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By V. F. Marsters

THE oil-producing territory of Peru is confined to the province of Tumbes and the department of Piura, located in the extreme northern end of the republic and adjacent to the southern border of Equador. The first real production came from Zorritos field, located on the shore line and in the province of Tumbes. The production of this territory was soon exceeded by that of the Negritos field, also located along the shore line and in the northwest corner of the department of Piura. Talara, lying a short distance north of the original or early producing area was made the shipping port. This field was developed by the London Pacific Petroleum Co.; it is now-operated by the International Petroleum Ltd. (Toronto, Canada). A little later, the Lobitos field came into prominence; it was first exploited by the Lobitos Oil Co. At present, it is operated by the British Oilfields Ltd. This field is located between Talara, on the south, and Zorritos, on the north. It is now the second largest producing area in the country, the Negritos being by far the largest both in area and production. In other parts of Peru, there have been periods of desultory prospecting, particularly in the department of Puno. This work was carried on in the surrounding region of what,is locally known as the "Pirin" field, developed by the Brown Brothers. It lies between Juliaca, a railway junction point and Lake Titicaca. No favorable results from the latest prospecting have been reported. During the past few months, an opinion has been expressed in various journals that it is doubtful if commercial production will be found in the high plains of the Lake Titicaca region. It is, however, due to the Peruvian oil industry to remember that the Pirin field, although covering but a small area, was a fair producer even under adverse circumstances. If the author's interpretation of the geology of the Titicaca section is correct, certain sections of the high plains will be found to be commercially productive, not-withstanding the unfortunate geographical position from the standpoint of transportation; or its elevation.

Jan 3, 1925

By P. P. Gregory

NATURAL petroleum gas occurring in the oil-bearing reservoirs is found to exist either as free gas associated with the oil and/or in solution in the oil. In some virgin fields practically no free gas is encountered under the reservoir conditions of pressure and temperature, although in other fields a considerable section of the ``pay" horizon is occupied by free gas. In other words, a given oil field may or may not have a gas cap before the exploitation takes place. However, when the reservoir pressure is reduced to a point below the critical saturation pressure by withdrawals of fluids from the producing formation, the gas dissolved in the oil inevitably begins to come out of solution and becomes free gas. Under the con-trolled methods of production and drilling, a portion of this gas is pro-duced with the oil to the surface and a portion of it remains within the reservoir to accumulate at higher structural levels toward which it migrates by virtue of its low specific gravity. The rate of growth of a gas cap in a-given structure depends primarily upon the rate of decline in the reservoir pressure. If the rate of pressure decline is rapid, the gas cap likewise will grog rapidly. On the other hand, shrinkage in the gas-cap area was noted in some fields in which reservoir pressures were increasing.

Jan 1, 1938

By Carl Scholz

Discussion of the paper of Carl Scholz, published in Bi-monthly Bulletin, No. 22, July, 1908, pp. 551 to 559. HOWARD N. EAVENSON, Gary, W. Va. (communication to the Secretary*) :-For some time before the publication of Mr. Scholz's paper, I had been collecting data bearing upon its subject, and I now take pleasure in presenting my results to the Institute in the form of a discussion. It has long been a matter of common opinion among mining-men that mice-explosions are, more frequent during the colder, or winter months, than during the warmer ones, and it is a matter of common knowledge among them that the air-ways and road-ways in most mines are much drier and are more in¬clined to be dusty during the winter than during the summer. In many mines, places which are wet and sloppy in the summer are dry and sometimes dusty during the winter. These changes, of course, can only be due to atmospheric conditions, and are caused by differences in temperature and humidity. Until recently, however, very little attention has been paid to the part that atmospheric conditions may play in mine-explosions, or, rather, to the effect they may have in rendering mine-conditions peculiarly dangerous, and in spreading and rendering more disastrous the effects of what would otherwise probably have been .small explosions. To show the difference in mine-conditions during sunnier .and winter months, I have tabulated in Table I. the results of 24 observations of hygrometric conditions in several different mines at different times of the year. Mines Nos. 1, 2, and 6 are located in the Pocahontas.coal -region, in McDowell couuty, W.Va., the first one being a shaft-mine shaft mine and the others drift. Mines 1A and 2A are drift-mines located in Logan county, W. Va. All of these are mines of fair size, but none of them has been in operation more than six years,

Jun 1, 1909

The Garfield plant of the American Smelting & Refining Company is situated about seventeen miles west of Salt Lake City, on the Los Angeles & Salt Lake Railroad, and has freight service by the Denver & Rio Grande Western. Western Pacific and Bingham & Garfield Railways. The site lies between the picturesque Great Salt Lake, with its mountain islands and the northern point of the Oquirrh Range, which forms the western boundary of the Salt Lake Valley.

Jan 1, 1925

By Boyd Guthrie, J. D. Lankford

A progress report on the oil-shale and shale-oil processing research program at the U. s. Bureau of Mines Oil-Shale Demonstration Plant. Legislation providing for the program and aims are briefly noted. The remoteness and rugged nature of the terrain at the plant site are important factors in construction and operations. Large-scale units now in operation are the crushing plant and two 40-ton N-T-U retorts. These are described in detail. Under construction are several retorting pilot plants and a 200 bbl per day refinery. The refineiy incorporates several types of thermal operation, three-stage low-temperature acid treating, doctor sweetening and rerunning. Data are presented on typical N-T-U retort runs. Yields of 90 to loo pct of assay are realized on 30 gal to the ton shale with a retort cycle time of 18 hr. Data also are presented showing a comparison of a Mid-Continent petroleum and N-T-U shale oil. This comparison indicates that shale oil has a high pour point, low API gravity, and contains about 0.8 pct sulphur and 2 pct nitrogen. The naphtha fraction contains 3 pct tar acids, 9 pct tar bases and jo pct olefins. The problems involved in refining shale oil into usable products are discussed in detail. Introduction The Bureau of Mines oil-shale program now under way at Rifle, Colo., was begun in July 1944 under the provisions of the Synthetic Liquid Fuels Act, which was passed in the spring of that year under the sponsorship of Senator Joseph C. O'Ma-honey of Wyoming and Congressman Jennings Randolph of West Virginia, aided by Michael W. Straus, former Assistant Secretary of the Interior, and others. The oil-shale plant is only a part of the Office of Synthetic Liquid Fuels, Bureau of Mines, which has under way projects to develop synthetic liquid fuels from coal and other solid materials at Pittsburgh and Bruceton, Pa., Morgantown, W. Va., Louisiana, Mo., as well as the Petroleum and Oil-Shale Experiment Station at Laramie, Wyo., and the oil-shale demonstration plant at Rifle. The oil-shale program is entirely experimental. It is not intended that oil will be produced in great quantities. Production will be limited to the volume obtained from plant-scale experimental operations, which will be kept to the minimum size needed to develop techniques and processes and to demonstrate costs. After the passage of the enabling act in the summer of 1944 a survey of the oil-shale resources of the Nation was made to determine the most suitable general area in which to establish the demonstration plant. The most suitable area was found to be in the Rifle-De Bequearea in Garfield County, western Colorado. Bureau of Mines field parties covered this entire area thoroughly

Jan 1, 1949

By PAUL AUDIBERT

THE downward trend of metal prices seems to act something like a reagent that precipitates selfishness in most business men's hearts; in the same way the upward trend precipitates altruism. Operators do not say: "I continue working my mine without curtailment because I can afford the present prices while my neighbor cannot and thus will give me way." They say: "I continue working my mine because 1 consider it a service for consumers. They will get better prices on a free market. Any curtail¬ment would be an attempt to raise prices artificially, that is to say, bad economics." Copper producers have learned how fallacious is such an opinion. It perhaps was not fallacious in olden times when all mines were worked on a small scale even if operating on a big deposit. At that time the supply and demand law played fair. When prices were too low and profits were vanishing for many mines, they would. shut at once, then little by little the metal scarcity would induce prices to climb up again; finally these prices would reach the point when it became profitable to again work the closed mines. Re-opening and shutting down mines was then a normal custom. Workers and operators weakly deplored this unstability, but there was nothing effective they could, do about it.

Jan 1, 1931

By R. F. Stahl, W. A. Martin, R L. Huntington

A marked gravitational segregation of liquid has been observed to take place in a number of volumetric fields toward the later stages of their oil-producing periods. This phenomenon has been pronounced in thick, highly permeable sand formations such as those of the wilcox zone in Oklahoma City. This observation has prompted considerable research directed toward the semiquantitative determination of the equilibrium saturation distribution of oil vertically throughout a formation at final depletion. In this paper, data are also presented showing the transient distribution of liquid at different stages of the depletion period. Other experimental results show the effect of temperature on the drainage rates of water, Wilcox crude oil, and a close-cut heptane fraction. Intermittent drainage of liquid produced saturation gradients that might well be expected from the flow theories involved, Yields of the various liquids varied from 50 to 75 per cent of the original fluid content of the sand-packed (4 in. by 8 ft.) vertical tube. Introduction In certain volumetric Oil fields the performance of the reservoir during the latter part Of its producing life is governed to a large extent by the downward movement of liquid due to the force of gravity. This is especially true of formations having thick or tilting beds of uniformly high permeability, free of shale breaks. Laverett4 and Katz3 have presented original data and discussed the theory relating to the capillary and gravitational forces acting On liquids contained in a sand body. These investigators have pointed out the importance of such studies in the estimation of future reserves as well as the original fluid content of a reservoir. In this previous work, no data have been reported showing the history of saturation distributions during the drainage period. Since a knowledge Of these transients is helpful in obtaining crude Oil from such a reservoir, the authors have obtained these data during this investigation. Experimental Apparatus The drainage tests were carried out in two vertical tubes, 8 ft. high and consisting of 2-in. and 4-in. standard wrought-iron pipe, respectively. Each tube was equipped with a water jacket, which could be kept virtually isothermal ( ± 1.0ºF.). A diagrammatic sketch of the 4-in. tube and its auxiliaries is shown in Fig. 1. At 6 in. above the base of the tube, and at every foot above this point, core nipples were inserted through the water jacket. These nipples were closely fitted with steel-plug inserts during each drainage run. At the end of the run, these inserts were removed so that cores could be obtained from the sand-packed tube.

Jan 1, 1943

By R. F. Stahl, W. A. Martin

A marked gravitational segregation of liquid has been observed to take place in a number of volumetric fields toward the later stages of their oil-producing periods. This phenomenon has been pronounced in thick, highly permeable sand formations such as those of the wilcox zone in Oklahoma City. This observation has prompted considerable research directed toward the semiquantitative determination of the equilibrium saturation distribution of oil vertically throughout a formation at final depletion. In this paper, data are also presented showing the transient distribution of liquid at different stages of the depletion period. Other experimental results show the effect of temperature on the drainage rates of water, Wilcox crude oil, and a close-cut heptane fraction. Intermittent drainage of liquid produced saturation gradients that might well be expected from the flow theories involved, Yields of the various liquids varied from 50 to 75 per cent of the original fluid content of the sand-packed (4 in. by 8 ft.) vertical tube. Introduction In certain volumetric Oil fields the performance of the reservoir during the latter part Of its producing life is governed to a large extent by the downward movement of liquid due to the force of gravity. This is especially true of formations having thick or tilting beds of uniformly high permeability, free of shale breaks. Laverett4 and Katz3 have presented original data and discussed the theory relating to the capillary and gravitational forces acting On liquids contained in a sand body. These investigators have pointed out the importance of such studies in the estimation of future reserves as well as the original fluid content of a reservoir. In this previous work, no data have been reported showing the history of saturation distributions during the drainage period. Since a knowledge Of these transients is helpful in obtaining crude Oil from such a reservoir, the authors have obtained these data during this investigation. Experimental Apparatus The drainage tests were carried out in two vertical tubes, 8 ft. high and consisting of 2-in. and 4-in. standard wrought-iron pipe, respectively. Each tube was equipped with a water jacket, which could be kept virtually isothermal ( ± 1.0ºF.). A diagrammatic sketch of the 4-in. tube and its auxiliaries is shown in Fig. 1. At 6 in. above the base of the tube, and at every foot above this point, core nipples were inserted through the water jacket. These nipples were closely fitted with steel-plug inserts during each drainage run. At the end of the run, these inserts were removed so that cores could be obtained from the sand-packed tube.

Jan 1, 1943

By JOHN A. MALONEY

AS noted in the February issue of MINING AND METALLURGY, an advisory committee to the Museum of Science and Industry of Chicago was authorized by the Institute's Board of Directors, with W. R. Wright of Chicago, former Director of the Institute, as chairman. Since that time the committee has been undergoing organization, and held its initial meeting at the Museum offices in Chicago on April 11 and 12. Functioning as consultants to the Geology and Mineral Industries branch of this new institution, the advisory committee is aiding in building an exhibit which will tell the story of geology, mining, and metallurgy to millions of visitors a year. Although patterned to some extent

Jan 1, 1932

By R. R. Sayers

TWO serious hazards from coal dust confront the bituminous-coal miner- -a physical or safety hazard and a physiological or health hazard. The first threatens the miner with loss of life from coal-dint explosions, and the second with loss of health and earning capacity from inhaling large quantities of the dust. Studies by the Bureau of Mines have shown that coal dust, except some grades of anthracite dust, is capable of initiating an explosion when no explosive gas is present and that its property of extending or propagating an explosion has been responsible for nearly all the widespread explosions that have occurred in bituminous mines in the United States in the present century. For years many mining people believed that low-volatile coal dust was not explosive but not only is it explosive but if the source of ignition is intense, it is as explosive as the dust of many high-volatile coals because the war is creating increased pressure for greater coal production and because of the trend toward greater mechanization in mines, explosion and health hazards from coal dust are likely !n increase considerably.

Jan 1, 1943

By A. W. Hesse

Twelve years ago, some coal-mine operators, mining engineers, oil and gas operators, Bureau of Mines engineers, geologists and state mine inspectors met in Pittsburgh, Pa. to discuss and solve if possible, the problems in connection with the drilling of oil and gas wells through or near coal mines and through the future coal reserves. Regulations were drafted and presented by O. P. Hood and A. G. Heggem of the Bureau of Mines.' . There was considerable discussion of the various articles, practically all of which appear in Bulletin 65, but the interest aroused at that meeting was short lived. Practically none of the important coal-producing states gave the matter the consideration it should have received. Notwithstanding the marked progress in safety work, coal mines still have an unenviable reputation for mine explosions. Our mining laws have become stricter and the enforcement, especially in Pennsylvania, more rigid, but what good will come from a rigid enforcement of the mining laws if some source of danger exists all around the mines, over which the operators have no control ? It is hardly necessary to recite all the cases of natural-gas explosions published in Bulletin 65, but with some of them I am especially familiar. In 1912, while visiting the Miners' Hospital, at Fairmont, W. Va., my attention was called to a patient swathed in in bandages so that no part of his face and hands were visible. He had not been told that his two sons, mere boys, had died of the burns they had received in the same accident—explosion due to natural gas leaking into a country mine at Peora, Harrison Co., W. Va.

Jan 1, 1925

By G. A. Reinhardt, Albert Sauveur

Although many metallurgists know that some pearlitic special steels can be made troostitic, martensitic, and even austenitic, without quenching, and, therefore, without exposing them to the dangers of the quenching-bath, the practical significance of such possibility does not seem to have received the attention it deserves. Let us recall briefly the mechanism of the transformation alluded to. In Fig. 1 (after Guillet) is shown the constitutional diagram of nickel-steel; that is, of alloys of iron, carbon, and nickel. Any steel the composition of which falls within the area LPO is pearlitic after slow cooling; any steel the composition of which is represented by a point within the area MLO is martensitic, and any steel within the area MNO is austenitic. Starting with pearlitic steel, then by increasing the carbon-content or the nickel-content, or both, the metal becomes marten-sitic and eventually austenitic; that is, its composition crosses first the boundary-line LO and then the line MO—and it remains martensitic or austenitic after slow (air) cooling.' We have in this way imparted to the metal without quenching it the properties of hardened carbon-steel. In other words, the steel is now self-hardening; Nickel cannot be introduced into solid steel, but by the well-known process of case-hardening it

Jan 1, 1913

By H. A. Dierks

PENNSYLVANIA's anthracite region lies in the heart of the richest and most densely populated area of the U. S. Nearly 70 million people live within a radius of 500 miles, in which 130,000 manufacturing plants employ more than 8 million workers. The region comprises some 3000 sq miles and contains 484 sq miles of coal measures, which folding and erosion have divided into four separate and distinct fields, known as the Northern, Eastern Middle, Western Middle, and Southern. One million people live in the anthracite region proper, and their prosperity depends to a great extent on the anthracite industry, which produces more than $200 million in new wealth for the U. S. each year. Nearly 80 pct of the tonnage shipped out of the region is handled by nine railroads, which depend on this traffic for a large part of their revenue. It follows that the economic health and the very existence 0: this industry is of real concern not only to the region itself but also to the state of Pennsylvania and the country as a whole. Anthracite mining is one of the oldest mineral industries in America. About 1760 burning rock or stone coal was discovered on the hillsides of northeastern Pennsylvania. Within a few years a systematic search for coal bed outcrops was under way, and hand mining was begun. At first production was very limited, since anthracite was difficult to burn and was not readily accepted as a fuel. Pennsylvania anthracite is one of the densest and hardest of all coals, and its content of volatile matter is low. Consequently it does not ignite easily and it burns without smoke. About 1808 Judge Fell of Wilkes-Barre burned anthracite in an open grate fireplace and demonstrated proper handling of an anthracite fire. From

Jan 1, 1958

By T. R. A. Davey

IN 1947 the author became interested in the fundamental aspects of the desilverizing of lead by zinc, conducted some experimental work, and searched the technical literature for all available fundamental data. Since then a revival of interest in the subject in Europe resulted in the appearance of quite a number of papers. It became evident that it would be more profitable to collect together and examine thoroughly the results of various workers, than to attempt to duplicate the experimental determinations. There are many inconsistencies in the various publications, and it is opportune to review at this time the present status of knowledge on the Ag-Pb-Zn system. There is also a need for a clear description, in fundamental terms, of the various desilverizing procedures. This paper is presented in four sections: 1—There is an historical review of the origins of the Parkes process, of the results of many attempts to find a satisfactory fundamental explanation for the phenomena, and of the modifications proposed to date. 2—A diagram of the Ag-Pb-Zn system is presented. This is believed to be free of obvious inconsistencies or theoretical impossibilities, although thermodynamic analysis subsequently may reveal errors. 3—The fundamental bases of the various desilverizing procedures, which have been used up to the present day, are described; and a new method is suggested for desilverizing a continuous flow of softened bullion in which the bullion is stirred at a low temperature in two stages producing desilverized lead at least as low in silver as that from the Williams continuous process and a crust which, on liquation, yields a very high-silver Ag-Zn alloy. 4—A suggestion is made for the revival of de-golding practice, following a recently published account which does not seem to have attracted the attention it deserves. The terms "eutectic trough" and "peritectic fold" as used in this paper are synonymous with "line of binary eutectic crystallization" and "line of binary peritectic crystallization" as used by Masing.' The German literature on ternary and higher systems is rather extensive and a fairly general system of nomenclature has arisen, whereas in English usage the corresponding terms are not as well established. For this reason the meanings of terms used in this paper, together with the equivalent German terms, are given as follows: 1—Eutectic trough—eutektische rinne: line at which a liquid precipitates two solids S1 and S2 simultaneously. If the composition of a liquid which is cooling reaches this line, it then follows the course of this line until a eutectic point is reached, or until all the liquid is exhausted. The tangent to the eutec-tic trough cuts the line joining S1S2. 2—Peritectic fold—peritektische rinne: line at which a solid S1 and a liquid L transform into another solid S2. If the composition of a liquid which is precipitating S1 reaches the line, on further cooling only S2 is precipitated. The liquid composition moves from one phase region (L + S1) into the other (L + S2), and does not follow the course of the boundary. The tangent to the peritectic fold cuts the line S1S2 produced nearer S,. 3—Liquid miscibility gap, or conjugate solution region—mischungslucke: the region within which two liquid phases coexist in equilibrium over a certain range of temperature. A system whose composition is represented by a point in this region comprises one liquid at high temperature; then as the temperature is progressively reduced, two liquids, one liquid and one solid, one liquid and two solids, and finally three solids. 4—Liquid miscibility gap boundary—begrenzung der flussigen mischungsliicke: the line along which the surface of the miscibility gap dome, considered as a solid model, intersects the surrounding liquidus surfaces. 5—Tie lines—konoden: lines joining points representing the compositions of two liquids, a liquid and a solid, or two solids, in equilibrium. In binary systems the only tie lines customarily drawn are those through invariant points, e.g., through the eutectics of the Pb-Zn and Ag-Pb systems, or the various peritectics of the Ag-Zn system, as in Figs. 1 to 3. In ternary systems it is desirable to draw sufficient tie lines to indicate the slopes of all possible tie lines. 6—Ternary eutectic point—ternares eutektikum: point at which liquid transforms isothermally to three solids, S1, S2, and S Such a point can lie only within the triangle 7—Invariant peritectic (transformation) point— nonvariante peritektische umsetzungspunkt: (a) — On the miscibility gap boundary, the point at which two liquids and two solids react isothermally so that L, + S, + L, + S2. (b)—On the eutectic trough, the point at which a liquid and three solids react iso-thermally so that L + S, + S2 + S3. Such a point must lie on that side of the line joining S,S which is further from S,. (c)—A further possibility, not found in this ternary system, is that the point is at the intersection of two peritectic folds when the reaction concerned is L + S, + S, + S Historical Introduction Karsten discovered in 1842 that silver and gold may be separated from lead by the addition of zinc.2 Ten years later Parkes used this fact to develop the well known desilverizing process which bears his

Jan 1, 1955

In the death of Major A. B. desaulles at South Bethlehem, Pa., on Dec. 24, 1917, the Institute lost a valued and esteemed member, one of the last few of those who, in May, 1871, at Wilkes-Barre, attended the first meeting of the Institute, in response to a call that had been issued by R. P. Rothwell, Eckley B. Coxe, and Martin Coryell. Major desaulles was born Jan. 8, 1840, at New Orleans, and was the son of Louis and Armidc Longer desaulles, each of French descent. As a boy he was privately tutored in the South, and then schooled in New England to enter the Rensselaer Polytechnic Institute, where he was graduated with honors in the class of '59. Following his graduation he studied in France and Germany for two years, returning to New Orleans in 1861 to enter the Confederate Army, in which he served with distinction as an engineer throughout the Civil War, rising to the rank of Major and the command of his Corps. After the close of the war he pursued his studies abroad for another year, returning to New York in April, 1866, when he became engineer for the New York & Schuylkill Coal Company, and remained at its plant near Wilkes-Barre until October, 1871, when it was sold to the Philadelphia & Reading Coal and Iron Company. He then returned to New York where for several years he was engaged in the practice of his profession. In 1869, he married Catharine M. Heckscher, daughter of Charles Heckscher of New York City. Mrs. desaulles survives him. In 1876, Major desaulles became superintendent of the Dunbar Furnace Company in Fayette County, Pa., with which company he remained until 1883. As a feature of the Pittsburgh meeting in May, 1879, Major and Mrs. desaulles entertained the members of the Institute at dinner at Dunbar on the occasion of the Institute's visit to Dun-bar furnace. In 1883, he took up the formation of the Oliphant Furnace Company in that county, of which he became and remained the head for five years. He was then called to the superintendency of the New Jersey Zinc Company at South Bethlehem, Pa., in which position he remained until his retirement,from active service in 1911, maintaining, however, hi.; keen interest in the metallurgy and smelting of zinc, in collaboration with his son Charles, a member of the Institute and a Director of the American Smelting and Refining Company. From 1888, until his death, he resided in South Bethlehem, a prominent and highly respected citizen of that progressive and stirring community. Major desaulles was a member of the Protestant Espicopal Church, and at the time of his death was a vestryman of the Church of the Nativity at South Bethlehem. He was president of the Men's Club of the Church of the Nativity. His kindly nature led him to take an active interest in the promotion of healthful sports among young men. He was ever active in all things pertaining to the general welfare and uplift of his fellowmen. In his death the profession has lost a distinguished engineer and mctallurgist and our country a patriotic able citi-zen and man of affairs—one greatly beloved by those whom he honored with his friendship, and respected and looked up to by all who were privileged to know him.

Jan 1, 1920

No. 526.-At liberty about Mar. 1, 1919. Just returned from France, a Captain of Engineers. Member A. I. M. E., A. I. E. E., 35 years old, technical education. Last six years of civil life as electrical engineer, master mechanic and superintendent of construction with large mining company. Salary expected, $3600 per year. No. 535.-Member, 'mining engineer, technical graduate, age 34 years, experience as engineer for coal companies. Three and one-half years with one company and five years with another. Have good recommendations. Recently honorably discharged, First Lieutenant, U. S. Army. Desires position, preferably in West. Salary last received, $175 per month. No. 555.-Metallurgical engineer having 18 years' experience in positions from chemist to manager, specializing in the smelting of copper, gold and silver ores, and now returning to the U. S. Available about May 15. No. 556.-Manager or superintendent, member, technical graduate, age 44, married, desires position. Good references, 18 years' experience in positions of responsibility and administration. Familiar with development, mining, milling, operation, construction and management. Available on short notice. , No. 557.-Member, technical education, married, age 30. Five. years' experience in construction work, four years superintendent of mining and milling operations. Looking for wider experience. Free Apr. 1.

Jan 4, 1919

By Paul F. Kerr

QUARTZ of a certain kind, is one of our strategic minerals, and Brazil is probably the one important available source. Crystals of quartz of suitable size and perfection for piezoelectrical application are rare; their most outstanding use is in radio work. Clear quartz, or "crystal," free from twinning, cracks, foreign particles of other disturbing lines of growth, and gaseous or liquid inclusions, is cut into plates which provide excellent control of frequency in broadcasting. The squares or rectangles are less than a millimeter in thickness and ordinarily on the order of 1 in. along each side. They are cut at definite angles with respect to the axes of the crystal, and ground with opposite surfaces parallel. Each small slab must be a section of one crystal, uniform throughout in atomic alignment. The thickness of the chip controls the frequency of a broadcast and it is most important to have the plates oriented and ground with utmost precision. Opposite surfaces are parallel to within 0.001 mm. and expansion or contraction due to the temperature is limited to one part in a million.

Jan 1, 1942

By CHARLES F. DEISS

The total pipe-line runs of petroleum in Indiana during 1945 were 4,114,000 bbl., a decline of nearly 17 per cent below the estimated 4,950,000 bbl. produced in 1944. Drilling activity during the year was centered in Posey and Gibson Counties, where seven new pools were discovered in the state. Four of the pools are in Posey County-Crunk, Farmersville, Jeffries and St. Wendells East-and the other three are in Gibson County-Johnson West, Lysle and Mt. Carmel East.

Jan 1, 1946

By AIME AIME

THE revised program for the San Francisco meeting, with assignment of the various papers to the several sessions is now available and is printed below : MONDAY, OCT. 7 . General Meeting, 11-12 A.M. Chairmen: Frederick W. Bradley and E. A. Hersam. Opening of the session by the Chairman of the San Francisco Section-E. A. Heraam. Address of welcome by the President of the Institute- Frederick W. Bradley. Address: The Mining problems of the West--Charles W. Merrill.

Jan 1, 1929

By J. R. Low, M. Gensamer

During the course of an investigation into the drawability of automobile-body sheet steel, it became apparent that certain advantages would be possessed by a deep-drawing steel with a very low yield strength, but almost normal tensile strength, provided a reduction in yield strength could be accomplished without sacrifice of ductility and fine grain size. It would also be desirable to have this steel free from strain-aging; that is, free from the tendency for the yield point to return after it had been eliminated by straining. It was known that, wet hydrogen treatment acted to eliminate aging, but as carried out by other investigators, at relatively high temperatures, this treatment resulted in grain coarsening. It has been established by some of the experiments reported in this paper that all of these objectives can be accomplished by treatment in wet hydrogen at a low temperature, in the neighborhood of 72o°C. The time of treatment is relatively short (about 3 hr, to completion with 20-gauge sheet) if the water content of the hydrogen atmosphere is made fairly high, say aimost 30 per cent by volume. At this temperature. the grain size remains fine in the time required. After this treatment sheet reduced the usual amount by cold-rolling has a grain size of about A.S.T.M. No. 7. The yield point is completely eliminated, and the yield strength is reduced to a very low value, in the neighborhood of 15,000 lb. per sq. in. The stress-strain curve departs gradually from the straight-line elastic part after the fashion of nonferrous deep-drawing alloys. This elimination of the yield point is accompanied by a verv low indentation hardness; for example, 32 Rockwell B or even lower. There is no aging as measured by increase in the yield strength upon aging at room temperature or for 3 hr. at 200°C., after stretching about 10 per cent in tension. Tensile strength is only slightly less than the box-annealed sheet, seldom dropping much below 40,-ooo lb. per sq. in. Elongation is practically unchanged, or increased slightly. The term yield point, as here used, refers to the phenomenon of heterogeneous deformation occurring at a substantiallv constant load, observed principally in annealed low-carbon steels. If such a steel is loaded in tension, the load increases steadily with elastic strain, suddenly falls, fluctuates slightly about some constant value for a time and then begins to rise again as deformation proceeds. The maximum initial load before the sudden drop is generally called the "upper yield point"; the value of the load where deformation proceeds at a

Jan 1, 1944