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By Cyril Smith

IN the study of the structure or the properties of a series of alloys or nonmetallic compounds, it is often advantageous to express the com-position not as percentage by weight, according to which the material is always made up and analyzed, but as the atomic percentage of the two constituents. The conversion from the one to the other is repre-sented by the formulas: 100A 100x Y x 100 ? x/A A [1] A+ B x + A/B(100-x) X _ 100yA 100y [2] yA+(100-y)B or y+A(100-y) where x and y are the weight and atomic percentages respectively of the element of atomic weight A, and (100 - x) and (100 - y) are the per-centages by weight and by atoms respectively of the element of atomic weight B. While calculations according to these formulas are simple, they are' time consuming if several conversions have to be made. In 1931 Water-man' constructed a nomograph for performing the conversion, but this did not permit an accuracy greater than about 1 per cent to be obtained in the neighborhood of 50 per cent. Olander2 has proposed a graphic method simpler than Waterman's and one that gives a uniform precision throughout the entire scale. The possible accuracy is about 0.5 per cent of the whole, depending on the size and accuracy of the coordinate paper used. Recently, Hermann3 has described a slide rule for making the calculations. These devices make use of the simple rearranged equation:

Jan 1, 1933

By Laurance Reid

HIGH compression ratios, resulting from high injection pressures and relatively low recovery process pressures, constitute a major problem, which has confronted those engaged in gas recycling for condensate production since the beginning of that practice. Despite the numerous process developments and improvements, no entirely satisfactory solution for this prob-lem has been presented to date. Often, where the residue gas from the recovery process must be recompressed for subsurface injection, there is a substantial difference between the required injection pressure and the plant-operating pressure required to produce maximum recovery of condensate. These limitations result in high compression ratios, which, in turn, neces-sitate excessive compressor investment and operating cost. As an alternative, the operating pressure may be increased in order to lessen the compressor requirements but such a saving often is purchased at the expense of decreased condensate recovery, caused by operation at the higher pressure. Regardless of the choice, the net result is a diminished return on the capital invested in the project. The goal of future development in this field must be the complete recovery of all valuable hydrocarbon components in the reservoir fluid at pressures that, regarded as compressor suction pressure, will require minimum compressor horsepower to inject the residue gas into the formation. A com-pression ratio of 1.5 has been established as an optimum for modern compressor equipment." Therefore, in order to con-form to this optimum condition, a 3000-lb. injection pressure would require that the condensate recovery process be operated at 2000 lb. per sq. inch.

Jan 1, 1940

By Eugene Stephenson

IN most instances the fluids produced from underground reservoirs have been described as they appear at the surface, and usually it has not been necessary to distinguish between surface and reservoir phases. More recently it has become imperative to recognize the fact that changes in phase may occur between the reservoir and the receiving unit. The simple terminology of "wet" and "dry" gases and "crude petro-leum oil" served our needs fairly well in the shallow, low-temperature and low-pressure fields. It has been left to the legislatures, regulatory com-missions, and courts to decide whether a field is or was a gas field, an oil field, or both. This they have done by direct definition and also by implication. For example, in Texas:1 (d) The term "gas well" is any well (a) which produces natural gas not associated or blended with crude petroleum oil at the time of production, or (b) which produces more than one hundred thousand (100,000) cubic feet of natural, gas to each barrel of crude petroleum oil from the same producing horizon, or (c) which produces natural gas from a formation or producing horizon productive of gas only encountered in a well bore through which crude petroleum oil is also produced through the inside of another string of casing. (e) The term "oil well" is any well which produces one (1) barrel or more of crude petroleum oil to each one hundred thousand (100,000) cubic feet of natural gas.

Jan 1, 1938

By V. H. Gottschalk

SEVERAL years ago a group in the metallurgical division of the U. S. Bureau of Mines began a study of the application of new developments in physics to metallurgical problems'. Among these developments were the extensions of what may be termed by analogy the "sound spectrum." Electromagnetic waves, from X-rays to radio waves, have been quite thoroughly explored for metallurgical use, but the sound spectrum, extending from low-frequency vibrations involved in certain types of metal failure by fatigue through the range of audible sound to inaudible vibrations having frequencies of many kilocycles, has had only meager consideration from metallurgists. Because of the general interest in the process recently demonstrated by St. Clair3 for flocculating smoke by means of sound waves, this article is written to point out possible applications of sound and supersonic (ultrasonic) waves in the metallurgical industry.

Jan 1, 1937

By J. E. Hilliard, H. E. Cook

It is shown that for systems having a miscibility gap the spinodal composition (c,) in the vicinity of the critical temperature (Tc) is related to the equilibrium composition (c,) by where cc is the critical composition. This expression is exart for the limit T — Tc and is a good approximation down to (T/Tc) - 0.9. If the miscibility gap meets the composition of the pure components THE recent theoretical treatment by cahn1,2 on spinodal decomposition of solid solutions has revived interest in methods of estimating the chemical spinodal, * i.e., the locus on a binary phase By use of the appropriate expression, the spinodal can be drawn on the Phase diagram almost by inspection with an accuracy comparable to that of lengthy calculations in which a free-energy function is fitted to the phase diagram. Satisfactory agveemenf is also obtained with spinodals comPuted from experimental free-energy curves. where G is the Gibbs free energy of the homogeneous solution and c the atomic fraction of component 2, the derivative being evaluated at constant temperature (T) and pressure (P). (These subscripts will hereafter be omitted from the partial derivatives.) If experimental measurements of G as a function of c and T are available in a single-phase region above the spinodal, then these can be extrapolated to obtain a series of metastable free-energy isotherms in the two-phase region, and from these isotherms a series of spinodal compositions can be calculated. Because the value of is very sensitive to experimental errors, an elaborate analytic procedure is required for

Jan 1, 1965

By James K. Stanley

When a plastically deformed mctal is heated to a certain temperature, it undergoes a complete change in microstructure, the consequence of which is a marked alteration of mechanical properties such as hardness, strength and ductility. This change in microstructure occurs by re-crystallization and is a process involving the formation and growth of strain-free nuclei in the deformed matrix. These nuclei continue to form with time and grow until a new grain structure replaces the cold-worked structure. The formation of the nuclei in the deformed sheet of I per cent silicon ferrite is illustrated in Fig. I. If a recrystallization is conducted iso-thermally, a nleasurement of the fraction of the matrix recrystallized plotted against time leads to an isothermal recrystallization curve, first established in 1942.1 Such recrystallization curves are shown in Fig. 4. These curves show that the recrystallization of a cold-worked metal is best considered as a rate process rather than a time independent process such as is suggcsted by the improperly named and misleading recrystallization diagrams involving deformation, temperature, and grain size.2-5 Any study of the rate of recrystallization resolves itself into a study of the component rates of nucleation and growth. The previous paper1 provided an account of the determination of the rates of nucleation; N, the number of nuclei formed per unit time per unit of unre-crystallized area, and growth, G, the radial growth in unit time, in the recrystallization of silicon ferrite (I per cent Si). A method was developed to furnish experimental data for evaluating the effect of the recrystallization variables on N and G. The mathematical analysis for the derivation of the isothermal recrystallization curve was developed for a two-dimensional case (in thin sheets where the diameter of the recrystallized grain is greater than the sheet thickness). The present paper is a continuation of the study of recrystallization of I per cent silicon ferrite begun in 1942.1 In this work the effect of the factors deformation, temperature, grain size, composition, and recovery is studied with respect to the rates of liucleation and grouth. At the same time it is shown how the cooperation of N and G affects the isothermal recrystallization curve. The study of these variables on N and G has a definite bearing on the mechanism of recrystallization and should lay a foundation for a rational theory on the subject. Procedure The procedure used in these experiments was essentially the same as that described previously but in certain details some changes were made in the interests of speed. With few exceptions, the procedure is the same for the study of all the variables. Where the procedure is different from standard manipulations attention is called to this fact.

Jan 1, 1945

By Edward L. Vickers

The Pacific rim countries, comprising more than half the globe, represent a complex mix of developed and developing nations. The area comprises a large segment of the industrialized world. Within its boundaries are also found many of the world's greatest mineral resources largely concentrated in the less developed countries. The conflicting objectives of these developed and developing nations are giving rise to changes in the traditional patterns of world resource development. Powerful political and socio-economic factors affecting the world today are having a great bearing on natural resource developments in the Pacific basin. New forms of partnerships have been emerging in developing nations which have had a great impact on the mining com- munity, lending institutions, as well as political relations. The United States and Japan have been substantially responsible in the past for the development of natural resources in this area of the world. Their role, however, is undergoing significant metamorphosis. The rapidly changing economic and social environment in the developing countries is producing new tensions which affect future collaboration between producers and users of natural resources. To understand current problems, I believe, it is worthwhile to examine historical trends in this area which may help defining alternatives facing us in the future. In modern times the United States was the first country in the Pacific basin to start development of resources on a massive scale. It began with the major exploration of the mineral-rich west of the United States and extended significantly later into Latin America and Australia. In the early 1950's, Japan became a significant

Jan 1, 1976

MINING ENGINEERING presents the annual membership report of the Society of Mining Engineers; see page 109.

Jan 7, 1963

By V. L. Elliott, C. L. Meyette

The conditioning of semifinished steel products such as billets, blooms, and slabs to remove surface defects before further processing to finished products is a necessary accompaniment to steel mill rolling operations. A knowledge of the kinds of defects which occur and of the conditions in melting, teeming, and rolling that may lead to their occurrence is favorable to the production of quality products. Surface defects may be classed as either of mechanical origin such as those that occur in the heating and rolling operations and include breaks, tears, guide marks, mechanical laps and the like, or they may have been in the ingot before heating and rolling. Examples of the latter are ingot cracks, blow-holes, scabs, and inclusions which lead to the numerous known types of seams and surface flaws. Most of the common types of surface defects and methods for their identification by visual examination or by the aid of macro-etch tests are well known. The conditions which caused their formation are also appreciably understood and this knowledge has been instrumental in the establishment of methods for metallurgical control. There are, however, defects of doubtful origin. In any endeavor to trace the causes for their occurrence, the question of first concern is: I. Whether they were formed in the rolling procedure. 2. Whether they existed in the ingot prior to rolling. In the case of semifinished products which are rerolled to finished products there is also the question of whether they were formed in the primary or in the secondary rolling. In metallurgical laboratories where numerous or routine examinations of the quality of rolled products are made over the course of time, there will doubtless be many puzzling cases of defect origin. Microscopic examination of the defects may, however, reveal a characterizing condition that can be used to classify them broadly with respect to their origin. Such a condition has been observed and, after detailed investigation, is described here with the thought that it may offer a usable and relatively simple solution to a bothersome problem. Basis For Classifying In this discussion the term "mechanical type defects" will be used to designate those that have occurred as a result of the rolling operations such as in rolling from the ingot to billets, blooms, or slabs or in rerolling to finished products. The term "steel type defects" will be used to designate those that were present in the ingot prior to primary rolling or that were in the semifinished product prior to secondary rolling to finished product. The basis for distinguishing between the two types of defects lies in the relative degree of subscale formation surrounding them. Subscale is defined1 as a zone of

Jan 1, 1949

By V. L. Elliott, C. L. Meyette

The conditioning of semifinished steel products such as billets, blooms, and slabs to remove surface defects before further processing to finished products is a necessary accompaniment to steel mill rolling operations. A knowledge of the kinds of defects which occur and of the conditions in melting, teeming, and rolling that may lead to their occurrence is favorable to the production of quality products. Surface defects may be classed as either of mechanical origin such as those that occur in the heating and rolling operations and include breaks, tears, guide marks, mechanical laps and the like, or they may have been in the ingot before heating and rolling. Examples of the latter are ingot cracks, blow-holes, scabs, and inclusions which lead to the numerous known types of seams and surface flaws. Most of the common types of surface defects and methods for their identification by visual examination or by the aid of macro-etch tests are well known. The conditions which caused their formation are also appreciably understood and this knowledge has been instrumental in the establishment of methods for metallurgical control. There are, however, defects of doubtful origin. In any endeavor to trace the causes for their occurrence, the question of first concern is: I. Whether they were formed in the rolling procedure. 2. Whether they existed in the ingot prior to rolling. In the case of semifinished products which are rerolled to finished products there is also the question of whether they were formed in the primary or in the secondary rolling. In metallurgical laboratories where numerous or routine examinations of the quality of rolled products are made over the course of time, there will doubtless be many puzzling cases of defect origin. Microscopic examination of the defects may, however, reveal a characterizing condition that can be used to classify them broadly with respect to their origin. Such a condition has been observed and, after detailed investigation, is described here with the thought that it may offer a usable and relatively simple solution to a bothersome problem. Basis For Classifying In this discussion the term "mechanical type defects" will be used to designate those that have occurred as a result of the rolling operations such as in rolling from the ingot to billets, blooms, or slabs or in rerolling to finished products. The term "steel type defects" will be used to designate those that were present in the ingot prior to primary rolling or that were in the semifinished product prior to secondary rolling to finished product. The basis for distinguishing between the two types of defects lies in the relative degree of subscale formation surrounding them. Subscale is defined1 as a zone of

Jan 1, 1949

By Arthur Green

A GROUP of 13 cities situated in Los Angeles and Orange counties in Southern California is engaged in constructing an aqueduct to carry water from the Colorado River at a point near Parker, Arizona, to a distribution point sear Riverside, California. The aqueduct will have a total length of approximately 241 miles, and is designed to deliver 1605 cu. ft. of water per second, or a little more than one billion gallons per day. The aqueduct crosses a barren, desert waste and the project includes approximately 91 miles of 16-ft. tunnel. The large amount of tunnel driving that has been done in this country in the past few years has resulted in some remarkable developments in equipment and methods. The building of the Colorado River Aqueduct, with its 91 miles of tunnels, has called on the best engineering knowledge in the country. New and better equipment has been designed for all phases of the work, and this equipment has been coordinated and adapted to the various conditions with a high degree of efficiency. The result has been that records for tunnel driving have been set under adverse natural conditions that exceed the estimates for progress under good conditions. All of the tunnels in the main aqueduct, except the Valverde and Bernasconi at the western end, have a finished diameter, inside the concrete lining, of 16 ft. Fig. 4 shows a section of the tunnel with the concrete lining in place. Fig. 5 illustrates the finished tunnel in three typical sections. The standard tunnel grade is 3.432 ft. per mile in the 16-ft. tunnels, but the Valverde and Bernasconi tunnels have a steeper grade and a finished diameter of 15 ft. 3 in. The rough bore of the large main aqueduct tunnels averages 12.95 solid cubic yards of material per foot of advance in timbered sections and 10.76 solid cubic yards per foot in unsupported sections.

Jan 1, 1936

By G. L. F. Powell

Bulk samples of silver have beat undercooled lo a large degree in contact with crystalline siliceous and ceramic oxide materials, indicating lhat stable oxides and oxide compounds are not the heterogeneous nucleants which normally catalyze cryslallization within a feu degrees of the equilibrium freezing point. Since 400-g samples were undercooled 250°C in contact with cristobalite, it is concluded that the undercooling required for homogeneous nucleation of sil11er is greater than 250°C. Undercooling was Jacilitated by precleaning the crucibles with a high-fires -sure blast of gas. IN numerous experiments on the undercooling of metal melts it has been assumed that a solid glassy surface, being non crystal line, will have no effect in catalyzing crystal nucleation from the melt. Conversely, it is usually accepted that any crystalline surface, in contact with a metal melt, will catalyze nucleation of metal crystals from the melt at degrees of undercooling less than that at which homogeneous nucleation will occur. Both these assumptions were implicit in the claim that homogeneous nucleation was observed in experiments1'2 on the undercooling of small metal droplets (10 to 100 mp diam). The droplets were thought to be freed of suspended crystalline particles which would otherwise catalyze heterogeneous nucleation. They were supported on flakes of silica glass which were assumed to be amorphous, and therefore incapable of acting as substrates for heterogeneous nucleation. In later experiments, large samples of molten metal were undercooled to temperatures similar to those achieved by the droplet technique by melting in a fused-silica crucible3 or a boro-silicate glass slag.4 Since these samples were usually fully enclosed in glass at the moment of freezing, it seemed possible that nucleation was homogeneous when maximum degrees of undercooling were achieved, despite the large size of the samples (up to 500 g). In experiments on the undercooling of silver5 the metal was contained in vitreous silica crucibles, the

Jan 1, 1968

The term metamorphism as commonly used means any change in a rock in either form or composition, from whatever cause. By metasomatism, according to Lindgren, is meant a metamorphism that involves a change in the chemical composition of a rock by the addition or subtraction of substance. Certain types of metamorphism are due to the action of mineralizing solutions, and are closely connected with ore deposition; they form, therefore, valuable guides in the exploration for ore- deposits. Other types of metamorphism are due to regional processes, and are not connected with ore deposition. By dynamo-regional metamorphism is meant a primary alteration of rocks over large areas under conditions of pressure, flowage, and heat. This process produces schists and gneisses from either sediments or igneous rocks. It is thought that there is little migration of minerals or of elements in dynamo-regional metamorphism, and that the changes are due chiefly to recrystallization and rearrangement of original minerals in bands with their major axes oriented normal to the direction of greatest pressure. Under these conditions limestones are commonly altered to marble, and sandstones to quartzite, basic igneous rocks to greenstone or serpentine, while rocks of normal or acid com- position commonly yield the usual types of schist or gneiss. Dynamo-regional metamorphism, extending over large areas, has no connection with mineralizing processes, and is, therefore, no guide to ore deposits; while this process has certain features, such as characteristic mineral associations, in common with contact metamorphism, the results of the two processes may usually be distinguished without difficulty.

Jan 1, 1932

By V. H. Wilhelm

During the first half of the year 1935, the oil industry in California was on a fairly profitable basis, owing mainly to the operation of the Petroleum Marketing Agency. Coincident with the discontinuance of enforced curtailment, California production surged upward from an average of about 500,000 bbl. per day (over the first five-month period) to approximately 625,000 bbl. per day (over the last seven-month period). On Dec. 9 the state production had reached a peak of over 700,000 bbl., a figure that had not been approximated since the early days of voluntary curtailment (Fig. 1). A price cut was instituted during the last half of August, but had no deterring effect on operators that were determined to take advantage of the breakdown of curtailment and produce to capacity. New reserve figures, compiled from actual potentials, available after cessation of curtailment, revealed the startling fact that California reserves were rapidly declining. This situation, coupled with the desire among operators to obtain a more equitable price for their dwindling reserves, caused a restoration in November of a portion of the August price slash. A further rise in price was effected in early December, and crude quotations at the end of the year closely approximated those in effect during the first right months. At the close of the year, the industry felt confident that the production situation was under control. In all fields where competition is keen because of close spacing, production is gradually declining. In the Los Angeles Basin especially there is no likelihood of a large amount of overproduction, unless a new pool is discovered or deeper drilling reveals a prolific source of crude. As long as the fields that are operated by a few companies, such as Kettleman Hills, North Belridge, Ventura Avenue, West Coyote, Dominguez, and some others, can be controlled, it is believed that the overproduction problem in California will be solved.

Jan 1, 1936

By V. H. Wilhelm

During the first half of the year 1935, the oil industry in California was on a fairly profitable basis, owing mainly to the operation of the Petroleum Marketing Agency. Coincident with the discontinuance of enforced curtailment, California production surged upward from an average of about 500,000 bbl. per day (over the first five-month period) to approximately 625,000 bbl. per day (over the last seven-month period). On Dec. 9 the state production had reached a peak of over 700,000 bbl., a figure that had not been approximated since the early days of voluntary curtailment (Fig. 1). A price cut was instituted during the last half of August, but had no deterring effect on operators that were determined to take advantage of the breakdown of curtailment and produce to capacity. New reserve figures, compiled from actual potentials, available after cessation of curtailment, revealed the startling fact that California reserves were rapidly declining. This situation, coupled with the desire among operators to obtain a more equitable price for their dwindling reserves, caused a restoration in November of a portion of the August price slash. A further rise in price was effected in early December, and crude quotations at the end of the year closely approximated those in effect during the first right months. At the close of the year, the industry felt confident that the production situation was under control. In all fields where competition is keen because of close spacing, production is gradually declining. In the Los Angeles Basin especially there is no likelihood of a large amount of overproduction, unless a new pool is discovered or deeper drilling reveals a prolific source of crude. As long as the fields that are operated by a few companies, such as Kettleman Hills, North Belridge, Ventura Avenue, West Coyote, Dominguez, and some others, can be controlled, it is believed that the overproduction problem in California will be solved.

Jan 1, 1936

By V.F. Marsters

Peru has produced petroleum since the early seventies, the first work being in the Zorritos field, in the Province of Tumbes, adjoining Ecuador. In the early nineties, the Negritos field, in the Department of Piura, came into prominence, and by 1905 had attained an annual production of 335,160 bbl. The early development of the field was under the general direction of the London & Pacific Petroleum Co., but it is now handled by the International Petroleum Co. In 1900 and 1901, the Lobitos field became the seene of marked activity. In 1905, its total production amounted to 75,000 bbl.; it has continued to increase, as has Negritos. From 1897 to 1902, there was prospecting in the region of La Brieta (or Fernandex), on the Mancora River, about 25 to 30 km. from the coast. Small production of a heavy oil was obtained from three different sands. So far as the author knows, no work has been done in that locality since 1902. There are thus four distinct fields in the north end of the Peruvian coasta1 plain. The remaining productive locality of Peru is the Pirin or Pusi field, at the northwest end of Lake Titicaca, Department of Puno, in southern Peru. The first prospecting near Pusi was done by Brown Brothers, of Los Angeles, Calif., who obtained modest production about 1906; according to reports, activities ceased about 1914 or 1915. The maximum annual production was obtained about 1908, estimated at 76,000 barrels. Peru possesses two distinct geographic provinces in which we may look for the development of a larger oil industry; namely, the coastal plain province, and the inter-Andean plains. Coastal Plain Province The coastal province is most prominently developed in the Province. of Tumbes and the Departments of Piura, and Lambayeque.l It 1 For details concerning the geology of this part of Peru, see Bol. No. 50, Cuerpo de Ingenirros de Minas "Informe preliminar sobre In Zona Petrolifera del Norte del Peru," par V. 1". Marsters.

Jan 1, 1923

By V. F. Marsters

Peru has produced petroleum since the early seventies, the first work being in the Zorritos field, in the Province of Tumbes, adjoining Ecuador. In the early nineties, the Negritos field, in the Department of Piura, came into prominence, and by 1905 had attained an annual production of 335,160 bbl. The early development of the field was under the general direction of the London & Pacific Petroleum Co., but it is now handled by the International Petroleum Co. In 1900 and 1901, the Lobitos field became the seene of marked activity. In 1905, its total production amounted to 75,000 bbl.; it has continued to increase, as has Negritos. From 1897 to 1902, there was prospecting in the region of La Brieta (or Fernandex), on the Mancora River, about 25 to 30 km. from the coast. Small production of a heavy oil was obtained from three different sands. So far as the author knows, no work has been done in that locality since 1902. There are thus four distinct fields in the north end of the Peruvian coasta1 plain. The remaining productive locality of Peru is the Pirin or Pusi field, at the northwest end of Lake Titicaca, Department of Puno, in southern Peru. The first prospecting near Pusi was done by Brown Brothers, of Los Angeles, Calif., who obtained modest production about 1906; according to reports, activities ceased about 1914 or 1915. The maximum annual production was obtained about 1908, estimated at 76,000 barrels. Peru possesses two distinct geographic provinces in which we may look for the development of a larger oil industry; namely, the coastal plain province, and the inter-Andean plains. Coastal Plain Province The coastal province is most prominently developed in the Province. of Tumbes and the Departments of Piura, and Lambayeque.l It 1 For details concerning the geology of this part of Peru, see Bol. No. 50, Cuerpo de Ingenirros de Minas "Informe preliminar sobre In Zona Petrolifera del Norte del Peru," par V. 1". Marsters.

Jan 1, 1923

By W. F. Dietrich

This paper deals with the methods of mining the high-grade clays of California. The fact that the majority of the clay pits in the state are operated on a scale that is small by comparison with most metal mines causes a diversity of methods and gives rise to problems of selection of the method best suited to given conditions. Two or three operators in California produce approximately 500 tons per day of a single kind of clay from a single pit. About five varieties of clay are mined on a scale of 200 to 400 tons per day; not over 15 varieties are mined on a scale of 50 to 200 tons per day; and more than 50 varieties are mined at the rate of less than 50 tons per day. It is the aim of this paper to delimit, as far as the data at hand permit, the conditions and scale of operations that favor the selection of each dominant method of mining that is actually being applied at California properties. Details of the occurrence and utilization of the clays of California have been given in a recent bulletin1 and will not be considered here. Geographical and Geological Features of California Clay Deposits The greater part of the high-grade clays consumed by clay-working plants in California is mined from one of three producing areas in the state: (1) Lincoln, Placer County, on the eastern edge of the Sacramento valley, 30 miles northeast of Sacramento; (2) Ione, Amador County, in the foothills of the Sierra Nevada, 38 miles northeast of Stockton, and 12 miles west of Jackson, one of the important towns of the famous Mother Lode gold-mining district; and (3) Alberhill, Riverside County, 90 miles southeast of Los Angeles. Other districts of minor importance are near Cardiff and Carlsbad, San Diego County, and El Toro and San Juan Capistrano, Orange County. In addition, there are a number of isolated properties in various parts of the state.

Jan 1, 1928

By I. Lowthian Bell

THERE has been probably no improvement introduced into the manufacture of iron which created more surprise in the minds of practical smelters and of scientific men than Neilson's discovery of the hot blast. In 1829, Messrs. Dunlop & Co. consumed at the Clyde Works, near Glasgow, nearly 7 3/4 tons of coal to make a ton of pig iron, of which about 20 cwts. was employed under the boilers of the blowing engines, leaving nearly 7 tons for the consumption of the furnace itself. In the year 1833, by heating the air to 612° F. (322° C.), they reduced the 7 3/4 tons to 3 tons by the mere burning of 8 cwts. of coal in the apparatus for raising the blast to this temperature. The statement just given is strictly true in a commercial sense, but when we come to consider the question as one of physical science, it is necessary to eliminate some of the conditions which conduced to so extraordinary a result. Anterior to Neilson's time the fuel employed in smelting iron was coke, and it was supposed at that period, erroneously, however, that coal in its raw state, when burned with cold air, was totally unfit for the purpose in question. This mineral, as it was obtained from the Lanarkshire coal-field, contained about 35 per cent. of volatile matter, but the process of charring it was performed in so unskilful a manner that instead of receiving 88 cwts. of coke from 135 cwts. of coal, 60 cwts. only was the product of the operation. Again, the reduced consumption of carbon in the furnace itself was accompanied by a corresponding diminution of blast, and this was followed by an economy of half a ton in engine coal. After making a proper allowance, however, for all these collateral circumstances, we are within the mark when we admit that in actual coke, which is really the form the fuel has to assume before it is burnt in the blast-furnace, not less than 30 cwts. was saved by heating the blast to 615° F. (322° C.). This unexpected economy, be it remembered, was obtained by the combustion of the 8 cwts. of coal, somewhat wastefully applied in the hot-air apparatus. Numerous have been the opinions advanced by different authorities in the scientific world to account for the apparent anomaly, but none,

Jan 1, 1877

By Ezequiel Ordonez

I HAVE read ill the Bulletin (May, '1914) a paper by H. von Höfer relating to the Origin of Petroleum, in which the author supports his and Engler's views, expressed before, of the organic origin of petroleum. Von Höfer pronounces strongly against the hypothesis of the volcanic origin of hydrocarbons, as particularly advocated by Eugene Coste. In Mr. Coste's articles, so well known by the public, he refers incidentally to our Mexican oil occurrences, especially of the Gulf coast, as proofs of the volcanic origin of the oils. This belief comes from the fact that, in our Mexican oil fields of the east coast, the majority of the producing wells are located near volcanic necks (remnants of small volcanoes, mainly of the explosive type), or near certain gibbosities in shales, resembling mounds, some of which' are really uplifts due to volcanic forces or to abortive eruptions. The first attempt to explain the oil coming up around volcanic necks in Mexico, was made by me in a small article1 published in 1905, soon after the investigation ordered by the Mexican government as to the outlook of the Mexican Gulf coast as a future oil producer. When E. L. Doheny of Los Angeles, Cal., and I located the first producing well of Mexico, I was also the first to predict the great future of the oil industry in Mexico, just at the time when the government and some Mexican geologists felt rather pessimistic. The Mexican investors and the general public, as a result of these discouragements, did not pay attention to this important source of common wealth until recent days. The realization of the value of this source of wealth has been so sudden that we are menaced by the consequences brought about by a great boom. It was quite impossible, about five years ago, to induce Mexican capitalists to invest money in oil lands. So the few large foreign companies operating since the beginning, easily secured large holdings, in spite of the trouble frequently resulting from faulty titles or ownership.

Jan 10, 1914