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By E. W. Davis

THE mysterious Lake Erie price for iron ore, established each spring, determines the maximum price that will be paid during the following season for ore of Mesabi Non-Bessemer base grade. This price is impor-tant to the ore producers, but since most of the ore in the Lake Superior district is owned or controlled by consuming inter-ests, the really important question to them is not the price of ore but how much it will cost them to mine and transport their season's requirements to their furnace plants. However, a few million tons are actually sold each year, and considerable quantities are traded for mixing purposes, and the negotiations for these sales and trades usually begin with some reference to the Lake Erie price. There is no difficulty with the Lake Erie price itself or with the manner in which it is established, but the system prescribed for determining the values of ores that are not exactly base grade is incomplete. The Lake Erie price takes into consideration only the iron and phosphorus contained in the ore, but when the ore producer is negotiating a sale or trade, he is confronted by the fact that his ore must be studied and the price adjusted, not only on the basis of the iron and phosphorus analyses, as specified by the Lake Erie price, but also on the basis of silica, alumina, man-ganese, structure, etc. The vague and unsatisfactory methods used in making these adjustments bear some relation to the manner in which the ore is supposed to act in the blast furnace. The ore producer may not understand all of the idiosyncrasies of the blast furnace, but if the smelting-plant operators have a system more accu-rate than the Lake Erie price method for determining the relative values of different ores, why not pass this information on to the ore producers, so that they can make use of it and perhaps modify their practice in such a manner as to benefit both them-selves and their customers? There is a lack of understanding and appreciation between these two groups that may, to some extent, be unavoidable, but in the interests of efficiency and conservation rules that are more accurate and complete than the Lake Erie price method in use at the present time should be established for the guidance of the ore producers.

Jan 1, 1940

By George Cole

WHILE many parts of Canada's pre-Cambrian shield are well served by railway, it is frequently necessary for prospecting purposes to proceed farther into areas in-accessible by rail. To such areas in summer the canoe was at one time the accepted means of travel for the prospector while the dog team was much used in winter. Al-though summer travel was much improved by the development of the outboard motor, the lack of facilities for cheap transporta-tion has been a serious hindrance to the employment of capital in opening up the distant fields. The pre-Cambrian surface of Manitoba, like that of Ontario, is hummocky, with rounded hills and ridges of rock alternating with basinlike depressions and valleys oc-cupied by lakes and rivers or by many low-lying portions covered with muskeg. Routes to the mines have not usually been direct or easy and seasonal vagaries have presented problems in themselves. In summer, water transportation may be the cheapest method for the longer dis-tances but it is not every water route that will satisfy the conditions of loading freight onto a boat or scow and of conveying it without interruption to its destination. By its location, a mine may require a large program of boat transportation in summer over part of its route, to be followed by winter freighting for the remainder. In order to carry on development and produc-

Jan 1, 1940

[Aalde, Kaare, ('40) New Mexico School of Mines, Socorro, N. M. Abadesco, Enrique A., ('39) Univ. of the Philippines, Manila, P. I. Abdul-Ahad, A., ('39) Montana School of Mines, Residence Hall, Butte, Mont. Abreu, Ovidio M., ('38) Univ. of Nevada, Reno, Nev. Acker, Voscoe, . ('39) Agricultural & Mech. College of Texas, College Station, Tex. Acosta S., Gonzalo, ('40) Univ. of Texas, Univ. Sta., Box 1785, Austin, Tex. Adams, Albert, ('38) New Mexico School of Mines, Socorro, N. M. Adams, Charles W.,' ('39) Michigan College of Min. & Tech., Houghton, Mich. Adams, Hugh T., Jr., ('39) Univ. of Oklahoma, Norman, Okla. Adams, Jack L., ('39) Univ. of Oklahoma, Norman Okla.]

Jan 1, 1940

By G. E. McElroy

[The ventilation of development faces In nines for diluting Gas or dist concentrations and, in hot nines for providing air-motion cooling effect, by fan-pipe units discharging high-velocity steams of air close to the face, is an important phase of mine ventilation. The effectiveness of such units depends largely on the air-flow distribution between the pipe discharge and the face, n subject on which little definite information is available. A study of the air flow from grills into rooms3/ has provided some basic data, but under conditions so different from mine fan-pipe installations in development ends that the data are of doubtful application to mine installations, owing to differences in air-flow conditions.]

Jan 1, 1940

By A. L. Engel

In previous reports5/ of ore-testing studies, teats made by established methods on typical ores selected as representative of certain mining districts have been described in considerable detail. In addition to established test procedures, such as screen analysis, Chemical analyses, microscopical examination of ores and products, sink-and-float separation, gravity concentration, floatation, and magnetic separation with or without roasting, it was sometimes necessary to apply other methods, such as leaching, in instances where physical separations were not feasible.

Jan 1, 1940

By Marcel Schlumberger

The electrical methods for surface-prospecting have been well developed in the last 20 years. The method involves, in the classic form, the sending of an electrical current into the soil, by means of two electrodes A and B, and studying the potential distribution at the surface, by measuring the difference of potential between pairs of points such as M and N. The points M and N are usually placed on a line between, and equidistant from, A and B. By increasing the distance AB, the current sent into the Earth, and likewise the distribution of surface-potentials, become influenced by regions of greater and greater depth below the surface. By varying the form and dimensions of the electrode-arrangements AMNB, called a "quadripole," one may make valuable deductions concerning the nature or thickness of beds, if one knows the electrical properties of these beds. On the other hand, if the form and dimensions of the electrodes AMNB remain fixed, the depth of penetration of currents in the Earth remains, so to speak, almost constant, although it tends to increase where the subsoil is more conductive, and conversely. Therefore, if one moves the constant-dimension quadripole over all the terrain to be Investigated, one achieves approximately a horizontal exploration. This permits a study of tilted beds or faulted horizon-tal beds. When the particular problem becomes deep, of the order of 2000 meters, or more, it is ne-cessary to Increase the distance between the current-sources AB to a length such that the work 'comes very troublesome, especially if the region is wooded. At the same time, the separation the points M and N must be likewise great (for example, one km) in order to obtain differences potential which are not too small; the measurement of potential differences across MN is then difficult because of the presence of parasitic potentials, due to a flow of telluric currents in fourth, and the order of greatness of these currents may exceed the quantities to be measured.

Jan 1, 1940

By Joseph Jensen

FROM Aug. 31, 1937, until Apr. 30, 1939, there were 40,872,610 bbl. of oil run to storage in California; from Apr. 30, 1939, to Aug. 31 of the same year 5,512,912 bbl. were withdrawn from storage. But from Aug. 31, 1937, to Aug. 31, 1939, the number of producing wells in the state has increased from 17,706, with a potential production of 1,323,202 bbl., to 18,910, with a potential of 2,302,282 bbl. Thus, in a period of two years, during the first 20 months stocks increased over 1/3 and during the following four months stocks decreased 1/30. In the same two years the number of productive wells increased 1/15 and potential increased 3/4. Undoubtedly, the large increase in stocks created the pressure that caused the reduction in stocks that followed; yet this has come about in spite of the larger number of wells and higher potential. Cause of the change was the adoption on May 17, 1939, by the Central Committee of California Oil Producers of a uniform method of oil curtail-ment for all wells throughout the state. Acceptance of the method in the four months following adoption by practically all fields in California indicates that producers generally are convinced of its merit and fairness. True, some operators still overproduce, but the restraint practiced by the remainder of the industry has been sufficient to turn a situation headed for chaos into one of reasonable stability. Credit for this change goes to the industry itself, because it has all been accomplished under voluntary oil curtailment.

Jan 1, 1940

By Norman D. Fitzgerald

The growth of domestic requirements for motor fuel has been phenomenal, rising year after year in a fashion almost unique among commodities, resisting depressions and forging rapidly ahead in times of prosperity. Consumption advanced from 226 millions of barrels in 1925 to 522 millions of barrels in 1938; or 130 per cent. The economic influences generating and sustaining this demand are of vital concern to the petroleum industry. The general factors affecting utilization of motor fuel are well known but it is the purpose of this paper to employ the recently developed technique of economic dynamics to describe them mathematically. Such problems in economic analysis are complicated by the freedom of all the variables to fluctuate, their mutual interdependence, changing incidence upon one another, and the nonquantitative character of some of them. Economic quantities and relationships, unlike those of the physical world, are continuously changing and this dynamic characteristic is both a distinguishing and confusing feature in economic research. The complexities of the problems require application of the analytical devices of mathematical statistics to uncover the probable relationships between factors. The procedure employed is to formulate a logical relationship linking the dependent to the independent variables, and then simultaneously, rather than sequentially, determine their separate effects by multiple correlation. This transformation of common knowledge to quantitative terms makes it possible to measure the probable effects of changing conditions upon requirements, assisting in the sound interpretation of economic policies. The utility of the results of such dynamic analysis is in sharp contrast to the sterility of the trends and other simple empiricisms of descriptive statistics. It is not intended in this study to throw light on the reasons why any motor fuel at all is consumed; but to discover relationships explaining why more was consumed at one time than at another. Specifically the problem is confined to the measurement of the influences of statistically

Jan 1, 1940

By Basil B. Zavoico

Production of crude oil in the U. S. S. R. during 1939 is estimated at, 226,111,000 bbl., as compared with 219,778,000 bbl. in 1938, an irlcreasc of 2.88 per cent but some 6.00 per cent under the planned output. During the past year a major readjustment took place in Russian oil fields, with the Grozny district falling into the third place, its former place having been taken by the fields of the Maikop-Kuban area of northwestern Caucasus. Production continued to grow in the Ural-Volg:t district and further large increases in this province in the coming years are certain. The drilling operations continued to be most unsatisfactory, falling far behind the plan, possibly as much as 25 per cent undvr the set objectives, and thereby interfering with the production plans, mora particularly since the Soviet oil industry is still based primarily upon the production from the naturally flowing wells without any proration whatsoever rather than upon stabilized production from either prorated oil wells or those operated with various mechanical lifts. The year 1939 started with the fulfillment of the drilling programs to the extent of about 90 per cent, but the situation rapidly deteriorated arid by the second half drilling programs were being fulfilled only to the extent of 60 per cent or less. Such breakdown in drilling operations was possibly due to poor equipment, which has not been able to stand increasing demands upon it, and this is substantiated by the rccent orders plaeed in the United States by the Soviet Government for some 60 drilling rigs of the latest design. Production Baku District.—-The fields of the Apshcbron Peninsula (Baku district) made a notable progrress during the past year and were able slightly to increase their production, to 166,000,000 bbt. as compared with 164,692,-000 bbl. during 1938. The c.rnphasis of production in the Baku district remained on the flowing wells, about 20 per cent of the total number of wells flowing about 70 per cent of production. During 1939 some 550 wells were complr.tcd in the Baku district with active rigs averaging

Jan 1, 1940

At its meeting on February 21, 1933, the Board of Directors passed the following resolution defining and expressing the policy of the Institute with respect to official participation or action in controversial matters: WHEREAS, the Board of Directors at its last meeting passed the following resolution: "The Board of Directors, having been appealed to by several Local Sections for advice concerning the attitude and policy of the Institute relating to the endorsement of candidates for public office, the following statement of policy is formulated: "Whereas, the American Institute of Mining and Metallurgical Engineers is organized for purely professional and scientific purposes, and whereas diversity of opinion among its members on partisan or political questions is inevitable, it is the expressed policy of the Institute to refrain from official participation or action in political and semi-political matters." AND WHEREAS, appeals for additional advice have been received: NOW, THEREFORE, IT IS RESOLVED: (1) That the policy of the Institute is to refrain from official participation or action in controversial non-technical economic subjects; further (2) That if any Local Section is in doubt as to the application of this policy to any particular subject, it should communicate with the Secretary of the Institute for advice.

Jan 1, 1940

Jan 1, 1940

By Gifford White

Considerable attention has been directed in recent years to methods of electric prospecting other than the conventional direct-current techniques. It has been extensively recognized that electrical data of a more general nature than that possible by direct-current methods might be useful in geophysical studies. To this end, a number of different types of electric currents have been employed, such as single-frequency alternating currents, square-topped periodic current waves,4 periodic surges of a less specific nature,s and suddenly applied direct current.1,2 Yet, to the author's knowledge, little analysis of these different types of driving currents has been made from the standpoint of network theory to determine just what typc of currents would give the most useful data, and, most important of all, to determine the relation of the data taken by one method to those of another. Without touching on the actual theoretical problem of how currents flow in the earth under specified boundary conditions, some very useful information can be obtained from the study of the fundamental integral equations of electrical networks, throwing light on the problem not ordinarily appreciated by the field worker. Some manipulation of the standard network equations will be made, with the sole purpose in mind of developing expressions leading to practical results. Suppose that four points in the earth have been located and it is wished to obtain the most useful type of electrical data by inserting current into two of them and measuring the potential developed between the other two. The first problem that arises is that of which pair of the four shall be chosen as current grounds. In the direct-current case, where only steady potentials are measured, the selection is of little consequence, but as soon as currents varying with time are used at the current grounds, a new effeet arises. The fact that a varying current is flowing in the current-carrying conductor between the current grounds means that magnetic and electric fields varying with time will be produced

Jan 1, 1940

By G. L. Oldright

THE upper limit of richness of concentrates that can be smelted by means of the blast furnace without added diluents is fixed by the opera-tion of sintering. A sinter feed with normal gangue constituents, con-taining more than about 50 per cent of lead, tends to fuse; as a result, air does not come sufficiently into contact with the sulphides at roasting temperatures, and sulphur elimination is poor. Since most lead con-centrates now contain 55 to 80 per cent lead, it is necessary to add diluents to lower the grade of such sinter feed to about 50 per cent or less. This not only entails the expense of providing barren diluents when adequate diluents containing precious metals are not available but also appreciably lowers the capacity of the blast furnace to produce lead and increases slag losses. Attempts to desulphurize rich lead concentrates by methods other than sintering have not proved successful. Flash roasting, for example, converts much of the lead sulphide to lead sulphate rather than to oxide. However, this suggested the possibility that deliberate flash roasting of the concentrates to sulphate, followed by sinter roasting of the resulting product, might prove promising, particularly inasmuch as the elimination of sulphur from lead sulphate requires heat alone and not contact with atmospheric oxygen. The sintering of lead sulphate products has additional interest because important amounts of such products are now treated by lead smelters. Considerable quantities of lead sulphate are present in rich lead flue dusts and other by-products; lead-chamber sulphuric acid plants and other

Jan 1, 1940

Full sets of 149 Vols., including 4 Indexes, covering 1871-1940 incl. Indexes to Vols. 1-35, 36-55, 56-72, 73-117 (set of 4 Indexes)

Jan 1, 1940

By George T. Faust

The Southern Experiment Station of the Bureau of Mines, United States Department of the Interior, in cooperation with the University of Alabama, is investigating the various types of clays to be found in the Southern States. In connection with this work, the petrographic laboratory is called

Jan 1, 1940

By David Sinclair

THE dimensions and shapes of mine structures may at present be determined by (1) field experience, (2) structural calculations, and (3) barodynamic tests.§ None of these, however, provide information as to the stresses, their direction and distribution in a mine structure. For the design of pillars, the placing of openings relative to working places such as gangways, haulage levels, etc., this information is desirable. Photoelastic methods provide this and, while relatively new, their appli-cation in all engineering fields is assuming increasing importance. This paper, therefore, will present the method with a few applications to mining, and with sufficient reference for further study by the reader. PART I THE PHOTOELASTIC METHOD The photoelastic method of stress measurement determines the stress distribution in a two-dimensional model by optical means. It makes use of the fact that when a piece of isotropic transparent material, such as glass, celluloid, or Bakelite, is stressed and viewed in polarized** light a picture is seen which indicates by its color bands of light, or fringes, the magnitude of the stresses, their direction and their distribution.

Jan 1, 1940

By I. E. Rosenzweig

GeophyGical prospecting by earth-resistivity methods is frequently applied to investigation of structural problems in geology. Fig. 1 indicates a scheme of the general arrangement used in these methods of measurements. The battery (or generator) E is connected with two "current electrodes" I1 and I2. The current of intensity J, supplied by this battery, passes through the earth between these elcc- trodes. A potential difference U will be measured between two other electrodes V1 and Vz, called "potential electrodes." According to the configuration of electrodes (Fig. I), the resistivity of a homogeneous soil results from the formula p — 2rca-j [1] where 1 C = -------------------------------------- a a 1 a a [2]

Jan 1, 1940

By G. F. Fix, R. E. Esarey

During 1939, Indiana experienced a grcat increase in prospecting and drilling for oil and gas. Major activity, as during the preceding year, was in the southwestern part of the state, the Indiana portion of the Eastern Interior Coal Basin. An increasing interest was evident during the year, however, in the entire state, chiefly in northern Indiana (on the south flanks of the Michigan Basin) and in the old Trenton field of east central Indiana. In the latter area several tests to deeper horizons in the Trenton and to the underlying St. Peter sandstone were completed. Results in this area have been discouraging, however, since these deeper horizons are very erratic. The regional structure in the Indiana portion of the Michigan Basin is generally favorable to oil accumulation, but the picture is complicated by a uniform mantle of glacial drift and a lack of subsurface information. Several wells were started during the last half of 1939 to test the Devonian and Trenton formations in this area. Production from these formations was found at several localities many years ago, hut, no sustained effort has been made to locate pools in this area, which covers perhaps 20 counties. There were 377 wells completed in Indiana during 1939, and 77 others were in various stages of drilling at the close of the year. Of the 377 completed, 255 were classed as field locations and 122 as wildcats. The field wells were divided as follows: 156 oil wells, 39 gas wells, and 60 dry holes; the wildcats: 98 dry holes, 19 oil wells and 5 gas wells (wildcat oil and gas wells include deeper production in oil fields and field extensions as well as new field discoveries). During the year 218 more wells were completed than during 1938. Outstanding developments for 1939 include the discovery of several new oil and gas fields. In the Griffin field, which was discovered during the closing days of the previous year, 103 wells were drilled, including field extensions. Of these, 97 were productive oil wells. This field now covers more than 2000 acres of productive area and has not as yet been defined. There are five producing horizons in the field, including the Waltersburg, Tar Springs, Elwren, and Aux Vases sandstones of Chester age and the McClosky horizon of the Ste. Genevieve limestone. Produe-

Jan 1, 1940

By John Norton

IN recent years, the damping capacity of metals has come to be recognized as an important index of certain types of structural change. In a number of instances, this property has proved to be particularly sensitive, but insufficient work has been done to permit a general inter-pretation. There is considerable question at the present time as to just what factors are responsible for the internal dissipation of energy when a metal is carried through a cycle of stress, and these factors must be ascertained if the value of the damping method as a metallurgical tool is to be determined. Since internal stresses are among the chief causes of dissipation of internal energy, or damping capacity, it was thought that a study of the changes in damping during the recovery and recrystalliza-tion of a cold-worked metal might throw some light upon the subject, particularly if the damping changes were correlated with other properties that are better understood. Probably more work has been done on the recrystallization phenomena of alpha brass than on any other metal, so this was chosen as the material for the present investigation. Damping measurements on brass have been made by Förster and Köster.1 They showed that the annealing of a brass that had been cold-drawn to 50 per cent reduction produced a rapid fall in the damping, a flat minimum occurring at approximately the temperature of recrystal-lization. The damping remained at a low value until grain growth was well under way and then it increased rapidly with increasing grain size. Köster and Rosenthal2 continued the work in greater detail. They pointed out that the damping decrease does not correspond to the hard-ness drop but occurs at a lower temperature, suggesting that the relief or redistribution of internal stresses has a large effect while the actual recrystallization effect is small. They also show the increase in damping at the higher annealing temperatures. Their curves are reproduced in Fig. 1.

Jan 1, 1940

Page Foreword. By Edmund M. Wise..................... 3 A.I.M.E. Officers and Dircctors...................... 4 Institute of Metals Division Officers and Committees............ 7 Institute of Metals Division Annual Award Certificate............ 8 Institute of Metals Division Lectures and Lecturers............. 9 Photograph of E. H. Dix, Jr., Institute of Metals Division Lecturer...... 10 PAPERS Acceleration of the Rate of Corrosion by High Constant Stresses. By E. H. Dm, JR. (Institute of Metals Division Lecture, T. P. 1204).......... 11 Variation of Internal Friction with Grain Size. By Clarence Zener and R. H. Randall. (T.P. 1146, with discussion) .............41 Changes in Damping Capacity during Annealing of Alpha Brass. By John T. NoRton. (T.P. 1168, with discussion)................49 An Electron Diffraction Study of Anodic Films. By R. A. HarrinQton and H. R. Nelson. (T.P. 1158).....................62 Determination of Orientations by Etch Pits. By Charles S. Barrett .and L. H. Levenson. (T.P. 1171, with discussion).............76 Process of Precipitation from Solid Solution, I—A Crystallographic Mechanism for the Aluminum-copper Alloys. By Carl H. Samans. (T.P. 1186). . . 85 Age-hardening of Aluminum Alloys, IV — Discussion of the Theory. By WilTJam L. Fink and Dana W. Smith. (T.P. 1083, with discussion). . . 95 Structure of Aluminum after Compression. By Charles S. BaRREtt and L. H. evensonON. (T.P. 1104, with discussion)................112 Recrystallization Texture of Aluminum after Compression. By ChaRlEs S. BarRett. (T.P. 1141, with discussion)................128 Plastic Deformation and Recrystallization of Aluminum Single Crystals. By J. A. Collins and C. H. Mathewson. (T.P. 1145, with discussion) . . . 150 Recovery and Recrystailization in Long-time Annealing of 70-30 Brass. By S. E. Maddigan and A. I. Blank. . (T.P, 1166, with disonssion).....170 Correlation of Deformation and Recrystallization Textures of Rolled 70-30 Brass. By R. M. Brick. (T.P. 1144, with discussion).........193 Tensile Deformation of Critically Oriented Brass Crystals. By H. L. Burghoff. (T.P. 1149).............................214 Recrystallization of Lead. By Paul A. Beck. (T.P. 1101, with discussion). . 222 Simple Method of Thermal Analysis Permitting Quantitative Measurements of Specific and Latent Heats. By Cyril Stanley Smith. (T.P. 1100, with discussion).............................236 Metallographic Study of Internal Oxidation in the Alpha Solid Solutions of Copper. By Frederick N. Rhines. (T.P. 1162, with discussion). . . . 246

Jan 1, 1940