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By T. Prof. Egleston

How to interpret the composition of rocks has been a question which has caused a great deal of discussion and investigation among geologists and chemists. It is evident that that analysis will give the clearest results, which will give the relative proportion of the different minerals composing the rock as well as the weight of their different constituents. This, however, is a very difficult matter, and in those rocks which seem to the naked eye entirely compact, like obsidian and other rocks of that class, appears to be impossible. Cordier, in the early part of the century, invented a process which is known as the " mechanical analysis of rocks," which is really a method of mechanical preparation, and consists in crushing the rock to a certain fineness, and then, by virtue of their density, washing out the different minerals, so as to make a mineralogical analysis, separating completely the different constituents of the rocks. In the hands of so skilful a man, this was a comparatively easy matter, and Cordier found no difficulty in ascertaining the mineralogical composition of a rock. The ultimate chemical composition was ascertained from the sum of the elements contained in the different materials. In the light of to-day, it is very easy to see that the complete chemical analysis of the rock does not necessarily lead to the explanation of its character. It has been so difficult, however, to have any other kind of analysis made that most chemical examinations have been made as ultimate, and not as mineralogical analyses. The panning out of the different minerals composing the rock, which are often very nearly of the same specific gravity, is so difficult that a person of ordinary mechanical skill is scarcely able to do it; consequently the mechanical analysis which Cordier proposed, and was able himself so skilfully to effect, has never been practiced to any extent. A school was formed in France consisting of a very small number of Cordier's followers, which, in face of the difficulty of acquiring the method, very soon died out as a school, though some of his most skilful followers are still living. The next important step in ascertaining their composition was to out the rock into transparent sections and examine the minerals with

Jan 1, 1875

By N. W. Perry

Some months ago a gentleman gave me a handful of minerals which he had collected in an arroyo, or dry stream-bed, that ran through the town of Ramos, State of San Luis Potosi, Mexico, as a sample of the class of ore that might be expected in the mines of that section. I was, however, familiar with those mines and their ores, and cast the pebbles aside as of no interest. I afterwards returned to Mexico and took charge of two groups of mines, one in the State of Zacatecas, and the other in the town of Ramos, State of San Luis Potosi. While I was thus engaged, it was a very frequent occurrence for parties to bring me specimens of rock, ores, etc., for my opinion on them; and one day a man brought me a half-dozen or more small pieces of a very black shiny mineral, desiring to know what it was. I did not recognize it, and desired him to give me the specimens for analysis, which he promised to do in a day or two. He never did give them to me, for he lost them ; but he said there were plenty more where these came from—at Ramos—and he could get them at any time for me. I thought no more of the matter until after my return to this country, when, one day, in looking over some of my old " trash," I came across the specimens at first referred to as having been cast aside so carelessly. I noticed two distinct minerals among the pebbles : one being erubescite or tetrahedrite, the predominating mineral of the mines of Ramos, and the other a hard black shining mineral, the same that I had wished to analyze in Mexico. On testing for hardness I was surprised that it scratched topaz with some degree of ease, thus placing it above 8 in the scale of hardness. Trying it with a corundum, I sometimes succeeded in scratching it, but at other times it would scratch the corundum, and at still other times neither would produce the slightest effect on the other. Crystallized topaz would be ground to a powder in attempting to scratch the black mineral, without abrading it in the slightest. It must, therefore, be placed at 9 in the scale of hardness. It is of the deepest opaque black, not unlike pitch-blende in ap-

Jan 1, 1884

By Henry Howe

1. The purpose of the National Research Council as organized for war purposes is twofold, to stimulate those outside its own personnel to conduct researches of importance for winning the war and to carry on such researches through its personnel to a limited extent. How this is clone is explained in Section 10. "Research" is used here in a very broad sense, including, for instance, inventing and developing mechanical and physical devices. The need of this work arises from the inevitable concentration of most of the governmental war agencies on the production and transportation of war materials of. the types now adopted, as distinguished from devising new kinds of instrumentalities, such as armor, guns, aircraft, and apparatus for detecting, locating, observing, signaling, transporting, and many other military purposes. But it is important that we should devise new agencies. The war came near being won by an invention, the submarine, and its course has been affected greatly by two other inventions, tanks and aircraft. In spite of our numerical superiority victory may well be snatched from us by an invention, if we allow Germany to outstrip us in inventing. Hence the importance of the Council's work in mobilizing and organizing the services of the patriotic civilian experts throughout the country, so as to bring their powers to bear on important war problems and on inventing war devices, as an adjunct to the development work of the regular governmental bodies. 2. Status of the Council.-Though President Wilson's request caused the Council to be created by the National Academy of Sciences under its congressional charter in 1916; though his executive order of May 11, 1918, directs the heads of "Governmental departments immediately concerned" to "continue to co-operate with it in every way that may be required;" and though the Government has contributed largely to its financial support (Section 12, page 10), it is not a department of the Government but an independent research body, aiming to evolve the necessary mechanism for the novel work of systematic stimulation and guidance of research. Thus the Government, which instigated the creation of the Council, recognizes and collaborates with it, and in part supports it. The Council acts moreover as the Department of Science and Research of the Council of National Defense.

Jan 12, 1918

By Ralph Arnold

While much geological work and drilling have been done in Venezuela, the incompleteness of geological evidence obtainable and the restricted areas in which drilling has been done make any estimates of oil resources extremely speculative. Nevertheless, it is felt that the data given are justified, in the belief that the ideas of a geologist familiar with the region are better than those of a promoter. The oldest beds of interest to oil men are those of the Cretaceous, which are well developed in eastern Venezuela and about parts of Lake Mara-caibo. In both cases, a hard massive limestone is overlain by a great thickness, most of which is shale. In the west, in places this shale is more than 2000 ft. (610 m.) thick, while in the east it-mag attain 3500 ft. (1067 m.). The limestone and parts of the shale are oil producing. In the east, the Tertiary where present is almost entirely covered by the Quarternary, but in the west it is well developed. In probable unconformity over the Cretaceous shales is found a series of sandstones and shales, which may be called the lower coal series. It is well developed southwest of the lake, where it is the oil container, and is probably the lowest series exposed east of the lake. Above this is the Pauji shale, which is probably the point of origin of all the oil east of Lake Maracaibo and in the State of Falcon. It has a thickness of about 3000 ft. (914 m.) in the Mene Grande region. The upper coal series is developed as a great thickness of sands, shales, and clays, with some partly consolidated limestone. Its thickness may be as great as 10,000 ft. It is the oil container of the Falcon-El Mene region and a probable location for oil in some of the area about the lake. It may or may not include the so-called Maracaibo series in which the oil is found at Mene Grande. Over much of Venezuela, the Quarternary is present in unknown thickness, which probably is not great. It obscures oil structure in all cases and presents the greatest hazard of oil exploration for the fields which probably exist below.

Jan 1, 1923

By Ernest R. Darby

If the correct balance between fuel and air is maintained in an open-flame furnace,' little chemical action may be expected between the products of combustion and the metal being melted. Physical' changes in the metal are the object of the melting operation, and indirectly, under certain conditions, may be the cause of subsequent chemical actions. If sufficient heat has been introduced into the metal to bring about the change from the solid phase to the liquid phase, and still further from the liquid to the vapor phase, the metal vapor in all probability will be carried from the furnace by the exhaust and rapidly combined with the oxygen of the outside air. The charge being melted in the furnace may contain elements which are chemically inactive at normal temperatures but which will form compounds at the elevated temperatures of the metal bath, or even at a lower degree. Such indirect chemical actions are very confusing and often lead to incorrect conclusions regarding furnace atmospheres. In the open-flame furnaces used in the melting of bronze, the furnace atmosphere is spoken of as being either neutral, oxidizing or reducing in its effect upon the metal. A neutral atmosphere, as mentioned, is generally considered as the atmosphere of the furnace that will produce melted bronze, neither oxidized nor gassed. It is in effect an atmosphere which is not directly the cause of any chemical action. In such an atmosphere absolutely pure metals may be melted and poured without the absorption of gases or the formation of metallic oxide. The metal has undergone a simple, physical change. An oxidizing atmosphere is one in which the air introduced to the furnace is in excess of that required to complete combustion of the fuel used. The oxygen of the excess air may combine with the metal being melted to form metallic oxide, which may or may not be dissolved by the metal. If an absolutely pure metal is melted in a furnace operating with such an atmosphere, a portion of the metal charged may be converted into metallic oxide, the amount depending upon the duration of the

Jan 1, 1930

By Richard Moldenke

ONE of the little-known characteristics of cast' iron, which neverthe-less has an important bearing on results where accuracy in machining-is essential, is the ability of this material to ease up internal strains when. .allowed to remain quiescent for a more or less extended period of time. At seems as if the molecules in such a casting, by virtue of their "mobility,? can adjust their relative positions to an extent sufficient to overcome some of the existing stresses. The following instance will perhaps give a fair idea of the condition a casting may he in when just shaken out of the sand. A very large sheave-wheel, after shaking out, was taken' outdoors to be, cleaned and made ready for turning up. It was leaned against the side of the building, but before much could be done an arm tore apart with a loud report. Investigation showed that the sun had been shining on the upper rim, this adding a slight strain to those already existing within the arm and thus overbalancing the strength of the metal in tension. Had this sheave been kept under cover for a while, or at least until machined, the-strains., would have eased off sufficiently to allow the sun to look upon it without disaster. It will not be necessary to multiply examples. Every engineer knows the danger of water-hammer in pipe lines, particularly if the latter are of cast iron. Every mechanic knows, or should know, that it is not good to strike a fitting that is under steam pressure. It will be necessary to say a few words on the "internal- strains" in castings-the so-called "casting strains" we hear so much about. We all know that to get a casting reasonably true to the dimensions wanted requires a slightly larger pattern. The usual allowance for gray iron is 1/8 in. to the foot (1 cm. per meter) and ¼ in. to the foot (2 cm. per meter) for white iron (all dimensions). This reduction in length, breadth and thickness in a casting is erroneously called "shrinkage." It should be called "contraction," as for practical purposes. it is simply the difference .in dimensions of the casting red-hot and cold.

Jan 2, 1917

By B. E. Lindsly

The withdrawal of gas and/or oil in appreciable quantity from a natural oil reservoir causes the pressure within the reservoir to diminish, and if the oil is completely saturated with gas, this dissolved gas begins to evolve from solution. The liberation of gas from solution in oil causes the oil to change in several ways, the principal changes being: (1) reduction in volume or "shrinkage"; (2) increase in specific gravity (decrease in degrees A.P.I.); (3) decrease of energy in the oil; (4) increased viscosity; (5) increased surface tension. As the writer's investigations have been concerned more with the first three items than with changes in viscosity and surface tension the following discussion relates particularly to the volumetric shrinkage of the oil, to the increased specific gravity, and to the decreased energy in the oil, each caused by the liberalion of dissolved gas. One of the most surprising facts that have developed in the study of high-pressure well-head and "bottom-hole" samples is the great reduction in volume that occurs in some oils when the naturally dissolved gas is liberated. High-pressure samples taken from well heads in the Oklahoma City, Kettleman Hills and Ventura, Calif., fields decreased in volume from 11.2 to 40.5 per cent when the dissolved gas was liberated in reducing the pressure on the sample to atmospheric. The amount of shrinkage an oil undergoes when gas is liberated depends upon the quantity of gas liberated and also upon its composition. A given volume of the heavier gases, propane and butane for example, will occupy more space in the oil than an equal volume of methane. The reason for this probably is that the molecules of the heavier gases are larger than those of the lighter gases. When gases are not in solution, and particularly when they are at low pressures, the distance between the gas molecules is so much greater than the dimensions of the molecules themselves that the mere size of the molecules has little effect upon the space occupied by the gas, Avogadro's hypothesis, which in effect states that all gases under the same conditions have the same number of molecules per unit volume, relates to this phenomenon. The fact that the heavier gases occupy more space than the lighter gases in the oil, and

Jan 1, 1934

By Theodore A. Blake

More than a quarter of a century has passed since the introduction of the machine known as the Blake crusher, the invention of Eli W. Blake, of New Haven, Conn. Although originally designed for breaking stone for road-metal, its importance for crushing ores of the precious metals, and those of iron, copper, and zinc, as well as emery, phosphates, plaster, etc., mas soon recognized, and for many years its use has been world-wide, and its construction so well known that no special description of it is deemed necessary. Following its introduction, many different machines for the same purpose, containing the same essential features of upright convergent jaws, one of which is movable with respect to the other, hut having some slight modification of such movement (generally a rubbing motion) or of the non-essential method of imparting motion to one or both of the jaws, have been offered to the public for sale and use, but have, as a rule, in time disappeared from the market. If we seek for the reason of the success of the Blake crusher, aside from its simplicity of construction, we shall find it in the adherence to the principle of crushing by simple pressure and careful avoidance of attrition. In this lies the economy of power and of wearingsurfaces. To reduce any hard and brittle material to a fine powder by many different methods—by attrition, impact, or percussion—is a comparatively easy matter; but to accomplish this by the employment of either of the above-mentioned principles involves such a consumption of wearing-surface? (generally iron) or of power, that the numerous devices that have hitherto been presented to the public as solutions of the problem of fine crushing have proved utter and complete failures when tested with reference to the power employed and the wear of iron in doing their work.. Aside from the use of crushers with the harder ores, the only two methods of fine crushing in general use, and, in the writer's opinion, worthy of consideration, are by means of stamps and rolls; the former doing their work by percussion, the latter by pressure, provided

Jan 1, 1885

By Jean Howard, E. V. Walker

ManY papers have been published during the last few years on the formation of cube texture in 3 1/4 pct Si-Fe, e.g., those of Assmus, Detert, Dunn, and Walter.1,5 All are concerned with the formation of the texture by a process involving secondary re-crystallization and the relative surface energies of (100) and other planes under certain conditions of annealing. The authors have found that cube texture can also be produced by heavily cold rolling strip in which the cube-on-edge texture has first been formed. Cube texture develops on annealing, but in this case it is not accompanied by secondary recrystallization. The starting material is a sintered compact, the preparation of which has been described elsewhere. Using a conventional processing schedule employed for producing commercial silicon-iron with the cube-on-edge texture, the sintered compact is cold rolled to such a thickness that, after annealing in pure hydrogen for 24 hr at 1350'~ to produce the cube-on-edge texture, the final thickness required can be obtained by giving a further cold reduction of 85 pct. Cube texture is developed by annealing at -900~~ in pure hydrogen: it has been produced in strip up to 0.024 in. thick. The microstructure of the strip consists of a mass of small primary grains within the boundaries of the much larger secondary grains which ex- hibited cube-on-edge texture before the final cold roll. If the strip is annealed at -1000 after the 85pct reduction, secondary recrystallization begins to take place, provided a strong cube texture is present. On raising the temperature more secondaries grow, complete secondary recrystallization being obtained on annealing at -1150'. From this it is concluded that the secondary crystals are produced by the texture inhibition mechanism: they show (110) and (111) planes in the surface of the strip, the former being the more numerous. It has been observed that the more perfect is the (110) [001] texture prior to cold rolling by 85 pct, the further from the ideal is the (100) [oo].] texture. A similar treatment applied to high quality commercial grain-oriented silicon-iron strip failed to produce cube texture. The tilt and rotation of the [loo] from the rolling direction was less than 10deg, but (to within a few degrees) the planes (130), (450) and (210) lay in the surface of the strip. Acknowledgment is made to the Engineer-in-Chief of the British Post Office for permission to use the information contained in this note.

Jan 1, 1962

By Howard Eavenson

THE eleven mines of the United States Coal and Coke Co. in the Pocahontas coal field are situated in McDowell County, W. Va., which is a mountainous region. The valleys rarely exceed 200 ft. (60 m.) is width, the hill sides slope from 25° to 33°, and the tops, from 600, to 900 ft. above the valleys, carry practically no level land. At least 80 per cent. of the area is covered with timber. All the workings are drift mines; and while the average grades of the seams worked are ample for drainage, local dips and swamps necessitate, the use of a large number of local pumps or of numerous drainage ditches to keep the mine free from water during heavy rains. The water handled in any mine is not great, compared with the coal output, and usually causes little trouble except during extremely wet periods. In hew workings, the water encountered, except in rare cases, is trifling; it is only after rib drawing has started and the surface has been broken that water troubles begin. The strata overlying the coal are sandstone, shales, and slates; as the soil is thin and sandy, it does not tend to puddle and stop the cracks, which remain open for a long time. As mining progresses and the robbed area increases, the broken area becomes larger, increasing the openings into the mined territory. The cover over the robbed portions of the mines varies from 30 to 750 ft. (9 to 228 m.). When the ground is saturated, considerable water finds its way into the mines the day after a heavy rainfall and for three or four days it tends to fill the low places, wash the tracks, etc. and. unless from three to four times as many pumps are installed as are normally needed, considerable', output is lost. In most cases the water will .flow from the mines, so the obvious solution is to provide drainage .ditches of ample size to carry the maximum flow expected, so that the inflow will have no opportunity to flood the working places.

Jan 1, 1921

He was born at Montreal, Canada, in 1875. His earliest education was received in Montreal hut was continued from 1885 to 1892 at schools and academies in Brooklyn, Whitestone, and Flushing, L. I. For his technical education he returned to McGill University, where he graduated in 1897. His first professional occupation was as transitman enga.ged in the running of township lines in the Rainy River District of Ontario. In 1899, he was made assistant chemist at the Cuggenheim smelter at Aguascalientes, Mexico. From 1900 to 1903, he was chief chemist for La Compañia Minera de Peñoles, at Mapimi, Durango. We have no information as to his pursuits during the next eight years, but from 1911 until 1914, when he became a member of the Institute, he was chief engineer for the Bankhead mines in Alberta, Canada. Lieutenant-Colonel Alfred Winter Evans Lieutenant-Colonel Evans, who was in command of the Third Battalion of the New Zealand Rifle Brigade, and had been cited in Distinguished Service Orders and received the Distinguished Conduct Medal, was killed in action on Oct. 12, 1917. Alfred Winter Evans was born in Natal, South Africa, in 1881, and received his preliminary education in the Durban High School. For the next five years he attended St. George's School at Harpenden Heights, England, until 1898. Returning to South Africa, he worked . for three months of 1898 as underground sampler for the Crown Deep Gold Mining Co., at Johannesburg, and for six months of the following year he was shift-boss for the Crown Deep, Ltd. At the outbreak of the Boer War he took an active part and was engaged on military service from 1899 to 1902. At the close of the mar, he came to New York and attended the Columbia School of Mines, where he graduated with the degree of E. M. in 1906. A part of that year he spent as assayer to a mining company at Poland, Arizona. In 1907, he returned to South Africa and engaged as underground contractor in charge of mining and development at a number of the South African mines, notably the French-Rand, the ViIIage Main Reef, the City Deep, and others. In 1908, he acted as shift-boss for the Fer-rerra Gold Mining Co. at Johannesburg. In 1909, he was appointed acting general manager for the Consolidated Goldfields of New Zealand,

Jan 1, 1920

By Joseph E. Pouge

For the purposes of this analysis it is assumed that the petroleum industry has undergone a basic economic change whereby the degree of competition present in its operation is reduced by the collective control of production brought about by statme-directed proration. Formerly freely competitive in all its parts, the industry is now fully competitive only in its marketing, its manufacturing and transportation, its search for new oil supplies, its drilling operations (with some qualifications), and its capital movements. The practical problem before the industry in its new status is the maintenance of equilibrium, with planned control of crude-oil production (proration) substituted for competition and price as the regulatory mechanism at one point in the supply-demand system. It is further assumed that proration has become so firmly established in the legal and operating framework of the business that it may be looked upon as an institution. The purpose of this paper is to call attention to the effect of unregulated drilling upon the orderly functioning of proration. Economic Structure of Petroleum Industry The economic structure of the petroleum industry, under the current form of proration, may be visualized, in simplified form, as shown in Fig. 1. This diagram is designed to indicate the existing mechanism whereby supply and demand are equated. Demand is created largely by conditions external to the oil business, whereas supply is conditioned by a series of stages incidental to the discovery, development and production of a resource. The time elements involved in changes in demand and supply are of an entirely different order, the demand factor being much more flexible and "quicker" than the supply factors. It should be observed, also, that the position of price, formerly between "demand" and "supply," has been moved to a sidewise location where it still affects demand but influences current supply only through its bearing upon proration, drilling and search. Proration has been substituted for price as a throttle at the well head, but at this point only. The mechanism now works in this fashion: a declining price stimulates demand and the

Jan 1, 1936

By W. C. Bednar

In all, 127 producing oil wells, 8 producing gas wells and 212 dry holes were drilled during 1936 in the Central Texas area; 76 wells in Bexar County, 62 in Caldwell County, 44 in Guadalupe County, 22 in Williamson County, 20 in Navarro County and 20 in Frio County. Less than 20 were drilled in each of the other counties and none at all in Ellis, Hill, Bosque, Coryell, Lampasas, Burnet, Llano, Kennedy, Mason, Real, Kinney and Uvalde Counties. The Pearsall-Austin chalk field in Frio County and the Zoboroski field in Guadalupe County were the only new discoveries and there were no important extensions to old fields. In this report Corsicana, Mildred (Elm Ridge), Angus-Edens-Hodge, Burke, and Rice-Oil Ridge, all shallow Navarro County stripper fields, are grouped together under the name of Corsicana. This grouping follows that of the Railroad Commission of Texas, thus facilitating the gathering of production data. A map showing the location of the oil and gas fields in the Central Texas Area was published in Volume 114 of the A.I.M.E. TranBactions, page 380. New Fields Pearsall-Austin Chalk.—The Amerada Petroleum Corporation completed 13 Austin chalk wells during 1936 on the large Amerada-Rycade block in Frio County. Other companies drilled two dry holes to the Austin chalk in this vicinity. Not enough wells were drilled to give control of the structure but it appears to be a nose plunging in a west-southwest direction. A second deep test is being drilled in the Pearsall area and at this writing has cemented off a show of oil and gas in the Edwards limestone. The Humble Oil and Refining Co. is building a 6-in. pipe line from Lytle, Tex., to serve the Pearsall field. Zoboroski.—Actual discovery of the Zoboroski field was made by W. J. Walton et al. in 1931. The discovery well, Anton Zoboroski No. 1, was a small producer making but from 3 to 5 bbl. per day, which was used locally for fuel oil. The discovery of the Darst Creek Extension in

Jan 1, 1937

By T. R. Armstrong

During the year 1939, Mexican production totaled 42,479,000 bbl.; a daily average of 116,381 bbl. or a little over 2 per cent of the estimated world production. The Mexican Government operates 100 per cent of the refining branch of the industry, 100 per cent of the domestic distribution, 96 per cent of the crude production and 92 per cent of the total exports. No discussion of the Mexican petroleum industry in 1939 is adequate without reference to the "expropriation" of the foreign-owned oil properties in Mexico by executive fiat on March 18, 1938. The forcible seizing of the properties culminated a long series of efforts on the part of the Mexican Government to obtain control of the oil properties developed through foreign initiative and with foreign capital in Mexico. The heart of the issue is whether the Mexican nation or any nation may with impunity confiscate the legally acquired properties of American citizens. The Department of State of our Government has in its communications to Mexico emphasized the fact that its "expropriation" of American properties was confiscatory because Mexico had failed to make "adequate, effective and prompt compensation"; that the taking was no less confiscatory "because there may be an expressed intent to pay at some time in the future," and that, consequently, "Mexico has assumed and continues to assume to exercise a right without compliance with the condition necessary to give such exercise a recognizable status of legality." Mexico has professed its willingness to pay for the oil properties but at the same time through its Supreme Court it has declared that the owners or lessees do not have the exclusive right to extract and dispose of the oil in the subsoil. This is a reversal of the Mexican position with respect to oil as set forth in the Mexican mining laws, affirmed by Mexican Supreme Court decisions, and as clarified in the Warren-Paync and the Morrow-Calles agreements, as well as in diplomatic correspondence. Efforts to Settle the Controversy Responding to suggestions from the State Department, representatives of the principal oil companies undertook in 1939 to effect a direct

Jan 1, 1940

Discussion of the paper of PHILIP W. HENRY, presented at the New York meeting, February, 1915, and printed in Bulletin No. 97, January, 1915, pp. 23 to 30. C. ,E. GRUNSKY, JR., San Francisco, Cal. (communication to the Secret ary*).-The difference of opinion of engineers on the subject of depreciation is justified, to some, extent, by the many viewpoints from which such a subject can be considered when applied to properties of widely differing physical characteristics. Mr. Henry takes up the subject of depreciation as applied alone to oil properties, and in doing so makes a clear distinction between amortization and the repair or renewal requirement. After carefully reading the paper the purpose of its author in suggesting a "depreciation" reserve or fund to keep the property at a constant value does not seem clear. As shown by Mr. Henry, the depreciation element as compared with the operating expense per gallon of oil is very large because of the comparatively short life of the oil properties, and it is also evident that such a "depreciation" fund would in a short time contain a very large amount of money. It seems desirable and permissible in income-tax matters to take into account the depreciation of property and to separate from the income such money as is necessary to amortize the invested capital to an extent warranted by the depreciation. However, it does not seem either necessary or desirable to create a large fund which will in time approximate the entire invested capital and which may he invested by the directors, as Mr. Henry suggests, "in the property itself or in outside securities." This method seems cumberome and liable to offer in the reinvestment of such a fund temptations to a directorate that might show more devotion to its own interests than that of the stockholders. A reserve fund is very frequently desirable in mining and oil operations, but to keep up a fund of this magnitude or to reinvest it in outside securities does not seem desirable from a stockholders' standpoint. The. money withdrawn from the receipts to be placed in the depreciation fund (not including replacements and the drilling of new wells necessary to keep up the productiveness) should he returned to the stockholders of the company, not as dividends, but as an amortization of the invested capital.

Jan 5, 1915

By J. J. Bodmer

THE substances or materials employed in this manufacture, are the same as those used in the preparation of mortar and concrete, viz., the different kinds of lime and sand. Instead of, or in conjunction with, sand there may be used calcined clay, blast-furnace slag, clinkers or ashes from furnaces, natural puzzolana, powdered chippings from stone quarries, etc. Of the different kinds of sand, pit-sand-siliceous sand, as it commonly occurs mixed with gravel-and the sand found on the seashore, where the salt has been washed out by long exposure, whilst out of reach of the tide, may be used. The purer the above-named materials are from admixtures of clay, earth, or organic substances, the more complete will be their combination with the lime, the quicker will the manufactured brick or block set, and the more satisfactory will be the quality which it ultimately attains. For this reason, subdivided blast-furnace slag is preferable in most cases to sand, and the only sand which, in reference to setting capacity, is analogous to blast-furnace slag, is the volcanic sand occurring in different localities in North and South Wales, as an almost pure calcined silica. The lime used for the manufacture may be either slaked or unslaked. In the first case, (slaked), in order to obtain satisfactory results, the lime must be strongly hydraulic. The use of unslaked lime, however, is by far preferable. A process for using fresh or unslaked lime has been patented in England by Major-General Scott. Lime thus prepared is called " selenitic lime," and consists of a mixture of fresh (un¬slaked) lime with sulphate of lime, or plaster of Paris. The gray-stone lime, for instance, found by the Medway, is mixed with from 5 to 7 per cent. of plaster, which has the effect of keeping the lime from slaking when water is added. This mixture also partakes of the nature of cement, and when used for mortar, or concrete, attains in a shorter time a greater degree of hardness than the same lime would ever have obtained after being slaked. Bodmer's process for the manufacture of artificial stone bricks consists chiefly in the use of automatic measuring, forwarding, and mixing apparatus, by means of which the materials are supplied and unite in a continuous stream, and are accurately measured. They

Jan 1, 1874

By F. Keller, E. H. Dix

The desirable high strength and hardness of the heat-treated strong aluminum alloys result from two distinct structural changes: (1) the formation of a solid, solution by heating at the required temperature for a sufficient period, and the substantial retention of this solid solution by rapidly quenching; (2) precipitation of particles of constituent and coalescence to a critical size to produce maximum strength and hardness. In alloys of the duralumin type, that is, alloys containing both copper and magnesium silicide precipitation takes place at normal atmospheric temperature, whereas in alloys containing copper without magnesium silicide or magnesium silicide without copper, maximum properties are obtained only after an accelerated aging treatment consisting of heating for 15 to 20 hr. at temperatures of about 150" C. The mechanical properties of these alloys subsequent to quenching but prior to aging are ideal for forming operations. Unfortunately, however, the alloys of the duralumin type age very rapidly during the first 24 hr. and aging is substantially complete after four days. For severe forming, such as the heading of rivets, it is desirable that this be accomplished within ½ hr. or at the most 2 hr. after quenching. Alloys containing magnesium silicide without copper also age at normal temperatures but the aging is less rapid and the material can be satisfactorily worked within several weeks after quenching. Some slight aging of alloys containing copper alone also takes place at room temperature but it is unimportant from the standpoint of workability. Any method of retarding the aging at room temperature of the duralumin type of alloys would be of considerable advantage in that the period during which the material could be worked successfully would be lengthened. For instance, in aircraft plants it is customary to supply the workmen with small lots of rivets that should be used within ½ hr . after heat treatment. Such procedure has the obvious disadvantage of being uneconomical, and furthermore there is always the possibility that the workmen would use the rivets after the time limit had expired, or the supply being depleted might use some that had not been heat-

Jan 1, 1931

By James O. Elton

This paper covers, besides laboratory work, a study of actual operation at the Washoe Smelter over a considerable period of time, together with the results of a visit to the Midvale plant of the United States Smelting & Refining Co., near Salt Lake. For the latter privilege, as well as permission to publish the resulting data herein given, I am indebted to George W. Heintz, General Manager of the Midvale plant, and here take pleasure in expressing my appreciation for the many courtesies extended to me by Mr. Heintz and members of the technical staff at the smelter. Almost all of the world's supply of arsenic is recovered as a byproduct in the smelting of other metals. It is seen 'on the market in various forms, the most common being arsenic trioxide, the " white arsenic " of commerce, which is sold as a heavy white powder, or in white, glassy, translucent masses. The trioxide is used in the manufacture of pigment, glass, and insecticides. About 50 per cent. of the domestic consumption is supplied by imports. Statistics of Arsenic Trioxide in United States.' Production. Consumption. Price Per Pound. Year. Tons. Tons. Cents. 1907..........1.010 5.471 5 1908,.........1,302 6,098 33/4 1909,.........1,007 4,600 2 7/8 1910,.........1,526 5,428 2 1/2 1911,.........3,081 6,539 2 1912,2........ 2,926 Closed at 4 7/8 Arsenic occurs in combitlation with sulphur and the metals in a large number of minerals. It is present in small amounts in many ores. In the roasting and smelting furnaces many of its compounds break down, liberating arsenic trioxide, which is volatilized and carried by the gases into the flue system, where a part is condensed and settles with the flue dust.

Jan 1, 1914

By Hamilton Bell, E. W. Webb

RepressuRIng, or gas drive, was first tried in the Seal Beach oil field during the fall of 1927, and was carried on until the spring of 1928. This experiment in the Upper or Bixby zone was highly successful in proving the feasibility of compressing gas to high pressures and also showed great increases in production. The project was discontinued because there were not enough wells to protect the property lines. In the development of the second or Selover zone, many more wells were drilled and after 2½ years of production the gas was depleted so that all producing wells in the zone were either pumping or on gas-lift. Edge-wat'er encroachment and the deepening of wells on neighboring properties to a third zone practically isolated the lease, so that during the spring of 1929 it was considered feasible to repressure the Selover zone on the Bixby lease of the Continental Oil Co. (Marland). As shown on Fig. 1, the main Seal Beach structure is an elongated dome with a northwest-southeast trend, and the north flank is cut by a fault nearly parallel to the axis of the structure. Bixby well No. 24 was chosen for the injection well on account of its location, as it is backed up by the fault and is surrounded by wells that protect the property lines. The results of the test made in the Bixby zone indicated that an injection well on the flanks of the structure would drive oil quickly to up-structure wells but would have a tendency to cause by-passing, while the drive to down-structure wells would be slower but more evenly distributed. Preferably the injection well would have been located on top of the dome but property divisions made this inadvisable. Well 24 had been completed in November, 1928, but on account of gas depletion the well failed to flow naturally. On gas-lift the well had an initial production of 1000 bbl. of oil with 30 per cent. emulsion. This well is 4825 ft, deep, penetrating 200 ft. of oil-bearing formation. At the time the well was prepared

Jan 1, 1930

By A. W. Hesse

TWELVE years ago, a meeting of coal-mine operators, mining engineers, oil and gas operators, Bureau of Mines engineers, geologists and state mine inspectors took place in Pittsburgh, Pa. for the purpose of discussing, and solving if possible, the problems in connection with the drilling of oil and gas wells through or near coal mines and through the future coal reserves. Proposed regulations were drafted and presented at that meeting by 0. P. Hood and A. G. Heggem of the Bureau of Mines.1There was considerable discussion of the various articles, practically all of which appear in Bulletin 65, but unfortunately the interest aroused at that meeting was short lived. Practically none of the important coal-, producing states gave the matter the consideration it should have received at that time. REASONS FOR AGAIN RAISING THE QUESTION Notwithstanding the marked progress in, safety work, coal mines still have an unenviable reputation for mine explosions. Our mining laws have become stricter and the enforcement, especially in Pennsylvania, more sternly carried out, but what good will come from a rigid carrying out of the mining laws if some source of danger exists all around the mines, over which the operators have no control? It is hardly necessary to recite all the cases of natural-gas explosions published in Bulletin 65, but with some of them I am especially familiar. In 1912, while making one of my usual Sunday visits to the Miners' Hospital, at Fairmont, W. Va., my attention was called to a patient in a horribly burned condition. He was swathed in bandages so that no part of his face and hands were visible. He had not then been informed that his two sons, mere boys, had died of the burns they had received in the same accident. This explosion was due to natural gas leaking into a country mine at Peora, Harrison Co., W. Va.

Jan 2, 1925