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By A. H. Bell

DEEPEST hole in the earth, and deepest producing oil well in the world-such is well No. K.C.L. A-2, of the Continental. Oil Co., completed on April 12 in the San Joaquin valley about four miles west of Wasco, Calif. It penetrated the earth's crust to a depth of 15,004 ft.- almost three miles-a depth that exceeds by over 2200 ft. that of the previous record holder in western Texas. It is now producing oil from sands at a depth from 13,092 to 13,- 175 ft., which is about 1500 ft. deeper than the record formerly achieved in Louisiana. Continental's new well was bottomed in what is possibly Domengine-Avenal Eocene sand, and is producing from the Middle Miocene equivalent to the Rio Bravo sand.

Jan 1, 1938

By Jay A. Carpenter

THIS preliminary report from the Committee to Study Relations Between Students and the Institute is submitted to our member- ship for consideration and discussion before the general subject comes up for action at the Annual Meeting in February. At present, the A. I. M. E. has a dual relationship with mining students, each relationship in no may connected with the other. To the individual student the Institute offers for $2 a year a Student Associateship in the Institute which carries with it a subscription to MINING AND METAL- 'LURGY, a watch fob, and the privilege of becoming a Junior Member after graduation without payment of the -first year's dues, if one's application is accepted. To the student's college society it offers the privilege, upon application, of becoming 'an Affiliated 'Society, which brings with it no specific supervision or aid, and in turn requires no specific conditions as to membership, fees, or rules. This Affiliated Society is distinctly a school organization which Student Associateship in the Institute can he given special status or ignored, is the local .society sees fit.

Jan 1, 1934

By J. L. Schroeder, W. G. Talman

EXPERIENCE has shown that certain known natural conditions and other indefinite characteristics combine to make a mining area vulnerable to mountain bumps. Some of the known conditions are heavy overburden, an overlying stratum of strong non-elastic rock, a structurally strong coal seam that does not crush easily and yet is the weakest stratum in the series, and a floor stratum of more than ordinary firmness. The indefinite characteristics could include resistance of top or bottom of a coal seam to lateral flow, effect of immediate top and bottom strata, nature of the coal seam, and other factors about which very little is known. It is in this area that exhaustive study is needed to achieve positive control of the dreaded mountain bump hazard. In the Gary district, West Virginia, two of the five operating mines have areas known to be vulnerable to mountain bumps.These are the No. 2 and 6 mines, which are working the Pocahontas No. 4 coal seam. In this area the seam is overlain at a zero to 10-ft interval by the massive Eckman sandstone, which is about 100 ft thick in the vulnerable areas. Total overburden, consisting of shale, coal seams, and sandstones, ranges from 700 to 1400 ft where bumps have occurred (Fig. 1). The coal seam is 4 to 8 ft thick and has a weak columnar structure of very soft and spongy or woody coal. The immediate top is either the Eckman sandstone or hard shale, both of which provide generally good roof conditions for mining operations. The bottom ranges from medium to hard gray shale. The incidence of bumps in the Gary district dates from about 1930 and can be correlated to some degree with the increased rate of extraction attained with mechanical mining. During early years of operation at the No. 2 and 6 mines, most of the work was development and under comparatively light cover. As overburden became heavier, together with an increasing percentage of coal coming from pillar extraction, mountain bumps began to occur. Before 1945 they were much less severe than in later years, and because there were no injuries or fatalities, no records were kept. But by 1951 the incidence of bumps had increased to such extent that it became evident a mining system would have to be designed to eliminate or at least minimize these occurrences. Drawing on experience with modified versions of old systems and certain characteristics peculiar to the Pocahontas No. 4 coal seam, the district mining engineer, Martin Hayduk, outlined the essential factors for bump control in the Gary district. These control factors indicated: 1) The highly stressed area, which lies within the limits of convergence effects, moves at approximately the same rate as the retreating pillar line. 2) There is a decided softening of the periphery of blocks which is greatest and deepest on the gob side. 3) Blocks less than 45 ft wide never have been known to bump in the Pocahontas seams. Fig. 2 shows the mining plan based on these observations—a thin-pillar system with a minimum of secondary development. It was recognized from the start that the Hayduk system had certain limitations. When pillar work backed up to an inevitable surrounded block it was no longer applicable; also, burnt bottom and/or unknown factors reduced the system's effectiveness in certain headings. Since there was no way to eliminate the loaded block, it was decided to experiment with auger drilling to attain controlled release of this stored-up energy. The decision to auger was made after consideration of three separate plants, which were: 1) To cut the solid block into pillars of maximum size by driving away from the fracture line and at such a distance outby that development

Jan 1, 1959

By W. B. Plank, A. C. Callen

WAR and normalcy do not walk hand in hand, whether it be in industry, the educational field, or in the daily lives of individuals. Schools and departments offering curricula in mineral engineering have been seriously disrupted, beginning with 1942 and reaching a low during 1944. Selective Service regulations and voluntary enlistments have effectually stopped the flow of college-trained men into the mineral industry, and the flow into the colleges is little more than a dribble. The year just closed has been a most serious one for our institutions. Until March many of our faculties had been kept reasonably intact because of the large training programs of the Army and Navy. Although the number of

Jan 1, 1945

By AIME AIME

AWIDE variety of subjects was discussed at the Wednesday sessions on Non-metallic Minerals. W. M. Weigel as chairman, presided at the morning session, and W. M. Myers, vice-chairman, in the afternoon. In the morning session a paper by W. N. Logan on "Mineral Wool Resources of Indiana" was read by H. H. Hughes. Mr. Logan explained that as Indiana is the principal source of mineral wool, the paper might well he entitled "Mineral Wool Resources of the United States."

Jan 1, 1932

By Meissner, C. A.

THE tendency all over Europe, just as it is with us, is to go to the use of turbines for new construction or replacement of old steam or even gas engines. 'The lower construction cost and the lower operating cost, when they can have high steam temperatures and pressures, together with their efficiency, is the cause of this change to turbines, both high and low pressure. The present trend is to equip plants with modern, efficient steam boilers, turbines, etc., and gradually work into high-pressure superheated steam equipment to accomplish a saving. One company has just completed a 375 to 400 lb., 700 deg. superheated steam installation and turbo-blowers with this end in view. Some of our new steam plants are using 350 lb. working pressure.

Jan 1, 1928

Jan 1, 1899

By William P. Shinn

Jan 1, 1881

By David W. Brunton

I. INTRODUCTION. THE list of our past-Presidents comprises the names of runny who, in their official addresses, have sketched the current progress of the arts and professions with which they were familiar. Such addresses are, in my judgment., highly useful, setting forth the results of our own work as a. society, and recalling to our minds the particular lines in which discussion would prove most fruitful. . Following this course with some hesitation, I venture to offer an outline of the recent improvements and the present situation in minim and metallurgy in the Western United States. The wonderful advances in mechanics, chemistry, and electricity have all combined to aid these arts to such an extent that. progress during the last decade has undeniably been more rapid than ever before in the history of the profession.. In all mining countries improved transportation-facilities, in many instances called into existence by the traffic created by the mines themselves, have done much- to enlarge the. field of operations by the reduction of freight-, operating- and living-expenses, thereby bringing lower-grade properties into the producing class. Under normal' conditions, as the age of a district in¬creases, all these differentt factors should combine to off-set. the augmented costs attendant on deep mining, and greatly tend to prolong the profitable life of the mines. The more recent and important improvements in our Western mining-practice which have contributed most toward the advancement of the art may be briefly summarized as follows; but, before beginning this portion of ray address, I wish to thank most heartily the many engineering friends who have so

Sep 1, 1909

By John W. Buch

IN my review a year ago I pointed out that a small coal-mining companies as well as large had decided that the so called ?central shop? was a benefit. These central shops replaced in a large measure the commercial shops operated by those who have no direct connection with production of cod. Central shops in this time of salvage and major repairs have proved their worth. In addition, many of the larger companies had in their central shops equipment available for the production of many thousands of parts for our vast war machine and, as subcontractors, are doing this type of work. This is a real contribution to the war endeavor. Lack of new supplies has resulted in exhaustion of those stocks formerly stored or hidden in underground shanties. This means that the small stock of repair parts likely LO be available to any mine

Jan 1, 1943

By J. W. Rutter, K. T. Aust

Observations are presented of the formation of annealing twins during the growth of a recrystallized grain into a striated, melt-grown crystal of high-purity lead. The formation of an annealing twin resulted in replacement of the original migrating boundary by a large-angle grain boundary of the caincidence-site type or by a near-twin boundary. The results support the Fullman-Fisher theory of annealing twins and demonstrate the usefulness of the coincidence-site model. FULLMAN and Fisher1 have advanced the following theory to account for the formation of annealing twins during grain growth. Whenever a grain A grows into a matrix of grains S1 and S2, a twin A' of grain A may form, as shown in Fig. 1, if the following energetic condition is satisfied: where "E" and "a" refer to the specific interfacial free energy and the area, respectively, of the boundaries indicated by the subscripts. In effect, the twinned grain will persist when the energy of the boundary between the twin(A') and the matrix grain (S, or S,) is less than that of the boundary between the original growing grain (A) and the matrix grain by an amount which exceeds the energy of the coherent twin boundary between A and A'. Experimental observations on the changes in grain boundary free energy accompanying the formation of twins1 are in agreement with the theory outlined in Eq.[l]. Direct observations of the formation of annealing twins at moving grain corners1"3 and the depend-

Jan 1, 1961

By R. E. Salvoti

IN underground coal mining, the increasing trend towards mechanical methods is ever apparent. Figures for 1939 showed that 28 per cent of the total bituminous coal production was mined mechanically 1940 statistic will reveal an even higher figure. Factors causing this trend are varied, but the important are the following;

Jan 1, 1941

By William P. Shinn

IT seems proper to present in the Transactions of the Institute, from time to time, formal record of the advances made in the arts and sciences to which our organization is devoted-milestones in the highway of progress-from which our successors may measure what they in their turn have gained. The admirable address of the Hon. Abram S. Hewitt, then president elect of the Institute, on "A Century of Mining and Metallurgy in the United States," read at the opening of the meeting held in this hall in June, 1876, forms a point of departure, and the conclusion of the eighth decade of the nineteenth century and the end of the first five years of our country's second century seem to offer a fitting time for again making up our record. The period since 1875 has been marked by a degree of activity in mining and metallurgical industry never before equalled in our history, while the progress made in the science and art has been, if possible, still more noticeable. Whether we consider the mining of iron, ore, and coal, or of the precious metals,-the advances made in smelting the former and in reducing the latter, the extraordinary increase in the production of Bessemer steel, or the science of Thomas and. Gilchrist, which makes the hitherto rejected phosphorus the corner-stone of success,-the past five years are alike memorable for the progress they have shown and to some of the most marked features of this progress I will now oriefly call your attention. It may be of interest in this connection to note the following figures, showing the growth of the population of the United-States during the last three decades :

Jan 1, 1881

George A. Packard, Boston, Mass. (communication to the Secretary†):—The very interesting results obtained by Prof. Hofman and his assistants came to my attention when I had temporarily assumed charge of the metallurgical department of the Missouri School of Mines, and had found it, pending the completion of a new building, lacking a furnace in which to roast ore preparatory to the customary lead blast-furnace run. An attempt at lime-roasting had been already determined upon, but the use of a charge which would make a slag of definite composition was a new idea. The results following were obtained by Messrs. Aubrey Fellows, J. C. Long, E. R. Wash, and Dr. T. C. Tseung, under my supervision. It is regretted that the data are not more complete; but the work was done simply incidentally to securing the desired ore for the blast-

Jan 1, 1908

By F. N. Ward, E. H. Bailey

Camp and sample-site methods useful for determining about 0.5 to 16 ppm of mercury in soils and rocks have been devised to complement the analytical methods already widely used in geochemical prospecting. In the camp-site procedure the sample solution is obtained by digesting the finely powdered sample with hot nine-molar sulfuric acid and bromine, the latter generated in place. The solution is buffered at a pH of 4 and the mercury is extracted into a relatively small volume of an organic solvent. Estimations are made by comparing the color of the mercuric dithizonate extracted from the sample with that extracted from a standard. In the sample-site method the mercury is volatilized as the iodide and the latter is dissolved in a buffer solution from which the mercury dithizonate is extracted as in the camp-site method. The estimation is made by a similar comparison with standards or by comparing the color of the mercuric dithizonate with artificial standards prepared from Orange II, an azo dye. Except for the establishment of standards, the time required by an experienced analyst seldom exceeds 10 min for a camp-site determination and 5 min for a sample-site determination. Camp-site determinations are useful for commodity studies and intensive exploration programs; sample-site determinations are applicable to extensive and reconnaissance-type geochemical prospecting programs. The results obtained on samples taken along traverses above known mercury ore deposits in the California Coast Range and western Nevada demonstrate the usefulness of both methods in geochemical prospecting. The increasing use of the mercury content of soils, rocks, plants, or water in geochemical prospecting emphasizes the need for analytical methods which are sensitive and at the same time require a minimum of readily available equipment. Sensitive methods based on the absorption of ultraviolet light by mercury vapor are common in the literature31 12. Although none of these methods have been used to analyze the large number of samples required in geochemical prospecting, they could be extremely useful except for the expensive instrumentation usually required to make the methods quantitative Also, such methods are perhaps too sensitive for field use, especially around areas of possible contamination. Other methods involve the distillation of mercury from a relatively large sample and subsequent collection of the vapors in nitric acid6. The mercury is then estimated by titration with a suitable reagent such as thiocyanate. These methods are not trace methods because the actual amount of mercury measured is often as great as 50 to 100 milligrams. Also, such methods are unsuitable for geochemical prospecting because of the amount of equipment necessary and the time required. Still other methods involve colorimetry, and the sensitive reaction between dithizone and mercury (11).. is the basis for a number of reports on the determination of mercury in biological materials 5,7. Moreover, by the judicious use of solvent extraction and suitable complexing agents, the dithiaone method can be made almost specific for mercury. However, none of the dithizone methods have yet been applied to the determination of mercury in soils and rocks. In most colorimetric methods he sample solution

Jan 1, 1961

By R. T. DeHoff

Saltykov's meihod for the determination of the size distribution of spherical particles from measurements made on random plane sections is extended to particle shapes which are not equiaxed. The analysis permits the deterrrzination of the size distribution of aggregates of ellipsoidol particles provided all particles have tlze same shape. V ARIOUS solutions to the problem of the determination of the size distribution of spherical particles from measurements made on random plane sections have appeared in the literature since the original solution was first published by Scheill in 1934. Solutions have been offered utilizing measurements of the diameter1y2 or area3'4 of circular sections that result when a test plane is passed through an aggregate of spherical particles, and the length of intercept5y6 that results when a test line is passed through the aggregate. To the best of the knowledge of the author, no method has been proposed which permits the determination of the size distribution of particles that are not equiaxed. The purpose of this paper is to develop a method which permits the determination of the size distribution for a specific class of particle shapes which cover awide range of axial ratios; namely, ellipsoids of revolution. In the interests of simplicity, it is necessary to limit consideration to aggregates of particles which are all similar in shape; that is, the ellipses which, by rotation about one of their axes, generate the particles, all have the same axial ratio. The size distribution, which is to be determined by the analysis, is arbitrary. It is also assumed that the section, or sections, upon which the measurements are made represent the average of all possible sections through the structure. This ideal condition can be approached as nearly as may be desired by observing a sufficient area of sections taken at random positions in a randomly oriented aggregate, and in random positions and orientations in an aggregate that has one or more axes of orientation. SIZE DISTRIBUTION FOR PROLATE ELLIPSOIDS Consider an aggregate of cigar shaped, geometrically similar particles (prolate ellipsoids), dispersed in an opaque matrix. Let the size of each particle be specified by the length of its minor axis, By Fig. 1, and the shape, q, be defined by the ratio of its minor to its major axis, B/A. Let the index, j, refer to dimensions of ellipsoids in a particular size class, and the index, i, to dimensions of an ellipse resulting from the intersection of a test plane and a particle. The size of such a section is specified by the length of its minor axis, b. Let the particles be arbitrarily divided into k size classes, and let the increment of size between each class be A, where A = &,$, B,,,being the minor axis of the ellipsoids in the largest size class. Since all sections are represented on the test plane, the minor axis of the largest of the sections observed, results from the intersection of the test plane with an ellipsoid in the largest size class at its center, and is therefore equal to Bmax Thus the increment, A = The final result will consist of the k numbers which represent the number of particles in each size class per unit volume of aggregate:

Jan 1, 1962

By A. L. Barnes, A. M. Rowe

A heat transfer study was made of hot gas injection into oil shale through wells interconnected by vertical fractures. This analysis involved the simultaneous numerical solution of a nonlinear, second-order partial differential equation that describes two-dimensional conduction heat transfer in oil shale and a nonlinear first-order partial differential equation that describes convection heat transfer in the fractures. Three nonlinear, temperature-dependent coefficients were used in this work; they are thermal conductivity, thermal capacity and retorting endothermic heat losses of oil shale. Vertical fractures were considered to be of finite height. Although vertical conduction heat transfer was not considered, an estimate of the error resulting from this limitation was made. The effects of injected gas temperature, injection rate, system geometry, cyclic injection and time upon retorting efficiency were investigated. Results from this study show that the rate of retorting oil shale is a direct function of both injection temperature and rate, and the theoretical producing air-oil ratio:(AOR) is an inverse function of temperature. Retorting rates are constant until "breakthrough" of the 700 F isotherm at the producing well, assuming constant injection parameters. Retorting rates for bounded systems are higher than the analogous unbounded systems and likewise AOR's are less. The use of an alternating injection-soak routine with high injection rates is less efficient than continuous injection at lower rates. These results indicate that injection temperatures on the order of 2000F or greater may give theoretical AOR's in the economic range. INTRODUCTION Over half of the known oil shale reserves are located in the U.S., and most of them lie in the Piceance Creek basin of Western Colorado. The Colorado oil shale outcrops on the edges of the Piceance Creek Basin. At the outcrops the shale beds are relatively thin, from 25 to 50 ft thick. In the center of the basin the oil shale is as great as 2,000 ft thick and is covered with 1,000 ft of overburden. It has been estimated that there are over 1,000 billion bbl of oil in shales having an oil content over 15 gal/ton in this basin. Oil shale does not contain free oil but an organic matter called kerogen. Kerogen yields petroleum hydrocarbons by destructive distillation. It must be heated to approximately 700F, at which temperature it decomposes into shale oil, gases and coke. The U.S. Bureau of Mines and, more recently, oil companies have conducted considerable research on surface retorting methods to economically recover oil from this shale. Another approach to exploit the oil shale deposits, in particular that portion having 1,000 ft of overburden, is to retort the oil shale in place and produce the liquid and gaseous hydrocarbons through wells drilled into the shale. Some research has been done on this approach.l,2 There are several variations to the in situ retorting approach. These variations fall into one of two groups, depending upon the geometry of the system: (1) retorting in a highly fractured or broken up matrix; (2) retorting from single fractures between production and injection wells. The latter is the group studied. Several investigators,3-6 using various assumptions, have studied flow of heat through horizontal systems. The objective of this work was to make a heat transfer study of in situ retorting oil shale by hot gas injection through wells interconnected by single vertical fractures of finite height. The oil shale thermal conductivity, thermal capacity and retorting endothermic heat losses were considered to be functions of temperature. A knowledge of the

Jan 1, 1969

By C. M. Smith

HOWARD N. EAVENSON, acting for the last time as president of the Institute, presided at the annual business meeting on Tuesday afternoon at 4 o'clock. He spoke briefly of his visits with Local Sections last fall, and read a scholarly address on "Mineral Fuels and Civilization," scheduled for early publication in these columns. Karl Eilers presented the Treasurer's report, showing last year's income to be $134,967.44, compared with expenses of $133.266.51. Comparable figures for 1933 were $121,689.90 and $115,462.60. The Institute's peak income was in 1923 about $208,000. Newell G. Alford read the report of the Membership Committee showing 750 new members elected and placed on the rolls in 1934, compared with 328 in 1933. Losses by resignation last year were 81, compared with 262 in 1933; and 691 were suspended for non-payment of dues, compared with 747 the year before. Total membership, including 579 Student Associates, was 7742 at the end of 1934. Applications for membership have been coming in freely the last few months.

Jan 1, 1935

By G. D. Boozer, W. H. Somerton

RESEARCH CORP., LA HABRA, CALIF. Thermal diffusivities of some typical sedimentary rocks have been measured by a rapid unsteady-state technique. Thermal data including diffusivity and conductivity are presented for the temperature range of 200" to 1,800°F. Diffusivities calculated from steady-state conductivity rneasurernents compared favorably with unsteady-state data at the lower temperatures. Unsteady-state data are less reliable at higher temperatures; reported values may be as much as 20 per cent high at temperatures in excess of 1,500°F. This is caused partly by the simplified method used in calculating diffusivity from experimental data and partly by the many thermal reactions which occur at the higher temperatures. The marked decrease in thermal diffusivity and conductivity at elevated temperatures indicates the importance of considering the temperature dependence of thermal properties in subsurface heat-transfer calculntions. Knowledge of the effects of liquid saturation, overburden and pore pressures, and heats of reaction of reservoir materials will be required before complete subsurface thermal analyses may be made. INTRODUCTION Heat-transfer calculations are becoming increasingly important in the analysis of in situ combustion and underground nuclear explosions. Thermal data for natural rock materials at elevated temperatures are generally unavailable. Calculations at high temperatures may be grossly inaccurate if temperature-dependent thermal properties of rocks are not considered. It is known that the heat capacities of rocks increase with temperature. Heat capacities may be calculated from chemical or mineralogica1 analyses of the rock system. Thermal bulk expansion of rocks is believed to be small, although few data are available. Thermal conductivities of most natural rock materials decrease with increased temperature. Thermal diffusivity, defined as the thermal conductivity divided by the product of the heat capacity and the bulk density of the material, is used in unsteadv-state heat-transfer calculations. It is apparent that thermal diffusivity decreases markedly with increased temperature. A new method, which gives a nearly continuous record of thermal diffusivity within the temperature range of 200° to 1,800°F and requires less than 1.5 hours for the run,' was used to measure the diffusivity of several sedimentary rocks. Thermal conductivities were calculated from measured bulk densities, heat capacities calculated from chemical analysis and the measured diffusivity values. Thermal conductivities were measured at lower temperatures by a steady-state technique1 to test the agreement of data obtained by the two methods.

By H. E. Stauss, E. I. Salkovitz, F. W. von Batchelder

EXISTING information regarding the structure of a spherulite in nodular cast iron is based on optical studies. According to these data, a nodule consists of an aggregate of graphite crystallites radiating from the center, with the closely packed basal planes at right angles to the radii. The c axes lie along the radii. This view faces some uncertainty in the fact that the c axis does not represent the accepted direction of fastest growth in graphite. To supplement the optical information, X-ray studies have now been made. The principle used was to screen the nodule in greater part from the X-ray beam and expose only a minor cap. As successively larger portions of the nodule were introduced into the X-ray beam, any differences in the X-ray patterns could be observed. Such photographs have been taken with chromium radiation and a Laue camera. The graphite nodule itself, about 0.010 to 0.025 in. in diam, was mounted with vaseline on a micrometer screw for control of the linear motion. The nodule rotated about 45" each time that it was translated linearly. The nodules were obtained from magnesium-treated hypereutectic iron by electrolytic solution of the iron in hydrochloric acid. In Fig. la is shown the pattern of the thinnest cap examined. In Fig. lb is shown the pattern of the same nodule moved 0.003 in. farther into the X-ray beam, and rotated 45" at the same time. Figs, la and lb indicate incomplete circles for graphite (the two outer circles arise from graphite) with the side arcs much weaker than the top and bottom ones. The arcs obtained are themselves not continuous in intensity but vary with maxima of intensity some 15" and 30" apart. The structure of the nodule that would give rise to such a pattern can be explained as follows. Basically the nodule consisted of small crystallites. The discontinuous character of the diffraction rings demonstrates that the nodule was not composed of randomly oriented crystallites. The strong vertical reflections and the weak lateral reflections show that the reflecting planes were roughly normal to the radii. The absence of sharp reflection spots suggests that the nodule did not contain large crystals. The sharpness of the diffraction rings in their radial direction shows that the variations in intensity along the arcs were not the result of line broadening resulting from extremely small crystals. In the diffraction patterns two rings corresponding to graphite were found. The third and inner ring in the figures originated in the vaseline. The graphite rings correspond to the a and ß lines reflected from the basal planes, showing that the radii of the nodules are the [0001] direction normal to the basal planes of graphite. The picture of the structure that is formed is, therefore, one of aggregates of crystallites. Within each aggregate the c axes of the crystallites tend to align themselves in the radial direction of the nodule, although these axes deviate somewhat in direction by a continuous variation of angle. Correspondingly the basal planes of the graphite crystallites are generally normal to the radii. It is a pleasure to acknowledge the assistance of M. C. Bloom and R. P. Dunphy of this laboratory.

Jan 1, 1952