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National Slate Association, Drexel bldg , Philadelphia, Pa. This Association has published a book entitled "Slate Roofs " It is primarily intended for users of slate but it contains some information on the geology, analysis, quarrying and origin of slate It may be had from the office of the Association for $1 50

Jan 1, 1933

By Alan Morris

In a previous paper1 the results of cutting tests on free-cutting brass rod were reported. Investigation was made of the effects of variation in lead content, microstructure and cold drawing. The author's reply to the discussion of that paper includes a study of the directional cutting properties of drawn and annealed rod. The present paper records the results of tests made on series of samples in which the tin, iron and copper contents have been varied. The apparatus used and method of testing are described in detail in the previous paper. The machine is of the pendulum-operated milling type used and described by Airey and Oxford.2 Angular readings of the height to which the pendulum rises after falling from a fixed position, both when a cut is made and when the pendulum swings freely, give the basis for calculation of the energy consumed in making a cut. Careful weighing of the sample before and after cutting gives a measure of the amount of metal removed. The results are expressed in footpoiinds per cubic inch of metal removed, and have been called "unit cutting energy." In the course of the discussion of the author's earlier paper, W. B. Price reported large-scale tests involving some 50,000 lb. of material. These tests indicated that the addition of as much as 0.6 per cent of iron and 0.25 per cent of tin had apparently no adverse effect on the highspeed cutting characteristics of the rod. The rod also contained a small amount of nickel. The test results reported here tend to confirm his observations. Effect of Variation in Tin Content The castings for this series were made 2 by 1 by 9 in. and were processed as follows: 1. Castings were annealed at 500" C. for 7 hr. 2. Cold-rolled to 0.700 in.

Jan 1, 1933

By J. S. Vanick

An extremely hard, tough, and strong, white or chilled cast iron has been applied for the past several years to industrial and mining services in which its unusual properties have been confirmed by its ability to deliver in many instances much better performance than plain chilled iron, or other wear-resistant materials. It is being produced regularly by alloying a good base composition of chilled or white cast iron with essentially 4 to 6 per cent of nickel and 1 to 2.5 per cent of chromium. Such a material can attain a hardness exceeding 600 to 750 Brinell as against 380 to 530 for corresponding grades of plain chilled iron. The strength is approximately doubled and the toughness significantly increased. These properties make it especially useful for many applications requiring a high hardness for resistance to wear, abrasion, attrition, deformation; to some extent to high compressive loading and to a lesser but important degree to corrosive action. A wide variety of commercial castings is being successfully produced from this iron, ranging in size from the small grain-grinding plates or burrs through medium-sized castings such as sand pumps up to large, heavy castings such as rolls for metal rolling or cement grinding. The composition of this white cast iron may be roughly bracketed within the range shown in Table 1.

Jan 1, 1933

By J. S. Vanick

AN extremely hard, tough, and strong, white or chilled cast iron has been applied for the past several years to industrial and mining services in which its unusual properties have been confirmed by its ability to deliver in many instances much better performance than plain chilled iron, or other wear-resistant materials. It is being produced regularly by alloying a good base composition of chilled or white cast iron with essentially 4 to 6 per cent of nickel and 1 to 2.5 per cent of chromium. Such a material can attain a hardness exceeding 600 to 750 Brinell as against 380 to 530 for corresponding grades of plain chilled iron. The strength is approximately doubled and the toughness significantly increased. These properties make it especially useful for many applica-tions requiring a high hardness for resistance to wear, abrasion, attrition, deformation; to some extent to high compressive loading and to a lesser but important degree to corrosive action. A wide variety of commercial castings is being successfully produced from this iron, ranging in size from the small-grain grinding plates or burrs through medium-sized castings such as sand pumps up to large, heavy castings such as rolls for metal rolling or cement grinding. The composition of this white cast iron may be roughly bracketed within the range shown in Table 1.

Jan 1, 1933

OUTSTANDING symbol of the machine age, the steam shovel needs no introduction. Few individuals there are, in the United States at least, that have not watched with fascination the almost human motion, the more than human strength, the rhythm of the whole steam-shovel cycle of crowding, digging, swinging, dumping, swinging, and crowding again. A mass of steel with some copper and other metals, fed with water and coal, guided by a single alert and dexterous operator, or perhaps two, does the work that would require 50 to 500 men or even more. The largest shovels working in the copper mines have loaded into waiting railway cars as much as 10,000 tons of ore in a single 8-hour shift. With no equipment but hand shovels, it would, in fact, be impossible to duplicate the work with any number of men; first, because they would be in each other's way, and second, because the steam shovel can lift single pieces of rock weighing 5 or 10 tons with effortless ease. Of recent years, internal-combustion engines and electric motors have displaced steam as a motive power in many instances; and of course the detailed design of the shovels has been improved immensely. Whereas the largest dippers used 30 years ago had a capacity of 3 ½ to 4 cu. yd., today the 350-ton shovel used at Chino has an 8-yd. dipper, as has the 320-ton shovel at Chuquicamata. Incidentally, for stripping at coal mines a shovel having an 18-yd. dipper is in use. However, the principle of operation of the modern shovel, regardless of the size and type of motive power, is essentially the same as that of the earlier shovels. It is fair to say that the indispensable of open-cut mining is the steam shovel, or, to be more precise, if perhaps less picturesque, the power shovel. Somehow the electric shovel seems to lack the glamour that

Jan 1, 1933

By Sir John Cadman

Since my previous review of the Persian fields, presented in 1929,' considerable progress has been made. The main feature of drilling development has been the delimitation of the Haft Kel field and its extensions. Although the limits have not yet been reached, a productive area of about 40 square miles has already been proved and it is now certain that the field will be of the same order of importance as the Masjid-i-Sulaiman field. Production to main pipe line from Haft Kel was begun in November, 1929, and to date about 4,500,000 tons have been produced. Normal production has continued from the Masjid-i-Sulaiman and Naft Khaneh fields. The search for oil in horizons below the main producing limestone is perhaps the most interesting and important exploratory drilling work in progress. Promising results have been obtained in the first well deepened in the Masjid-i-Sulaiman field with this objective, and the exploration of these lower formations is being continued. In this connection an allied program of geochemical research work on the nature of the oils and oil-bearing rocks of different horizons is at, present being undertaken. Masjid-i-Sulaiman Field Since the Haft Kel field was brought into production in 1929, production from Masjid-i-Sulaiman has been reduced in order to equalize to some extent the producing lives of the two fields. The production for the last four years has been as follows: m Approximate Equivalent in TonB Barrels 1929 5,434,071 38,038,497 1930 4,925,869 34,481,083 1931 4,248,086 29,736,602 1932 Approximately 4,500,000 31,500,000

Jan 1, 1933

By Frederick Beckett

WIDESPREAD experimentation has been conducted in recent years to devise a means of preventing intergranular corrosion in austenitic chromium-nickel steels of the 18 per cent chromium-8 per cent nickel type. Additions of titanium to these steels have been used commercially to overcome this difficulty, as advocated by Krupp of Germany, and the latest literature reference concerning improved details of this method is the article by Bain, Aborn and Rutherford.1 Extensive work by the present authors has shown columbium also to be a particularly valuable agent for inhibiting intergranular corrosion. This paper does not deal with steels that are largely or wholly aus-tenitic ; it is limited to a discussion of the results obtained through the use of titanium and columbium in plain high-chromium steels. For many years titanium has been used commercially by some steelmakers as a cleanser, and to a lesser extent as a hardener, but then in greater per-centages. The results of the work to be described disclose that titanium and columbium in proper proportions act as effective softeners in the high-chromium steels. It is well known that chromium intensifies the hardening effect of carbon in steel; it imparts pronounced air-hardening properties within a rather wide range of chromium content; it provides increased ductility in steels of given strength and hardness; and it enhances resistance to corrosion and oxidation at elevated temperatures to a marked degree. However, in applications requiring a combination of some of these valu-able properties great hardness is frequently a detriment rather than a merit. When the objective is a soft and ductile steel having optimum corrosion resistance, the producer strives for a carbon content as low as commercially practicable.

Jan 1, 1933

By William Vietti

WEST TEXAS and New Mexico has been overshadowed by the develop-ment in East Texas to such an extent that the area has been placed on a settled production basis by most of the operators. Considerable develop-ment work on both proven and unproven acreage remains to be carried on, but the incentive, a ready and profitable market, has been lacking. The main characteristics of the fields in this area are so well known that they are not described again in this paper, which thus resolves itself into a statistical review of the more important production features of the area. Proration has been in effect during the year and has been rigorously applied with the full cooperation of all producers. Proration in West Texas and New Mexico is based in the more pro-ductive fields on a potential and acreage distrbution of the allowance to the individual wells or acreage units. Potentials are determined generally by a short production test of from 1 to 4 hr.; and the hourly rate is multiplied by 24 to obtain the 24-hr. production or rated potential of the separate wells. The potential values thus set up have been questioned by many production men who are not willing to concede that the instantaneous (hourly) capacity of a well to produce is its potential capacity for a day with all other wells in the pool producing at their capacity. However, the potential of a well determined as above remains its chief rating as a measure of the permeability in place and as an indication of the possible reserve feeding that well. , The acreage factor has made it unnecessary to overdevelop properties in order to obtain an allowance proportionate to neighbors who are willing to drill an excessive number of wells on a piece of acreage in the hopes of a quick drainage and a corresponding profit. Proration has resulted in an orderly development of many of the pools in this area on the base as out-lined above, resulting in more reasonable spacing of wells and the more even withdrawal of oil and the ensuing expectation of high recoveries.

Jan 1, 1933

FEW whose good fortune it has been to gaze on the Utah Copper mine but will agree that it is one of the two or three most magnificent man-made spectacles in the world. Skyscrapered Manhattan Island perhaps is more inspiring; but there the effect is obtained by aggregating a thousand separate units. The Utah mine is a single thing- the biggest thing that men have made. By the end of 1931 there had been moved at Utah 222,000,000 cu. yd. of material, including ore and the waste rock that overlay it. This figure will be increased at an average rate of nearly 20,000,000 yd. per year. Excavations for the Panama Canal are estimated at 232,300,000 cu. yd., but the Canal is 50 miles long, and it is impossible to obtain a comprehensive view of the whole project at one time. The spectator, on the other hand, need only walk part way up the east slope of Bingham Canyon to see unfolded before him the whole panorama of the great copper mine. In the foreground is a huge pit bottomed for the time being 100 ft. below the normal floor of the canyon, which also is the elevation of the main railroad yard. Here from 500 to 800 standard steel railway cars, each of 80-ton capacity, are assembled daily to carry the ore to the concentrators. But the main part of the mine and that from which ore is now coming lies above this level. As can be seen in the accompanying photograph, a series of terraces or benches reaches to the top of the mountain that projects between the main branch of Bingham Canyon and Carr Fork. From bench A (the yard level) to bench W is a vertical distance of 1500 ft. In height the benches vary from 40 to 70 ft. and in width from 30 to 450 ft. The lower benches, as they skirt the mountain,

Jan 1, 1933

By L. C. Graton

INTRODUCTION CLEAR recognition by Lindgren1 of the important control exerted by physical conditions on the formation of ores laid the foundation for that long-sought attainment, a classification? of mineral deposits based consistently on origin. In probably no other portion of the realm of mineral deposition has the importance of physical influences been so manifest or the validity of Lindgren's genetic classification been so well proved as in that extremely important family of ore deposits which are now universally classed as hydrothermal and generally regarded as of magmatic derivation. While many varieties of deposits, some of them possessing great scientific interest and economic importance, fall outside the limits of this hydrothermal group, inclusion within it of most of the veins and a vast number of the replacement deposits of the world gives to this grand genetic class at once a dominating importance and a powerful scientific appeal. Nowhere are these vein and replacement deposits of hydro- thermal lineage more generously distributed, more extensively exploited or more thoroughly known than in the Cordilleran province of the United States. One of the respects in which these hydrothermal deposits command the interest of both geologists and mine operators is in their relation to depth: the great vertical range through which many of them have already been developed, the disappointing failure of others at relatively shallow levels, and the noteworthy downward changes in character and tenor exhibited by still others. In this hydrothermal category (if the Rand be granted place here) are included the ores of all the very deep mines of the world, ranging from 5,000 to nearly 8,000 ft., as well as of many other mines undoubtedly destined in time to attain corresponding depths.

Jan 1, 1933

By H. J. Struth

Conditions in the gasoline market undoubtedly influence the oil industry's general economic situation to a greater degree than perhaps any other single factor. No matter how efficiently the oil industry manages to conduct its producing operations, a drop in the price of gasoline exerts definite pressure upon the posted price of crude oil in the field. Efforts of the recent past have shown that profits from the producing division of the industry are closely tied in with the course of the gasoline market. When refinery gasoline prices are depressed, as they have been during recent months, it is utterly impossible for purchasers to maintain a crude market that is commensurate with the cost of production, regardless of how well balanced the producing situation may be. In fact, the producer can no longer regard his operations in the light of an independent unit of the oil industry, since his financial well-being is directly dependent upon the well-being of the refiner. Because gasoline is the principal constituent of crude oil, it is obvious that profitable refining operations can only be maintained through profitable gasoline markets. Likewise, when the price of gasoline influences a profit for the refinery it also influences the prosperity of the producer, through the advent of higher and more profitable posted prices for crude oil in the field. Financial results for 1932 showed material improvement over the preceding year, primarily because the price of gasoline was maintained at levels somewhat above those of 1931. Consequently, the producer was able to record improvement in the crude market, through a somewhat higher level of posted prices. While effective methods of prora-t,ion of crude production are given credit for the advance recorded in the crude market last year, it is also a fact that the advent of higher prices for gasoline had a direct influence upon the posted prices of crude oil. For example, when gasoline was sold in Group 3 at 2 3/4 a gallon in June and July, 1931, the price of 36-gravity Mid-Continent crude was down to its lowest point of only 18c a barrel. As refinery prices advanced, however, there was a corresponding advance in posted prices of crude oil. Thus, when Group 3 gasoline commanded a price of 5c a gallon

Jan 1, 1933

By W. Spencer Hutchinson

THE outstanding engineering accomplishment of the last three decades has been the development and application of more and cheaper power and its use instead of the labor of men and animals. Substitution of power for manual labor has taken effect on every hand in the United States. With the aid of energy mechanically available to his hand, one man does the work that only a few years ago required two, three or even a greater number of laborers. The results in respect to the favorable economic effects are well known; namely, increased production, higher wages and lower costs. On the other hand, the vast social effects, both good and bad, have been none the less important, even if less understood and only casually regarded. The chief sources of energy today are the mineral fuels, coal and petroleum. In the United States they yield more than 90 per cent of the total energy demand. Thirty years ago the proportion of energy supplied by the mineral fuels was likewise above 90 per cent, but the division according to origin was very different. These relations. are shown for the years 1900, 1930 and 1950 in Table 1.

Jan 1, 1933

By Charles W. Henderson

THE influence of mineral production on the development of the western United States has been profound. From 1848 to 1860, there was only gold production, the effect of silver began in 1860, and from then on both had a powerful influence. Lead production started in 1863, copper in 1863, and zinc in 1885, but was small until 1898. Gold alone was therefore the stimulus of the early settlement and exploration of the Western States.. But mineral deposits caused neither acquisition of territory nor determination of boundary lines. Arizona, California, Nevada, New Mexico, and parts of Utah, Wyoming, and Colorado were formally acquired from Mexico fourteen days after the actual date of the discovery (January 19, 1848)1.2 of gold at Sutters Mill, near the present town of Coloma, California (a discovery which, with the immediate new discoveries, aroused the world several months later) ; but the acquisition was by treaty (under negotiation for some time but signed February 2, 1848)3 in settlement of a war involving the boundaries of the grassy plains of Texas, an area at that time not known to contain any metals, and to date found to have but few metal deposits.4 The international boundary at 49º latitude for the far northwest states was determined by causes other than mineral deposits.

Jan 1, 1933

By E. A. Stephenson

In spite of tremendous handicaps notable advances in production engineering have been achieved during 1932. The technique of deep well drilling has continued to progress, notably in California and at Big Lake, Texas. In the latter field a method has been devised by which two grades of oil in contact with each other are produced without intermingling. In rig design many improvements have been made whose objective is to facilitate deep drilling with reduced power losses and increased life of the equipment. Flush joint casing and drill pipe have been improved further, careful tests indicating that the drilling time can be reduced by from 5 to 20 per cent where flush-joint pipe is used. Slow-speed pumping has come into wider use, with further increases in over-all efficiencies. A number of improved well pumps also have been developed and are being tested. One of the most important of these is a positive displacement pump of the rotary type, directly connected to an electric motor placed in the bottom of the hole, and adaptable to various sizes of tubing and casing. In some localities the trend is towards the replacement of electric motors and large-cylinder engines by multiple-cylinder gas engines. Experiments have been conducted and critical analyses made of flow conditions in wells equipped with various styles of tubing which give promise that tubing may be designed to fit individual well conditions. In those wells producing at less than maximum capacity, the gas-oil ratio has been shown to depend on the rate rather than on the method of production, or the design of equipment. Important factors in the design of screened pipe have been carefully analyzed and made the basis of a method for determining the required mesh. Remarkable progress has been made in the use of subsurface pressure data. In East Texas particularly, use of such data is providing a means for the control and equalization of water encroachment and is also pointing the way to a sound means of allocating to individual tracts an

Jan 1, 1933

Jan 1, 1933

Virginia Polytechnic Institute, Department of Mining Engineering, Blacksburg, Va Otto C Burkhart, Professor of Mining. The titles of pertinent publications have been abstracted from the Bulletins on Research and Publication This material has also appeared, in most cases, under other auspices Presumably, the Bulletins whose titles are quoted may be had for the cost of postage The coals of Virginia (1927), Ceramic resources of Virginia and their development (1929), Effect of ilhum crucibles on volatile determinations of coal (1930), Possibility of briquetting southwest Virginia coals (1930), Coking of semi-anthracite coal of Virginia (in preparation), Distribution of ash in the Merrimac coal seam (1929); Unit coal studies on some Virginia coals (1931), Sulphur forms in Virginia coals (1931); Comparison of results of fusion point of coal ash obtained by two different methods

Jan 1, 1933

By William Rawles

THIS report is the first of a series planned by The Mineral Inquiry, organized by the American Institute of Mining and Metallurgical Engineers to make factual studies of the world's mineral resources in their political and international relations. The efforts of The Inquiry are directed toward filling certain notable gaps in available information, without duplication of many other investigations touching this field which are being conducted by other organizations, public and private. Much of its work is indirect-suggesting topics for study by other individuals and organizations and aiding in their planning and correlation. The present report is designed to show the nationality of the commercial control of mineral resources, in addition to the geographic distribution of production by nation-in other words, the overlapping of political and commercial control. Detailed accuracy cannot be claimed for the figures presented. For some companies division of ownership by nationality has been very difficult to ascertain, as many companies are reluctant to dis-close the extent of their holdings in other corporations, and the impossi-bility of tracing all stock ownership is obvious. Also there are frequent changes in the distribution of stock control. The percentages given rep¬resent only the participation that has been identified definitely, even though it is known in some cases with fair certainty that larger interests exist, as, for instance, American participation in foreign chromite companies. In bringing together these figures we have had the cordial co-operation of the United States Bureau of Mines, the United States Geological Survey, the Mineral Division of the Bureau of Foreign and Domestic Commerce, the Brookings Institution, and of many specialists connected with the mineral industries covered. The report does not cover the entire list of minerals. Coal, although it is, one of the most important minerals, was omitted because not more than one or two per cent of the world's production comes from mines that are owned by companies foreign to the countries where the coal is produced. Others, such as gold, are omitted because sufficient data have not yet been accumulated. It is hoped that some of these may be covered in subsequent reports. It is not our purpose here to discuss the significance of the figures sub-mitted, but only to point out the general nature of the problems on which they have a bearing.

Jan 1, 1933

By T. C. Desollar

THE group of iron-ore mines known as the Red Ore Mines, owned and operated by the Woodward Iron Co., is on Red Mountain approximately ten miles southwest of Birmingham, Ala. At the, present time No. 1 and No. 3 mines are active, No. 2 mines having been abandoned in 1928. Ore from this group of mines was first mined in 1882, and originally came from open cuts along the outcrop, but, when the "soft ore" (weathered hematite) was mined out and the harder ore was encountered, it became necessary to develop the orebody by means of slopes driven in the ore formation. The three mines to date have produced more than 22,000,000 tons, and the two operating mines now have a capacity of over 1,000,000 tons per year.

Jan 1, 1933

By O. B. Hopkins

DuRing 1931 Peru lost its place as ninth among the oil-producing countries of the world, to Argentina, and even in tenth place its production only slightly exceeded that of Trinidad. The preliminary figures for 1932 indicate that Peru will lose tenth place for that year to Trinidad. The production in barrels of the three coastal fields of Peru during the past three years was as follows: In addition to this crude production, the International and Lobitos companies produced approximately 770,000 bbl. of casinghead gasoline during 1932. There was no outstanding development in the oil industry in Peru during 1932; activity in the fields was very much restricted due to curtailment of production and the low price of oil. The potential production of the property of the International Petroleum Co. Ltd. greatly exceeded the actual production. By the beginning of 1932, a total of 2348 productive wells had been drilled on the property of the International, of which 547 had been abandoned, leaving 1801 productive wells at that' date. These wells cover a total productive area of approximately 13,500 acres. The crude produced has an average gravity of 37° to 38° Be. The Lobitos crude is of approximately the same gravity. The earliest oil pool developed in the Peruvian Coastal area is now more than 40 years old and is still producing. The major development in the area took place between 1920 and 1930. Production at the present rate can be maintained for 10 years or more.

Jan 1, 1933

OBSERVERS in more than negligible number appear to believe that the achievements of engineers during the last generation have been an affliction rather than a blessing to society. Quite accurately they perceive that scientific progress and technologic advance have reduced to a fraction-often a small fraction-the amount of manual effort required to accomplish a given unit of useful work. They have seen men, as a consequence, deprived of employment in a particular industry; and this so-called technological unemployment they have denounced as inimical to the workers and consequently to the whole social order in progressive nations. To those who subscribe to this thesis the story of the Porphyry Coppers may not make palatable reading, for it is an amazing record of engineering and technologic achievement. But to those others who take the longer and broader view that economic and social progress cannot enduringly lag far behind advance in the realm of science and engineering; and that any improvement in the means and method of doing essential things eventually must make the world a better place in which to live; to these the record of the development of these great mines can- not but be a source of delight. It is an outstanding example of the advantages of mass production coupled with the fruits of scientific research and inventive genius. More, it reflects the pioneer spirit, the initiative, the self-reliance, the independence of thought and action that are traditional with the mining engineer. The word porphyry is a geologic term, the significance of which will be elaborated in later chapters. The essential characteristics of the deposits that are universally, if not quite

Jan 1, 1933