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By H. D. Wilde

DURING 1934 conditions in the production division of the petroleum industry were reasonably satisfactory but nevertheless a decided feeling of insecurity existed largely because of the uncertainty of controlling production to consumptive demand. Over-production, especially in the East Texas field, threatened a general collapse of crude prices but in spite of this, posted prices were high. Stimulated by the prevailing posted prices, wildcatting activities were wide-spread. Although a number of small discoveries were made, particularly in the Gulf Coast belt and Oklahoma, no fields of major importance, unless it was the Fitts pool in Southern Oklahoma, were brought in. Meanwhile, the Petroleum Division of the A.I.M.E. continued its activities. It sponsored the collection of production and geological data on both foreign and domestic fields. The data on all but a few producing districts in the world were published in the "Petroleum Development and Technology" volume of the "Transactions" and comprise one of the most complete tabula¬tions of this sort ever published. Work of this kind is being continued.

Jan 1, 1935

By Charles A. Stetefeldt

This treatise is the sequel of a paper on "Russell's Improved Process for the Lixiviation of Silver-ores," etc., read at the Chicago meeting, in May, 1884, and published in the Transactions, vol. xiii., page 47. The facts it presents are principally compiled from Mr. Russell's notes on his practical experience gained in various places where the Russell process has been introduced. For a complete understanding of this paper a perusal of my former one is desirable, as can be seen from the frequent references here made to it. All silver-ores that do not carry a large percentage of lead or copper can be treated by Russell's process with success and economy. I do not mean to create the impression that from ores containing considerable quantities of lead and copper a high percentage of the silver cannot be extracted by this process. Such ores, however, will, in many localities, be reduced to better advantage by smelting. In case lead-bearing silver-ores are suitable for concentration, it may be profitable to concentrate the ore by Krom's dry system, obtaining a smelting-product high in lead, and to lixiviate the tailings and the dust. This plan has been adopted in a mill recently erected in Cortez District, Nevada. The dry system of concentration deserves the preference because it delivers the tailings and the dust in a condition ready for chloridizing-roasting. In wet concentration the drying of the tail ings would be expensive, and there would be a considerable loss of silver in slimes. Oxidized ores, containing silver chloride and lead minerals, may be lixiviated after crushing, and the tailings may be concentrated for lead. In this case wet concentration would be most suitable. This has been done at the Old Telegraph Mine, Utah. I would give, however, the preference to dry concentration in all cases which, of course, requires that concentration should precede lixiviation. The Russell process is also adapted to the treatment of tailings resulting from ores which have been worked either by the old

Jan 1, 1887

By John F. McElhiney, Hosseim Kazemi

This chapter is a review of fluid flow and mass trans- port in fractured rocks. The topics include: single-phase and multiple-phase flow theory, formation productivity or injectivity improvement by artificial fracturing, and mass transport associated with fracture acidizing. Possible extension and application of such ideas to in situ mining in fractured rocks are presented.

Jan 1, 1974

By H. E. Kramm

(New York Meeting, February, 1919.) DURING the summer of 1911, I had the opportunity to study in detail the geological conditions of what is known in northern California as " Harrison gulch," in Shasta county. Though the district, as a whole, that is, the western part of Shasta and the eastern part of Trinity county, has contributed during the last 15 years a considerable share of the gold-production credited to Shasta county, very little is known of its geology, perhaps because the country is covered with a dense growth of brush which makes exploration and prospecting extremely difficult. Topographically the district presents a succession of ridges trending approximately N-S.; and alternating with deep narrow canyons. The drainage is partly into . the Sacramento, partly into the Trinity river. Climatic conditions in summer time are almost ideal. It is true, the thermometer may climb to 115°, but the air is dry and the heat is bearable, especially as the nights are always cool. It seldom rains during the summer months, and creeks and springs dry out towards the end of the summer. The winter is severe, lasting from November to April, and usually a thick layer of snow covers the mountains. By reason of the character of its gold-deposits, the region is known to miners as "the pocket country." It contains a series ?of eruptive rocks intruded into slates, cherts, limestones, and conglomerates. Dikes, laccoliths, and batholiths are frequent. In a day's ride it is possible to find all the common igneous rocks from the very acid to the very basic. Serpentines are especially abundant.. The sedimentary rocks are, as rule, broken and shattered as well as folded, and show the effects of intense metamorphism. ? Pocket-hunters " speak of the contact of diabase and slate as the ? pocket-contact." Some rich gold-pockets, however, have also been found in the diabase.

Jul 1, 1912

By AIME AIME

GENERAL COMMITTEES. SAN FRANCISCO:-ExECUTIVE, Hon. William C. Ralston, Chairman; RECEPTION, Prow. Samuel B. Christy, Chairman; SESSIONS, Frederic W. Bradley, Chairman; PRESS, H. Foster Bain, Chairman; FINANCE, Mark L. Requa, Chairman; EXCURSIONS AND ENTERTAINMENTS, Edward H. Benjamin, Chairman. Assisted by Harry P. Stow, C. W.Merrill, F. W. Griffin, Gelasio Caetani, Albert Burch, Newton Cleaveland, Corey C. Brayton and R. E. Cranston. Los ANGELES :-EXECUTIVE, Theo. B. Comstock, Chairman; R. W. Hadden, Secretary; H. R. Simpson, Treasurer. Institute Headquarters at Hotel St. Francis. The first and opening session, held Tuesday afternoon, Oct. 10,. in the Reception-Hall of the St. Francis, was called to order by State Senator William C. Ralston, Chairman of the Executive Committee, who in a few well-chosen words welcomed the visiting members and guests of the Institute to San Francisco. He said it was twelve years since the last meeting on the Pacific Coast and that it was here that the greatest feats. of mining had been accomplished in the history of the country. He told of the work that had been done on the continent and of the new methods introduced by the mining engineers for the betterment of the nation. He then introduced Capt. Robert W. Hunt, twice past President of the Institute, and present Acting President for the San Francisco meeting and the subsequent visit to Japan, who responded cordially to Mr. Ralston's welcoming address. By unanimous vote, the Secretary was instructed to send a telegram to President Charles Kirchhoff expressing regret for his absence, and hoping for a rapid improvement in the health of his mother. The following papers were presented in brief oral abstract by the authors: . * Electrolytic Refining at the U. S. Mint, San Francisco, Cal., by Edward B. Durham, San Francisco, Cal. The Parral Tank System of Agitating Slime-Pulp, by Bernard MacDonald, Guanajuato, Mexico. * The Newport Iron-Mine, Ironwood, Mich., by B. W. Vallat, Ironwood, Mich. (illustrated by lantern-slides). * Distributed in pamphlet worm.

Nov 1, 1911

By Becket, Frederick M.

CHROMIUM is but one hundred and thirty years of age-a mere youngster as related to many metals that' have speeded world progress. It was Vauquelin of France who proved conclusively that the so called red lead of. Siberia contained a new element. The variety and characteristic colors of the compounds suggested the name chromium. He also succeeded in reducing oxide of chromium to the metallic form and described the product as very brittle, infusible, needle- like crystals on which acids had very feeble action. His metal was not pure chromium, of course; it must have contained appreciable carbon in the combined form as a result of reducing the oxide by carbon at high temperatures. Vauquelin's description in 1798 of this work is a gem-indeed, literally, he went so far as to discover the presence of chromium oxide in the emerald. The metallic product did not seem to interest Vauquelin greatly, but a new chemical industry began shortly after his discoveries.

Jan 1, 1928

ALABAMA Aldrich.-Lloyd, T. W. Anniston.-Carrington, F. G. Klugh, B. G. Bessemer.-Abbott, C. E. Dobbs, G. G. Ferguson V. Salmon, h. S. Stuart, Q. W. Birmingham.-Adams, J. H. Aldrich, T. H. Aldrich, T. H., Jr. Allen, A. W. Armstrong. W. D. Ball, E. M. Bonnyman, J. Bush, M. W. Carter, E. Crawford, G. G. Davis, C. B. Dryer. T. B.

Jan 1, 1923

By E. H. Hamilton

THE furnace on which the following investigation was based had dimensions 48 by 160 in., and was in continuous operation during the three days of the test. The average charge consisted of PER CENT. LB. PER HOUR Bed ore?14.5?2,980 Roast from Dwight-Lloyds?44.5?9,160 Siliceous ore?3.5?720 Iron flux?2.1?430 Battery plates?0.5?103 Lime rock?23.9?4,925 Briquettes?4.0?825 Scrap iron?2.1?430 M. P. slag?4.2?865 L. P.speiss?0.7?142 Total 100.0 THE furnace on which the following investigation was based had dimensions 48 by 160 in., and was in continuous operation during the three days of the test. The average charge consisted of PER CENT. LB. PER HOUR Bed ore?14.5?2,980 Roast from Dwight-Lloyds?44.5?9,160 Siliceous ore?3.5?720 Iron flux?2.1?430 Battery plates?0.5?103 Lime rock?23.9?4,925 Briquettes?4.0?825 Scrap iron?2.1?430 M. P. slag?4.2?865 L. P.speiss?0.7?142 Total?100.0?20,580

Jan 1, 1924

By C. K. Leith

GENERAL GEOLOGY OF THE LAKE SUPERIOR IRON-BEARING AND COPPER-BEARING SERIES. THE geology of the Lake Superior region is of general interest, both from an economic and a scientific standpoint. The presence of large and rich iron- and copper-deposits has made a knowledge of the geology of the region necessary for purposes of exploitation and exploration. The ores of the region are contained in rocks of pre-Cambrian age, 'pith for most of the country up to recent years have usually been referred to as « crystalline schists " or " crystalline complex;" and regarded principally as metamorphosed basement-unit upon which the sedimentary rocks, beginning with the Paleozoic, were laid down. In the Lake Superior re¬gion this pre-Cambrian complex presents an unusual variety of rocks with determinable relations. It has been possible, with the large expenditures which-the magnitude of the iron-mining industry warrants, to work out their stratigraphy to a larger extent than has been possible in almost any other area of pre-Cambrian rocks. The real complexity of Lake Superior geology, the confusion of names and the multiplicity of reports covering small parts of the region, are such that interested persons, other than. geologists directly engaged in the work, may well hesitate to attempt to comprehend the geology of the region as a whole. The following paper is a somewhat elementary outline of the geology of the Lake Superior region with special reference to new developments not yet covered in published reports. Geological information concerning the region has been gath¬ered by mining companies, and by the geological surveys of Michigan, Wisconsin, Minnesota, Ontario, Canada, and the United States.. Perhaps in no other part of the country have the mining men themselves spent such large sums in purely geological work. This has made possible the publication of ,reports and maps by the State and Government surveys in much less time and at far less cost than would have been otherwise possible. The. U. S. Geological Survey is the only organization which has covered all of the region on the United 'States side of the boundary, and as its reports include the in¬formation gathered by the mining companies and State organi

Mar 1, 1905

(Members are urged to send in for this column any notes of interest concerning themselves or their fellow-members.) Members and guests who called at the Institute headquarters during the period Oct. 10; 1916 to Nov. 10, 1916. Edwin C. Bloomfield, Montreal. Roy E. Hoffman, Hannibal Mo. A. H. Collbran, Seoul, Korea. E. C. Harder, Cienfuegos, Cuba. Eugene Coste, Calgary, Canada. B. Jaeger, London, England. Fred Crabtree, Pittsburgh, Pa. Herbert H. Lauer, Philadelphia, Pa. P. St. John Dixon, London, England. Frank C. Laurie, Los Angeles, Cal. A. E. Drucker, London, England. 0. T. Lempriere, Melbourne, Australia. F. N. Flynn, Clifton, Ariz. W. C. Phalen, Washington D. C. Justice Grugan, Edwards, N. Y. William H. Rea, Pittsburgh, Pa. Fred A. Hale, Jr., Goodsprings, Nev. Thor Warner, Kingman, Ariz. P. S. Haury, Seoul, Korea. Arthur P. Allen has resigned his position with the Calumet & Hecla and is now connected with the Highland Mining Co., Ashcroft, B. C., Canada. H. Foster Bain, editor of the Mining Magazine of London, has resigned his position.

Jan 12, 1916

By W. J. Romanow

RECENT papers by Williams, Sherwood, and Boothby,1 Seybolt et al.2 Heikes; and Roberts4 attest to the increasing importance of the hexagonal ferromagnetic compound MnBi. Since the magnetic properties of MnBi crystals are highly anisotropic, it is useful and necessary to have appropriate aids for determining their orientations—a (00.1) standard stereographic projection and a corresponding table of crystallographic angles for this structure. The tables of crystallographic angles for the hexagonal system available in the literature5 are computed for c/a ratios greater than that of MnBi and cannot satisfactorily be used to find the crystallographic angles of MnBi. A table of angles between the crystallographic planes (HK.L) and (hk.1) was calculated for MnBi from the formula0 F=are cos Hh+Kk+ 1/2(Hk+hK) + 3/4 (a/c)2Ll/v(H2 + K2 + HK + 3/4 (a/c)2L2) (h2+ k2+hk + 3/4 (a/c)2l2) on an IBM Type 650 Magnetic Drum Data Processing machine. The lattice constants used are listed in Table I and are those determined by Willis and Rooksby7 at 20°C. More recently published values obtained by both X-ray and neutron diffraction"' show no difference from these significant to the calculation. From the crystallographic angles between the basal plane (00.1) and the general plane (hk.1) in Table I, an (00.1) standard stereographic projection was made for MnBi which is shown in Fig. 1. Acknowledgments The author wishes to thank R. G. Treuting and J. N. Hobstetter for their technical assistance, and Miss D. P. Booth for programing the IBM machine for the calculations. He appreciates the opportunity to read the paper of B. W. Roberts of General Electric Co. prior to its publication. References 1H. J. Williams, R. C. Sherwood, and 0. L. Boothby: Bulletin Amer. Physical Soc., 1956 vol. 1, p. 132. 2 A. U. Seybolt, H. Hangen, B. W. Roberts, and P. Yurcisin: AIME Trans., 1956, vol. 206, p. 605: Journal oF Metals, May 1956. 3R. R. Heikes: Physical Review, 1955, vol. 99, p. 446. .B. W. Roberts: A Neutron Diffraction Study of the Structures of Manganese B.W.Roberts:ANeutronDiffractionBismuthide, Physical. Review, 1956, vol. 104, p. 607. 5 A. Taylor and S. Leber: AIME Trans., 1954, vol. 200, p. 190; JouRNal of Metals February 1954. « C. S. Barrett: Structure of Metals, 2nd Ed., p. 635. McGraw-Hill Book Co. New York and London, 1952. 7B. T. M. Willis and H. P. Rooksby: Proceedings Physical Soc., London, 1954, vol. 67B, p. 290.

Jan 1, 1958

By H. H. Power

THE PETROLEUM DIVISION of the A.I.M.E. continued with its diversified activities during 1.935. Sessions at the New York meeting in February were devoted to production engineering, domestic and foreign oil production, and petroleum economics. The symposiums on domestic and foreign production proved their increased usefulness. The data accumulated for 1935 were added to those published during prior years in "Petroleum Development and Technology." A joint session on the use of metals in the petroleum industry was held by the Institute of Metals, Iron and Steel, and Petroleum Divisions. W. S. Farish, chairman of the board of the Standard Oil Co. (N. J.), was the principal speaker at the annual dinner. The October meeting, held in Hous¬ton, was characterized by an excellent program and large attendance. Four sessions were devoted to problems in estimating reserves, reservoir energy, properties of drilling muds, electrical logging, water flooding, and other subsurface studies. Foreign representatives of the Anglo-Persian Oil Co. presented a paper on surface tension and specific gravity of crude oil under reservoir conditions. The address by President Buehler, the dinner at San Jacinto Inn, a trip to various lo

Jan 1, 1936

By GEORGE W. HARHIS

IN the earlier period of anthracite-ruining, much coal was wasted, both underground and in the culm-banks on the surface. Such waste is common in the development of new mining districts, in which, as a rule, only the richest material can be profitably treated. In the anthracite-region, special causes operated to increase this evil. The mines were generally operated under 20-year leases, and royalties were paid upon such coal only as was actually marketed. The lessees consequently cared for immediate profit only. They were- not bound to win all the coal they exposed, or to leave it in such condition that their successors could win it. Nor was it their interest or duty to educate consumers in the use of their product. The market called for coal of large sizes ; and such coal they furnished, throwing away the rest. Any pains taken by them to bring about a more rational use of coal by their consumers would have borne fruit, after their leases had expired, to the benefit of somebody else. A full statement of the situation wits given in 1893, in the report of the State Commission, appointed in 1889 to investigate the subject.` That body included the names of Heber S. Thompson, William Griffith and the late Eckley B. Coxe.2 Its report gives special attention to the utilization of the old culm-banks.

Nov 1, 1905

By William P. Prof. Blake

WHEN we consider the efforts made in Europe to promote the physical and moral well-being of the working classes, the question is suggested whether in this country, where, theoretically, every man is peculiarly the arbiter of his own destiny, we may not be too prone to expect every man to take care of himself, and neglect to make those provisions for the welfare of the employed, demanded alike by enlightened economy and humanity. In the older countries, where the disproportion between capital and labor is greater, and the working classes are more dependent, their welfare largely occupies the attention of employers. The subject is involved in the problem of the just relations of capital and labor, and we are rapidly approaching the time, if we have not already reached it, when a generous paternal interest in the welfare of the employed should be more generally manifested. It is a subject which is of special importance to mine-owners and engineers in this country, especially to those located in the coal regions. My own attention has been particularly directed to it by a visit made to the Hassard collieries, a few miles from Liege, Belgium, under the direction of M. Andrimont. This celebrated engineer has established a comfortable home for the miners near the mouth of the shaft of the mine. It has been highly successful and beneficent in its results, and may to a great degree be regarded as a, model for such undertakings. It is known as "Hotel Louise," this being the name of Madame d'Andrimont, who laid the corner-stone of the building April 4th, 1871. The structure is of brick, upon three sides of a square, and

Jan 1, 1875

By William P. Blake

When we consider the efforts made in Europe to promote the physical and moral well-being of the working classes, the question is suggested whether in this country, where, theoretically, every man is peculiarly the arbiter of his own destiny, we may not be too prone to expect every man to take care of himself, and neglect to make those provisions for the welfare of the employed, demanded alike by enlightened economy and humanity. In the older countries, where the disproportion between capital and labor is greater, and the working classes are more dependent, their welfare largely occupies the attention of employers. The subject is involved in the problem of the just relations of capital and labor, and we are rapidly approaching the time, if we have not already reached it, when a generous paternal interest in the welfare of the employed should be more generally manifested. It is a subject which is of special importance to mine-owners and engineers in this country, especially to those located in the coal regions. My own attention has been particularly directed to it by a visit made to the Hassard collieries, a few miles from Liège, Belgium, under the direction of M. Andrimont. This celebrated engineer has established a comfortable home for the miners near the mouth of the shaft of the mine. It has been highly successful and beneficent in its results, and may to a great degree be regarded as a model for such undertakings. It is known as ((Hotel Louise," this being the name of Madame d' Andrimont, who laid the corner-stone of the building April 4th, 1871. The structure is of brick, upon three sides of a square, and

By George M. Fowler, J. P. LYDEN

T HE relationship of geological structure to orebodies and to the great masses of chert in the Tri-State mining district is of such significance that it prompts a brief recital of the existing information regarding the various periods of structural deformation. We began to note a relationship between structure and orebodies early in our studies of the field, and further work revealed a like relationship of structure to the great masses of chert so commonly associated with the ore-

Jan 1, 1934

By Donald F. Hammer, Donald W. Peterson

The Magma mine at Superior, Arizona, has produced over 13 million tons of ore yielding 1.5 billion pounds of copper. It is a mesathermal deposit, and, although the bulk of the ore has come from the Magma vein, most of the recent production has come from replacement deposits in limestone. The mine lies in a Precambrian and Paleozoic sequence of rocks that includes schist, diabase, quartzite, shale, and limestone; nearby, these rocks are intruded by igneous bodies of Mesozoic age that were probably the source of the ore-bearing fluids. Locally, these rocks are overlain by Cenozoic volcanic rocks and conglomerate. Layered rocks at the mine dip eastward about 30°. The area is extensively faulted, and surface faults are grouped into an earlier east-trending set and a later northtrending set. An additional set of diagonal faults that trends northwest and northeast is recognized underground. The east-trending Magma vein-fault, with its splits and branches, is the principal mineralized structure of the district. The bulk of the ore occurs in large ore shoots that plunge steeply westward and are sporadically connected by irregular ore shoots dipping gently eastward. The main ore controls apparently are selective zones of permeability related to the transverse faults. A bed of crystalline limestone near the base of the Martin Limestone (Devonian) is the host for the replacement ore bodies-discontinuous tabular pods dipping eastward parallel to the bedding. Selective permeability is again the apparent ore control, caused both by local hydrothermal solution of limestone and by deformation along faults. The principal copper minerals in the vein are chalcopyrite, bornite, enargite, tennantite, chalcocite, and digenite; these minerals vary in abundance according to a distinct zoning pattern. The upper part of the mine yielded considerable zinc as sphalerite, and the oxidized zone was rich in silver. The chief gangue minerals are pyrite, quartz, and hematite. In the limestone replacement bodies, chalcopyrite and bornite are the chief ore minerals.

Jan 1, 1968

By R. B. G. Yeo

Pronounced isothermal martensite formation at room temperature was measured dilatometrically in a steel containing 0.01 pct C, 24.9 pct Ni, 0.26 pctAl, 2.58 pct Ti and 0.25 pct Cb. It is shown that martensite will form isothermally if stabilization of the austenite-martensite transformation is eliminated by removal of carbon. The decarburization of two iron-nickel alloys allows isothermal transformation to martensite to occur at temperatures above their athermal Ms temperatures. In an Fe-22.4 pct Ni alloy, at the 0.008 pct C level, the Ms temperature during air cooling is 85°F higher than that during- water quenching-. At the 0.15 pct C level this difference is reduced to only 5°F. The introduction of carbon causes stabilization during air cooling which lowers the Ms temperature virtually to the same level as determined during mate?. quenching. Thus in the 0.15 pct C alloy, the Ms temperature is almost independent of cooling rate. It is suggested that rival theories of martensite formation should be reexamined in alloys of sufficiently low carbon and nitrogen content to eliminate the complication of stabilization. The Ms temperature of a steel containing 0.01 pct C, 24.9 pct Ni, 0.26 pct Al, 1.58 pct Ti and 0.15 pct Cb, solution treated at 1500°F and air cooled as 1/8-in. diam specimens, was found to be 57 °F. 1 However, when held for several hours at room temperature the steel hardened slightly and became appreciably ferromagnetic. Isothermal transformation to martensite was first revealed by Kurdjumov and Maksimova2 in an iron-base alloy containing 0.6 pct C, 6.0 pct Mn and 2 pct Cu. Most of the other studies of isothermal martensite have also been confined to highly alloyed steels which transform at subzero temperatures; for instance, DasGupta and Lement, 3 Cech and Hollomon, 4 Machlin and Cohen,5 Shih, Averbach, and Cohen.6 Averbach and cohen7 noted a rapidly decaying volume increase at room temperature in a steel containing 1 pct C, 1.5 pct Cr and 0.2 pct V. cina8 and Marshall, Perry, and Harpster9 have described the isothermal transformation to martensite at room and subzero temperature in stainless steels. Kurdjumov10 has recently reviewed the subject, noting that the isothermal formation of martensite can be observed only in the temperature range somewhat below Ms or below -50°C. The isothermal formation of martensite may be characterized as follows: 1) It occurs in steels of widely different compositions, the main prerequisite being a low transformation temperature. 2) The transformation occurs by the formation of new plates and not by the growth of old ones. 3) The isothermal transformation is suppresed by stabilization during slow cooling or holding at temperatures near room temperature. However, the factors governing this mode of transformation are still not fully understood. The formation of martensite isothermally suggests an activated process. The early theories of martensite formation did, in fact, utilize classical nucleation concepts. Kurdjumov 11 first proposed the presence of thermally activated nuclei of different sizes and compositions which would grow if they reached critical size during cooling. This treatment was enlarged and developed quantitatively by Fisher, Holloman, and Turnbull12,13 and was later reviewed by the latter two authors.14 Fisher15 associates Ms with a nucleation rate of one per cc per sec. At slightly higher temperatures the nucleation rate is so low that isothermal formation of martensite is not observed in reasonable times. At slightly lower temperatures the nucleation rate is so high that it could not be suppressed by rapid cooling. By judicious use of parameters Fisher 16 was able to obtain good agreement between classical nucleation theory and the incubation times of martensite formation.4 However the application of these principles to martensite formation in iron-nickel alloys15 predicts that an alloy containing about 30 pct (31 at. pet) Ni would not transform. The presence of an Ms temperature at -223° C in an alloy containing 34.1 pct (33 at. pct) Ni led Kaufman and cohen17 to reject the hypothesis of homogeneous nucleation in favor of the reaction path theory originally proposed by Cohen, Machlin and Paranjpe.18 This theory conveniently explains the formation of martensite athermally but becomes labored when dealing with isothermal formation. Kaufman and cohen19 did explain the isothermal activation of embryos by assuming it to be a result of the expansion of their boundary dislocation loops but this treatment predicts an upper temperature limit of isothermal martensite formation.

Jan 1, 1962

By Harvey N. Davis

MUCH has been written and said during the last twenty years about the place of the engineer in modern life, about the fundamental role that he plays both in developing and in maintaining the material foundations of modern civilization, about the advantages, and also the dangers, of the machine age that he has inaugurated, about the Frankenstein problems that he has unconcernedly foisted upon a generation utterly unable to cope with them, and about the obligation that rests upon him to stop inventing machines and turn his almost legendary energy and skill to inventing institutions that will constitute a solution of the problems he has raised, and contrariwise about his utter inability to offer wise or useful counsel in fields outside the narrow boundaries of his technical training.

Jan 1, 1938

By C. David Mann

Metal prices continued to improve in 1964, resulting in the opening of new mines and re- activation of old ones. Larger and deeper shafts are being bored. At the AEC's Nevada Test Site, a 72-in. diam shaft is being bored to 3200 ft. In New Mexico a 1650-ft shaft was bored with a 48-in. bit, then reamed to 124 in. to 935 ft, and 102 in. to 1650 ft. Deviation was only 26 in. In California a shaft sinking machine has been developed which combines drilling and mucking equipment into one mobile, integral unit.

Jan 2, 1965