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H ORACE VAUGHN WINCHELL was born at Galesburg, Michigan, Nov. 1, 1865, and died at Los Angeles, California, on July 28th of this year, at the age of fifty-seven. Mr. Winchell was one of the conspicuous geologists of his time. It may fairly be said that he was a geologist born and reared. His father, N. H. Winchell, was professor of geology at the University of Minnesota; his uncle, Alexander Winchell, was professor of geology at the University of Michigan. Under both of them Horace studied, graduat-ing at the University of Michigan in 1889. Mr. Winchell at once began that active life in the field which he followed for 34 years and until his death. The first years of his professional life were largely spent in the study of the iron ranges of Min-nesota. In 1898, he re-moved to Butte and became geologist in charge of the geological depart-ment of the Anaconda Copper Mining Co. and allied companies. There he remained for eight years. This period covered the trying days of the mining controversies be-tween the Anaconda and associated companies and the Heinze interests, and it fell to Mr. Winchell to direct the geological studies and development in connec-tion with that litigation. Recognizing the importance of careful geological study in the practical operation of mines, he organized and developed the splendid geological department of the Anaconda Copper Mining Co. This was one of his greatest contributions to the mining industry. Probably no mining company has attached the impor-tance to geological study and continuity of geological mapping in connection with mining operations that the Anaconda company has. It has given broad authority to its geological department and the development of its mines is under the direction of its geologists. The broad vision of Mr. Winchell was responsible for the adoption of this policy, one which is being profitably employed by many other organizations.

Jan 9, 1923

By Daniel M. MacNeil, Raymond L. Presbrey, Carle R. Hayward

At the February, 1916, meeting of the Institute, a paper presented by Hayward and Raymond gave the results of a study on the effect of time in tempering medium-carbon steel, when the following conclusions were reached: It is not fair to consider the question settled when only three specimens were used for each treatment, but the results obtained indicate that for reheating quenched medium-carbon steel to temperatures below 500" it is only necessary to heat it through. Longer heating has little or no effect on the tensile strength, ductility, or hardness. At temperatures above 500°, increasing the time of treatment causes a slight falling off in hardness and tensile strength with a corresponding increase in ductility. In the discussion of the paper these conclusions were attacked and evidence was presented that seemed to throw doubt on their accuracy. The authors, however, showed that this evidence was based on high-carbon or alloy steels and no facts regarding medium-carbon steel were presented. During this study the heat treatment was carried out in a small electric resistance furnace. It held nine specimens, but when these were placed in the furnace the temperature was lowered to such an extent that 30 to 40 min. were required to reach the desired heat. The authors pointed to this as a weak point in the investigation and it seemed wise to supplement the research by work on similar steel but using a different method of heating. This has been done and the results are given in the present paper. The Rhode Island Tool Co. coöperated by furnishing the steel and turning the tensile specimens. The steel used in this investigation came in three bars 3/4 in. in diameter; analyses are as follows: Carbon. MaNGanese, Phosphorus, Sulfur Bar NUmber PeR Cent. Per Cent. Per Cent. Per Cent. 1 0.46 0.56 0.010 0.055 2 0.44 0.58 0.007 0.042 3 0.48 0.58 0.007 0.048

Jan 1, 1922

The work of the Committee during the year 1914 was especially directed to the securing of a larger representation in the Institute of those engaged in coal mining and coking. While these industries exceed in volume and in monetary importance all other mining industries in the United States, the membership of the Institute representing them has in recent years been relatively small. It was thought that an increase in the membership of the Institute obtained from among those engaged in these industries was desirable in order to increase interest in the work of the Institute, for this result can only be reached by securing the presentation and publication of a larger number of papers relating to these industries. It is evident that the reading of such papers will tend to increase the attendance at the local and general meetings of the Institute. Sessions of the Coal and Coke Committee were held and a number of papers relating to these subjects were presented at the meetings at Butte, Salt Lake, and Pittsburgh, the Pittsburgh meeting especially being planned with this in view. The activities of the Local Section of the Institute organized in the Pennsylvania Anthracite region have reawakened interest in that district and it is hoped that the same object can be obtained in the bituminous coal fields, either through the organization of one or more. local sections, affiliation with some of the local coal-mining societies, or through activities of the Coal and Coke Committee. Referring to the work of the Committee in its efforts to increase the membership of the Institute, the Committee desires to acknowledge the services rendered by many members scattered throughout the various coal-mining districts of the United States, in compiling lists of those qualified for membership in the Institute, but who have not yet become members. The lists so compiled comprised about 1,100 names, which were furnished to the Committee by the co-operation of 40 or 50 members of the Institute.

Jan 3, 1915

By W. G. Matteson

THE Oklahoma legislature recently passed a bill providing for "the creation of an oil and gas department under the jurisdiction of the Corporation Commission, authorizing the. Corporation Commission to appoint a chief oil and gas conservation agent, and conferring exclusive jurisdiction on the Corporation Commission in reference to the conservation of oil and gas, and the inspection of gasoline and oil, the product of crude petroleum, and repealing all acts or parts of acts in conflict therewith and declaring an emergency." Some of the functions of the new bureau include the receiving and filing of all well logs and the direction and supervision of plugging all abandoned oil and gas wells under rules prescribed by the Corporation Commission. The two leading petroleum-producing States of the country, Oklahoma and California, have now established oil and gas bureaus with a staff of inspectors to see that the important rules relating to the conservation of oil and gas are thoroughly enforced. The economic significance and the value of well logs in the conservation work has been recognized and the necessary legal action taken to insure and procure them. William B. Heroy, of the Government Land Classification Board, in a personal communication to the writer, says that the drilling of wells is also regulated by public authority in the Roswell artesian basin in southeastern New Mexico, where a permit must be obtained for the drilling of any well and a certified log of the well recorded with a county official. The method is said to give fairly satisfactory results. In a recent article 1 a National instead of a State Bureau was suggested for collecting and filing well logs. In discussing the paper, L. L. Hutchison characterized such a plan as impractical because the average driller or contractor will often juggle or guess at the log and will not keep the record sufficiently close or accurate, making it necessary to maintain a special man at each well for the sole purpose of obtaining

Jan 6, 1917

By E. H. Griswold

The surveying of oil wells has in recent months become a common practice in the deep fields of the Mid-Continent area. Borehole surveys have been made by mining companies for many years, but the introduction of such methods into the oil fields has been delayed until the past few years, because the value of survey data was not fully appreciated. The acid and gelatin bottle methods of obtaining the angle of deviation and the floating compass method of obtaining the direction of horizontal drift have been in use for more than 20 years. A photographic recording instrument consisting of a plumb bob, magnetic needle and electrically operated camera was devised and used in the Rand mining fields of South Africa prior to 1912.1 Another and improved photographic instrument, depending upon orientation of the drill pipe instead of polar magnetism for direction, has been invented and used. The acid bottle method has also been used in conjunction with oriented drill pipe. The magnetic compass is not reliable for oil-well work because of the unsymmetrical attraction of the needle to the well casing and possible magnetic formations. Many engineers also concur in the opinion that orientation of the drill pipe from instrument to surface will be inaccurate because of the torque exerted between the drill pipe and walls of the hole, causing the lower sections of pipe to twist. When it is considered that 4000 ft. of 6 in. drill pipe has approximately the same slender-ness ratio as 6 ft. of silk thread, such twisting effects can be readily visualized. The gyroscopic compass has been suggested for use in direction finding, but the high cost of such instruments will prohibit their use, except in special cases. Due to the lack of accurate direction-finding instruments, almost all of the survey work in the Mid-Continent fields has been of the acid bottle method alone.

Jan 1, 1929

By Thomas Fraser, Abreu Alvaro

THE work described in this paper was carried out under the sponsorship of the Foreign Economics Administration and in cooperation with the Departamento Nacionál da Produção Mineral, Rio de Janeiro. The project was undertaken to obtain complete data on the variations in washability of coal to be used for coke manufacture in the steel industry and to determine the economy of preliminary hand-sorting operations. The coal-producing industry of Brazil is in that pioneering stage in which operat¬ing practices and methods are just being developed. Increased wartime demand for fuel, coincident with a drastic curtailment of foreign supplies due to lack of shipping facilities, has put a tremendous pressure on the national industry to furnish more coal. Under this incentive, production facilities are being expanded and new methods of operation are being tested. Such changes are being developed both by improvement of existing methods that originated in the field and by adaptation and modification of methods introduced from the United States and Europe. These mining condi¬tions and mining practices in Brazil are typical of what the American mining engineer will find in many instances when he goes pioneering into the developing coal fields of the Southern Hemisphere. The producing coal fields of Brazil are all in the southern states of that country. The coal measures are in a band roughly paralleling the coast and extending in a generally southwesterly direction from northern São Paulo through the states of Paraná, Santa Catarina and Rio Grande do Sul to near the Uruguayan border in the vicinity of Bajé. The accompanying map1 (Fig. I shows the general location of these fields and also the principal routes of movement of both national and imported coal in a late pre-war year (1940). Statistical data on production by states up -to that year are given in Table I. Rio Grande do Sul is still the largest producer among the coal states; but wartime

Jan 1, 1946

By John Chipman

HE lecture on 'Thermodynamic Properties of Blast Furnace Slagso prepared in 1959 and published two years later required revision in one particular before it appeared in print. The activity of SiO, was deter mined through studies of the equilibrium: SiO, (in slag) 2C (graphite) = (in Fe) 2C0 (1 atm) The ratio for each experimental temperature was found from the heat of formation of cris-tobalite, the entropies and heat capacities of the re-actants, by virtue of the third law of thermodynamics. Discrepancies between several kinds of data led to investigations regarding other equilibria involving SiO, on the suspicion that there might be an error in the third-law value of its free energy. In particular the equilibrium: was restudied by Kay and Taylor who Confirmed the earlier results of Baird and Tayloron which their SiO, activities depended. The free energy of Sic was also rechecked4 independently. These and other equilibrium measurements led to the conclusion6 that the free energy of SiO, at high temperatures is in error and requires a correction of about -5 kcal. The exact source of the error is uncertain; it could lie either in the entropy of SiO, or in its heat of formation, but it more probably lies in the latter. Adjustment of this free energy lowers the ratio by a factor of approximately 4. Accordingly it will be necessary to multiply by this factor all of the SiO, activities determined by this method.',B Referring to the lecture cited, this correction should be applied in Figs. 8, 9, 10, 19, and 20. It applies also to the experimental data of Fig. 13, bringing these as well as those on the ternary system into good agreement with the work of Taylor and associates. At the same time it eliminates the discrepancy shown in Fig. 11, lowering both lines until the upper

Jan 1, 1962

By H. C. Howarth

This paper gives observations on ground movement and subsidence resulting from pillar drawing in the Lick Run section of Montour No. 10 mine of the Pittsburgh Coal Co. adjacent to solid coal owned by the U. S. Bureau of Mines at its Experimental mine in Snowden Township, Allegheny County, Pennsylvania. The investigation was planned by George S. Rice, chief mining engineer of the Bureau, who arranged the necessary cooperation with Dr. L. E. Young, vice president of the Pittsburgh Coal Co. Engineers of that company placed permanent monuments on the surface to establish the boundaries of the coal owned by the Bureau and to furnish fixed points to which all levels were referred. Engineers of the Experimental mine staff then covered the ground under observation with a checkerwork of monuments made of oak pegs set into the ground at 50-ft. intervals in two directions at right angles to each other. The level of these pegs was determined first from Dec. 16 to 30, 1929; again from May 25 to June 5, 1930, and finally from July 7 to 15, 1931. Observations were then discontinued because work had been stopped temporarily in this part on Montour 10 mine. General Conditions Fig. 1 is a plan of the part of the area under observation with which this paper deals. The mine is developed on a room and pillar system known locally as half advancing and half retreating. As Nos. 35 and 36 butt entries were advanced, rooms were driven from No. 36 and drawing of the room pillars followed their completion. When the entries reached the boundary, rooms were started from No. 35 butt beginning at that point, and all remaining pillars were drawn as rapidly as possible. The rib lines of Jan. 9 and June 13, 1930, were surveyed a week to 10 days after the first and second sets of levels were run, and there was some advance in that period. The rib line of July 15, 1931, agrees in time

Jan 1, 1934

By G. A. Reinhardt, H. J. Cutler

ThE Youngstown Sheet & Tube Co. has produced a large tonnage of 0.35 to 0.45 carbon forging steel, the acceptance of which was based on the physical properties of test specimens obtained by forging the original 5 3/4-in. (14.5 cm.) square bloom to a 3/4-in. (1.9 cm.) round. Annealed and tempered specimens were required. The test bars were annealed by heating from 900" to 950' C. and cooling slowly in mica. The test bars were tempered by heating to 825' to 875" C., quenching in water, and drawing to 515" to 535" C. Immediately after heat treatment, the test pieces were machined to a diameter of 0.534 in. (1.38 cm.) and tested. Very good physical properties were obtained and no difficulty was experienced in meeting the specifications called for. UlTimate Strength.. Elongation, Lb. pER Sq. In. PEE Cent.. in 4 In. Not LeEs Than Annealed specimens.............. 78,230 to 92,450. 18 Tempered...................... 120,000 to 149,350 9 After experience on this material, production of slightly higher carbon forging steel was started. The method of testing this material required that test blooms be either normalized or annealed. The normalizing consisted in heating to 850" to 900" C. and cooling in still air; the annealing, in heating to 850" to 900" C. and cooling in the furnace or in mica. From the treated bloom, the test pieces were taken either by core drilling or by sawing from points midway between the edges and the intersection of the diagonals. The cores or blocks were turned to a standard 2-in. test piece with a diameter of 0.564 in. and tested without further treatment. The physical requirements of the test pieces were: yield point, pounds per square inch minimum, 44,800; ultimate strength, pounds per square inch, 89,600 to 112,000; elongation, per cent. in 2 in. not less than 17. Difficulty was encountered as soon as work on this material was started. Many precautions and refinements were instituted but it was found very difficult to secure the required elongation.

Jan 1, 1920

By C. P. Watson, R. E. Collom

Various chapters already written in the history of development of the North Dome of Kettleman Hills are monotonoysly identical in the one underlying' theme of conservation of oil and gas. Discovered on Oct. 4, 1928, by Milham Exploration Co. with its wildcat Elliot No. 1, the field has been subjected to practically every modern form of production restraint in the name of conservation. The record thus far developed shows that conservation was had for a time, at a price; and that unitiza-tion must be blessed by single ownership or 100 per cent participation to be effective. In fact, incomplete unitization places a heavy handicap upon its participants in the competitive development that follows. Shut-in Agreement of July 25, 1929 Not long after discovery at Kettleman but after the Continental Oil Co. and the Standard Oil Co. had completed several producing wells in the discovery group, came the so-called Shut-in Agreement negotiated at the instance of the Department of the Interior. This agreement became effective July 25, 1929. The fundamental purpose of the agreement was to prevent bringing on production of some 30 wells then being drilled and forestall a flood of Kettleman oil on the market. A cooperative scheme was developed whereby wells in the discovery group would continue to produce. Two of them could not be shut in. Drilling wells would be completed to a water shutoff in top of Temblor and operations suspended. Producing wells would contribute the value of 10 to 25 per cent of their production to the owners of suspended qualifying wells. The percentage rate of drainage contribution was left to a committee or umpire. Some acreage was not placed under the agreement. This same acreage later did not come into the Kettleman Unit Agreement. Several wells on this acreage did not contribute to the drainage fund. The total amount of oil produced during the 17 months of the shut-in agreement, by Milham, Continental and Standard from wells in the discovery group, was 5,297,262.22 bbl. The total amount paid out in "drainage" contributions was $2,046,048.18, representing sales value of 1,266,044.06 bbl. of oil.

Jan 1, 1937

By P. Somasundaran

Almost a decade has elapsed since the problem of fine particles processing was first discussed at the National Science Foundation workshop in Arden House (Somasundaran and Fuerstenau, 1976). Problems involved in processing fines are as enormous now as they were then. We still lose 20 to 50% of mineral values during the processing of many ores. While the problem's magnitude has remained at as high a level as ever, our perspective on the causes for the difficulties, I believe, has changed. While we do not yet see any grand unified solution to all the problems in this area, I do feel that we are beginning to get an understanding of the basic reasons for the behavior of fines. I would like to share my views on the fundamental reasons for the problems we face. They are based essentially on results obtained during the last few years. A decade ago, I presented the reasons shown in the [Fig. 1] as the causes for the difficulties in separating fines. We have seen the same type of information discussed by others during the years since then. I now believe that these are not the only primary causes. Indeed, they do contribute, but there are other major reasons we ought to recognize. Mass certainly would have its effect, but since microorganisms and even ions can be separated from each other using flotation, provided correct conditions are used. I do not believe that fines 10,000 times bigger suffer fundamentally from their smallness or lightness. Similarly, the surface energy increase cannot be as important a fundamental factor since, theoretically, we should not see significant changes in surface energy until we get down to particles a hundred times finer than we are concerned with. Increase in surface areas, again, cannot be a primary problem except for an increase in reagent consumption. What possibly could be the reasons? I have added these three items to the list in [Fig. 1]: morphology, mineralogy, and surface chemical composition. Differences that I believe are partly responsible for the behavior of mineral fines are those due to alterations in morphology or mineralogy and surface chemical composition with decrease in size.

Jan 1, 1985

By Charles T. Van Winkle

Until the advent of the porphyry coppers and the introduction of flotation which soon followed, crushing and grinding for many years proceeded along somewhat stereotyped lines, without important alteration in type of machinery. For the finer crushing and grinding, stamps, rolls, and various patterns of Huntington and Chilean mills were in general use. Ball-mills were in use abroad, but owing to their small capacity and the high cost of screens and steel, they never obtained much footing in the United States. Tube-mills were first introduced into the crushing departments of cyanide plants when it was found that for crushing finer than 30-mesh other types of crushing machinery were not efficient. In order to crush with one pass, these mills were made 18 to 22 ft. (5.5 to 6.7 m.) in length. Pebbles were used as a grinding medium and the mills were lined with either silex blocks or fragments of quartz or flint pebbles set in cement. While the cylindrical tube pebble-mill had been used to some extent in small installations of concentration mills, the first instance of its use on a large scale was at the concentrating plant of the Miami Copper Co., where 8-ft. by 22-in. (2.5-m. by 55.9-cm.) Hardinge mills were tried out against Chileans. The results of these experiments led to the gradual replacement of the Chilean by the Hardinge mill. Robert Franke published an article' describing the work done, comparing the two types of mills. At the same time, according to Franke, a test was run using a 6-ft. (1.8-m.) Hardinge ball-mill as a substitute for rolls for intermediate crushing on 1/2-in. material. According to Franke, this mill was soon discarded, since it was found that to obtain the desired product the mill must be limited in capacity. The Miami Copper Co. made no test with other types of ball- or pebble-mills. Following this example, others installed the conical type; and when the Inspiration Consolidated Copper Co. decided to build a concentrator, it adopted the conical mill. As the requirements for mills would be very large, it purchased manufacturing rights in the State of Arizona from the

Jan 1, 1918

By Paul A. Farrar, Felix Ermains, Harold Margolin

The systems Ti-Crand Ti-Vhave been reinvesti-gated in the region up to 40 wt pct alloying addition using both conventional and rapid quenching techniques. The Ti-Cr eutectoid temperature was determined to be at 667° & 10° C and 14.5 wt pct Cr. The solubility of the Cr in a Ti was found to be less than 1 pctat 700"C. The P transus of the Ti-V system was found to be depressed to 510°C at 40 wt pct V and the solubility of V in a Ti was found to be less than 2 wt pct at 700°C. Investigation by a. d. McQuillan1-3and m. k. McQuillan4 on the systems Ti-Co, Ti-Cr, Ti-Cu, Ti-Fe, Ti-Mn, Ti-Ni, and Ti-V has cast doubt as to the position of the ß/a + ß boundaries in many of these systems. Their investigations were carried out using hydrogen pressure and/or rapid quenching experiments, as opposed to the conventional quartz capsule techniques employed by most other investigator.'" By these methods, the ß/a + ß boundary was found to be lower than that obtained by conventional techniques in all except the Ti-Fe system. In the latter, the ß/a + ß boundary was essentially the same as the boundary obtained by conventional technique.7' On the basis of rapid quenching results in the Ti-Cr system, M. K. McQuillan4 placed the eutectoid temperature below 550°C whereas other investigations using conventional techniques had placed the eutectoid variously as between 650' and 700°C,5 between 675' and 700°C,6 between 650" and 675°C,7 at 670°C,8 and above 625"C.la9l3 In order to check these results, a reinvestigation of four of the systems was undertaken using both conventional and rapid-quenching techniques. The Ti-Fe and Ti-Mn systems will be dealt with in anoth er paper, with only the Ti-Cr and Ti-V systems being discussed here. EXPERIMENTAL TECHNIQUES Alloys employed for the delineation of the systems under investigation were prepared from iodide titanium sheet capsules containing the alloying materials,

Jan 1, 1962

By A. G. Roach

This paper deals with a plant built under joint agreement between the Canadian and United States Governments to supply the strategic mineral, corundum, at a time when African production was dwindling and war demands still increasing. The operation began in September 1944, retreating the tailings from a former mill by gravity methods, and is still in production (Sept. 1946). In 1942, when it became apparent that South African production would be insufficient to meet mounting wartime requirements of corundum, a survey was made of Canadian sources of the mineral, at the request of the Foreign Economic Administration of the U. S. Government. The investigation' indicated that the quickest and cheapest supply would be obtained by reworking the tailings deposit at Craig-mont, Ontario. Sampling of the dump by Canadian Government engineers revealed that 125,000 tons of tailings, averaging 2.96 pct corundum, was available for retreat-ment. Ore-dressing tests on representative samples of the deposit were conducted by the writer in the laboratories of the Industrial Minerals Section of the Department of Mines and Resources at Ottawa; and gravity concentration on tables was indicated as the most suitable method of treatment. Decision to proceed with the project was deferred until May 9, construction was begun on May 18, and tune-up operation of the plant begun on Sept. IS, 1944. Corundum—Its Properties and Uses Corundum is an oxide of aluminum having the formula Al2O3. Its outstanding characteristic is its great hardness; 9 in the Mohs scale. In this respect it is second only to the diamond. It usually occurs in barrel-shaped crystals in nepheline syenites and other feldspathic rocks deficient in silica. It has a specific gravity of 3.95 to 4.1 and is insoluble and infusible. In color it ranges from white, through red and green, to black. Ruby and sapphire are gem varieties of corundum. Corundum is supplied to industry as closely graded grain.= The coarser roducts (10 to 24-mesh) are used largely for snagging wheels in the steel-castings industry, while the finer grades (from 70-mesh down to flours) find a wide application in the polishing of lenses and for other uses in the optical trade. All sizes of corundum grain are in close competition with synthetic abrasives such as carborundum and alundum. In some fields of application the artificial product is superior to the natural grain but not in' all. The shape of the particle and its behavior under conditions of actual use determine its sphere of employment. The United States is the largest 'Onsumer of corundum, annual consumption in peacetime approaching 3000 tons; during the war this figure was roughly doubled. During the years 1902 to 1913, the bulk

Jan 1, 1948

By A. G. Roach

This paper deals with a plant built under joint agreement between the Canadian and United States Governments to supply the strategic mineral, corundum, at a time when African production was dwindling and war demands still increasing. The operation began in September 1944, retreating the tailings from a former mill by gravity methods, and is still in production (Sept. 1946). In 1942, when it became apparent that South African production would be insufficient to meet mounting wartime requirements of corundum, a survey was made of Canadian sources of the mineral, at the request of the Foreign Economic Administration of the U. S. Government. The investigation' indicated that the quickest and cheapest supply would be obtained by reworking the tailings deposit at Craig-mont, Ontario. Sampling of the dump by Canadian Government engineers revealed that 125,000 tons of tailings, averaging 2.96 pct corundum, was available for retreat-ment. Ore-dressing tests on representative samples of the deposit were conducted by the writer in the laboratories of the Industrial Minerals Section of the Department of Mines and Resources at Ottawa; and gravity concentration on tables was indicated as the most suitable method of treatment. Decision to proceed with the project was deferred until May 9, construction was begun on May 18, and tune-up operation of the plant begun on Sept. IS, 1944. Corundum—Its Properties and Uses Corundum is an oxide of aluminum having the formula Al2O3. Its outstanding characteristic is its great hardness; 9 in the Mohs scale. In this respect it is second only to the diamond. It usually occurs in barrel-shaped crystals in nepheline syenites and other feldspathic rocks deficient in silica. It has a specific gravity of 3.95 to 4.1 and is insoluble and infusible. In color it ranges from white, through red and green, to black. Ruby and sapphire are gem varieties of corundum. Corundum is supplied to industry as closely graded grain.= The coarser roducts (10 to 24-mesh) are used largely for snagging wheels in the steel-castings industry, while the finer grades (from 70-mesh down to flours) find a wide application in the polishing of lenses and for other uses in the optical trade. All sizes of corundum grain are in close competition with synthetic abrasives such as carborundum and alundum. In some fields of application the artificial product is superior to the natural grain but not in' all. The shape of the particle and its behavior under conditions of actual use determine its sphere of employment. The United States is the largest 'Onsumer of corundum, annual consumption in peacetime approaching 3000 tons; during the war this figure was roughly doubled. During the years 1902 to 1913, the bulk

Jan 1, 1948

By George Sachs

I deeply appreciate the honor of being selected to deliver the twentieth Annual Lecture of the Institute of Metals Division. The subject of my paper is extremely involved and voluminous, therefore I shall discuss only some more recent experimental material and speculate somewhat on the physical and mechanical fundamentals of these changes. The flow and the rupture of a solid material are rather different phenomena. It is therefore surprising that up to a rather advanced stage in metallurgical science these two fundamental phenomena have been simultaneously treated and forced into the general conception of the "failure" of solid material. Only in this century, and particularly during the last 20 years, have the very different physical meanings of flow and rupture been clearly recognized. Several hundred of the more recent publications deal with these subjects.1 LAW OF SIMILARITY The basic values commonly considered responsible for the mechanical behavior of any material are the stresses. From this standpoint both a large and a small article made from the same homogeneous metal and of geometrically similar shapes should behave identically, i.e., they should deform geometrically in a similar manner, if subjected to the same stress values at corresponding points. This "law of similarity" was introduced about 60 years ago simultaneously by Barba2 and Kick3 and was derived from the classical theory of elasticity. As far as the plastic behavior of a metal is concerned, this rule appears to be valid. The conventional properties of large and small tension or compression test bars, machined from larger sections, are identical; while the force required to deform a section is proportional to its cross-sectional area and the work consumed in deforming geometrically similar articles in a geometrically similar manner is proportional to its volume. The general trend of the stress-strain diagram of a metal is independent of the section size (Fig. I). No exceptions from this rule are known. However, if the deformation of a metal is continued until rupture occurs, and the breaking stress or the work consumed is measured, a test bar of large cross section appears to fail before or at lower stresses than does one having a small cross section. Thus, the specific impact energy has been often found to decrease with increasing size of the test specimen, particularly for materials with a limited ductility.4 Another exception from the rule of similarity is offered by fatigue-strength values, which usually decrease with increasing section size. 5,6 The conclusion must be drawn from these experimental facts that the ductility of a homogeneous metal decreases with increas¬ing section size (Fig. x). This effect has been actually confirmed by Docherty,7 who observed that in static notch bending tests large specimens failed earlier and in a more brittle fashion than small specimens ma-

Jan 1, 1941

By William M. Newton, John E. Sherborne

The relation between the properties of electric logs and the fluid used in drilling a well is briefly discussed in this paper, and the fact that the resistivity of the drilling mud and its filtrate can appreciably affect such logs is shown. Apparatus was designed and a procedure established to determine the effect of various factors on the resistivity of drilling mud. Five muds commonly employed in California were tested and the following observations were made: I. The effect of raising the temperature from 80°F. to 180°F. is to decrease the resis-tiviiy of the mud or filtrate approximately 50 per cent. 2. The resistivity of the mud in most cases closely approximates that of its filtrate. 3, The change in the resistivities of muds caused by the addition of chemical is not the same function of the amount of chemical added for each mud. 4. The effect produced by increased sodium chloride content is to reduce markedly the resistivity of the mud and its filtrate. 5. Weighting materials, such as Baroid and limestone, tend to increase the resistivity of drilling mud. 6, Cement and counteracting reagents reduce mud resistivity. Introduction During recent years, the practice of "electrically logging9' a geologic formation by means of a system of electrodes lowered in a well bore has provided data of inestimable value concerning the nature of the sediments penetrated. Thus, it is generally possible, by means of electric logs, to distinguish readily the differences between shales, sandstones, cherts, limestones, and other rock forms. The distinguishing characteristics recorded in this manner have made possible long-range and closely detailed mapping and visualization of deeply buried structures1-5 to a degree not to be obtained with a reasonable expenditure of money by any other means at present in use. Besides being of value in correlation work, electric logs have been found, in some instances, to be useful in estimating the nature of fluid contained within the pores of a rock. In special cases, even the relative permeabilities at different horizons have been determined.6 That electric logs should reflect in some measure such physical properties of rocks as porosity and permeability and, in addition, give rise to data pertaining to the fluid content of rock interstices, becomes evident when the conditions giving rise to the electrical phenomena measured are known. However, it is not the purpose of this paper to review the present status of electric logging; rather, the reader is referred to the papers cited on page 220 for the principles and practice involved. Importance of Drilling FLuid in Electric Logging Because the drilling fluid must be the medium through which the electric logging device is made to traverse the formations penetrated by a borehole, and since, in general, the drilling mud completely surrounds

Jan 1, 1942

By John E. Sherborne, William M. Newton

The relation between the properties of electric logs and the fluid used in drilling a well is briefly discussed in this paper, and the fact that the resistivity of the drilling mud and its filtrate can appreciably affect such logs is shown. Apparatus was designed and a procedure established to determine the effect of various factors on the resistivity of drilling mud. Five muds commonly employed in California were tested and the following observations were made: I. The effect of raising the temperature from 80°F. to 180°F. is to decrease the resis-tiviiy of the mud or filtrate approximately 50 per cent. 2. The resistivity of the mud in most cases closely approximates that of its filtrate. 3, The change in the resistivities of muds caused by the addition of chemical is not the same function of the amount of chemical added for each mud. 4. The effect produced by increased sodium chloride content is to reduce markedly the resistivity of the mud and its filtrate. 5. Weighting materials, such as Baroid and limestone, tend to increase the resistivity of drilling mud. 6, Cement and counteracting reagents reduce mud resistivity. Introduction During recent years, the practice of "electrically logging9' a geologic formation by means of a system of electrodes lowered in a well bore has provided data of inestimable value concerning the nature of the sediments penetrated. Thus, it is generally possible, by means of electric logs, to distinguish readily the differences between shales, sandstones, cherts, limestones, and other rock forms. The distinguishing characteristics recorded in this manner have made possible long-range and closely detailed mapping and visualization of deeply buried structures1-5 to a degree not to be obtained with a reasonable expenditure of money by any other means at present in use. Besides being of value in correlation work, electric logs have been found, in some instances, to be useful in estimating the nature of fluid contained within the pores of a rock. In special cases, even the relative permeabilities at different horizons have been determined.6 That electric logs should reflect in some measure such physical properties of rocks as porosity and permeability and, in addition, give rise to data pertaining to the fluid content of rock interstices, becomes evident when the conditions giving rise to the electrical phenomena measured are known. However, it is not the purpose of this paper to review the present status of electric logging; rather, the reader is referred to the papers cited on page 220 for the principles and practice involved. Importance of Drilling FLuid in Electric Logging Because the drilling fluid must be the medium through which the electric logging device is made to traverse the formations penetrated by a borehole, and since, in general, the drilling mud completely surrounds

Jan 1, 1942

By Tell Ertl

THE Piceance Creek Basin in northwestern Colorado is believed to contain the richest large deposit of oil shale in North America. The major portion, about 1650 sq miles, is bounded by the White River on the north, the Grand Hogback, which runs from Meeker to Rifle, on the east, the Colorado River to the south, and the drainage basin of Salt and Douglas Creeks on the west. The Basin is a plateau 7000 to 9000 ft high, composed of 3000 ft of the Green River series of Eocene age and surrounded by a steep escarpment of 1000 to 3000 ft. From the escarpment the beds dip gently toward the center. Although oil shale is found in all members of the Green River series, the rich thick beds are found chiefly in the Parachute Creek member. This is normally capped by 100 to 200 ft of the Evacuation Creek, the youngest member of the Green River series. Actually the Piceance Creek Basin oil shale is not a shale, nor does it contain oil. It is magnesium marlstone holding solid organic matter capable of being broken down by heat into gases, some of which can be condensed into oil. The marlstone is resilient nonporous rock, difficult to sample by pick or hammer and moil. Many companies and individuals prospected the Colorado oil shale shortly after the first World War,' see Fig. 1, but because of the discovery of large quantities of petroleum in the late 1920's in Cali- fornia, Oklahoma, and East Texas, interest in oil shale development waned and did not revive until World War 11. In 1944 the writer, employed by the Bureau of Mines, prospected the high grade oil shale in numerous places along the southern outcrop of the Piceance Creek Basin. Several channel samples about 100 ft in length were cut, see Fig. 2. An eight-man crew needed a week to cut a satisfactory channel 80 ft long in the cliff face. The Phillips Petroleum Co., the Union Oil Co. of California and others also prospected the oil shale outcrop. In 1945 the Bureau of Mines initiated a core drilling program for the purpose of obtaining accurate samples from the Piceance Creek Basin. The U. S. Geological Survey set up a program for the geological study of the Basin that is still going on." Until the end of 1951 a total of 31 holes was drilled for core with diamond drills, and, in addition, cuttings through the oil shale have been obtained from 4 gas wells drilled by standard rotary oil well rigs. The Bureau of Mines drilled 12 of the holes, the Union Oil Company of California 8, the Standard Oil Company of California 6, the Sun Oil Company 3,

Jan 1, 1953

By Tell Ertl

THE Piceance Creek Basin in northwestern Colorado is believed to contain the richest large deposit of oil shale in North America. The major portion, about 1650 sq miles, is bounded by the White River on the north, the Grand Hogback, which runs from Meeker to Rifle, on the east, the Colorado River to the south, and the drainage basin of Salt and Douglas Creeks on the west. The Basin is a plateau 7000 to 9000 ft high, composed of 3000 ft of the Green River series of Eocene age and surrounded by a steep escarpment of 1000 to 3000 ft. From the escarpment the beds dip gently toward the center. Although oil shale is found in all members of the Green River series, the rich thick beds are found chiefly in the Parachute Creek member. This is normally capped by 100 to 200 ft of the Evacuation Creek, the youngest member of the Green River series. Actually the Piceance Creek Basin oil shale is not a shale, nor does it contain oil. It is magnesium marlstone holding solid organic matter capable of being broken down by heat into gases, some of which can be condensed into oil. The marlstone is resilient nonporous rock, difficult to sample by pick or hammer and moil. Many companies and individuals prospected the Colorado oil shale shortly after the first World War,' see Fig. 1, but because of the discovery of large quantities of petroleum in the late 1920's in Cali- fornia, Oklahoma, and East Texas, interest in oil shale development waned and did not revive until World War 11. In 1944 the writer, employed by the Bureau of Mines, prospected the high grade oil shale in numerous places along the southern outcrop of the Piceance Creek Basin. Several channel samples about 100 ft in length were cut, see Fig. 2. An eight-man crew needed a week to cut a satisfactory channel 80 ft long in the cliff face. The Phillips Petroleum Co., the Union Oil Co. of California and others also prospected the oil shale outcrop. In 1945 the Bureau of Mines initiated a core drilling program for the purpose of obtaining accurate samples from the Piceance Creek Basin. The U. S. Geological Survey set up a program for the geological study of the Basin that is still going on." Until the end of 1951 a total of 31 holes was drilled for core with diamond drills, and, in addition, cuttings through the oil shale have been obtained from 4 gas wells drilled by standard rotary oil well rigs. The Bureau of Mines drilled 12 of the holes, the Union Oil Company of California 8, the Standard Oil Company of California 6, the Sun Oil Company 3,

Jan 1, 1953