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By F. J. Martin, W. G. Hubler

The Beattie mine is at about the center of Duparquet township in the Province of Quebec, Canada. It is 22 miles northwest of the town of Noranda. The elevation is approximately 1200 ft. above sea level. This locality, long considered a favorable one from the geological point of view, has been prospected for over 20 years, but no discoveries of economic importance were made until the present orebody was found by John Beattie in 1930. The specific gravity of the ore is 2.77. The gold occurs in intimate association with the sulfides, pyrite and arsenopyrite, which in turn are very finely disseminated in a silicified porphyry. The bulk of the gold is associated with the pyrite, only a small proportion being with the arsenopyrite. There are small amounts of magnetite, ilmenite and chalcopyrite present in the ore. There is also some hematite in the ore that is mined from near the surface in the open pit. Metallurgical Problems and Methods or Attack 1. The ore is extremely hard and resistant to grinding. 2. The sulfide minerals are finely disseminated in the gangue. 3. The gold, in turn, is so intimately associated with the sulfides that grinding to even 5 microns will not release all of the values for cyanidation. 4. It is necessary to make a high ratio of concentration in order to obtain a product sufficiently high in gold to meet high shipping and treatment charges. Hardness of the Ore.—Owing to the extreme resistance of the ore to grinding, it was recognized that grinding costs would be high. Microscopic tests showed that grinding to 95 per cent minus 325 mesh would be necessary to liberate a sufficient amount of the values in order to obtain a tailing assaying 0.02 oz. gold per ton, which is considered to have the economical minimum gold content that can be obtained. It is not feasible to grind this hard low-grade ore (0.18 to 0.20 oz.) to 95 per cent minus 325 mesh, so it was necessary to overcome the problem in another way. The following method was decided upon: (1) Fine crushing to minus 1/4 in.; (2) relatively coarse primary grinding; flotation of low-grade concentrates in the primary and rougher circuits and discarding the

Jan 1, 1935

By Marion Rice

The copper-mining district of Jerome, Ariz., is of such economic importance that the following brief notes may be of interest. The ore deposits are said by Ransome1 to be pre-Cambrian, and are contained in the pre-Cambrian schists of the region. In the vicinity of the mine (the United Verde) the schist stands nearly vertical and strikes a little west of north. At least three varieties are distinguishable—(1) a green rock, schistose on its margins but grading into massive material, which is evidently an altered dioritic intrusive; (2) a rough gray schist with abundant pheno-crysts of quartz, apparently an altered rhyolite; and (3) a satiny, greenish gray, very fissile sericitic schist that may be a metamorphosed sediment. The ore occurs in varieties (2) and (3), the main belt of dioritic rock (1) lying just west of the orebodies. The ore is said to follow as a rule the layers of fine sericitic schist. T. A. Rickard2 Says that the ore at the United Verde Extension mine is found at the contact of diorite and schist, that both diorite and ore are earlier than the regional metamorphism, and that the quartz porphyry ("rhyolite" of Ransome) is of post-Cambrian age. The material considered here, a part of which was gathered by the writer, came from four of the mines of the district, and its study was undertaken at the suggestion of Dr. Berkey of Columbia University. The field relations and exact locations of the different specimens are not known, but a microscopic study of the thin sections gave some evidence as to the origin of the ore, which will be discussed below. The indications are that both ore and porphyry were introduced at the closing stages of the metamorphism, this being in accord with Ransome's view of the genetic relation of porphyry and ore rather than with the opinion that the ore is related to the diorite. Certain field occurrences mentioned in the literature also support this theory. Rickard, in the same article to which reference has been made, speaks of a vein of chalcocite several inches wide at the contact of one of the porphyry dikes, and Provot,3 although he regards the porphyry as subsequent to the ore, says: "Acid dikes encountered underground should be followed as they have been found in practice to lead to orebodies."

Jan 1, 1920

By Noel Cunningham

Many excellent descriptions of the mills of the Porcupine district have been written, but no discussion exclusively devoted to the metallurgical technology has been given. These notes are intended to cover this feature briefly. They are based upon 21/2 years' mill operation in the district—i.e., practically since the beginning of metallurgical operations. Character of the Porcupine Ore.—There is no oxidized ore in the district, the surface having been deeply planed by glacial action in recent geologic time. The precious-metal content is about in the proportion of 85 of gold to 15 of silver by weight; hence, the silver is practically negligible. There are two classes of Porcupine ore, having very different characteristics; these will be referred to throughout this paper as Class A and Class B. Class A ore is a pure quartz with inclusions of schist. Generally it is heavily fractured and breaks down readily to sharp, hard grains, about minus 10 plus 20 mesh, requiring further comminution to release the gold. It carries very little pyrite; the gold is entirely free and apt to be coarse, but often spongy, going into solution readily on that account. This gold is 60 per cent. to 85 per cent. free milling, depending on the grade of ore. Class B ore is an iron silicate schist, strongly laminated, carrying 4 to 5 per cent. pyrite; its specific gravity is 2.8 to 3.0, depending upon the amount of mineralization. In breaking the ore in the mine, generally over 25 per cent. of material through a 1/2-in. ring is made; the ore readily breaks down in milling and makes a comparatively large amount of non-crystalline slime; owing to its high specific gravity, however, it is quick settling. In my opinion, the gold in this ore is free, but so finely divided that it will neither pan nor amalgamate; it appears to be disseminated through the rock and not chiefly associated with the pyrite. Veins of Class A ore occur with or without side walls of Class B, and veins of Class B occur unassociated with Class A; more often the veins are closely banded, Class A and Class B alternating, generally with Class B in excess. Both classes of ore are more or less blocky at times, and with reference to Class B this is indicative of low gold content.

Jan 1, 1915

Cortez Gold Mines operated a conventional 2,100 mtpd (2, 300 stpd) cyanidation plant until the 5 million ton ore body was worked out in 1973. (See Gold and Silver Cyanidation Plant Practice by F. W. McQuiston, Jr. and R. S. Shoemaker, Society of Mining Engineers, AIME 1975.) Sub-grade material was dump leached at the mine -mill location in 1971, and the resulting pregnant solutions were added to the feed in the plant's Merrill-Crowe precipitation unit for gold recovery. In early 1973, however, Cortez put into operation their Gold Acres mine which was located about 13 krn (8 miles) to the west of the 'Cortez mine. Economics at that time dictated the heap leaching of the lower grade portion of the ore body with the higher grade being trucked to the Cortez plant for milling. Leach ore was moved directly from the open pits to prepared leach pads located on a gently sloping terrain of 570 grade. Preliminary pad preparation at the leach site included removal of vegetation which was composed of sagebrush and grading of the base. Pads were comprised of mostly minus 74 micron (200 mesh) materials and were made of clay-silt or slime tailings spread on the pad area in thin 50 to 75 mm (2 to 3 in. ) layers, compacted with a vibrating roller compactor to a depth of about 380 mm (15 in.). This was followed with a 100 mrn (4 in.) layer of coarse rock to prevent erosion on the pad and to allow solutions to move laterally under the heaps. Leach solutions normally traveled the length of the heaps and were collected in plastic-lined ditches from which they flowed by gravity to the pregnant solution storage pond. Both pregnant and barren ponds were constructed in the same manner as the leach pads - being lined with compacted tailings or clay silts. The Gold Acres facility required pregnant solution storage of 6 million liters (1.6 million gal) and barren storage of 3.8 million liters (1.0 million gal) designed to handle two to three days of heap drainage or to retain run-off from a major rainfall. Various heap heights were tried including 3, 6, and 9 meters (10, 20, and 30 ft), with a 6 m (20 ft) height selected. Ore was dumped by trucks in a single 6 m (20 ft) lift using a D8 Caterpillar dozer for

Jan 1, 1981

By R. A. Bergier

The Transactions of the Institute contain nothing, as yet, on the subject of pocket-compasses; and in the belief that American miners, explorers, geologists, and engineers will gladly welcome any infor mation about new forms of apparatus, simple in construction and adapted to rapid use, I offer a short description of an improved French combination pocket-compass, which, if once introduced into use, would seem likely to supersede similar instrumens of older pattern. The instrument in my possession I owe to the kindness of M. G. de.La Bouglise, of Paris. The frame of the compass is a double-bottomed box, 2 1/2 inches square and 9/16 of an inch high, made of white metal, and with its sur faces very carefully planed. The sides of the box make true right angles with each other. Two sides are parallel with, and two are normal to, the north and south line of the principal graduation. The bottom is accurately planed, so that the instrument will lie true on a plane surface. A glass, 2 3/8 inches in diameter, is set in the top plate. The graduation for the needle is engraved on the upper face of a ring, connected with the flat disk, in which the center-pin is in serted. Between this disk and the bottom of the box there is a hollow space a quarter of an inch deep. The needle is 1 7/8 inches in length, and can be balanced by means of a small sliding piece of metal. The graduation extends from 0° to 360°, reading from right to left. The stopping of the needle is effected by a screw, A, on the side of the box near the handle, H (Fig. 1). There is also a clinometer attachment, the graduation for which is engraved on the upper face of the silver-plated disk. The compass has two sights. The north sight, B, is a simple pin, a little more than an inch high, which, when not in use, is kept folded down, and is partially protected by the exterior sliding-plate, C. When raised for use, the sight is stopped in a vertical position by a projecting pin attached to the side of the box.. The south sight, D, is connected with the handle, H, and the sight and handle

Jan 1, 1890

By R. Dawson Hall

The stresses in the simplest structures are often those we find most difficult to analyze. The most complex condition in mine stresses is found in simple tunnels where the roof, the sides, and the floor are a monolith. The functions of the parts are like the parts themselves not distinct and spccialized, and the problems to be solved are like those in a metal structure with riveted joints or a redundancy of bars. This difficulty explains perhaps why the condition has not been treated. But just because it cannot be discussed in its entirety is no reason why it should be treated as an action of parts with spccialized functions as a roof beam with supports and a foundation. The problern cannot be ignored on the ground that it is not of sufficient importance to warrant careful consideration, because conditions of complete monolithism, of which the tunnel is the type, are found materially unchanged in room-and-pillar and in longwall work. This unity between roof, sides, and floor, which to the coal miner is a difficult conception, really deserves a scientific appellation, and perhaps holoid (from holos, whole, and eidos, form) will serve the purpose as well as any other. In a simple tunnel the roof, the sides, and the floor form integral parts of one and the same structure, and the distortion of one cannot be conceived without a consequent strain in the others. Thus when the roof of the tunnel droops by reason of its weight, the upper parts of the sides are drawn in becausc they are integrally connected with the roof and must approach each other whenever, by the sagging of the roof, the distance between any two points in it is diminished. (See Fig. 1.) Thc sides in their turn operate on the floor of the holoid structure, producing a tensile stress. The writer has always been impressed with the value of soap as a means of illustrating the action of mine stresses. With that idea in mind' a cake of naphtha soap measuring 43/8 by 2¼ by 19i in. was taken and a tunnel was made through it 13/4 in. long, 21/2 in. wide and 1¼ in. high. (See Fig. 2.) A load was then placed at the mid-span of the tunnel. Eventually, the upper bar, or "roof," broke at the

Jan 1, 1916

By R. S. French, W. R. Hibbard

M. Balicki—As one who some years ago spent much time searching for an alloy with high thermoelectric power that would be suitable for heat energy-electric energy converter based on the principle of a thermoelectric pile, I would like to make a few comments touching upon that aspect of this excellent paper. The specifications which one of the authors has formulated so aptly do not appear to me as complete, and I would like to add to them the following two demands: (1) Melting point not less than 500°C and (2) elongation on 2 in. at least 5 pct. Condition 1 would insure good thermodynamic efficiency of the pile by permitting a reasonably high temperature of the hot junction and at the same time making it suitable for such application as salvage of vast amounts of energy which is lost in the form of sensible heat of waste gas leaving industrial and other furnaces. Condition 2 is also a very important one; particularly, because of the fact that all elements and alloys which exhibit attractive thermoelectric properties seem to be as a rule very brittle. The design, erection, and maintenance of a pile incorporating a brittle material in one of the most crucial parts of the converter would be a very difficult and costly affair indeed. To illustrate this point I may mention great difficulties I encountered when trying to make thermocouples of silicon. Casting of 1/4-in. rods in iron or graphite mould yielded only broken pieces which had to be welded into a bar. Such a bar had to be handled very carefully during the determinations. Raising the molten silicon by vacuum into a silica tube and solidifying it there solved the problem of stability as well as that of electrical insulation of a bar. On tests this bar (98.5 pct Si) showed dE/dT = — 275.5 microvolts per degree C vs. copper. Thermocouples made of this grade of silicon and pure nickel developed 0.39 v when temperature of the hot junction was approximately 1000°C. The possibility Dr. Gonser has mentioned of trying to impart to metals good thermoelectric properties by alloying them with silicon, has been considered. The preliminary survey which I have made was, however, disappointing. Perhaps, it will be advisable to record the results obtained (table VI), as this might save repetition of search in fields already covered.

Jan 1, 1951

The production of petroleum in India (including Burma) increased from 334,811,624 gal.' ill 1936 to 350,322,222 gal. in 1937, the highest figure in the history of the industry. The increase in 1937 was clue to an increase of some 20 million gallons from Singu, 51/2 million gallons from Attack, 11/4 million gallons from Thayetmyo, and 1 mi1lien gallons from Digboi, accompanied by decrcases of 91/2 million gallons from Yenan-gyaung and 2 million gallons from Yenangyat,. The amount of gasoline produced from natural gas during the year was 10,616,313 gal. in Burma and 456,780 gal. in the Punjab. Yenangyaung Field.—The Yenangyaung field maintained its reputation of being one of the most wonderful oil fields in the world. The total production during 1937 was less than in the previous year but the resources of the field as a whole are sufficient to ensure an adequate supply of oil for many years. At the end of 1037 there were 2910 wells producing in the field. Besides a large number of ells drilled to shallow sands, this total includes 180 hand-dug wells, whose continued existenice is one of the interesting features of the field. During the year the deep drilling activities of 1936 in the southern part of the field died down, owing to the disappointing results obtained. On the eastern flank the limit of present economic extension of the oil sands was approximately demareated. Satisfactory results continue to be obtained from gas drives in the leased blocks; gas is also injected for repressuring and storage. Casing policies continue to be carefully designed to protect the oil sands against the danger of flooding by water and, in general, production methods throughout the field are characterized by a realization of the importance of the conservation of oil and gas and the prevention of waste, whether simple or underground. Singu Field.—-In 1937 the increase in the output from the Singu field was continued. This increased production was due not only to the rapid development of the valuable area in the southern part of the field but also to the successful results obtained from the first wells to produce from behind the practically completed river training wall of the Burmah Oil

Jan 1, 1939

The production of petroleum in India (including Burma) increased from 334,811,624 gal.' ill 1936 to 350,322,222 gal. in 1937, the highest figure in the history of the industry. The increase in 1937 was clue to an increase of some 20 million gallons from Singu, 51/2 million gallons from Attack, 11/4 million gallons from Thayetmyo, and 1 mi1lien gallons from Digboi, accompanied by decrcases of 91/2 million gallons from Yenan-gyaung and 2 million gallons from Yenangyat,. The amount of gasoline produced from natural gas during the year was 10,616,313 gal. in Burma and 456,780 gal. in the Punjab. Yenangyaung Field.—The Yenangyaung field maintained its reputation of being one of the most wonderful oil fields in the world. The total production during 1937 was less than in the previous year but the resources of the field as a whole are sufficient to ensure an adequate supply of oil for many years. At the end of 1037 there were 2910 wells producing in the field. Besides a large number of ells drilled to shallow sands, this total includes 180 hand-dug wells, whose continued existenice is one of the interesting features of the field. During the year the deep drilling activities of 1936 in the southern part of the field died down, owing to the disappointing results obtained. On the eastern flank the limit of present economic extension of the oil sands was approximately demareated. Satisfactory results continue to be obtained from gas drives in the leased blocks; gas is also injected for repressuring and storage. Casing policies continue to be carefully designed to protect the oil sands against the danger of flooding by water and, in general, production methods throughout the field are characterized by a realization of the importance of the conservation of oil and gas and the prevention of waste, whether simple or underground. Singu Field.—-In 1937 the increase in the output from the Singu field was continued. This increased production was due not only to the rapid development of the valuable area in the southern part of the field but also to the successful results obtained from the first wells to produce from behind the practically completed river training wall of the Burmah Oil

Jan 1, 1939

By B. D. Cullity, J. T. Norton, M. Telkes

M. Balicki—As one who some years ago spent much time searching for an alloy with high thermoelectric power that would be suitable for heat energy-electric energy converter based on the principle of a thermoelectric pile, I would like to make a few comments touching upon that aspect of this excellent paper. The specifications which one of the authors has formulated so aptly do not appear to me as complete, and I would like to add to them the following two demands: (1) Melting point not less than 500°C and (2) elongation on 2 in. at least 5 pct. Condition 1 would insure good thermodynamic efficiency of the pile by permitting a reasonably high temperature of the hot junction and at the same time making it suitable for such application as salvage of vast amounts of energy which is lost in the form of sensible heat of waste gas leaving industrial and other furnaces. Condition 2 is also a very important one; particularly, because of the fact that all elements and alloys which exhibit attractive thermoelectric properties seem to be as a rule very brittle. The design, erection, and maintenance of a pile incorporating a brittle material in one of the most crucial parts of the converter would be a very difficult and costly affair indeed. To illustrate this point I may mention great difficulties I encountered when trying to make thermocouples of silicon. Casting of 1/4-in. rods in iron or graphite mould yielded only broken pieces which had to be welded into a bar. Such a bar had to be handled very carefully during the determinations. Raising the molten silicon by vacuum into a silica tube and solidifying it there solved the problem of stability as well as that of electrical insulation of a bar. On tests this bar (98.5 pct Si) showed dE/dT = — 275.5 microvolts per degree C vs. copper. Thermocouples made of this grade of silicon and pure nickel developed 0.39 v when temperature of the hot junction was approximately 1000°C. The possibility Dr. Gonser has mentioned of trying to impart to metals good thermoelectric properties by alloying them with silicon, has been considered. The preliminary survey which I have made was, however, disappointing. Perhaps, it will be advisable to record the results obtained (table VI), as this might save repetition of search in fields already covered.

Jan 1, 1951

By Maynard H. Jameson

EARLIER investigations of the potential-drop-ratio method of electrical prospecting have indicated that under suitable conditions this method is well adapted to the location of formation boundaries in stratified ground. A description of this development was given several years ago by H. Lundberg and Th. Zuschlag.1 The curves published by these authors for the potential-drop-ratio variation above a horizontal contact indicated a definite relation of the position of the curve peak to the depth of the interface. The theory underlying this relation was subsequently studied by Z. Mitera in greater detail,2 and the theoretical deductions were compared with the results of tank experiments. The investigations available at this writing were confined to studies of horizontal formation boundaries. It is the purpose of this paper to extend the scope of the previous work to the problem of dipping layers. THEORY Consider the case of three media of different resistivities, whose interfaces are not parallel. If a point-source is located in one of these interfaces, its images do not lie in a straight line, but on the circumference of a circle whose center is at the hypothetical junction of the interfaces. R. F. Aldredge3 determined the relation that exists between the degrees of dip of the two interfaces and the distances between the various images and the point for which the potential is to be found. As seen in Fig. I, three media of resistivities po, pi, and p2 are involved, and the source I is located at the interface of the media (po) and (pi). The perpendicular depth of the lower interface is h,? is the dip, R is the distance between source I and potential point P, and r is the distance between the images and that point. To distinguish between images lying above the ground interface and those below, the notation "odd" and "even" images will be employed; images below the ground interface will be termed "odd" and those above "even." The following relations govern the distances between either kind of images and the potential point: [ ] As previously pointed out, the images of the source are on the circumference of a circle. If the angle of dip is ?, the angle measured from the horizontal to the first image is 2? to the second image it is 4?,, and so on. Since the limit of the reflecting interface is at its outcrop, the last possible

Jan 1, 1941

By G. S. Hume

Petroleum is produced in Canada in the provinces of New Brunswick, Ontario and Alberta and in the Northwest Territories. The total production, however, is relatively small in comparison with the consumption, the value of imports exceeding 40 million dollars a year. Production figures are given in Tables 1 and 2. In Turner Valley, still the largest producing gas and oil field in Canada, five wells were completed during the year. The largest of these

Jan 1, 1936

By G. S. Hume

Petroleum is produced in Canada in the provinces of New Brunswick, Ontario and Alberta and in the Northwest Territories. The total production, however, is relatively small in comparison with the consumption, the value of imports exceeding 40 million dollars a year. Production figures are given in Tables 1 and 2. In Turner Valley, still the largest producing gas and oil field in Canada, five wells were completed during the year. The largest of these

Jan 1, 1936

LIMA (PERU) Established May, 1952 (Official year begins in June) Luncheon meetings third Wednesday monthly Ernesto A Baertl, Chairman Arthur C Hall, Chairman-elect Raymond R Beard, 1st Vice-Chairman Edgardo Portaro, 2nd Vice-Chairman Walter E King, Secretary-Treasurer Av Santa Cruz 331 San Isidro, Lima, Peru Alberto E Brazzini, Asst Treasurer Daniel M Rodriguez, Asst Secretary Robert P Koenig, '56, Section Delegate Arthur C Hall, Alternate Section Delegate

Jan 1, 1955

By Claude H. P. Lupis, John F. Elliott

WAGNERL described the thermodynamic behavior of a metallic solution consisting of the solute components 2, 3,... at very dilute concentrations in the solvent, 1, in terms of the excess partial molar free energy, or alternatively the logarithm of the activity coefficient. In the Taylor expansion of FiE, by neglecting the second- and higher-order differential terms, he obtained the excess partial molar free energy as a linear function of the composition:

Jan 1, 1965

United Engineering Society WILLIAM L SAUNDERS,, President GEORGE H PEGRAM, 1st Vie-president ALFRED D FLINN, Secretary J V W REYNDERS, 2d Vice-president JACOB S LANGTHORN, Treasurer HENRY A LARDNER Assistant treasurer Finance Committee House Committee GEORGE H PEGRAM, Chairman ALFRED D FLINN, Chairman J 'VIPOND DAVIES FREDERICK F SHARPLESS BANCROFT GHERARDI . JOHN H DUNLAP WILLIAM L SAUNDERS CALVIN W RICE W F M GOSS, ex-officio F L HUTCHINSON

Jan 1, 1923

Executive SIDNEY J. JENNINGS, Chairman GEORGE D. BARRON J. E. JOHNSON, JR. EDWIN LUDLOW ROBERT M. RAYMOND Membership KARL EILERS, Chairman LEWIS W. FRANCIS J. E. JOHNSON, JR. LOUIS D. HUNTOON ARTHUR L. WALKER Finance GEORGE D. BARRON, Chairman CHARLES-F. R AND BENJAMIN B. THAYER Library E. GYBBON SPILSBURY,1 Chairman ALEX C. HUMPHREYS8 GEORGE C. STONE2 J. H. JANE WAY' BRADLEY STOUGHTON Papers and Publications BRADLEY STOUGHTON, Chairman

Jan 4, 1918

South Carolina Geological Survey, University of South Carolina, Columbia, S. C. Stephen Taber, State Geologist Two bulletins have been issued by the South Carolina State Geological Survey: Bulletin 1, A preliminary report on the clays of South Carolina (1908), and 2, Catalogue of the mineral localities of South Carolina. Members of the staff of the Department of Geology of the University have published many papers which have appeared in print from various sources

Jan 1, 1933

[NUMERICAL CODE TO MAPS (Region Listed in Roman Numerals after Each Petroleum Section) 1 Alaska 2 Arizona 3 Black Hills 4 Boston 5 Carlsbad Potash 6 Central Appalachia 7 Chicago 8 Cleveland 9 Colorado 10 Columbia 11 Connecticut 12 Delta (VIII) 13 Detroit 14 East Texas (VI) 15 El Paso 16 Gulf Coast (VII) 17 Kansas (IX) 18 Lehigh Volley 19 Mid-Continent (IX) 20 Minnesota 21 Montana 22 Nevada 23 New York]

Jan 1, 1961

By E. R. Parker, T. H. Hazlett

An understanding of the mechanism of creep of metals requires an accurate knowledge of shape of the time-deformation curve. An expression is developed which accurately expresses the creep curve for a number of structurally stable metals and alloys. VAST strides have been made in the development of high temperature creep resistant alloys; however, no sound understanding of the physical mechanism of creep exists to date. Consequently, creep resistant alloys are still developed by "cut and try" methods formerly so successful but now yielding returns at a continuously diminishing rate. It is apparent to all workers in the field that if the mechanism of creep were understood, much fruitless labor could be avoided. The dirth of fundamental knowledge has not discouraged the theorists. Speculation has flourished and numerous theories of creep have been proposed. A critical review of these theories reveals that, even though there are some general areas of agreement between the majority of the workers, there are many basic questions yet to be resolved.' It is generally conceded that theoretical speculation is far in advance of experimental evidence. The shortage of reliable creep data greatly hinders more rapid progress in this field. It is essential that the effects of different stresses and temperatures on the creep characteristics of metals be quantitatively determined. Once this has been accomplished, it will then be possible to evaluate the effects of alloying additions and, it is hoped, to provide a firm basis of facts for theoretical treatment of the creep phenomenon. The work reported herein was undertaken to determine the effects of such variables as stress, temperature, alloying, and structure on the creep characteristics of some metals. Material and Equipment Nickel was selected as the base material for the current investigation and an experimental program was initiated to determine the effects of temperature and stress on the creep characteristics of this material. Since a large quantity of high purity nickel was required for the proposed program and such material was not commercially available, it was decided to refine, cast, and prepare the required metal in our own laboratory. The resulting nickel test bars had the following composition, given in percentage by weight: Fe, 0.030 (1); Si, 0.003 (2); Ca, 0.001 (1); Mg, 0.020 (2); and S, 0.002 (2); to make total impurities of 0.056. The nickel (balance by difference) is 99.944 pct. The details of the purification process are described elsewhere.' This

Jan 1, 1954