbon is the usual reducing agent for oxide ores and attempts have been made to agglomerate fine ores with coking coal in order to get the metallurgical advantages of intimate contact and increased particle sizes suitable for subsequent smelting or reduction.1-3 For the past three years, research has been in progress on two processes for combining fine sized ores with reactive carbon in the form of low temperature coke. By one process, designated Orcarb, the ore is coated with coke carbon in amounts limited to that required for reduction and the result is an appreciable but limited increase in product particle size over that of the original ore. The second process, called ore-carbon pellets, produces pellets of fine ore bound by low temperature coke. The first objective was to develop a process for combining an oxide ore with only enough carbon for its reduction, the amount being that derived from the simple reduction equations. The carbon (that amount theoretically required for the reduction of the oxides in an agglomerate with ore), calculated to CO, ranges from 10 pct for zinc calcines or phosphate ores to 21 pct for rutile and 26 pct for silica. The carbon required for reducing iron oxides falls between the extremes—10 and 26 pct. When the carbon in the agglomerate is low temperature coke, reduction by hydrogen may be expected to take place, thus modifying the calculated carbon require- ment. On the other hand, in practice, an excess of reducing agent over that required in theory is normally used. Screen sizes of three iron ores on which the greater part of the experimental work was performed are given in Table I. Most of the testing was done with Freeport (Renton Mine) coal, but Pittsburgh and Elkhorn bed coals were also used. The first objective was to agglomerate the ore with sufficient low temperature coke to provide carbon for reduction, i.e., in the range from 10 to 25 pct. This was accomplished by preheating the ore, mixing with pulverized coking coal, and completing the coal carbonization in a plain steel rotating retort. The pilot retort, as it is now constituted, is shown by diagram in Fig. 1 and photograph, Fig. 2. Ore is fed into the upper kiln by a screw; it is heated to 900" to 1100°F by direct flame and it is then discharged into an insulating hopper from which it goes

Jan 1, 1956

The pressure of the gas in equilibrium with sphalerite has been determined in the temperature range of 680' to 825°C, using the Knudsen orifice method. A comparison of these experimental pressures with those calculated from thermal data and from other equilibrium measurements shows that the vapor above sphalerite is predominantly dissociated ZnS. Equations have been given for correctly calculating dissociation pressures using the Knudsen orifice method. It has been shown that the experimentally determined pressure is the same, whether the zinc sulphide is sphalerite or not, or a mixture of wurtzite and sphalerite. CONFLICTING points of view appear in the literature on the constitution of the vapor in equilibrium with solid zinc sulphide in the vicinity of 800°C. By comparing the dissociation pressure calculated from thermodynamic data and the vapor-pressure determination of ZnS by Veselovski,1 Lumsden2 has concluded that the vapor consists largely of dissociated ZnS. Sen Gupta,' however, concludes from his spectroscopic determinations that the vapor is largely ZnS molecules. In view of the fact that the thermodynamically calculated' dissociation pressure is higher than that experimentally measured by Veselovski, it seemed in order to repeat Veselovski's measurements. Experimental Procedure The method used for the determination of the pressures in this papel- is the Knudsen effusion cell. The apparatus and procedure were described in a previous paper- from this laboratory on the determination of the vapor pressure of silver. The only difference is that the Knudsen cell in this work is made from platinum and there is no external cover around the cell. The cell is an ordinary platinum crucible of 2.2 cm top diameter with a capsule cover. It was thought that platinum might stand up at these temperatures to the solid and gaseous ZnS, since it was found that the weight of the platinum cell itself did not change appreciably on heating ZnS in it at the working temperatures. To insure that reaction of the zinc sulphide with the cell was not giving' a false value, a stabilized zirconia cell was employed for check runs. Fig. 1 shows the comparison, which is satisfactory. Veselovski previously had measured the vapor pressure of ZnS using a silica Knudsen effusion cell. On repeating his experiment in this laboratory, it was found that ZnS at-tacked the silica cell, giving it a marked frosty appearance. This led to the belief that Veselovski's result:; may be in error. Also, he was operating at pressures above the range ordinarily considered safe for the Knudsen method. The effusion rate was measured by weighing the cell before and after each run. The weight loss during heating to temperature and cooling down was measured and subtracted from the weight loss during the actual run. The zinc sulphide used in this investigation was from two sources: Fisher cp grade, and a sample of pure sphalerite supplied by Mr. E. A. Anderson of the New Jersey Zinc Co. Before and after the series of runs with Fisher ZnS, X-ray analysis showed that both wurtzite and sphalerite were present. However, the ratio of sphalerite to wurtzite increased. All measurements were made below the transition temperature which has been reported" to be 1020°C. The data obtained in this investigation are tabulated in Table I. The pressure was calculated by the usual Knudsen formula" on the assumption that ZnS molecules were effusing. From these data, using pure sphalerite in the platinum Knudsen cell, the vapor pressure of ZnS, in mm of Hg, as a function of temperature is given by the solid line in Fig. 1. The best straight line, as determined by the method of least squares, is given by 14405 logpzns =-14405/T +11.032. A comparison of these results with Veselovski's shows that his results are about 50 pct lower. Discussion The vapor in equilibrium with solid zinc sulphide in the temperature range of this study will consist of Zn, S2, and ZnS mol, since other species of zinc and sulphur' are relatively unstable. The question to be settled is whether or not ZnS is largely dissociated. The derivation8 which follows gives the method of calculating the pressure of zinc and sulphur over solid ZnS, assuming complete dissociation, from Knudsen cell data. The free energy of the reaction 2 ZnS(solid) ? 2 Zn(gas) + S2(gas) is given by ?F?° = -RT In K = —RT In p12p2 where p1 is the zinc pressure and p is the sulphur pressure. If dissociation occurs in a closed system,

Jan 1, 1955

By F. C. Langenberg, R. W. Lindsay

COPPER sometimes is added to steel and cast iron as an alloying element to improve or impart specific properties. However, in some steels it exerts an impurity effect in impairing response to fabrication by hot working and deep drawing. The resid-

Jan 1, 1955

MAY began with a general strike of the bituminous and anthracite coal miners in the United States in progress, while in Great Britain about three quarters of a million workers became idle by a lockout, caused by a dispute respecting the question of the rights of management in their shops. The employers opened their shops on May 3 to men wishing to resume work, but few availed themselves of the opportunity. Up to this time the statistics had been showing a little increase in the rate of employment in Great Britain and business conditions were considered to be improving. From Russia came reports that the results of the famine had not been so bad as had been prophesied, which is not to say that they were not grievous. In prognostications such things are habitually overesti-mated. Seeding for the new crop has now begun in Russia, with hopes for better results than last year. However, the general economic situation in Russia steadily becomes worse. We had advices during May to the effect that the Soviet Government had decided to abolish the gold ruble even as a theoretical calculating unit and substitute a "goods index." This idea would be somewhat on the lines of Professor Fisher for stablizing the dollar, and there may be a chance to see how it will work in practice. There was a contradictory report from Russia, however, that it had been decided to revert to the gold basis. This is the more plausible report, for if there be anything to be deduced from economic theory and history the present paper rubles will completely collapse and return to gold basis will ensue simply because the people will refuse to sell their goods on anything else. The civil war in China came to a head during the first week in May when General Wu-Pei-fu crushed the forces of General Chang Tso-lin around Pekin. The victor declared his intention to be to reunite the North and the South and in course of time to arrange for a constitutional convention. We probably do not under-stand the conditions in China, but recent events do not appear to have solved the grave difficulties there, though they may be a step toward it. However, the immediate outlook does not appear good, General Chang having retired to the north and declared the secession of Manchuria and Mongolia.

Jan 6, 1922

The income of the Institute is derived from dues, subscriptions to MINING AND METALLURGY and sale of publications. These sources are fortunately supplemented by the interest from invested funds now amounting to over $500,000, a considerable portion constituting endowments for especial purposes. Aside from the medal funds the principal endowments are the James-Douglas Fund for support of the Library, the Rocky Mountain Fund and the Seeley W. Mudd Memorial Fund. The income from the two last named is available for the support of research and a variety of other purposes. It is allocated by the Board of Directors upon recommendation of standing committees in each case. An active effort is being made to increase the endowments of the Institute, it being felt that unusual opportunities exist for research and public and professional service through the organization.

Jan 1, 1934