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By Lawrence Veiller, D. Eppelsheimer

D. Eppelsheimer, * Middletown, Ohio.—The housing of employees has so many and so varied aspects that in order to reach even an approximately correct solution it is necessary to have in mind a few fundamental principles; but it is not possible as yet to write these housing principles in the clear and correct form that is possible with many of our natural laws. Manifestly, the problem depends first on the kind of people it is necessary to house. What is suitable for the Southern unattached negro is not suitable for the married skilled American. The influx of colored labor has affected quite a number of what were satisfactorily housed communities. The second important factor is the relative proportion of the number of employees to the total employable population of the community in which the industry is located. The employer of a hundred men in a large city has little responsibility in the matter of housing his employees. If he employs 75 per cent. of the employable population in a community of 27,000, as is the case of the company with which the writer is connected, it means a large responsibility. In the establishment of an entirely new plant in a more or less isolated place, the responsibility becomes greater. As engineers, we design and write the specifications for the machinery to accomplish a definite purpose, and proceed to house it, provide the necessary buildings with their accessories in the way of cranes, or heating systems, or sprinkling systems, as the case may be. There is no reason why the operating force should not be built up in very much the same way: design the organization, write its specifications so that the employment department can secure the proper men, and then house that organization with just as much thought and care as is given the plant. In the plant, the various machines will work along certain definite lines and accomplish certain results; but even if we start with the proper organization it takes considerable time to get that organization working together. One of the most important elements to this end is the proper housing of the organization. A man usually spends more time at home than at work. Proper surroundings and a comfortable, convenient house of good appearance exercise an influence that cannot be denied, and an employee situated in such surroundings is far more inclined to follow the policies of his employer and take an active part in furthering them than one dissatisfied with his home and surroundings, which feeling

Jan 1, 1919

By G. K. Burgess

G. K. BURGESS* and R. W. WOODWARD,? Washington, D. C.-From a metallurgical standpoint, there are several ways in which a reduction of the tin consumed in commercial non-ferrous and white-metal alloys can be effected. First, a reduction of the tin, content of the alloy; second, substitution of part or all of the tin content by some other metal; third, a substitution of a different type of alloy, which in some cases also involves a change in mechanical design. The Bureau of Standards has been studying these methods of conservation for tin alloys, particularly in regard to babbitts and bearing metals, bronzes, and solders. Much of the information secured by the Bureau was obtained from answers to questionnaires sent to manufacturers and users of these materials, so that, in general, any of the following suggestions or recommendations can be considered as being practical and as having already been thoroughly tried. Bearing Metals There is no question that the tin content of nearly all bearing metals can be reduced to some extent, and in some cases actually eliminated

Jan 12, 1918

F. Lynwood Garrison, Philadelphia, Pa. (communication to the Secretary): I have been specially interested in Mr. Drake's valuable contribution to our knowledge of the Chinese coalareas, as I had occasion, about a year ago, to make a reconnoissance over some of the coal-fields in the Yangtse river valley. I noticed, as he appears to have done, certain peculiarities which may eventually prove to be characteristic of the Chinese coal-measures, at least in central and northern China. The most striking feature, perhaps, is the invariable proximity of the great granite masses to those coal-deposits which have an anthracite character. In common with all other anthracite areas elsewhere, the Chinese show evidences of profound stratigraphical disturbances. The sedimentary rocks are folded, faulted and dislocated in a manner similar to those of the Pennsylvania anthracite-regions. It would seem that the intrusive granite had much to do with converting the original bituminous into present anthracite. The action of the granite was probably direct as a conveyor of heat, and indirect as dynamic force in dislocating, overturning, and compressing the coal-measures. My stay in China was unfortunately cut short, so that I was unable to collect fossils, or to give this highly interesting and important subject more than passing attention. Cholnoky* and Richthofen are practically agreed that these granite eruptions took place during the Tertiary period—probably the Eocene. This profound tectonic movement has had a most important effect upon the geological conditions in central and northern China, and will be, I am sure, a potent factor in the economic development. Evidences of disturbances and metamorphism are very abundant in the anthracite-areas of the Yangtse valley. I noticed the coal in them, as did Mr. Drake in northern China, to be often flaky and " slickensided."

Jan 1, 1902

By A. C. Callen

This, report represents the comments of the individual members of the A. I. M. E. Sub-committee on Physics of Mine Ventilation on the proposals of a special committee of the Institution of Mining Engineers (London). As might be expected, there is a certain diversity of opinions, for owing to the shortness of time- it was not possible for the sub-committee to get together for informal discussion. The report is presented in this form in the hope that it will bring out a full discussion by other members in the Institute. OLE SINGSTAD?, New York, N. Y.-The Atkinson formula, P =SV2 K a is quoted and it is stated that this formula is especially applicable to mine galleries but is unwieldy in application, as in many problems the value of K, S and a are assumed not to change. This is the same formula that was used during the preliminary calculations for the ventilation of the Holland Tunnel, and where the above-mentioned values were constant for a number of cases, it was a very simple matter to rewrite the equation n the form P = K1V2 and avoid the repeated use of identical figures. The Atkinson formula assumes 1. That resistance to flow is independent of the pressure. 2. Changes in volume due to change in pressure may be neglected. 3. Changes in density and viscosity may be neglected. 4. That the coefficient K is a constant. 5. That P is proportional to V2. We found, from our experiments in connection with the ventilation of the Holland Tunnel, that all the above assumptions could be safely made, with the exception of No. 3, and No. 4 at, very low velocities. In mine work, where many assumptions must necessarily be made, it would seem inconsistent to attempt to make any allowance for the other factors, which are so small that they can be determined only by the most careful experimental work. However, P does depend directly on the density of the air, and to that extent the Atkinson formula is incomplete.

Jan 2, 1926

By G. F. Tagg

EARTH-REISTIVITY measurements are often of service in obtaining information regarding geological formations, particularly when applied to structural problems. In such problems the masses of the various bodies are large, and have a corresponding effect on the average resistivity of the soil. Much work has been done using such measurements, but in general the method of interpretation employed is empirical. Since certain simple cases can be investigated mathematically, it appears to be quite sound to endeavor to apply the mathematical solutions to the practical results, in order to deduce from the latter such unknown quantities as depth. This paper deals with such a method of interpretation for the simple case of a single horizontal stratum. SURFACE Of EARTH In the method described by FIG. 1.-WENNER'S METHOD OT MEASURING Wenner1 for measuring earth resis- EARTH RESISTIVITY. tivity, four stake electrodes are driven into the earth in a straight line as shown in Fig. 1. A current I amperes is passed between the two outer stakes and the potential difference . V volts between the two inner stakes is measured. Then if a is the electrode separation, the specific resistance of the soil, which is assumed to be homogeneous, is given by the formula

Jan 1, 1932

By Edwin Ludlow

I DEEPLY appreciate the honor which has been conferred upon me by my election to the presidency of this Institute, as I feel that it is the highest honor a mining engineer can receive, and I also feel that I am especially fortunate in being called to take the presidency in the year following Mr. Hoover, as I may be enabled in that way to carry on the work which he has initiated. The constructive work that Mr. Hoover has inaugurated has been of inestimable benefit in bringing not only this Institute but the entire engineering profession into a place in the public esteem to a degree which it had never before occupied.. This work Mr. Hoover will now carry on in the broader field of the Federated American Engineering Societies, of which he is president. Through that organization the engineers of this country, in all branches of the profession, will be welded into one compact body reaching from the Atlantic to the Pacific, making the united engineering profession a power for maintaining American . . ideals and standards throughout the land.,

Jan 1, 1921

By Luiz C. Correa da Silva, Robert F. Mehl

An experimental study of the movement of markers in the systems Cu/a-brass, Cu/Sna-solid solution, Cu/Ala-solid solution, Cu/Ni, Cu/Au, Ag/Au, employing many types of markers and a variety of temperatures. Marker movement is confirmed and undoubtedly associated with the manner in which atoms move during diffusion. EVERAL years ago Smigelskas and Kirkendall' •S reported measurements on the interdiffusion of copper and a-brass and on the movement of inert markers placed at the original join. These markers were observed to move toward the a-brass side of the join, and from this it was inferred that zinc diffuses in a-brass more rapidly than copper. Similar results were reported a little earlier for the diffusion of solvents into high polymer solids.' This has attracted much attention, particularly from those interested in the mechanism and the theory of diffusion: Seitz3 has employed it in supporting the vacancy theory of diffusion; from the data Darken4 has calculated separate diffusion coefficients for copper and zinc, developing a "phenomenological" theory of diffusion; and Bardeen5 has employed it in constructing a general theory, including therein the work of Seitz and Darken, as has Le Claire. These matters have recently been reconsidered in a sympo~ium.7 Some reason has existed for questioning the work of Smigelskas and Kirkendall.' Their technique consisted in electroplating copper on a-brass, upon the surface of which Mo-wires had been secured, and then diffusing, measuring the extent of diffusion along the normal to the join, and measuring the marker displacement in the same direction by a comparator determination of the distance between Mo-wires on opposite sides of the electroplated brass sample. It has been suspected that the copper plate might have been porous, and that the original interface might have been an imperfect join, both contributing to the transfer of the volatile zinc by vapor transfer;' it has also been questioned whether the marker movement might not in a measure be a property of the marker itself; etc. These legitimate questions require experimental answers; the present paper offers such answers. Moreover, Smigelskas and Kirkendall studied the effect only in the Cu-Zn system and at one temperature; the attention which the work of Smigelskas and Kirkendall has commanded recommends similar

Jan 1, 1952

By ED. E. Furman, R. H. Atkinson

HITHERTO the practical creep testing of precious metals has received little or no attention. The only previous creep tests of precious metals have been made with wires under conditions such as to yield much more rapid rates of creep than in engineering tests.', ' Up to the present time the value of creep bars of adequate size, in the absence of real need for engineering data, has deterred investigators. However, the increasing use of platinum at high temperatures has demonstrated the need for reliable creep data for the guidance of engineers, especially those engaged in designing certain specialized chemical plant equipment. In order to supply this need, creep tests were conducted at 1382°F (750°C) on 0.290 in. diam specimens of platinum, 90 pct Pt, 10 pct Rh and palladium. The platinum was high purity, nominally 99.95 pct Pt. The 90 pct Pt, 10 pct Rh was of the same high quality as is used for making gauzes for the catalytic oxidation of ammonia. The palladium was also of high purity; two batches of palladium bars were tested, one deoxidized with calcium boride and the other with aluminum. Spectrographic examination of the palladium confirmed its good quality; the only significant impurities apart from the residual deoxidizers were traces of silicon and lead. Procedure The creep bars, which were furnished by Baker and Co. to our specification, were 6 ¾ in. in overall length with a 4½ in. (4 in. gage length) reduced section 0.290 in. in diam and had the ends threaded (?-NC16). It may be of interest that the bars were valued at up to $600 each. The specimens were supplied in a 50 pct cold-worked condition to facilitate attachment of the creep extensometer, which was of the push rod type. Because of the softness of the platinum and palladium, the extensometer rings were secured to the test section by means of circular knife edges instead of the usual pointed set screws. The extensometer rods extended through the bottom of the furnace and readings were taken with a 0.0001 in. "Last Word" dial gage fastened to the rods for the duration of the test. The bars were directly loaded by hanging weights from the lower specimen grip. All tests were conducted at 1382°F ± 2°F, and an effort was made to maintain the temperature gradient over the test section within 2°F. The ends of the furnace tube were packed with asbestos wool, which allowed a very slow circulation of air through the tube. Annealing was accomplished in the creep furnace before the load was applied. The platinum and palladium specimens were annealed at the test tem- perature for about 17 and 24 hr respectively; in the case of the rhodioplatinum it was found expedient to anneal for 1 hr at 1922°F (1050°C). Pilot samples cut from the same stock as the bars were used to check annealing procedures. Pertinent measurements of grain size and hardness were recorded. Results and Discussion The creep data obtained are given in Table I and the creep curves are plotted in Figs. 1, 2, and 3. Two platinum specimens, tested under a stress of 250 psi, had almost identical creep rates at 2000 hr, namely 0.000008 and 0.000009 pct per hr. A third platinum specimen, stressed at 400 psi, had a creep rate at 2000 hr of 0.000026 pct per hr; the reason for a rather sharp decrease in creep rate during the period from 1200 to 1600 hr is unknown. As it was thought that 90 pct Pt, 10 pct Rh would have a lower creep rate than platinum, the first sample was tested at 400 psi; however, the creep rate was approximately 50 pct greater. Microex-amination revealed that differences in grain size might be responsible for the unexpected result, as annealing at 1382°F developed an average grain diameter of 0.0021 in. in the rhodioplatinum specimen compared with 0.004 in. in the platinum bar. Annealing the alloy for 1 hr at 1922°F (1050°C) increased the average grain diameter to 0.0032 in. and materially improved the creep resistance, making it much better than platinum. A second specimen annealed at 1922°F (1050°C) and tested under a stress of 550 psi had a creep rate of 0.000022 pct per hr at 2000 hr, which was still substantially lower than that shown by the specimen annealed at 1382°F (750°C) and stressed at only 400 psi. In contrast to the creep behavior of the platinum and rhodioplatinum specimens, the palladium bars, whether deoxidized with calcium boride or aluminum, were characterized by high first stages of creep. However, after about 1200 hr of test, the creep

Jan 1, 1952

By Frank H. Kneeland

Safety First is a popular motto—most mining companies have adopted it. It is probable, however, that in the majority of cases it is only a motto and gets no further than the office stationery or the bulletin board at the mine's entrance. In but few industries is there employed a greater diversity of machinery and mechanical devices than in coal mining. The list ranges all the tray from mechanical stokers to wood-working machinery and undercutters. Many of these devices, particularly those employed in wood working, are extremely dangerous. In 1913,23 per cent. of all fatalities occurring in coal mining in the U. S. were caused by machinery of some sort or other. Although the forms of accidents occurring with mining machinery are legion, they generally arise from one or more of five causes: (a) Falls from ladders, platforms, etc.; (b) coming in contact with moving machines or parts thereof; (c) electric shocks; (d) failure of some machine part; (e) mismanipulation of valves, levers, switches or other hand-operated controlling devices. The steps which may be taken to prevent accidents from the above causes are almost as numerous as the accidents themselves. There is, and can be, no panacea for all mishaps, nor for any one class of accidents. There is no mathematical or other formula that will bring immunity under any set of conditions. Common sense is the only guide. The remedy for the first-named class of accidents is simple and generally effective—namely, make the staging, ladder, platform, or other support, abundantly strong to carry any possible weight that it may be called upon to bear; provide ample railings on platforms or runways, and non-slipping feet on movable ladders. Coming in contact with moving machine parts is one of the greatest dangers met with in the operation and maintenance of mining machinery. Unfortunately, machine manufacturers have not as a class adopted the idea of thoroughly protecting and incasing the dangerous parts of their product. No one has, or should have, a better or more thorough knowledge of what the dangerous parts or elements of a machine may be than its builder. The desire to construct a piece of mechanism as cheaply as

Jan 1, 1915

During the year this Committee has had the benefit of the services of 75 Committee members, resident in the various States of the Union and in foreign countries, 10 of them representing us abroad. A number of plans for awakening the interest of possible new members have been carried out and the results have been very gratifying. The comparative results for 1913 and 1914 are as shown in the following table: 1913 1914 Applied for membership 630 946 Elected 450 1,006 Accepted election 433 921 When it is remembered that the depression following the outbreak of war in Europe has had more serious effect on the mining industry than almost any other, these results cannot be regarded as anything other than very encouraging. Because of the unsatisfactory conditions still prevailing it will doubtless be difficult to make even as good a showing next year. It is considered, however, that the function of this Committee is not merely to secure new members, having no regard for other than numbers; its true function is to exercise a proper supervision over the growth of the Institute, building it up in those fields in which it is weak, and directing its growth in such a way as to make it most effective in fulfilling its proper function as the national organization representative of the mining profession. The plan of inviting the alumni of the leading mining schools to apply for membership, which was initiated last year, was completed this year, with the exception of one or two schools, notably the University of California, from which we have not been able to obtain a list of alumni. With these exceptions we have now extended to the graduates of all the important mining schools of this country, and several of those abroad, an invitation to apply for membership in the Institute. It. is not thought desirable to repeat this invitation too frequently, and it is therefore suggested that this field be left alone for a year or two, when, if the mining industry experiences a marked revival of interest, it will be well to send out a second letter to the same men.

Jan 4, 1915

By John Gross

The study of the energy used in crushing operations has advanced from a period of perplexing confusion to one of greater clarity. Only within the last few years has any true conception of the work in crushing been possible, owing to the chaotic state of theoretical knowledge. For some 20 years a controversy existed between those advocating the Rittinger law and those advocating the Kick law. The Kick law now appears to be definitely out of the picture, and crushing efficiency may be based confidently on the Rittinger theory. There also seems to be a generally crystallized conception as to the meaning and nature of sub-sieve material. There is needed a simple, direct method for determining surface on a crushed ore product, and also a simple and accepted method for size determination on minus 400-mesh material. The Crushing Law The Rittinger(l)‡ theory of crushing was advanced in 1867 and the Kick(3) theory in 1885. While the Rittinger theory might have been accepted without much question and actually had been accepted by many investigators, a serious doubt as to its validity was raised by Stadler(10) who upon purely theoretical grounds proclaimed the Kick "law" as the true law of crushing. According to Rittinger the energy required in successive steps in reduction increases geometrically, while according to Kick the energy increases arithmetically. These "laws" therefore are at variance, and the establishment of the true law was recognized as of first importance. Many simple experiments have been made to demonstrate the application of the Rittinger theory to crushing, and it would seem that its simplicity should favor its acceptance. Experimental evidence, however, was not convincing, as no reliable data could be obtained on the finer material from a crushing or grinding operation. Gates,(13) Bell,(19)

Jan 1, 1935

[Aamot, Clav Crone, (Member '29) Met., Det Norske Aktieselskab for Elektrokemisk, Industri, Inc., Oslo, Norway. Aamot, 0, Crone, (Member '29) c/o Elektrokemisk, Radhusgaten 23, Oslo, Norway. Aase, Glenn D., (Junior Member '40) Jr. Met., American Smelt. & Refin. Co., Selby, Calif. Abadie, Henry G., (Junior Member '43) Div. Petr. Engr., Union Pacific R.R. Co., 422 W. 6th St., Los Angeles 14, Calif. Abbott, Clarence E., (Member '04) Civil Engr., V.P., Tennessee Coal, Iron & R.R. Co., 1542 Brown Marx Bldg., Birmingham, Ala. Abbott, Fred E., Jr., (Member '44) Petr. Engr., c/o Arabian American Oil Co., A.P.O. 816, c/o Postmaster, New York, N. Y. Abel, Raymond L., (Member '28) Chem. Engr., 0. 0., Pittsburgh Chem. Warfare Procurement Dist., American Bank Bldg., Pittsburgh, Pa.]

Jan 1, 1946

By E. Sengier

At the Director's dinner of the A.I.M.E. on. April 22, Mr. Sengier of the Union Minière du Haut Katanga was a guest. Though a member of the Institute for sev-eral years this was the first occasion on which he had had opportunity to meet with it, and in response to an invitation from President DeGolyer, after expressing his pleasure at being present, he told informally of the present development of the Congo with which he has been so closely related. From his remarks the follow-ing has been prepared.-EDITOR. AS you know, the Belgian Congo, a fairly large colony compared with the territory of Belgium, is in the center of Africa. Natural waterways, railroads now built and new railroads under construc-tion, give increasing means of transportation and are helping toward development. The mining industry is by far the most important part of our colonial activity. Considering that we are all engineers, I will confine my figures to mining enterprise. First I will show you the relative importance of the mining industry com-pared with the total exports of the Belgian Congo. During 1925 there was exported 100,000 tons of cop-per, valued at about $25,000,000; 900,000 carats of diamonds, 8000 lb. of gold, 1700 tons of cassiterite, 300 .tons of cobalt, and 20 grams of radium, of a total value of about $35,000,000. Other products to a value of about $12,000,000 and consisting mainly of palm nuts, palm oil, cotton, ivory, copal, rubber, were also exported. From this you will see that mineral products account for about 72 per cent of the total exported value. Copper alone amounts to 52 per cent of the total and 72 per cent of the mineral exports. All minerals, with the exception of gold, which is mined by the government, belong practically toy two mining companies in which American and British capi-tal is interested with Belgian. These two companies (one called Forminière, interested in the diamond busi-ness, and the other called the Union Minière, interested in copper, cobalt, tin and radium) were formed twenty-five years ago. They started producing in 1911, but the war prevented normal operations, and active de-velopment could only be carried on after the Armistice.

Jan 5, 1927

In order to assist in the building up of the industries and commerce of France, by cooperating with the Congres General du Genie Civil, the four Founder Societies have appointed the following committee: E. G. Spilsbury and Arthur S. Dwight representing the American In-stitute of Mining and. Metallurgical Engineers; George F. Swain and Nelson P. Lewis to represent the American Society of Civil Engineers; Charles T. Main and George W. Fuller to represent the American Society of Mechanical Engineers; Lewis B. Stillwell and Andrew M. Hunt to represent the American. Institute of Electrical Engineers.

Jan 12, 1919

By AIME AIME

THE accompanying photograph: submitted by C. L. Bransford, assistant district manager of the Republic Steel Corp., in Birmingham. Ala., shows the remains of the old Tannehill blast furnaces, one of the first furnace plants in the South. They were built by Moses Stroup and operated during the Civil War period, when cannon balls were cast there. The record day's run of this furnace plant was said to be 30 tons of iron. The furnaces were fed by a water-wheel-operated bellows and used charcoal, a product of the neighboring forest. They were first owned and operated by the Pioneer Mining & Manufacturing Co., that later became the Republic Iron & Steel Cu., and subsequently the Republic Steel Corp. in that district.

Jan 1, 1936

Page The Cobaltchromium Binary System (paper by A. R. Elsea, A. B. \Yesterman, and G. K. Manning, Met. Tech. June, 1948, Mechanism of Precipitation in a Permanent Magnet Alloy (paper by A. H. Geisler and J. B. Newkirk, Met. Tech. Aug. 1948, Tp 2444)................................................................................................. 300 Some Effects of Applied Stresses on Precipitation Phenomena (~aper by W. L. Finlay and W. R. Hibbard, Jr., Met. Tech. Sept. 1948, Tp 2470)....................................................................................... 301 Diffusion of Carbon in Austenite with a Discontinuity in Composition (paper by L. S. Darken, Met. Tech. Sept. 1948, TP 2443) 304 An Electron Diffraction Study of Oxide Films Formed on Nickelchromium Alloys (paper by J. W. Hickman and E. A. Gul- bramen, Met. Tech. June 1948, Tp 2372)..................................................................... 305 An Electron Diffraction Study of Oxide Films Formed on Copper-nickel Alloys at Elevated Temperatures (paper by J. W. Hickman and E. A. Gulbransen, Met. Tech. June 1948, TP 2391)................................................ 307 Decarburization of Chrome Nickel Alloys by Their Surface Oxides in High Vacua and at Elevated Temperatures (paper by E. A. Gulbransen, W. S. Wysong, and K. Andrew, Met. Tech. Sept. 1948, TP 2438)................................ 307 Fractographic Study of Cast Molybdenum (paper by C. A. Zapffe, F. K. Landgraf and C. 0. Worden, Met. Tech. Aug. 1948, TP 2421)................................................................................................. 308 Effect of Composition on Grain Growth in Aluminum-magnesium Solid Solutions (paper by L. J. Demer and P. A. Beck. Met. Tech. June 1948, TP 2374)............................................................................. 309 Effect of a Dispersed Phase on Grain Growth in Al-Mn Alloys (paper by P. A. Beck, M. L. Holzworth and P. Sperry, Met. Tech. Sept. 1948, TP 2475)................................................................................. 310 Statistical Rate Theory of Metals—Mechanism of Flow and Application to Tensile Properties (paper by J. W. Fredrickson and H. Eyring, Met. Tech. Aug. 1948, TP 2423)............................................................... 315 Nucleation of Slip Bands (paper by J. G. Leschen, R. P. Carreker, and J. H. Hollomon, Met. Tech. Sept. 1948, TP 2476) and.. 318 Transient Plastic Deformation (paper by R. P. Carreker, J. G. Leschen, and J. D. Lubahn, Met. Tech. Sept. 1948, TP 2477).. 318 Plastic Deformation of Large Grained Copper Specimens (paper by W. R. Hibbard, Jr., Met. Tech. Sept. 1948, TP 2469). ... 323 Plastic Flow in Anisotropic Sheet Steel (paper by L. R. Jackson, K. F. Smith, and W. T. Lankford, Met. Tech. Aug. 1948, TP 2440)................................................................................................. 323 The Effect of Thermal-mechanical History on the Strain Hardening of Metals (paper by J. E. Dorn, A. Goldberg, and T. E. Tietz, Met. Tech. Sept. l948, TP 2445)....................................................................... 325 The Room and Elevated Temperature Properties of Some Sand Cast Magnesium-base Alloys Containing Zinc (paper by T. E. Leontis, Met. Tech. June 1948, TP 2371)..............................................................., 327 The Low Temperature Properties of Tin and Tin-lead Alloys (paper by H. S. Kalish and F. J. Dunkerley, Met. Tech. Sept. 1948, TP 2442)............................................................................................335 Thermal and Electrical Properties of Ductile Titanium (paper by E. S. Greiner and W. C. Ellis, Met. Tech. Sept. 1948, TP 2466).................................................................................................... 335 Property Changes during Aging (paper by A. H. Geisler, Met. Tech. Aug. 1948, TP 2436)............................... 337 Factors Affecting the Tensile Notch Sensitivity of Magnesium Alloy Extrusions (paper by I. Cornet, Met. Tech. Aug. 1948, TP 2419)................................................................................................. 338 Effect of Grain Size on Tensile Strength, Elongation and Endurance Limit of Deep Drawing Brass (paper by H. L. Walker and W. J. Craig, Met. Tech. Sept. 1948, TP 2478)............................................................. 339 A Copper-base Alloy Containing Iron as a High-strength, Highconductivity Wire Material (paper by W. Hodge, R. I. Jaffee, J. G. Dunleavy, and H. R. Ogden, Met. Tech. Aug. 1948, TP 2422).............................................. 340 A High Strength-High Conductivity Copper-silver Alloy Wire (paper by W. Hodge, R. I. Jaffee, J. G. Dunleavy, and H. R. Ogden, Mel. Tech. June 1948, TP 2366)...................................................................... 340 The Effect of Chronlium on the Ma Point (paper by J. B. Bassett and E. S. Rowland, Met. Tech. Aug. 1948, TP 2417.... 341 The Kappa Eutectoid Transformation in the Copper-silicon System (paper by W. R. Hibbard, Jr., G. H. Eichelman, Jr., and W. P. Saunders, Met. Tech. Sept. 1948, TP 2441).............................................................. 343 Stabilization of the Ausknite-martensite Transformation (paper by W. R. Harris, Jr. and M. Cohen, Met. Tech. Sept. 1948, TP 2446)................................................................................................ 344 Secondary Hardening of Tempered Martensitic Alloy Steel (paper by W. Crafts and J. L. Lamont. Mel. Tech. Sept. 194,8, TP 2439)................................................................................................. 345

Jan 1, 1950

By C. H. Mathewson

CHARACTER OF THE WORK IN HAND IN planning the present experiments, we have made a particular effort to secure that adjustment of working conditions which would render the forthcoming tests most serviceable by way of indicating the comparative properties of the three different commercial grades of copper used. More specifically, we have endeavored to obtain certain definite information with respect to the relative behavior under test of ordinary electrolytic copper and furnace-refined lake copper containing (a) a moderate percentage of arsenic and (b) a rather large percentage of arsenic, in addition to the usual content of silver and other impurities. These comparisons were made systematic and comprehensive by testing throughout a series of (eight) reductions running from 0 to 70 per cent. in the case of cold-rolled metal, and throughout a series of (15) temperatures running from 100° C. to 1,000° C. in the case of annealed metal. In other words, a survey of properties similar to that made by Grard,1 in the case of electrolytic copper, was here repeated (with modifications) and extended to two other commercial varieties of copper.

Jan 7, 1916

By John B. Miles

The present period of depression in the iron industry, with the resultant close approximation of the cost of production to the selling-price of pig-iron, should make the discussion of this subject at this time not only interesting but profitable. It is possible that it may result in the collection of data, which when added to those set forth in this paper will clearly indicate the influence of the rate of driving a blast-furnace upon its fuel-economy. The question is not whether an excessive rate of driving (meaning a rate definitely in excess of the average rate in the United States) results in an increase in the fuel-consumption, but rather whether a rate considerably less than the average does not result in a marked decrease in the fuel-consumption. The commercial and metallurgical sides of this problem must be kept separate. With a large margin between the cost of production and the selling-price of pig-iron, and a plant already in operation, it is frequently profitable to sacrifice a couple of hundred pounds of fuel per ton of pig-iron in order to secure the greater gross profits resulting from a larger tonnage. When this margin decreases with a plant in operation, or when the determination of the size of a new furnace intended for a certain production confronts the management, a clear understanding of the effect of the rate of driving upon fuel-economy becomes necessary. If it be granted that slow driving leads to low fuel-consumption, it should be borne in mind in the design of a new plant for the production of a certain tonnage that the adoption of an economical rate of driving increases only the size of the furnace proper, whereas, due to the decrease in quantity of blast required on account of the decrease in fuel burned, the stoves, the blowing-engines, the boilers and the piping may be de-

Jan 1, 1909

By Charles C. Towle, Irving Rapaport

URANIUM mineralization along the north flank of the Zuni Uplift, in the vicinity of Haystack Butte, was discovered by Paddy Martinez, a Navajo Indian, in the spring of 1950. The find was reported to the Santa Fe Railway Co., which initiated a program of exploration upon its holdings in the district in December of 1950. The Anaconda Copper Mining Co. secured numerous leases in January and February, 1951, and began an intensive exploration and development program in March 1951. The district was extended into the Lucero Uplift in August of 1951 by the discovery of uranium mineralization in Todilto limestone by Joy Sinyella, a Supai Indian living on the Laguna Reservation. Initial reconnaissance was performed in the district by the Atomic Energy Commission in November 1950. A field office under the direction of the Denver Exploration Branch of the AEC was established at Prewitt, N. Mex. in January 1951 to study regional and detailed guides to ore, to evaluate the ore deposits, and to promote the development of the district by providing geologic services for the companies and individuals engaged in exploration. With the development of sufficient ore to warrant construction of a mill, the Grants area of New Mexico has come of age as a full fledged uranium mining district. The carnotite-type deposits of Grants, the first of major economic importance found in limestone, have extended the Colorado Plateau carnotite field into the more complex structure of the Basin and Range Province. General Geology The Grants uranium district is in northwestern New Mexico, along the southern flank of the San Juan Basin, between the cities of Gallup and Albuquerque. The region is at a mean altitude of about 6800 ft, vegetation is sparse, and outcrops are excellent. Mt. Taylor volcanic peak, at an elevation of 11,400 ft dominates the surrounding area. The overlying cliff-forming Dakota sandstone is the most resistant formation in the Grants District and characteristically erodes into dissected mesas as much as five miles wide. The principle uranium ore-bearing horizons are found in the underlying Morrison formation, and the Todilto limestone of the San Rafael group. The Morrison weathers into. a series of steep slopes and precipitous cliffs near the lower part of the Dakota-capped rims, while in contrast, the relatively resistant underlying. Todilto [ ] limestone forms broad benches extending out from the base of these Dakota rims as much as five miles wide. The Todilto benches are covered with overburden to an average depth of about 5 ft in the first thousand ft away from the Dakota rim, but increases to about 200 ft at the base of the rim. In many places however, a thick mantle of upper Cretaceous sediments and Tertiary volcanics "obscures the ore-bearing Jurassic, and precludes exploration. . The known uranium deposits of the Grants District are distributed throughout a zone 85 miles long and about 10 miles wide. Stratigraphy Rocks from pre-Cambrian through Tertiary are exposed in the uplifted areas, but uranium appears to be restricted chiefly to two zones in Jurassic sediments. The Jurassic sediments of the Colorado Plateau have been subdivided into three units, in ascending order: (1) Glen Canyon group, (2) San Rafael group, (3) Morrison formation. The Todilto limestone zone within the San Rafael group has produced the bulk of ore to date, but the promise of the Morrison zone is rapidly increasing. The Todilto formation extends about 300 miles east-west and about 100 miles in a north-south direction. It is composed of a lower, extensive, limestone member and a central, more restricted, thick, pure gypsum member. The Todilto is believed to be of lacustrine origin. The Morrison formation in this area is subdivided, rather arbitrarily, into three members: Recapture Creek, Westwater Canyon, and Brushy Basin. Ore

Jan 1, 1952