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By Frederic Benard

Recovery of selenium and tellurium at Copper Cliff by the Ontario Refining Co. has been previously described by the writer.l During 1935 a new building was erected to house this operation and description of the new plant and process form the subject of this paper. The building, of modern steel and tile construction, covers an area of 5900 sq. ft. with a volume of approximately 166,000 cu. ft. The large monitored center bay is flanked by two smaller outside bays, one of which is devoted to the tellurium section. All equipment, ceilings and upper walls, are treated with aluminum paint, giving good illumination and facilitating good housekeeping, essential from a health standpoint in handling material of this nature. Equipment Layout and type of equipment conforms to the requirements of the process as described below. In the selenium section, storage tanks, neutralizing tanks and precipitators are of steel construction, lead-lined and arranged for gravity flow (Fig. 1). The neutralizing tanks are equipped with water-cooled lead coils for controlling solution temperature, agitation being accomplished with compressed air. The precipitators are provided with mechanical agitators, and sulphur dioxide is introduced into the solution through 1/2-in. lead pipes leading from a manifold attached to the cover of the precipitator. Each precipitator has internal cooling coils and an air-jet exhauster to carry off fumes. Neutralized solutions are filtered in a 29-plate wooden filter press using heavy cotton duck as a filter medium, forced feed being maintained by a Welmet centrifugal pump. Dilute solutions are concentrated by evaporation in a vacuum evaporator, constructed of cast hard lead. Heat is supplied by an outside steam chest operating under 15 Ib. steam pressure. The solution is circulated through the steam chest by a pump of antimonial lead at a rate approximating 400 cu. ft. per min. The evaporator is evacuated by a water-jet condenser that creates a vacuum of 26 in. of mercury under normal operating conditions. The capacity of the vessel is 60 cu. ft. and the rate of evaporation 25 cu. ft. per hour.

Jan 1, 1943

By Frederic Benard

Recovery of selenium and tellurium at Copper Cliff by the Ontario Refining Co. has been previously described by the writer.l During 1935 a new building was erected to house this operation and description of the new plant and process form the subject of this paper. The building, of modern steel and tile construction, covers an area of 5900 sq. ft. with a volume of approximately 166,000 cu. ft. The large monitored center bay is flanked by two smaller outside bays, one of which is devoted to the tellurium section. All equipment, ceilings and upper walls, are treated with aluminum paint, giving good illumination and facilitating good housekeeping, essential from a health standpoint in handling material of this nature. Equipment Layout and type of equipment conforms to the requirements of the process as described below. In the selenium section, storage tanks, neutralizing tanks and precipitators are of steel construction, lead-lined and arranged for gravity flow (Fig. 1). The neutralizing tanks are equipped with water-cooled lead coils for controlling solution temperature, agitation being accomplished with compressed air. The precipitators are provided with mechanical agitators, and sulphur dioxide is introduced into the solution through 1/2-in. lead pipes leading from a manifold attached to the cover of the precipitator. Each precipitator has internal cooling coils and an air-jet exhauster to carry off fumes. Neutralized solutions are filtered in a 29-plate wooden filter press using heavy cotton duck as a filter medium, forced feed being maintained by a Welmet centrifugal pump. Dilute solutions are concentrated by evaporation in a vacuum evaporator, constructed of cast hard lead. Heat is supplied by an outside steam chest operating under 15 Ib. steam pressure. The solution is circulated through the steam chest by a pump of antimonial lead at a rate approximating 400 cu. ft. per min. The evaporator is evacuated by a water-jet condenser that creates a vacuum of 26 in. of mercury under normal operating conditions. The capacity of the vessel is 60 cu. ft. and the rate of evaporation 25 cu. ft. per hour.

Jan 1, 1943

By Frederic Benard

RECOVERY of selenium and tellurium at Copper Cliff by the Ontario Refining Co. has been previously described by the writer.1 During 1935 a new building was erected to house this operation and description of the new plant and process form the subject of this paper. The building, of modern steel and tile construction, covers an area of 5900 sq. ft. with a volume of approximately 165,000 cu. ft. The large monitored center bay is flanked by two smaller outside bays, one of which is devoted to the tellurium section. All equipment, ceilings and upper walls, are treated with aluminum paint, giving good illumination and facilitating good housekeeping, essential from a health standpoint in handling material of this nature. EQUIPMENT Layout and type of equipment conforms to the requirements of the process as described below. In the selenium section, storage tanks, neutralizing tanks and precipitators are of steel construction, lead-lined and. arranged for gravity flow (Fig. 1). The neutralizing tanks are equipped with water-cooled lead coils for controlling solution temperature, agitation being accomplished with compressed air. The precipitators are provided with mechanical agitators, and sulphur dioxide is introduced into the solution through 3-in. lead pipes leading from a manifold attached to the cover of the precipitator. Each precipitator has internal cooling coils and an air-jet exhauster to carry off fumes. Neutralized solutions are filtered in a 29-plate wooden filter press using heavy cotton duck as a filter medium, forced feed being maintained by a Welmet centrifugal pump. Dilute solutions are concentrated by evaporation in a vacuum evaporator, constructed of cast hard lead. Heat is supplied by an outside steam chest operating under 15 lb. steam pressure. The solution is circulated through the steam chest by a pump of antimonial lead at a rate approximating 400 cu. ft. per min. The evaporator is evacuated by a water-jet condenser that creates a vacuum of 26 in. of mercury under normal operating conditions. The capacity of the vessel is 60 cu. ft. and the rate of evaporation 25 cu. ft. per hour.

Jan 1, 1938

By F. Benard

Recovery of selenium and tellurium at Copper Cliff by the Ontario Refining Co. has been previously described by the writer.l During 1935 a new building was erected to house this operation and description of the new plant and process form the subject of this paper. The building, of modern steel and tile construction, covers an area of 5900 sq. ft. with a volume of approximately 165,000 cu. ft. The large monitored center bay is flanked by two smaller outside bays, one of which is devoted to the tellurium section. All equipment, ceilings and upper walls, are treated with aluminum paint, giving good illumination and facilitating good housekeeping, essential from a health standpoint in handling material of this nature. Equipment Layout and type of equipment conforms to the requirements of the process as described below. In the selenium section, storage tanks, neutralizing tanks and precipitators are of steel construction, lead-lined and arranged for gravity flow (Fig. 1). The neutralizing tanks are equipped with water-cooled lead coils for controlling solution temperature, agitation being accomplished with compressed air. The precipitators are provided with mechanical agitators, and sulphur dioxide is introduced into the solution through 1/2-in. lead pipes leading from a manifold attached to the cover of the precipitator. Each precipitator has internal cooling coils and an air-jet exhauster to carry off fumes. Neutralized solutions are filtered in a 29-plate wooden filter press using heavy cotton duck as a filter medium, forced feed being maintained by a Welmet centrifugal pump. Dilute solutions are concentrated by evaporation in a vacuum evaporator, constructed of cast hard lead. Heat is supplied by an outside steam chest operating under 15 Ib. steam pressure. The solution is circulated through the steam chest by a pump of antimoniallead at a rate approximating 400 cu. ft. per min. The evaporator is evacuated by a water-jet condenser that creates a vacuum of 26 in. of mercury under normal operating conditions. The capacity of the vessel is 60 cu. ft. and the rate of evaporation 25 cu. ft. per hour.

Jan 1, 1944

By Richard J. Robbins

Mechanical moles have developed through a tedious process of evolution. At times it has seemed that tunnel borers have been subject to the same Darwinian rules of evolution as their zoological namesakes who, despite their efficiency, are highly specialized and still restricted to soft soil conditions near the surface of the ground. HISTORICAL HIGHLIGHTS The Robbins Co. began its work in this field in 1947 with the development of a twin-bore continuous coal miner. Although these machines were used primarily in coal, two of the early prototypes were used to bore tunnels through shale. Disk cutters were first used on these machines and showed promising results as core breakers between drag-bit kerfs. In 1953, James S. Robbins and Assocs. undertook the development of a 25-ft 9-in.-diam circular tunnel borer for Mittry Construction Co. to be used at Oahe Dam in South Dakota (Fig. 1). This is believed to be the first rock tunnel-boring machine built since the end of the 19th century when short sections of the Channel tunnel were successfully bored in chalk from both the English and French shores. Another Oahe Dam machine was built in 1955, and then a series of three small-diameter machines for the company's first real experience with medium-hard and hard rock (Fig. 2) None of these three could be considered a success, although they laid the groundwork for the success that followed. Interbedded shale and limestone in Pittsburgh and hard limestone in Chicago quickly pointed up the weaknesses in these machines which were used by Perini, Dravo, and Healey. Among the problems were the high breakage rate of tungsten-carbide drag bits, too much flexibility in the drive shafts, failure of high-pressure hydraulic systems, chain-conveyor failure, and general lack of rigidity and strength. In 1956 another attempt at medium-hard and hard rock-boring proved this time to be a success and a significant turning point in the development

Jan 1, 1970

THOSE MARKED THUS * ARE MEMBERS, MARKED THUS ?ARE ASSOCIATES. THESE SIGNS DOUBLED INDICATE LIFE MEMBERS AND ASSOCIATES RESPECTIVELY. THE FIGURES AT THE END OF THE ADDRESS INDICATE THE YEAR OF ELECTION. HEAVY-FACED TYPE SIGNIFIES HONORARY MEMBERSHIP. *AARONS, J. BOYD, Vivian Gold Mining Co., Ltd., Harris, West. Australia. '05 *ABADIE, EMILE R., Cons. and Min. Engr., 214 Union Savings Bank Bldg., Oakland, Cal. '76 ?ABBÉ, MAX F., Prest., Abbé Engineering Co, 220 Broadway, New York, N.Y. '07 *ABBOTT, CHARLES W., Min. Engr. Pioche, Nev. ?08 *ABBOTT, JAMES W., Min. Engr: Ploche, Lincoln Co., Nev. '94

Jan 1, 1917

By N. A. Gjostein

The real and apparent dependence of the surface self-diffusion coefficient, Ds, of gold on crystallo-graphic orientation has been investigated by isolated scratch smoothing and grain boundary grooving experiments. No systematic variation of Ds with orientation was found along the [100] zone. In view of the experimental scatter in these results, however, only aniso-tropy ratios, p, greater than -1.3 would be detectable. Anomalously low values of Ds were found on the [0ll] and [110] zones when the diffusion direction lies along (the scratch or grain boundary groove is perpendicular to) these zones. By comparing these results with a previous y plot study of gold, it is hypothesized that this is not an intrinsic diffusivity effect, but rather it results from a decreased driving force for mass transfer at orientations where the y-plot curvature is negative and appreciable in magnitude relative to y. The characteristics of this type of anisotropy do not appear sEVERAL investigations1-7 have dealt with the anisotropy of the surface self-diffusion coefficient, Ds, of metals as measured by the decay of single or multiple to be in agreement with the hypothesis of fast diffusion along ledges in the surface structure. In certain cases the Fourier method of determining Ds, described in Paper I of this series9 was compared with the second moment analysis in order to determine whether or not the method of analysis affects the anisotropy ratio. While the type of analysis does influence the magnitude of the anisotropy ratio, this effect is not associated with the shape of the profile, but rather is connected with the iterative volume diffusion correction used in conjunction with the second moment analysis. It is further demonstrated that the volume diffusion correction can be too large by either method when the y-plot curvature effect is large. Certain orientations exhibit an unusual temperature dependence of Ds ; this is discussed in terms of the y-plot curvature effect and/or the influence of impurities on Ds . scratches in the surface. Depending on the system investigated, both large1"3'6'7 and small4'5 anisotropies in Ds have been found. Although adsorbed impurities undoubtedly play an important role in determining the magnitude of the anisotropy,8 there are other factors that can give rise to an apparent anisotropy in Ds, thus obscuring the true nature of an intrinsic anisotropy in

Jan 1, 1968

JAmes E. Howard, Watertown, Mass.:—In connection with this paper, it is the desire of the Watertown laboratory to receive suggestions as to the lines of work and the particular direction along which the examination of the ingot-metal should proceed, and any suggestions so offered will be noted with care, and the tests conducted so as to embrace such features as it is thought desirable to have investigated. To me the question of structural continuity seems of para-

Jan 1, 1909

By Alec M. Crowell, C. H. Thigpen

Continuing the increase in production of crude oil and condensate started in 1937, the oil fields of South Arkansas reached a 13-year peak with 26,570,704 bbl. for the year 1942. The stability of the production branch of the industry in the area is demonstrated by Fig. I, which reflects the fact that although the number of producing wells in the state has declined from 3280 in 1931 to 2957 at the end of 1942, total production has continuously increased since the beginning of 1937. This is because all fields discovered since Jan. I, 1937, have observed spacing patterns up to one well to each 160 surface acres, the dual completion of wells where there is more than one producing horizon Eight new pools were brought into production in South Arkansas during 1942 (Fig. 2) They increased the state's crude oil and condensate reserve by 121,000,000 bbl., bringing the total recoverable reserve figure to 450,000,000 bbl. (Table 3) as of Jan. I, 1943. Abandonment of wells in the stripper areas of the state increased by 32 per cent over the preceding year, there having been 142 wells permanently abandoned in 1942. For economic reasons 279 wells were temporarily shut down as of Dec. 31, 1942. A price increase may start these wells to pumping again and also be the incentive toward the commencing of several secondary recovery projects in the fields discovered between 1922 and 1937. There were 149 wells brought into production in 1942 as against 119 for the

Jan 1, 1943

By C. H. Thigpen, Alec M. Crowell

Continuing the increase in production of crude oil and condensate started in 1937, the oil fields of South Arkansas reached a 13-year peak with 26,570,704 bbl. for the year 1942. The stability of the production branch of the industry in the area is demonstrated by Fig. I, which reflects the fact that although the number of producing wells in the state has declined from 3280 in 1931 to 2957 at the end of 1942, total production has continuously increased since the beginning of 1937. This is because all fields discovered since Jan. I, 1937, have observed spacing patterns up to one well to each 160 surface acres, the dual completion of wells where there is more than one producing horizon Eight new pools were brought into production in South Arkansas during 1942 (Fig. 2) They increased the state's crude oil and condensate reserve by 121,000,000 bbl., bringing the total recoverable reserve figure to 450,000,000 bbl. (Table 3) as of Jan. I, 1943. Abandonment of wells in the stripper areas of the state increased by 32 per cent over the preceding year, there having been 142 wells permanently abandoned in 1942. For economic reasons 279 wells were temporarily shut down as of Dec. 31, 1942. A price increase may start these wells to pumping again and also be the incentive toward the commencing of several secondary recovery projects in the fields discovered between 1922 and 1937. There were 149 wells brought into production in 1942 as against 119 for the

Jan 1, 1943

By A. W. Hull

The new valves described in this article are the latest product of the Research Laboratories of the General Electric Co. Some of them are still in the laboratory stage, others have already found important applications. Some of the larger ones, which have graduated from the laboratory, are waiting for their apprenticeship in industry, there to refine their frailties and complete their preparation as electrical servants. The career that awaits them, though dimly foreseen, appears fascinating. And as surely as history repeats itself, scenes still more romantic, now beyond the horizon, will unfold as we approach them. This is the romance of science. Counting Electrons Let the smallest tube lead the march of review. It is a special Pliotron, designed to measure currents smaller than any yet detected. It goes by the unromantic name of Pliotron FP-54. Fig. 1 shows this miniature tube—miniature in performance rather than size, for it is the size of an ordinary radio receiving tube. Its appearance has nothing distinctive, except the quartz beads above and below the plate, which support the grid. They minimize insulation leakage. In principle, the FP-54 is like any grid-controlled high-vacuum electron tube; but in structure and operating characteristics it is entirely special. An extra "space-charge" grid, maintained at 3 volts positive with respect to the filament, holds back the small but pernicious current of positive ions emitted by the filament; the normal plate voltage is 6 volts, grid bias 3 volts, thoriated-tungsten filament temperature 1700" K., plate current 40 microamperes. These conditions are essential to the avoidance of grid-currents, which may consist not only of insulation leakage and positive ions from the hot filament and from residual gases, but of high-speed electrons from the filament, photo emission from the grid due to the light of the filament, and electron emission caused by X-rays generated by the impact of electrons on the plate.

Jan 1, 1932

A LARGE attendance at the annual dinner of the Institute, to be held this year on Tuesday eve-ning of convention week, is already assured. Presentation of the Douglas, Hunt and Saunders medals will attract unusual attention since not only in Blaylock, Mathews and Hoover the Institute will be honoring men who have made notable contributions to the advance-ment of their profession, but as to one of them each person as he passes down the reception line will be won-dering whether in renewing acquaintance with our past-president and present Secretary of Commerce, he is not greeting the next president of the United States. Elsewhere in this issue accounts of the professional careers of these three men appear as also of the two younger men, Charles H. Herty, Jr., and P. H. Royster, who are to receive the Robert W. Hunt and the J. E. Johnson awards. Institute honors go for technical achievement, but the Institute will be proud and happy if the nation should later confirm its own judgment by placing larger responsibilities on one of its members. The medals are to be presented at the annual dinner following the President's reception and preceding the dance. There will be no. other speeches and since the occasion falls on Carnival Night a particularly gay evening is anticipated. The event will be at the Wal-dorf as usual, and members are urged to return prompt-ly the reservation cards sent them by mail. Other entertainment features will include a Smoker, Monday evening at 8.15, held at Mecca Temple and in charge of a new committee with Fred Kay of the Petro-leum Division as chairman. He promises that vocal music will not be allowed to interrupt conversation. Lunch will be served each day on the Fifth Floor of the Engineering Societies Building, and ten special luncheons and dinners have been arranged for particu-lar committees and groups as shown by the detailed program. The Woman's Auxiliary has laid out a gen-erous program including luncheons, teas, a theater party on the night the men folks go to the Smoker, visits to museums and, not the least important, a round of the leading shops. The Excursion Committee is arranging for an excur-sion sure to be of interest. The American Smelting and Refining Co. has opened its great Perth Amboy plant to the Institute, and on Thursday, Feb. 23, a party will be taken to it by bus traveling through the Holland Tunnel en route. Full opportunity will be afforded those interested to see the workings of the ventilation system of that great public work. If a sufficient number indicate interest, arrangements will be made for group excursions to other plants in the vicinity of the city.

Jan 2, 1928

By John M. Kelly

New Mexico produced 39,751,868 bbl. of oil in 1941 and ranked seventh among the oil-producing states. Its 1941 production established an annual record, exceeding the 1940 record year by 854,498 bbl. The average daily production for the year was 108,909 bbl. The average daily non-marginal well allowable for New Mexico on Jan. I, 1941, was 36 bbl.; at the close of the year it was 43 bbl. The average daily pipe-linc runs were approximately 3 per cent less than the allocations of the New Mexico Oil Conservation Commission, which followed closely the recommendation of the United States Bureau of Mines in setting the daily outlet demand. The production in Lea County was 34,333,448 bbl.; Eddy County, 5,009,354 bbl.; and northwestern New Mexico (San Juan and McKinley Counties), 406,306 barrels. The total number of completions in the state was 402, of which 301 were oil wells, 19 gas wells, and 82 dry holes. Drilling during 1941 was 68 per cent of 1940, and the ratio of dry holes to producers, I to 4, was the greatest since 1935. Of these dry holes 43 were drilled in proven fields and 39 were wildcats. One new oil field and one new gas field were discovered as a result of the 1941 wildcatting program. However, numerous extensions were made to the existing fields, which, although they were called extensions to proration areas, were in reality field discoveries, being on separate geologic structures. Southeastern New Mexico Lea County The Monument field was the largest producing field in Lea County, with 6,973,808 bbl. It was closely followed by the Eunice field, with 6,644,181 bbl.; Vacuum field, with 4,800,608 bbl. and Hobbs, with 3,624,159 bbl. Hobbs field, however, still has the largest total recovery, this being 97,407,929 bbl. at the end of 1941. The new oil-field discovery in Lea County during 1941 was the Salt Lake field, T. 20 S., R. 33 E. The discovery well was Leonard-Welch State No. I, NW. NW. of sec. 18, T. 20 S., R. 33 E. This well was drilled to a total depth of 3103 ft. and was completed for an initial production of 250 bbl. per day pumping. The oil is 26" gravity and the producing horizon is in the San Andres limestone of Permian age. The discovery well was completed on June 22, 1941, and since that date four more producers have been completed, with no failures. The area is about 10 miles north-west of the Lynch pool, to which the oil from this field is being trucked because there is no pipe-line connection. The greatest drilling activity during 1947 was in the Maljamar field of western Lea County, with 62 completions, 59 being oil wells and 3 dry holes. The limits of this pool are now being defined on the north and south but to date have not been defined either to the east or west. The total number of 40-acre oil-producing units in the field at the close of the year was 158. On April I, 1941, a pressure-maintenance project was installed at the southern end

Jan 1, 1942

By John M. Kelly

New Mexico produced 39,751,868 bbl. of oil in 1941 and ranked seventh among the oil-producing states. Its 1941 production established an annual record, exceeding the 1940 record year by 854,498 bbl. The average daily production for the year was 108,909 bbl. The average daily non-marginal well allowable for New Mexico on Jan. I, 1941, was 36 bbl.; at the close of the year it was 43 bbl. The average daily pipe-linc runs were approximately 3 per cent less than the allocations of the New Mexico Oil Conservation Commission, which followed closely the recommendation of the United States Bureau of Mines in setting the daily outlet demand. The production in Lea County was 34,333,448 bbl.; Eddy County, 5,009,354 bbl.; and northwestern New Mexico (San Juan and McKinley Counties), 406,306 barrels. The total number of completions in the state was 402, of which 301 were oil wells, 19 gas wells, and 82 dry holes. Drilling during 1941 was 68 per cent of 1940, and the ratio of dry holes to producers, I to 4, was the greatest since 1935. Of these dry holes 43 were drilled in proven fields and 39 were wildcats. One new oil field and one new gas field were discovered as a result of the 1941 wildcatting program. However, numerous extensions were made to the existing fields, which, although they were called extensions to proration areas, were in reality field discoveries, being on separate geologic structures. Southeastern New Mexico Lea County The Monument field was the largest producing field in Lea County, with 6,973,808 bbl. It was closely followed by the Eunice field, with 6,644,181 bbl.; Vacuum field, with 4,800,608 bbl. and Hobbs, with 3,624,159 bbl. Hobbs field, however, still has the largest total recovery, this being 97,407,929 bbl. at the end of 1941. The new oil-field discovery in Lea County during 1941 was the Salt Lake field, T. 20 S., R. 33 E. The discovery well was Leonard-Welch State No. I, NW. NW. of sec. 18, T. 20 S., R. 33 E. This well was drilled to a total depth of 3103 ft. and was completed for an initial production of 250 bbl. per day pumping. The oil is 26" gravity and the producing horizon is in the San Andres limestone of Permian age. The discovery well was completed on June 22, 1941, and since that date four more producers have been completed, with no failures. The area is about 10 miles north-west of the Lynch pool, to which the oil from this field is being trucked because there is no pipe-line connection. The greatest drilling activity during 1947 was in the Maljamar field of western Lea County, with 62 completions, 59 being oil wells and 3 dry holes. The limits of this pool are now being defined on the north and south but to date have not been defined either to the east or west. The total number of 40-acre oil-producing units in the field at the close of the year was 158. On April I, 1941, a pressure-maintenance project was installed at the southern end

Jan 1, 1942

NEARLY one hundred members of the Mining and Metallurgical Society of America and friends of Professor Peele met at dinner at the Aldine Club, New York, on the evening of April 26, to take part in the ceremonies attending the presentation of the Society's annual gold medal. This had been awarded to Professor Peele by the Society in recognition of his laborious and painstaking work as Editor-in-chief of the monu-mental "Mining Engi-neers' Handbook. Carl A. Meissner acted as toastmaster. W. Y. Westervelt, a student and lifelong asso-ciate of Professor Peele, then recounted some of his friend's early exploits, be-ginning with his mining adventures in the paternal cellar, whereby the neces-sity for adequate ventilation was indelibly impressed on his mind. Graduating from the Columbia School of Mines in 1883, Robert Peele for several years followed the typical mining career, as assayer and superinten-dentatan outlying Colorado mine; mill foreman and assistant superintendent of the Silver King, in Ari-zona; in charge of a mine at Fairplay, Colo.; and superintendent for the Ore-gon Gold Mines Co., at Cornucopia. At intervals during this experience, he spent parts of four years on two mineral investigations m in Peru, Bolivia, Colombia, and Dutch Guiana. He i was called to Columbia as Adjunct Professor of Mining in 1892, and became Professor in 1904. During his sabattical leave in 1903 he travelled around the world, r stopping at some of the most important mining cen-ters, and in 1910 he renewed his acquaintance with South Africa and South America.

Jan 6, 1923

By Dunbar D. Scott

The development in the perfection of mine-surveying instruments has been by no means rapid, as it has depended somewhat on the details of construction borrowed from astronomical and geodetic theodolites, largely on the restrictions laid down by mining companies and the prejudices of mine managers themselves, but more than all on the methods used in conducting surveys and the importance attached thereto. Mine-surveying, in some form or other, has been practiced from the very earliest times; but it has never kept pace with the other branches of surveying, or even with the art of mining itself, and cannot be recognized as an exact science until shortly before the beginning of this century. The works of Hero of Alexandria, who lived in the second century B.C., are still extant, and contain descriptions of a rectangular sighting-instrument, which he invented and called a diopter. His improvement upon this simple construction, which possibly he devised for use in the Greek mines for rough leveling-purposes and for laying out any angle, must be considered, says Hübner," as the origin of the highly perfected theodolite of to-day. Whether this instrument came into general use during the first centuries of the Christian era, is not recorded; in fact, no writer undertakes to tell how mine-surveying was conducted until 1556, in which year Agricola expounds the principles of mining and metallurgy in his De Re Metallica, devoting the entire fifth chapter to the practice of mine-surveying (see Fig. 1). In mediæval times those who possessed any knowledge of engineering skill made strenuous effort to keep their art a secret, partly on account of the miners' proverbial conservatism and partly for their own personal aggrandizement, and were, in

Jan 1, 1899

By Howard Martens, Pol Duwez

XPERIMENTS were performed on a Cr-Fc alloy Econtaining 44.7 pet Cr in order to determine the heat evolved during the transformation of the a solid solution into the s phase, and the change in volume accompanying the transformation. Since previous measurements on the rate of formation of a from s indicated that the reaction was quite fast as soon as the equilibrium temperature of 820°C was exceeded by some 50°, standard thermal analysis experiments were performed on heating specimens of s at the rate of approximately 40°C per sec. A definite thermal arrest was observed at 870"C, Fig. 1. This result indicates that the reverse seaction of into a is exothermic. From the heating curve of Fig. 1, taking 15°C per sec as the heating rate in the neighborhood of the transformation, 2.4 sec as the time for transformation, and assuming that the specific heat of the alloy at 850°C is an average between iron and chromium, namely 9.5 cal per mol per "C, the latent heat of transformation is approximately 342 cal per mol. The order of magnitude of this latent heat was also obtained by comparing the heating curve of Fig. 1 with a similar curve obtained with pure iron under identical experimental conditions. It was found that the length of the thermal arrest for s was about 1.8 times as long as that for iron. Since the latent heat of the a to 7 iron transformation is 203 cal per mol1, 2 the latent heat of it to a would be 365 cal per mol, which is in relatively good agreement with the value determined from the heating curve. For the determination of volume change, thermal expansion curves were recorded using a specimen containing 44.7 pet Cr and completely transformed to cr by previous treatment. The curves were recorded at a rate of heating of about 4°C per min and at approximately 840°C a sharr, increase in length of about 0.08 pet took place. Fig. 2. It is therefore established that the specific volume of a near the transformation temperature is about 0.24 pet smaller than that of a, and consequently, when the s phase forms in an a matrix, it would tend to shrink away from the matrix. Since the s phase is known to be extremely brittle, these results offer an explanation for the microscopic cracks often observed in the a phase under the microscope. The results of this study are in qualitative agreement with previously published data on stainless steel 19-9DLa and on a Cr-Fe alloy containing 45 pet Cr.' The increase in density due to the transformation from n to s given in ref. 4 is 0.90 pet. These measurements, however, were made at room temperature. whereas the presently reported 0.24 pet is the change at the temperature at which the transformation takes place during heating. In the graph of Fig. 2, the percentage change in length that would be observed at room temperature is given by the length X, which is about 0.27 pet. This would correspond to 0.81 pet in volume change. Acknowledgment This work was done at the Jet Propulsion Laboratory, California Institute of Technology, under Contract No. DA-04-495-ORD-18 with the Army Ordnance Corps, Washington, D. C. The authors wish to thank this agency for permission to publish the results of this investigation. References I H. Klinkhardt: Measurements of True Specific Heats at High Temperatures. Annalen der Physik (1927) 84, pp. 167-200. - H. Esser and W. Runghardt: Influence of the Method, of Dctcrmination on the Measured Heat Content of Iron. Archtvo ffur Dct Eisenhiittenwesen 11934) 8, pp. 37-38. J. J. Gilman, P. K. Koh, and 0. Zmeskal. Delta Ferrite Formation and its influence on the Formation of Sigma in a Wrought Heat Resisting Steel. Trans. ASM 1 1949) 11, pp. 1371-1388. 1 J. M. Thomas: Discussion of ref. 3. Trans. ASM (1949) 41, pp. 3 390-1392.

Jan 1, 1957

By AIME AIME

The Washoe plant, 1 in Anaconcla. Mont., together with the local street-railroad, ranches a. foundry and machine-shop a brick-plant and the Montana hotel, form a property under one management; to which should be added the mines in Butte owned by the company, from which part of the ore-supply of the plant comes. The Anaconda Copper Mining Co., controlled by the Amalgamated Copper Co., was reorganized under the laws of Montana in 1893. A map of the plant, showing the numerous departments and illustrating the details of tracks, pipe-lines, and charging-stations for compressed-air locomotives, is given in Fig. 1.

Jul 1, 1906

[Secretary's Note.—The following official tables, prepared by the government of the State of Nuevo Leon, and presented to the Institute at the fifth seseion of its Mexican meeting, held at Monterrey, November 26, 1901, present in compact form a general summary of the mineral and metallurgical industry of the State for the preceding calendar year, together with a statement of the railway-shipments of ores from January 1 to October 31, 1901, which, in the absence of direct official mining and metallurgical statistics (not yet available for that year), clearly indicates an increased activity and productiveness of these industries. In other words, the mines are reported to have yielded in 1900 a total product of 83,960,169 kilos of ore; whereas, the railway is reported to have carried, in 10 months of 1901, a total of 108,318,647 kilos of ore. At this rate, the railway-shipments for 1901 mould amount to nearly 130,000,000 kilos. It is, of course, possible that the railwaystatistics include other freight than ores, or that they include duplications, such as would be involved in the record, first of certain ores transported, and afterwards of the " base bullion " produced therefrom. An accurate comparison is therefore impossible ; yet, after making all reasonable allowances for such items as have been named, it seems safe to infer that the mining and metallurgical industry of this State accomplished in 1901 a substantial progress.]

Jan 1, 1902

By David B. Brooks

INTRODUCTION Resources are not; they become (Zimmermann 100) . The companion concepts of reserves and resources appear, one way or another, in almost all considerations of mineral supply. Yet, no other concepts in the economics of the mineral industries have occasioned so much confusion. Whereas everyone agrees that in general the terms refer to the amounts of material that-depending upon technology, market conditions, and institutions-will become available for production in the near or more distant future, the apparent agreement disappears when we come to more specific definitions or to application of the definitions. Some definitions emphasize the physical aspects of reserves and resources, while others emphasize the economic. Some treat reserves and resources as fixed quantities, while others regard them as continually varying. Some consider that reserve and resource estimates have validity only for individual deposits, while others insist that they can be measured with sufficient accuracy for regional or national planning. This confusion in concepts that lies at the very heart of mineral economics is both strange and not so strange. It is common in the social sciences to find concepts that have been adopted into scientific jargon from popular usage and given rather special meanings -at the same time that they continue to be widely used without such qualifications. Psychologists have the same trouble with personality and sociologists, with community. Nevertheless, an attempt must be made to straighten out the various meanings of reserves and resources, or at least to clarify the conditions under which different meanings are applicable, before much progress in analysis of mineral problems can be expected. That is the objective of this chapter. Throughout the chapter, an attempt has been made to provide enough references to guide the interested reader to the most pertinent works on the concepts under study. However, even in a review article, it is no longer feasible to provide a comprehensive set of citations; there are simply too many. In many instances the works cited will themselves include the bibliographies needed to complete a literature search; those that are particularly useful in this respect are so noted. Also, because of the limited availability of foreign periodicals, some important works -originating largely in Canada, France, the

Jan 1, 1976