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By AIME AIME

LAST month we published (p. 440) the first half of the L discussion by O. E. Kiessling of the paper on copper by Mr. Vogelstein that appeared in the same-issue, but lack of space made it necessary to hold the remainder for this number. Mr. Kiessling now asks to have the last " sentence of the part already published revised to the form given in the first sentence which follows, and also asks that the two parts, though necessarily published separately, be read together, as a mistaken impression may be derived from the first Dart unless it is read in connection with the statement of the Bureau of Mines policy respecting secondary metals which is here published. .

Jan 1, 1931

By Henry M. Stanley

The methods about to be described have been tested in practice, and are believed to be specially adapted to such extended topographical surveys as mining engineers in particular are sometimes called upon to execute. The assistance of Mr. H. 0. Flipper in the preparation of this paper, and his practical authorship of the second part, is hereby acknowledged. I. Photographic SuRveying. The writer was recently employed; together with Mr. H. O. Flipper, to survey the properties of the Plata-Reina de Sonora Mining and Milling Company, situated in the mining district of Las Planchas, District of Magdalena, State of Sonora, Mexico. These properties, now owned by an American corporation, of which M. W. Evans, of New Orleans, is president, and Richard A. Pomeroy is resident superintendent, are famous in the history of Mexican mining, as the place where planchus, or bolas de plata were foulld about the beginning of the last century. Ward, the English CILargh d7Affaires in Mexico from 1826 to 1828, writing at that epoch, says: "The idea [that the ores in the north of Mexico were richer than those in the south] probably originated in the discovery of the famous bolas de plata [balls of silver] of Arizona [Planchas de Plata de Arizona, a stock-ranch in northern Mexico], in the beginning of the last century, which was, and probably still is, believed in Europe to be one of those fables with which mining countries always abonnd. But the attention of the present government of Mexico having been drawn to the subject, a search was made in the viceregal archives, by order of the president, for the correspondence which was known to have taken place respecting it in the year 1736. This correspondence I have seen, and I have in my possession a certified copy of a decree of Philip the Fifth, dated Aranjuez, 28th May, 1741, the ohject of which was to terminate a prosecution, instituted by the Royal Fiscal, against the discoverers of Arizona, for having defrauded the treasnry of the duties payable upon the masses of pore silver found there. The decree states the weight of the balls, sheets and other pieces of silver discovered (bolas, planchas, y otras piezas de plata), to have amounted to 165 arroba, 8 pounds, in all, 4133 pounds; and mentions particularly one mass of pure silver, which weighed 108 arrobas (2700

Jan 1, 1892

By A. U. Seybolt, R. A. Oriani

The pressure and composition of the solid solution of nitrogen in chromium has been investigated as a function of temperature. The partial molal heat of solution, the activity of nitrogen in solid solution, and the partial molal free energy have been computed. The enthalpy of three reactions is summarized: N + 2Cr(3) = Cr2N(4), H° = —28,500 cal per mol 1/2N2(p) + 2Cr(8) = Cr2N(3)1 ?HO = —23,500 cal per mol 1/2N2(p) = N, ?H° = 5,000 cal per mol. WORKERS who have investigated the problem of the preparation of ductile chromium have been concerned with the effects of minor amounts of impurities upon this refractory metal. In particular, gaseous impurities such as oxygen and nitrogen have been suspected of causing trouble because of many known cases where brittleness in transition elements has been definitely traced to these elements. In order to evaluate the possible effects of the nitrogen impurity in chromium, it appeared desirable to learn something of the dependence of the nitrogen solubility upon temperature and pressure. Previous Work Maier3 in 1942 in his treatise on sponge chromium reviewed the thermodynamics of the chromium nitrides Cr2N and CrN, both of which are well-estab- lished compounds, but which apparently have not been studied in much detail. Maier presented some free energy-temperature expressions for the reactions 2 Cr,N = 4 Cr + N2 [1] and 4 CrN = 2Cr2N + N2 PI based mainly on the work of Satoh2 and Sano." Pearson and Ende3 in 1953 briefly reviewed the thermodynamics of Cr-N using the same data available to Maier, and also derived a free energy-temperature expression for reaction 1. Of the two nitrides mentioned previously, the present investigation was only concerned with Cr,N, since this nitride is in equilibrium with the metal phase, at least over most of the temperature range, Blix4 in 1929 established the structure of Cr2N (close-packed-hexagonal) by X-ray diffraction methods, and indicated that its homogeneity limits extend from 11.2 pet to 15.1 wt pet N. At a temperature of 1200°C, 38 mm Hg from the Maier expression and 43 mm Hg from the Pearson

Jan 1, 1957

H. H. Hill.—I believe that as petroleum engineers you are all more or less interested in geophysical prospecting. A large number of the papers that have been written on that subject are too detailed or too much involved to be of much value to a person who is not familiar with the subject, so I suggested to Mr. Fohs that he might bring us something that we could all understand. As I take it, we are interested in learning something about the different methods, the places where they have been used, their limitations and in general whether they have given satisfaction in locating oil deposits. F. J. Fohs, New York, N. Y.—I will briefly summarize some of the results as I Bee them from my practical contacts with them and my discussion of the subject with some of the more important rnen both in this country and Europe. Geophysical Methods 1. Seismographs: A. 1. Sonic refracting seismographs of Karcher, McCullom and Reiber. For rapid reconnaissance and also for detail—perhaps, the best type of instrument. 2. Mechanical refracting seismographs of the Weichert-Mintrop type. B. I. Sonic seismographs using reflected sound from contacts of sufficiently unlike beds where latter are thick enough, being used for detail of both salt domes and ordinary structures where a good reflecting key bed occurs. 2. Torsion Balances: Made in three sizes with greater portability and loss of but 20 per cent. in medium size and loss of 40 per cent. efficiency in smallest size. A. Used to best advantage in detailing salt domes, in noting anomalies of deep-seated structures of the Edgerly, La., type (but not always certain here and dependent on interpretation which involves both experience and the human equation to a large degree). R. Used to advantage in mapping faults where a lime or other denser bed occurs upthrown, and the topographic irregularities are not too involved. C. Of use where buried granite plugs and buried-hill structures occur as in the Western Texas fields. D. Believed of little use for other types of structure. 3. Magnetometers or Variometers: Now built horizontal and vertical with declinometer combined in one instrument. A. Practical in mapping granite or basic igneous rock plugs and intrusions, or of detritus therefrom. Adams has recently demonstrated definite results in mapping the well known Panhandle arch.

Jan 1, 1928

Discussion of the paper of HOWARD N. EAVENSON, presented at the New York meeting, February, 1915, and printed in Bulletin No. 98, February, 1915, pp. 413 to 430. WILLIAM H. GRADY, Bluefield, W. Va.-Mr. Eavenson gave a comparison between accidents in the State of West Virginia and in the Pocahontas field. The figures quoted are, I presume, taken from the reports of the State Mine Inspector. There are no statistics available, in readily accessible form, giving a comparison between the Pocahontas field and the mines of the United States Coal & Coke Co. which are a part of the field. It occurs to me that the paper would be more complete with these data and I will say that the mines of the Pocahontas field produced during the year 1913 about 15,000,000 tons, about 3,000,000 tons of which was produced by the United States Coal &Coke Co. This gives an indication of the extent of its operations. The Pocahontas field lies largely in the counties of McDowell, Mercer, and Wyoming in West Virginia, and Tazewell in Virginia.: Without consulting maps, I should say that all of the acreage under operation at present by this company lies wholly in McDowell County and that the average conditions off roof top and bottom in its mines are the average of the county, but that the worst conditions in some of these mines are the worst to be found in the county. The average conditions in Tazewell County are about the same as in McDowell County, except that the average thickness of the seam is much greater. The average conditions of top and roof and bottom are better in Mercer and Wyoming counties than in the mines of the United States Coal &. Coke Co.; the worst conditions in these counties are not so bad as in McDowell and Tazewell counties and the best are better than those encountered in McDowell and Tazewell counties; also the thickness of seam is less in Mercer and Wyoming counties. THOMAS W. DAWSON, Scottdale, Pa. (communication to the Secretary*).-The H. C. Frick Coke Co., the mines of which are in Fayette and Westmoreland counties, Pennsylvania, in the Connellsville coke region, has been pursuing a safety campaign for a number of years and a short resume .of its practices will be of interest in connection with Mr. Eavenson's paper.

Jan 5, 1915

By A. Ross Rornmel

ABILITY to speak effectively is one of man's most longed for and coveted abilities. It is the ability to stand on one's feet, transfer knowledge and thoughts to others, to reach an objective professionally or otherwise by leading groups through a channel of planned thought. Each day group speaking plays an important part in making or marring success, and the engineering profession often provides this opportunity and requirement. An ability to speak effectively develops courage, poise, confidence, and prestige for the speaker. The technical man cannot be reluctant to face an audience. He is often called upon to do this in presence of employees, supervisors, and other groups. His ability to speak effectively is as much a requirement as the fundamentals of his profession. The three fundamentals of effective speaking are: (1) Enthusiasm and Confidence. These are joined because of their close relation. (2) Preparation. This includes knowledge of the subject. (3) Presentation. By this is meant the features of delivery.

Jan 1, 1946

Discussion of the paper of ROSWELL H. JOHNSON, presented at the New York meeting, February, 1915, and printed in Bulletin No. 98, February, 1915, pp. 221 to 226. A. C. LANE, Tufts College, Mass.-About a year ago Mr. Washburne read a paper on the same characteristic oil-sand waters, discussing their chemical character, and the possibility of their chemical character being modified by adsorption in passing through the shale. We are used to consider circulation as being in one stratum, and I have often gone so far as to think that 2,000 or 3,000 ft. clown I could recognize the chemical character as in part connate to a given water. For instance, the St. Peter sandstone, far underneath oil sands, seems to retain' a relatively fresh and peculiar character. I am, therefore, tempted to ask the writer if in his experiments lie has made any test to see whether the chemical character of these waters is also changed, where there is any adsorption, so that the water passing through these fine-grained beds should leave behind its salt as well as its oil. In many cases salt-waters are associated with oil and-gas. A second question has occurred to me. In these days when we hear a good deal about oil flotation, may it not be well to repeat these experi-ments with pyritic concentrates, and see if they observe precisely the same with regard to the selective accumulation of oil and gas. ROSWELL H. JOHNSON.-I thank Profesor Lane for bringing this question forward. I recognize its importance, but. am not able to say I have any data upon that point. It is also very interesting in connection with Dr. Day's hypothesis of fractional filtration, and we may very easily get something happening to the water corresponding in some degree to what we get with oil. D. B. REGER, Morgantown, W. Va.-Mr. Johnson in his paper states his belief that the oil is formed originally from organic matter in the shale, and is forced out of the shale into the porous reservoir of the sand above the shale. He states further, that as you go deeper iii the measures where there is an increasing overburdens, the oil becomes less and the gas increases in large proportion, or lie says that the oil is forced back out of the sand by pressure, into the shale.

Jan 5, 1915

By Arthur F. Taggart

A general awakening of interest among mill men concerning the mechanical efficiencies of their crushing machines is evident from a perusal of the recent files of mining publications. Considering the large part of the power bill which must be debited to the crushing department, such interest is natural. When, however, the articles on the subject are read, the only statement upon which the writers agree is that fine grinding consumes a large amount of power, and that the machine which, from a concentration standpoint, offends as a slime producer is, for that reason, a serious offender in wasting power. When the mill man attempts to find a method for measuring the power wasted, or to compare the efficiency of one machine with that of another for the same work, he is confronted with a choice of methods which lead to conflicting results. There are two reasons why the work of crushing is not more generally understood. In the first place, experimental data are difficult to obtain; and in the second place, before these data can be put in general form certain assumptions must be made. A difference in these assumptions by different investigators has led to conflicting conclusions. This conflict has resulted in the proposal of two laws. The first of these is the so-called Rittinger's law, which is variously stated as follows: "The work of crushing is proportional to the reduction in diameter."—R. H. Richards: Ore Dressing, p. 304 (1903). "The work required to crush rock is very nearly proportional to the reciprocals of the diameters crushed to."—A. Del Mar: Engineering and Mining Journal, vol. xciv, No. 24, p. 1129 (Dec. 14, 1912). "The work done in crushing is proportional to the surface exposed by the operation, or better expressed for this purpose, the work done on a given mass of rock is proportional to the reciprocal of the diameter of the final product, assuming that all the mass has been reduced to one exact size, which is only theoretically possible."— A. 0. Gates: Engineering and Mining Journal, vol. xcv, No. 21, p. 1039 (May 24, 1913). ' ' " Of this law as variously stated above H. Stadler says (Grading Analyses and Their Application, Author's Reply to Discussion, Transactions of the Institution of Mining and Metallurgy, vol. xx, p. 426 [1910-111):

Jan 1, 1915

The Iron and Steel Committee of the American Institute, of mining and Metallurgical Engineers held a joint session with the American Foundrymen's Association during the Annual Meeting of the Institute in February, 1928, for the purpose of discussing blast-furnace operations and the character of pig iron and castings. Dr. Richard Moldenke presided. H.. H. Sweetser, who was named on the program as the presiding officer of the session, was unable to be present, but sent a letter in which he said: " The meeting we had here last year and the meeting held in Chicago last June showed a desire on the part of blast-furnace men and users of pig iron to get the facts regarding the influence on castings made from pig iron produced in blast furnaces under varying conditions of temperature, mixture and local furnace operations. It has been my hope that at this Round Table we might he able to formulate a series of tests that, would give us the desired information. "Several independent blast-furnace investigations have. been, and still are being, carried on in different sections of the country. The furnaces investigated include a southern furnace, a middle-west furnace, a western furnace and a Chicago district furnace. The results so far show distinct characteristics for each of the four furnaces. It is possible that a furnace in the eastern part of the United States would be different from all the others. "It is hoped that a plan of action can be worked out at your meeting today whereby the IT. S. Bureau of Mines will be able, to carry on more extensive work in connection with the research departments of the different iron and steel companies and the big consumers of pig iron. "No one group can get all of the, information but if the different investigations can be coordinated it will he possible for us to (Iran. conclusions regarding the effects of varying conditions in blast-furnace practice on the pig iron produced and the castings made there from." DISCUSSION R. Moldenke, Watehung, N. J.—I was across the -water this summer and saw some of those interested in an investigation of this kind. 'I'hey told me that in Germany, where they had a joint committee of blast-furnace operators and foundry-

By F. W. Lee

A GREAT CURTAILMENT of field activities among the geophysicists occurred last year, especially in prospecting for the common metals. In gold, however, an "outstanding achievement . . . was made by the engineers of Consolidated Goldfields. Here the suboutcrop of the Main Reef Series was traced from Middelvlei through properties of the westward area, a distance of from 30 to 40 miles. Here Drs. Reineche and Krahman prospected with the aid of a sensitive magnetometer and established the singularities of the various beds which heretofore had not been sufficiently appreciated. Several underlying shale beds were used to determine this suboutcrop under the dolomite. This area promises to be the equivalent of one-half the size of the present gold fields and to rank in value with the Far East Rand." The present temperature compensated magnetometers permit accurate field observations to less than 5 gammas. Since magnetic anomalies may have their origin due to a change of elevation as well as to the outcropping of a bed of another magnetically different material, intimate geological knowledge is of great assistance in the interpretation of these measurements. To what extent magnetic measurements reflect the basement when the material is homogeneous, consisting primarily of red granite, was determined by members of the Bureau of Mines and described by Dr. J. H. Swartz. Because of the diverse causes of magnetic anomalies, some of which were discussed and correlated by Stratton and Joyce upon known conditions, magnetometer measurements are often difficult to interpret.

Jan 1, 1933

By Robert E. Allen

The organized curtailment of California oil production is not yet one year old but during its first year it has accomplished so much that it is now firmly established as an agency of economic efficiency. The principle of cooperative curtailment has been adopted by other states and it is safe to say that the principle will continue as long as the demand for petroleum is notably less than the potential production. It' is interesting to note that this same principle of regulating supply to meet demand is now being urged for other industries, such as agriculture and mining. Since Oct. 31, 1929, when curtailment was instituted by the oil producers of Santa Fe Springs and Long Beach in an effort to avert the disaster of ruinously low prices which confronted them, there has been a constant and increasingly effective curtailment program in California. Prior to that time a notable effort toward the restriction of oil production was made under the direction of F. C. Van Deinse during the early summer months of 1929. A considerable reduction of oil output was recorded as the result of this effort, but because of incomplete cooperation and the discovery of still deeper zones at Santa Fe Springs the effort was abandoned; flush field production became unrestrained and prices soon fell to low levels. This initial curtailment movement was educational and experimental. It showed all operators a way out of their overproduction difficulties and developed the principles followed in later curtailment efforts. Thus it was that only a few days after their oil had been reduced to 60 c. per barrel, the operators of Santa Fe Springs got together and agreed to restrict their current production of more than 270,000 bbl. daily to not more than 150,000 bbl. daily. The operators at Long Beach followed the same course a few clays later and agreed to limit their production to not more than 110,000 bbl. daily. The Santa Fe Springs operators chose H. P. Grimm as umpire and director of their proration program. Neal H. Anderson was chosen umpire for Long Beach. Since that time, as the need for curtailment has increased, practically every field of the state has come under the curtailment of these two umpires. Curtailment of the Elwood and

Jan 1, 1931

By F. G. BREYER

ZINC metallurgists continue to follow with keen interest reports of successful results from the continuous retort plants at Palmerton, Pa., and Meadowbrook. W. Va. The new process had already demonstrated its ability to reduce the lead content of the metal and to effect savings in labor and fuel. The past year has shown that the retorts themselves can he built to last long enough so that the retort cost per ton of metal is lower than in past practice with small horizontal re- torts. A number of the latest type of retorts are reported to have been in continuous operation for over 18 months without a failure and are said to be still in good condition. This seems a complete answer to the last question which remained before continuous zinc smelting could he pronounced commercially practicable.

Jan 1, 1932

By W. A. Dunkley, W. W. Odell

The sulfur content of coal is perhaps more important in the manufacture of illuminating gas than in any other coal-using industry. Whether the gas is made by the distillation of coal in retorts or ovens or by steaming incandescent coal or coke in the water-gas process, a portion of the sulfur present in the fuel always passes into the crude gas. Practically all the sulfur that remains in the finished gas is transformed into sulfur dioxide (SO2) when the gas is burned. Sulfur dioxide is a pungent suffocating gas and, if present in the air in any perceptible amount, is deleterious to health and comfort and damaging to house furnishings. SO universally is this recognized that laws regulating the amount of sulfur that may be permitted to remain in the gas are very generally in force. The capacity of a plant to purify gas frequently limits the selection of coal for gas making. This condition may arise from different causes. Some plants were originally designed to handle a certain grade of low-sulfur gas coal, and very little leeway was allowed for growth or for the use of inferior coals. Other plants, when built, had ample capacity to purify gas from relatively higher sulfur coals, but their output has grown so rapidly that their purifying capacity is now limited and only the low-sulfur coals can be handled. There is a great quantity of coal in the United States that would satisfy the requirements of the gas manufacturer, were it not for the high sulfur content. The coals containing less than 1 per cent. sulfur are becoming scarcer year by year and, in time, the gas industry will probably be compelled to use coals that are now considered out of the question. Sulfur Compounds in CRude Gas Sulfur exists in unpurified illuminating gas in a variety of compounds; chief of these are hydrogen sulfide (H2S) and carbon disulfide (CS2). In crude coal gas H2S is usually present to the extent of 0.5 to 2.0 per cent., by volume, equivalent to about 300 to 1200 gr. per 100 cu. ft. of gas. In carbureted water gas, the amount of sulfur compounds depends not only on the sulfur content of the coal or coke used, but also upon cite

Jan 1, 1920

By R. E. H. Pomeroy

The statistical data given in this paper are taken from the actual performance of the No. 2 reverberatory furnace of the Nevada Consolidated Copper Co., Mc Gill, Nev., for a period of four months, from April to July, 1914. The principal furnace dimensions are: Length, 132 ft. % in. at the skim-line level; average width, 18 ft., 10 in. at the skim-line level. The roof is 7 ft. above the skim-line level at the firing end. The average area in the uptake flue is 36 sq. ft., and the area above the skim line under the vulcatory arch is 24.3 sq. ft. Fig. 1 shows a diagrammatic plan and sectional elevation of this furnace. The furnace is equipped with two 400-b.h.p. Stirling waste-heat boilers set in parallel. California crude petroleum is used for fuel and has a specific gravity of 16.5" B., flashing in open test at 199" F. The oil is heated to about 200" F. in a steam heater before going to the burners, requiring about 9 b.h.p. per furnace day to heat it from the line temperature to the burning temperature. Measurement is made by oil meter, checked daily by reservoir readings. The oil is fed by gravity (34 Ib. static pressure) to seven low-pressure blast burners of the Steptoe type (Fig. 2). The blast for these burners is supplied at about 40-08. pressure by a motor-driven Connersville blower of 42 cu. ft. capacity per revolution. The air supplied by the blower through the burners for atomizing the oil amounts to about 10 per cent. of the theoretical air necessary for complete combustion of the oil. The remainder of the necessary air enters the furnace through the burner openings in the firing wall. No checker holes are provided, and the charge holes in the roof are equipped with slide gates and " dog houses" to minimize air leakages. The combustion of the fuel, as shown by gas analysis at the front of the furnace, is practically complete, the carbon monoxide in the gases being less than 0.5 per cent. The draft at the firing end of the furnace is 0.18 in. of water. At the throat or in the uptake above the "verb" the draft is about 1 in.

Jan 1, 1915

By Jacob T. Wainwright

AS a means for increasing the efficiency in modern blast-furnaces by supplying to them blast of a much higher temperature than is now possible, the writer offers as a suggestion a modification in the construction of regenerative hot-blast stoves. Stated briefly, the plan proposed is to pre-heat both the gas and the air for its combustion in a manner similar to that generally adopted in Siemens openhearth furnaces. After thus carrying the temperature of the stove to a point much higher than that common in hot-hlast stoves, the cold blast passes through it. Without entering into the details relating to the reversing valves and the system of flues, the general plan may be outlined as follows, referring to the accompanying drawings: The valves are so placed in heating up the stove that the blast-furnace gas enters at B, Fig. 1, and the cold air for combustion at A. Ascending in flues, F and E, respectively, combustible gas and air meet and mix in the combustion-chamber, I. Flowing through K, they descend through the flues, G and H, escaping through the chimney. In this manner the walls of the combustion. chambers, I and L, are highly heated, and the right-hand side of the stove is carried to a higher temperature. By reversing the valves, blast-furnace gas enters at C and cold air for combustion at D. Both are pre-heated in their ascent through the flues, G and H. They burn in the combustion-chamber, L, and the hot gases of combustion, flowing through K, I, E and F to A and B, heat the left-hand side of the stove. In this manner the stove is carried to a temperature greater than that of those now generally in use, in which air and gas are burned without preliminary pre-heating. In the plan proposed, that side of the stove will, of course, be relatively cooler through which cold air and furnace-gas last passed in its ascent to its combustion-chamber. After having sufficiently heated the stove in the manner outlined, the cold blast is admitted through all the flues, A, B, C and D. It ascends through the highly-heated regenerative material to the chambers at the top and descends through the flue, P, Fig. 2 (dotted

Jan 1, 1889

By J. A. Ede

The object of the writer is to call attention to a rather unique aggregation of economic products distributed over a line of succeeding formations about 3 mi. long, to be seen within a few miles of La Salle, Ill. Fig. 1 is an ideal section of the stratification exposed and exploited along a distance of 3 1/5 mi. in a southwesterly direction from the quarry of the Utica Hydraulic Cement Co. located near the historic site of Kaskaskia village to the Oglesby shaft at Oglesby. No attempt has been made to cover the whole field, special mention only being made (with the exception of two places) of the operations found along the course or parallel to the direction assumed in the ideal section. I have used Fig. 2, after J. R. Bent and De Witt Kelly, to locate the relation of the La Salle anticline to the coal mines of this district and to show the operation of No. 1 and 3 mincs of the Illinois Zinc Co. Anticline and the Rock Formations Owing to the structural deformation between La Salle and Utica, the older rocks of the state are exposed to the surface along the northern embankment and the bottoms of the Illinois River valley near the latter place. At; the Illinois Zinc Co. works, Sec. 16, Tp. 33, R 1, a well for water mas sunk 1828 ft. and samples taken every 10 ft. of the ground penetrated; duplicates were sent to Mr. Cady of the Illinois Geological Survey. A general compilation or synopsis study of this section is here presented. As the well is over 1 mi. west of the Western limb of the anticline, the section affords some reliable data. These samples were studied and interpreted by H. M. DuBois as Lower Magnesian, and by G. H. Cady as the Lower Magnesian. The results are given in Fig. 3. The most interesting geological feature of this district is the La Salle anticline. In 1865, Leo les Quereux, looking at Split Rock, asked how it happened that the upper coal measures overlie strata of the Lower Silurian and what has become of the formations which are generally found intermediate—the Upper Silurian, the Devonian and sub-carboniferous, and the lower member of the coal measures?

Jan 1, 1920

By Riki Kobayashi, D. L. Katz

The conditions at which methane and water form solid hydrates have been extended from 4,000 to 11,200 pounds per sq. in. The curve at high pressure had been in doubt because of Villard's report of a critical decomposition temperature. The paper explains the nature of the hydrate curve at high pressure and its dependence on fluid phase behavior. Extropolation of the methane hydrate curve indicates a pressure of 40,000 pounds per sq. in. will cause hydrates to form at a temperature of 100" F. INTRODUCTION The conditions under which natural gases form hydrates when liquid water is present have been studied by several investigators up to pressures of about 4,000 pounds per sq. in. The early work by Villard on hydrates of methane and ethylene13, ethane'', and propane14 included references to critical decomposition temperatures of the hydrates. Villard's work raised the question as to whether the pressure-temperature curve for methane-water hydrate continued above a temperature of 70.7°F. or whether this was the maximum temperature at which hydrates would form. This paper extends the experimental data on methane hydrate to 11,200 pounds per sq. in. A discussion of phase relations in the hydrate region for the hydrocarbons and of the methane-water system at high pressures is included. PREVIOUS WORK Villard suspected that methane hydrates could not be formed at temperatures above 21.5°C. (70.7°F.)la irrespective of the pressure of the liquid-vapor system. However, he was limited in his studies by his apparatus in 1888 to pressures not greater than 300 atmospheres (4,410 pounds per sq. in.) so that there has remained some doubt as to the existence of such a maximum temperature in this region. For the case of ethylene hydrates, however, Villard does specifically state the occurrence of what he terms a "critical temperature for the decomposition of the hydrates"13. Fig. lB shows a pressure-temperature projection of the three-phase locus, hydrate-ethylene rich liquid-vapor (H-L2-V) terminating at the critical locus in which L² and V assume similar properties. Throughout this paper the following phase designations will be used: H for hydrate, Ll for the water rich liquid. L2 for the

Jan 1, 1949

By Riki Kobayashi, D. L. Katz

The conditions at which methane and water form solid hydrates have been extended from 4,000 to 11,200 pounds per sq. in. The curve at high pressure had been in doubt because of Villard's report of a critical decomposition temperature. The paper explains the nature of the hydrate curve at high pressure and its dependence on fluid phase behavior. Extropolation of the methane hydrate curve indicates a pressure of 40,000 pounds per sq. in. will cause hydrates to form at a temperature of 100" F. INTRODUCTION The conditions under which natural gases form hydrates when liquid water is present have been studied by several investigators up to pressures of about 4,000 pounds per sq. in. The early work by Villard on hydrates of methane and ethylene13, ethane'', and propane14 included references to critical decomposition temperatures of the hydrates. Villard's work raised the question as to whether the pressure-temperature curve for methane-water hydrate continued above a temperature of 70.7°F. or whether this was the maximum temperature at which hydrates would form. This paper extends the experimental data on methane hydrate to 11,200 pounds per sq. in. A discussion of phase relations in the hydrate region for the hydrocarbons and of the methane-water system at high pressures is included. PREVIOUS WORK Villard suspected that methane hydrates could not be formed at temperatures above 21.5°C. (70.7°F.)la irrespective of the pressure of the liquid-vapor system. However, he was limited in his studies by his apparatus in 1888 to pressures not greater than 300 atmospheres (4,410 pounds per sq. in.) so that there has remained some doubt as to the existence of such a maximum temperature in this region. For the case of ethylene hydrates, however, Villard does specifically state the occurrence of what he terms a "critical temperature for the decomposition of the hydrates"13. Fig. lB shows a pressure-temperature projection of the three-phase locus, hydrate-ethylene rich liquid-vapor (H-L2-V) terminating at the critical locus in which L² and V assume similar properties. Throughout this paper the following phase designations will be used: H for hydrate, Ll for the water rich liquid. L2 for the

Jan 1, 1949

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 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