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By C. P. Sandberg

INTRODUCTION. NOTWITHSTANDING the growing importance of this subject, no work specially devoted to it has hitherto been published. Having had to inspect during the last twenty years nearly a million tons of iron and steel rails for various countries, I have obtained experience of what rail manufacturers can practically execute, as well as of what railway engineers practically require. Bearing these two points in mind, I have from time to time published observations with a view to unite both interests, -that of the producer and that of the consumer,-and to reduce the specifications and the forms of sections to standards, or types, in order to facilitate the execution of the works and to improve the construction of permanent way. The Swedish government railways, as well as private companies owning railways in Sweden, Norway, and Denmark, have during the time above mentioned consulted with me and intrusted to me their rail inspection. I therefore owe to these countries much of the opportunity which I have enjoyed of gaining experience and position. Next to Sweden, America is the country which has most liberally favored me with its confidence in placing these matters in my hands. Through circumstances not under my control there has been little exportation to, and less work done by Europe for, America during the last six years ; but the recent revival of the rail trade has been the more gratifying to me, seeing that almost all the importers of American rails are still specifying for the Sandberg rail sections and inspection. It is therefore with .feelings of gratitude that I now beg to lay before the American Institute of Mining Engineers, and I hope, through that body, before the American railway world, the results of some experience which I have gained in the execution of work for their country, and which therefore belongs rightfully to

Jan 1, 1881

By E. S. Machlin

The possibility that formation of voids under creep-rupture conditions may take place by the condensation of vacancies has been investigated theoretically. It has been concluded that nucleation of voids under creep-rupture conditions by vacancy condensation is highly improbable. However, growth of pre-existant voids by vacancy condensation is probable. A number of predictions made in this theory have been verified by the data. It has been predicted and checked that the product of rupture life and steady-state creep rate for preannealed metals and single phase alloys is an approximately invariant quantity, independent of stress, temperature, and atomic number for a given type structure. The direction of the effect of cold work on this product has been predicted and found in agreement with experiment. A number of experiments to evaluate the vacancy condensation mechanism further are described. SEVERAL papers have appeared recently which speculate on the origin of voids formed at grain boundaries under stress.' ' The object of this paper is to examine quantitatively the proposition that the voids produced in a creep test are a result of vacancy condensation. A result of this paper is a theory of creep-rupture. Void Nucleation Application of standard nucleation theory" to the problem of void nucleation leads to the following conclusions: 1—Homogeneous nucleation of voids requires a supersaturation ratio (concentration of vacancies in supersaturated to that in saturated solution) of 400 for a reasonable surface energy of 1000 erg per cm-and 1.4 for the improbably low surface energy of 10 erg per cm. 2—Heterogeneous nucleation of voids at plane interfaces between two phases requires a supersaturation ratio of 2.5 for a typical contact angle of 145 3-—Void nucleation about a solid particle may be accomplished at a supersaturation ratio of 1.17 for a typical value of work of adhesion? of 60 erg per The work of adhesion is the surface work 10 replace two solid-vauor surfaces by a solid-solid interface. enr ' between an oxide and a metal in the presence of a surface active element such as sulphur. Estimates of the supersaturation ratio at which voids are produced in diffusion experiments yield a maximum of 1.01. Inasmuch as the foregoing mechanisms of void nucleation probably will not operate at this level—too low a surface energy is required—the investigatol. is led to the conclusion that voids must already exist. That is, nucleation of voids probably does not occur. Rather, existing submicroscopic voids grow out to visible size. Already existing voids might be produced during solidification or working. Supercritical sized parlicles which contain cracks may act as heterogeneous void nuclei. Gas pockets may act as void nuclei. Experiments are desired to determine the nature of the heterogeneous void nuclei which grow out to voids in both diffusion and creep experiments. Void Growth Void growth might occur in at least two possible ways, depending upon whether the already existing void nuclei are at grain boundaries or within the grains. In the case of a spherical void far from a crystal boundary, vacancies are generated during creep as a consequence of the migration of suitable dislocation jogs' and are also annihilated at sinks. Under these conditions, a steady-state concentration of vacancies is built up in the crystal, defined by the condition that for any differential volume the rate of generation of vacancies in that volume equals the rate of annihilation of those vacancies." This equality would lead to the development of a gradient of vacancy concentration radially outward from the void surface up to a radius where the vacancy lifetime becomes equal for all directions of vacancy migration. The distance over which this vacancy concentration gradient extends equals about 2vD,T* where D, is the vacancy diffusivity and T:' the vacancy lifetime in a crystal outside the gradient in a zone of constant vacancy concentration. The vacancies generated in the region over which the gradient exists will annihilate more often at the void than elsewhere. Approximately a little over one-half the vacancies generated in the gradient zone will annihilate at the void. Hence, the growth rate of the void is given by on where R is the radius of void in centimeters, is the atomic volume, and R is the rate of generation of vacancies, number per centimeter" per second. R D and T* may be estimated in terms of other physical parameters." In particular, R = n.j e/b [3] where n is the average number of vacancy produc-

Jan 1, 1957

By AIME AIME

TEXAS not only produces millions of barrels of petroleum daily, but supplies the oil industry with an asset infinitely more valuable than liquld gold. That asset is leadership. The oil industry was built from its humble beginning a few decades ago into a potent force in world economy by human hands and human brains. One of these great leaders in the busy world of oil is Wallace Pratt, of the Humble company, who has been called to a position as director and member of the executive committee of the Standard Oil of New Jersey. So reads the Houston Post of June 3, 1937.

Jan 1, 1944

By AIME AIME

IN times of stress nations pick strong men to lead them. Similarly the Coal Division selected forceful Larry A. Shipman, fuel engineer for the Southern Coal and Coke Co., Knoxville, Tenn.. to lead it through the year 1945. He was born in Indianapolis May 13, 1891. Following graduation from a technical high school in that city Larry began his fuel career approximately 35 years ago attached to one end of a scoop shovel, firing locomotives for the Pennsylvania Railroad. At the end of two years he transferred to the New York Central Lines and held these jobs successively: locomotive fireman, engineer, fireman instructor, supervisor of instructors, and fuel engineer.

Jan 1, 1945

By W. C. Meyer

In an effort to conserve and extend oil resources, the use of powdered coal-in-oil mixtures (COM) as an alternate fuel in oil-fired boilers is receiving increasing attention. For the approach to be successful, some degree of stability of the suspension against settling is needed. The variety of means available to achieve stability of this nonaqueous slurry is reviewed along with some of the physical and chemical concepts which underlie each method.

Jan 1, 1983

By F. W. Bradley

MY first Nevada City mining reminiscence is one of seeing Capt. Thomas Mein, over 52 years ago, in the old Wyoming mill on Deer Creek about a mile below the town of Nevada City. Captain Mein was then superintendent of the Wyoming mine, where the old fashioned Cornish pump was used, as well as hurdy-gurdy water wheels for power. This mill was one of the typical, up-to-date mills of that time and consisted of stamps, fed by Chinese hand feeders, who also cobbed the ore down to a small enough size to be fed into the mortars. Stamps at that time were of light weight and crushed about one ton to one and a half tons to the stamp, the pulp going over plates, then into sluices with self-raising gates. When a sluice became full the pulp was shut off and directed into the parallel sluice, also with a self-raising gate. The concentrate thus collected in the sluice was shoveled out and carried to Cornish buddles and there cleaned up, preparatory to being sent to a local custom chlorination works.

Jan 1, 1929

By Vincent P. Gi. ccnella

GOLD was discovered in Gold Canyon on May 15, 1849. Following this discovery placer miners worked the gravels in the canyon for-ten years, finally discovering the outcrop of the Comstock lode at Gold Hill in May, 1859, and in Ophir ravine on June 12 of the same year. Before long large quantities of gold and silver, were taken from the lode and one of the West's most spectacular mining booms drew thousands of fortune seekers to Nevada. After a long period of production activity waned and in late years little mining was done. The recent reopening of the old mines and the discovery of ore in other parts of the vein, and in other veins of the district, has led to a revival of interest in the Comstock. Virginia City, Gold Hill, and Silver City, situated along the great vein system, are enjoying a period of prosperity and a large influx of people.

Jan 1, 1934

By AIME AIME

ALMOST as many attended the annual dinner this year as last, when the presence of Mr. Hoover was such an attraction that almost two-thirds more than had ever attended before were present. Only by putting the late comers at tables in the balcony could everybody be accommodated. Past President De-Golyer was the toastmaster and in opening the post-prandial exercises referred to the regrettable fact that this was the last of the long series of dinners which have been held at the Waldorf, as the hotel will be torn down to give way to an office building before another year. To the delight of the gathering "Oscar" appeared and, in a delightfully brief but characteristic speech, referred to the long association that had existed and hinted that a new Waldorf-Astoria may arise, where the Institute could continue to gather annually in an enlarged replica of the room they had met in so long. Before taking up the presentation of the medals, Mr. DeGolyer referred to the Institute's "Legion of Honor," the 34 men who have been members continuously for over fifty years. For various reasons only five of them, W. S. Ayres, F. G. Corning, Henry D. Hibbard, A. F. Schneider and Arthur Thacher, could be present. They were all seated at the speaker's table, and W. S. Ayres, 56 years a member, as the dean of the group, was called on to respond for them all. He said: "The introduction I have just received would indicate that this particular group of men to which I belong is considered by the chairman to be a group of real antiques. Possibly you are questioning the accuracy of his judgment. I hope you are, although there may be some first-sight evidences tending to substantiate the view held by the chairman.

Jan 1, 1929

By E. D. Hummer

During the planning of the fine coal cleaning addition at the Gary, W. Va., Coal Preparation Plant of United States Steel Corp. careful consideration was directed toward the problem of minus 48 mesh refuse disposal. The plant flow sheet included wet screening the raw coal at ¼ in., pumping the minus ¼ in. raw coal to bowl desiltors for desliming, and then cleaning the deslimed raw coal on tables. The material to be removed from the circuit as minus 48 mesh refuse consisted of the minus 100 mesh desiltor overflow thickened in two 120 ft diam thickeners and minus 1 mm screened from the table refuse. Later a flotation plant was added to recover coal from the desiltor overflow, and a classifier replaced the screens to make a sharper size separation of the table refuse at 48 mesh. Today the minus 48 mesh refuse at Gary consists of thickened flotation tailing and thickened spiral classifier overflow. The transportation of large quantities of fine, wet refuse filter cake mixed with jig and table refuse over existing conveying equipment would have been neither dependable nor economical. Filtration was therefore impractical, and disposal of the fine materials was a problem. The decision was to pump the material to storage ponds.

Jan 3, 1965

By R. E. Wagner

MISSOURI's famous lead area, in what is known as Southeast Missouri, is locally termed the "Lead Belt." These deposits are in the Bonne Terre dolomite of late Cambrian age which has a thickness of nearly 400 ft. Underlying this is the La Motte sandstone which varies in thickness from 0 to 400 ft. The La Motte beds are deposited directly on the ancient erosion surface of Pre-Cambrian porphyries and granites of probably Algonkian age. The buried igneous peaks extend up into the Bonne Terre in several areas within the Lead Belt. Overlying the Bonne Terre are shales and siliceous dolomites of late Cambrian and early Ordovician age. Within the Lead Belt these have a thickness of from 0 to 500 ft. The district is bounded in general on the southwest by the Sims Mountain fault, on the northwest and north by the Big River fault, and on the

Jan 1, 1947

By A. L. Moore

KAISER Bauxite Co., a subsidiary of Kaiser Aluminum & Chemical Corp., has been mining and shipping Jamaican bauxite for over a year. On Feb. 10, 1953 the first boat load of bauxite left Port Kaiser, Jamaica, for the company's alumina plant at Baton Rouge, La. To provide its own source of the aluminum ore, a Kaiser Aluminum & Chemical Corp. exploration party started initial reconnaissance in 1947. This work, and subsequent exploration, led to the acquisition of reserves sufficient to warrant a full-scale mining operation for several decades.

Jan 3, 1954

Jan 1, 1880

By Coolbaugh, Franklin

CRUSHING of Climax mine-run ore is carried out in two plants: No. 1 plant (flowsheet in Fig. 1) has a capacity of approximately 5000 tons per day. It is used as a stand-by except when maximum production is required. No. 2 plant (Fig. 2) has a top capacity of approximately 17,000 tons per day. The No. 2 crusher is more efficient to operate on reduced tonnages regardless of the wide variation in peak capacities. The system of crushing is similar in both plants: Mine ore, of a size which can be drawn through 48 by 96-in. slusher openings underground, is dumped into the crusher bins from ten-ton mine cars and fed into 48 by 60-in. Buchanan jaw crushers by means of chutes and Ross chain feeders. The jaw crushers are set to discharge at approximately 9-in. size. Jaw crusher discharge is conveyed to 7-ft. Symons standard cone crushers where it is broken to minus-2-in. size,

Jan 1, 1946

By AIME

Lewis E. Young, who will formally assume his duties as President of the AIME at the Annual Meeting in San Francisco in February 1949, was born in Topeka, Kansas, Oct. 1, 1878. Dr. Young received his engineering education at the Pennsylvania State College, where he received the degree of B.S. in Mining Engineering in 1900. In 1904 he received his E.M. degree from Iowa State College, and in 1915 a Ph.D. from the University of Illinois. In 1947, the University of Missouri conferred on Dr. Young honoris causa the degree of Doctor of Engineering. His active career began in the educational field as instructor at Iowa State College, and following that, as professor of mining at the Colorado School of Mines, 1903-1907. While he was at Golden he launched hi: career as consulting mining engineer for various Western companies. Leaving the Colorado School of Mines, Dr. Young returned to Missouri, serving the University of Missouri as director of the School of Mines and Metallurgy at Rolla, 1907-1914. Leaving Missouri he went to the University of Illinois as assistant professor of business organization, 1915-1918, during which period he wrote exhaustive treatises on mine subsidence and mine taxation, which won for him the degree of Ph.D. before mentioned.

Jan 1, 1949

By F. Keller, A. H. Geisler

Some of the important changes that take place in the structure of aluminum alloys are largely submicroscopic in character. This is especially true of the changes that accompany age-hardening and recrystallization. Although improved metallographic practices have been helpful in indicating some of these changes indirectly, results are limited by the resolving power of optical microscope lenses. The electron microscope, however, provides a new and important means for investigating the fine structure of metals in a range not possible heretofore. It is anticipated that this microscope will yield new and useful information to metallurgists when suitable techniques are developed to utilize its very high resolving power. Several unique methods have been devised to permit the examination of the structure of opaque samples by the electron microscope. These are all based on the principle of producing a very thin film that represents the prepared surface of the opaque metal sample, which can be examined in the transmission microscope; however, the available methods fall into three categories, depending on the manner in which the film is obtained. With the oxide-film method developed by Mahl3-17 a very thin surface layer of the metallographic sample is converted into oxide by a thermal, chemical or anodic treatment. After removal from the metal sample by one of the special techniques described by Evans,19 this oxide film is examined in the electron microscope, and is found to portray the structure of the original metal surface. Films formed on aluminum,8,17 nickel,7 iron 3,8,9 and a nickel-beryllium alloy" by heating; films formed on iron 8.9 by chemical action; and films formed on aluminum3-16 by anodic oxidation, have been examined. The other two are more recent methods developed principally in this country; they consist in making the thin film in the form of a mold or replica of the surface contour of an etched sample. With the negative replica method the thin film is made directly on the sample; with the positive replica method it is made on a negative reproduction of the sample. With both methods, variations in the contour of the metal sample, caused mainly by etching, produce variations in the thickness of the surface replica. Because of the direct dependence of the amount of scattering of the illuminating electrons upon the thickness of the film penetrated, only the variations in thickness of the replica are responsible for tones in the electron image. Negative replicas are made by forming a thin film of some suitable material directly on the polished and etched metal sample, and derive their name from the fact that after removal from the sample they have the high and low points in the sample reversed, as shown in Fig. I. Nega-

Jan 1, 1944

By AIME AIME

TWO weeks ago the writer was lunching in the Engineers` Club in New York with a man who has perhaps the widest acquaintance among engineers of anyone in the country a member of another of the Founder engineering societies. "By the way," lie asked. "who have they nominated for your next president."' "Doctor Becket," I told him- "Oh. that's line," he replied, in a heartfelt tone that rang with sincerity. "I have come in contact with him occasionally and he is just the right type.' And that is the way Dr. Frederick M. Becket impresses everybody. The right type. Most Institute members of the western group of hard-rock minors do not know him, but then they meet him in his swing around the circle next year they will not require a long acquaintance to sense his kindly and outstanding personality, to realize that he is a gentleman in the bet meaning o1 that word, a man of wide sympathies and interests.

Jan 1, 1932

By Gerard Matthes

ONLY in recent years has any practical headway been made in the application of aerial photography to geological problems, and up to the present time its principal value to the geologist and mining engineer has been in "areal geology;" i. e., the study of formations as revealed at the surface. The object of this paper is to set forth briefly the principal advantages that may be derived from aerial photographic data in geological work and to serve in a measure as a guide to those who may be con-templating its use. Geophysical prospecting has for object the locating of mineral under the surface. Inasmuch as the geologist's chief complaint in life is a dual one-inability to see under the surface and inability to visualize comprehensively what he does see on top of the ground-geophysical prospecting coupled with aerial photography should do much to lessen his burdens. To what extent aerial photography can be made a useful adjunct to geophysical prospecting remains to be proved, but the inference drawn here is that it holds many alluring possibilities. To avoid disappointments, it should be stated at the outset that to the :geologist or mining engineer an aerial photograph or mosaic is only a tool, the effecient use of which he must set out to master. Upon his skill and ingenuity in applying it to particular problems will depend largely the value of the results that he will obtain. Under the most favorable conditions an aerial mosaic or even a few loose photographs, because of the exceptionally comprehensive oversight which they afford of field data, such as dips and strike observations at isolated outcrops, local indications of faulting, mineral and fossil finds, greatly facilitate study and correlation, save much tedious foot work, and may repay their cost many times. Even so, types of country may be found where the most, skillful use of the best of pictures will produce results so meager as to render the cost of aerial photography entirely unwarranted.

Jan 1, 1928

By A. M. Gaudin

CHANGES in industrial practice, in plant design, and in research methods which are so clearly to be seen on every hand, have affected the mineral industry as well as others. In particular, ore dressing has passed through a revolution in practice brought about by the introduction of flotation and other quasi-chemical methods, until it has ceased to be solely the mechanical preparation of ores. In fact, the term "ore dressing" itself is obsolescent, and "mineral dressing" has been growing in popularity. This assures adequate recognition of the fact that mineral substances other than ores, e.g. coals, clays, and cement rock, are treated by the same general methods. As a result of these industrial changes it was felt that a complete rearrangement of the curriculum and laboratories at the Massachusetts Institute of Technology would be ad-vantageous. Such a rearrangement would allow instruction and research to proceed in wider accord with industrial evolution and the needs of our times.

Jan 1, 1942

Jan 1, 1888

By AIME AIME

THE petroleum engineers have the conference habit. They drop in, thresh things over, and drop out. No time is wasted. So it was at the Fort Worth meeting of the Petroleum Division, Thursday and Friday, Oct. 8 and 9; headquarters, Blackstone Hotel. Associate Chairman Albertson arrived the morning of the 7th, to tie in any loose ends of the technical program. S. M. Greenidge, chairman of the local committee, checked the arrangements with his committeemen at a luncheon that noon. By mid-afternoon the next day's attendance was anybody's guess-there were no noses to count. But when the gavel sounded Thursday morning 175 members and guests were present, also the official A.I.M.E. party consisting of President Lovejoy, Secretary Parsons, and George Otis Smith. Shortly after adjournment Friday afternoon all but a handful had vamoosed, lit out, disap¬peared. But, in the meantime, it was a grand conference, attendance maximum every session, and the discussion fast and furious. The discussion came from all over the floor, sometimes as good-natured sniping, sometimes in long volleys that were almost fatal to the reporter. Everyone knew his subject and few there were who had nothing to say.

Jan 1, 1936