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By Kenneth Cottingham

The number of wells drilled in Ohio in 1943 was slightly in excess of the number drilled in 1942. Compared with the average annual completions for the five years preceding, the year 1943 was short 11 per cent, hut the average initial volume of gas wells was considerably improved. In 1942 the average initial open flow per gas well was 668 M cu. ft., whereas in 1943 the average was 913 M cu. ft. Although no large gas-producing areas were discovered during the year under review, some 30 small pools were found in 17 of the counties of eastern Ohio. These new pools averaged about 300 acres each, and most of them were not extensions but were separate pools adjacent to older production. The Clinton sand furnished most of these discoveries, although six were from the Berea, one was Newburg, and three were shallow sands. No discoveries were made outside former producing counties, and there was no new development the Trenton area of western Ohio. The number of oil wells decreased from 181 drilled in 1942, to 170 in the year 1943. The production of Pennsylvania-grade oil increased 7644 bbl. The total Corning production, however, decreased 91,325 bbl. The present price of Corning-grade oil, $1.31 per bbl., is too low, in the opinion of the operator, to justify exploration. Until something is done in correcting the price level of Corning grade, the production probably will continue to decline. The oil industry in Ohio is making a concentrated effort toward increased production and improved methods of recovering Pennsylvania-grade oil, and a.s this report is written a research and engineering program is being formulated for the benefit and information of the various producers of that grade in Ohio.

Jan 1, 1944

By Robert L. Zerga

Mining equipment and systems have been incorporated into the San Manuel mine to meet the requirements of ore development and extraction. A general discussion of the existing equipment as it relates to the specific methods is presented. A comparison is made between original and present equipment, and future equipment needs. The problems, successes and failures of mining equipment adaptation for the San Manuel mining system are highlighted.

Jan 1, 1981

By Howard M. Graff, Sidney C. Bouwer

The economics of mining has traditionally been viewed quite apart from the economics of blast furnace operations. It was realized, of course, that blast furnaces would operate best with good raw materials, but the shipping grade of ore, for example, was decided by a sort of collective bargaining process between the ore producers and the blast furnace operators. The mine operators had to keep their costs down, and were usually successful in convincing management that the ore in any particular deposit was endowed by nature with a certain iron content and that the mine grade could not be raised beyond a certain economic limit. The blast furnace operators would have liked a better grade, but as long as they were able to make a fairly good showing it was more or less accepted that they had to take the ore as it came. The mine operators were able to ship to the nation's blast furnaces thousands of tons of iron ore that would be completely unacceptable by present-day standards. As late as the early 1950's, the major steel companies were witnessing an actual decline in the iron content of their incoming ore supply as the mining companies mined progressively leaner material and upgraded it only enough to pass competitive market requirements

Jan 8, 1965

By Fred P. Dewey

Although coke is the acknowledged metallurgical fuel, and has been extensively used in this country for more than thirty years, yet the facts on record in regard to its physical properties are exceedingly meagre; and this is also true, but in a less degree, of its chemical composition. An investigation is being carried on in the National Museum which is intended to supply, so far as may be, this deficiency, and through the kindness of Professor Baird, Director of the Museum, I am permitted to present to the Institute a summary of a portion of the results already obtained. So far as I am aware, the credit for the first systematic investigation of the physical properties of coke belongs to Mr. John Fulton, Mining Engineer of Cambria Iron Co. The results of this investigation have been published in Report L, Second Geological Survey, Pennsylvania, 1875, and in a pamphlet setting forth the advantages of the Connellsville coke, the latter published also by the " Virginias"* His results are not altogether free from experimental errors, and the assumption that "the specific gravities of coke and water are very nearly alike "- is scarcely warranted. It has seemed to me, therefore, desirable to make an independent investigation of the physical properties of coke on a plan somewhat different from that adopted by Mr. Fulton. This is the investigation now being carried on at the National Museum.

Jan 1, 1884

By C. D. Hunter, J. B. Browning

During the year 1934, Kentucky oil and gas operators have partly overcome their past depression fears and in the oil industry, with possibly more abandonments of old oil producers than the completion of new oil wells, produced 4,814,904 bbl. of oil in 1934 against 4,501,511 bbl. in 1933. In the gas industry of eastern Kentucky, 115 gas wells were completed during 1934. This production is delivered through two 20-in., one 16-in., one 12-in., one 10-in., and two 8-in. pipe lines to supply both domestic and industrial markets in Cincinnati, Ohio; Louisville, Lexington, Frankfort, Winchester, Ashland, Covington and other Kentucky towns; Washington, D.C., and other eastern cities. The largest percentage of these gas wells and production are from the Devonian black shale area of Floyd, Pike, Knott, Martin and Magoffin counties, Kentucky. In this area the largest percentage of 1889 wells, developing 421,-215 acres, has been completed in the past 10 years, of which 55.3 per cent produce from the 400 to 550 ft. of Carbonaceous Devonian black shales. The successful results obtained from these Devonian shales are due to the physical effects of the 5000 to 6000 lb. of gelatinated nitroglycerin with which the entire 400 to 550 ft. of shale is shot. A very small number of the shale wells are natural producers and do not require shooting. Other than the Devonian shale gas production, the remaining 44.5 per cent of the gas in this field is encountered throughout the entire strati-graphic section above this horizon; namely, salt sands of Pennsylvanian age and Maxon, Big Lime and Weir of Mississippian Age. A very small percentage is encountered in the Corniferous Devonian lime and the Silurian Big 6 below the black shales. In western Kentucky, in the counties of Henderson, Webster, Hopkins, McLean, Christian, Muhlenburg, Ohio, Daviess, Hancock, Brecken-ridge, Hart, Barren and Warren, many gas wells have been completed, but, because of insufficient market, activity has been somewhat desultory. The area is served by the pipe lilies of the Kentucky Natural Gas Corporation, with headquarters at Owensboro. Their market is increasing and the gas is delivered to Owensboro, Henderson, Madisonville, and many

Jan 1, 1935

By A. T. Tye

REGARDING the results of preferential flotation at Cananea, Weinig has stated that "The concentrating mill of the Cananea Consolidated Copper Company at Cananea, Mexico, furnishes an excellent example of modern flotation practice. The complete figures are given because they present so forcibly the advantages of modern selective flotation."' L. O. Howard notes that "Perhaps the outstanding example so far published of improvements in results through the use of selective flotation is that at Cananea, Mexico." The following notes indicate the conditions under which the results were obtained at Cananea; also the effect of preferential flotation at the concentrator and at the smelter. In the majority of cases the full benefit of selective flotation is not fully realized, as the concentrates are shipped from the mill to smelters owned by other companies. The saving made at a certain concentrator by this method of flotation may be well understood but the saving resulting at the smelter from the results of preferential flotation at the mill is not so apparent, as the data are contained in the smelting records of some other company. Even at the smelter the great gains following preferential flotation may not be noted, as a variety of ores and concentrates from various sources are received and the difference from the changed concentrator operations of a certain mill may be obscured. As noted by Professor Weinig and Professor Howard, the results obtained at Cananea brought about a veritable metallurgical revolution at the smelter. There are probably plants at which a better preferential separation is being made than at Cananea. Many ores contain barren iron pyrite which, when depressed, does not carry copper into the tailing. Some concentrators use clean uncontaminated water for milling and in others the ore is ground much finer than at Cananea. All of these items are concerned in perfect separation. The details of preferential flotation at Cananea, therefore, are not presented on account of the perfection of the

Jan 1, 1928

By E. C. Robertson

Observations of faults in mines, at outcrops, and in the laboratory lead to the conclusion that the displacement d of a fault increases irregularly but monotonically with the thickness t of its associated fault gouge and breccia, not including adjacent undisplaced jointed rock. The general trend of data points has a slope d/t of about 100. (The correlation coefficient of a logarithmic regression line is r = 0.94.) The rather wide scatter of the points can be accounted for by inaccuracies in measurement of d and t, and by variation in the conditions at faulting of confining pressure, rock type, water pressure, and deformation history. Limestone is an exception to the relation. Until the data can be corrected and refined, the relation should be used only qualitatively for estimating displacement of ore bodies in mines. The suggested relation is based on observations of 48 steeply- dipping normal and reverse faults and nine small flat-dipping thrust faults, with displacement less than 5 km (3 miles). It does not apply to large strike-slip and low-angle overthrust faults because their large displacements are poorly determined and their breccia thicknesses are widely variable.

Jan 1, 1984

By Alvin Kaufrnan

This chapter will deal with the policy issues relating to mineral land disposal. The first portion of the chapter will discuss in general terms the legal systems utilized in disposing of mineral rights and the major problems encountered; the second section will comprise an analysis of the policy alternatives with emphasis on the pricing aspects. In this section, we are not attempting to provide a legal text, but simply to outline very briefly and sketchily the details of the systems. More detailed information can be obtained by contacting the appropriate governmental agency for specific information. Mining laws throughout the world are based on two major legal groupings: English Common Law and the Civil Law. These basic systems are often modified by Islamic Law and by negotiated -mixtures of these. Under English Common Law, which is embraced by the United States, Canada, and many of the members of the British Commonwealth of Nations, individuals can hold property and can extract minerals from it. The owner can dispose of minerals as he sees fit, either through contract, deed, or whatever other system is appropriate. CIVIL LAW Under Civil Law (also known as Regalian Law), mineral ownership is normally placed in the state, regardless of who owns the surface. This legal system applies in most European countries and their former colonies. It is derived from Roman law. The mineral deposits, thus, are worked under concessions. Most countries use a negotiated concession system and sometimes a combination of negotiation and competitive leasing. The negotiated system has advantages as well as disadvantages for both government and industry. In a system where the government administratively determines who is to get what, the concessions are normally large. Frequently they range up to several millions of acres and involve a considerable investment on the part of the concessionaire. There is no duplication of effort on the part of producers to obtain information, since a single concessionaire controls a given area. Consequently, less money is spent in toto because several prospective operators are not required to seek the same information. The system also has the advantage to the industry of permitting the concessionaire to select and retain the best producting area. Thus, major developmental expenditures are made on the production unit only, with a resulting reduction in the risk factor. The large initial size of the concession also minimizes the possibility of expending a large bonus payment for a barren property. The major governmental advantage of a concession is its flexibility in accomplishing other national objectives. For example, a lease could be negotiated at less than fair market value, but requiring substantial de-

Jan 1, 1976

By Jed H. Mosgrove, Paul M. Budzak

INTRODUCTION Good mine ventilation starts at the drawing board. A coal mine will either be adequately ventilated or not, depending upon how good a job was done in the planning. Poor planning will not only result in inadequate ventilation, but may also lead to low productivity. A mine foreman cannot achieve high productivity while trying to maintain 4.2 m3/s (9000 cfm) of air at his last open crosscut. PLANNING What will provide adequate ventilation? A rule of thumb in laying out a coal mine is to provide enough entries in the main entry system to keep air velocities at 2.5 m/s (500 fpm) or less; at this rate of flow, good ventilation may be expected. The intake and return air courses of a coal mine do not improve with age. Entries will deteriorate, ribs will slough, roof will fall, and clutter will accumulate. The resistance offered to air travel will continue to increase with each passing year. Providing enough airways for the present and the future cannot be emphasized too strongly. In order to better appreciate good planning and bring it into better focus, assume a hypothetical mine has the following features: entries 1.5 m (5 ft) high and 6.1 m (20 ft) wide; one intake and one return entry; the mine development is 4.8 km (3 miles) from the intake and upcast ventilation shafts; and the ventilation requirement is 141.6 m3/s (300,000 cfm). Air travel of 4.8 km (3 miles) into a mine and the same distance back to the fan is not unusual. However, to do so with one intake and one

Jan 1, 1981

By Richard W. Smith

There are three distinct varieties of phosphate rock, in Tennessee, known commercially as: (a) the "brown" rock, which is the residual product of the weathering and natural concentration of certain phosphatic Ordovician limestones; (b) the "blue" rock, which is an unaltered phosphatic stratum of Mississippian or Devonian age; and (c) the "white" rock, which is the result of chemical replacement and deposition. Before 1894, South Carolina and Florida had supplied most of the phosphate of the United States, South Carolina leading until that date and Florida from then until the present time. In December, 1893, the blue phosphate of Tennessee was discovered almost simultaneously on Swan Creek, in Lewis County, by two independent parties—by one as the result of a careful and systematic search for a workable deposit of the long known kidney phosphate, and by the other through mistaking it for a "bloom" of coal. Leases were taken and, with further prospecting disclosing other deposits in the region, the development progressed as rapidly as could be expected without railroad transportation. In January, 1896, Judge S. Q. Weatherly, who was interested in the development of the blue phosphate, while riding along the road south of Mt. Pleasant, noticed some slabs of a brown rock in place above the limestone. He took samples, and had them analyzed, thus discovering the high-grade brown phosphate of this district. This discovery was kept a secret until July, 1896, when mining was started at the village of Mt. Pleasant. Development proceeded rapidly, many owners obtaining their capital by the sale of their rock fences, which were largely composed of slabs of high-grade brown phosphate. The development of the brown rock, which is richer and more easily mined than the blue, caused Tennessee to advance from a poor third in production to second, surpassing the output of South Carolina, and being excelled only by Florida.

Jan 1, 1927

By C. W. Phillips, R. S. Busk

WITH most cast metals the grain size may vary within wide limits, depending upon the conditions at the moment of freezing. These conditions are subject to control in magnesium-base alloys, by proper melting and superheating techniques, enabling production of quite uniform and fine-grained castings, almost independent of section thickness. However, such variations of grain size as do exist, in common with all metals, are reflected in corresponding changes in mechanical properties. It is the intent of this paper to present data giving the relationship between grain size and mechanical properties. Data are also included on the combined effects of grain size and microporosity. In addition, a short discussion of factors influencing the grain size of sand castings is included. MEASUREMENT OF GRAIN SIZE By grain size is meant the statistical distribution of volumes occupied by the individual crystallites in a metal section. Since this is almost always impossible of direct measurement, several methods of estimating and expressing the size have been evolved. Most exact methods make use of the microscope. This involves study of a single plane cut at random through the metal. What is seen in the microscope are polygons, each the cross section of a grain. The diameters or areas of these polygons are then measured and the grain size is expressed as an average diameter, number of grains per unit area, average area per grain, or, rarely, average volume per grain. Rutherford, Aborn, and Bain3 have discussed extensively the errors involved when using a plane section to estimate volume. They clearly point out that the tendency is to underestimate the true grain size because of the nature of the measurement. The A.S.T.M.. recommends that measurement be made by comparison with a standard chart, by means of Jeffries' planimetric method' or Heyn's intercept method. The Society recommends that the notation be in terms of the number of grains per unit area (as is the grain-size number used for steel) or as an average diameter, expressed in inches or millimeters (as for copper and brass). The method of measurement used for this study was comparison with a standard chart, which has been described by P. F. George.', The chart was constructed by photographing at i00 diameters a uniform specimen with an average grain diameter of 0.003 in. The average diameter of this specimen was determined by numerous measurements, using both the Jeffries and Heyn methods. The other grain sizes were then obtained by appropriate enlargement of the master sample. Careful comparison of the chart method with other methods on identical samples indicates that though the differences be-

Jan 1, 1945

By Jed H. Mosgrove, Paul M. Budzak

INTRODUCTION Good mine ventilation starts at the drawing board. A coal mine will either be adequately ventilated or not, depending upon how good a job was done in the planning. Poor planning will not only result in inadequate ventilation, but may also lead to low productivity. A mine foreman cannot achieve high productivity while trying to maintain 4.2 m3/s (9000 cfm) of air at his last open crosscut. PLANNING What will provide adequate ventilation? A rule of thumb in laying out a coal mine is to provide enough entries in the main entry system to keep air velocities at 2.5 m/s (500 fpm) or less; at this rate of flow, good ventilation may be expected. The intake and return air courses of a coal mine do not improve with age. Entries will deteriorate, ribs will slough, roof will fall, and clutter will accumulate. The resistance offered to air travel will continue to increase with each passing year. Providing enough airways for the present and the future cannot be emphasized too strongly. In order to better appreciate good planning and bring it into better focus, assume a hypothetical mine has the following features: entries 1.5 m (5 ft) high and 6.1 m (20 ft) wide; one intake and one return entry; the mine development is 4.8 km (3 miles) from the intake and upcast ventilation shafts; and the ventilation requirement is 141.6 m3/s (300,000 cfm) . Air travel of 4.8 km (3 miles) into a mine and the same distance back to the fan is not unusual. However, to do so with one intake and one

Jan 1, 1981

By Calvin C. Brown, John Bigando

Pit slopes at Cananea commonly vary from 50-55°, and some have been standing for over 25 years. Their maximum vertical extent is 700 ft. Investigation of these slopes and the rocks of which they are composed has led to the decision to experiment with final pit slope angles of up to 70". Precision blasting to obtain a smooth final pit wall with minimum raveling is an integral part of this field experiment. Presplitting, one of the precision blasting techniques, requires the drilling of a single row of holes along the limit of a pre- designed excavation. The hole spacings and charge concentrations must be experimentally determined in the field, using published data as a base (Table 1). The holes are fired prior to the main round and carry no burden and therefore produce no broken rock. Thus, it is an operational cost with no direct return on investment.

Jan 9, 1972

By K. V. Lindell

THE 70-mile serpentine belt of eastern Quebec, producing 70 pct of the world's chrysotile, has 11 operating mines, two of which are underground, eight are open-pit, and one is both open-pit and underground. The combined operation, the Jeffrey mine, of the Canadian Johns-Manville Co., Ltd. is the largest producer in the group. Haulage All four of the separate operations falling under transportation at the Johns-Manville Jeffery Mine at Asbestos, P. Q., is handled by the company owned Asbestos and Danville Railway. A variety of equipment is operated over the 25 miles standard gage railway. Included in the scope of transportation are: 1-Hauling mill rock to the mill. 2-Hauling stripping and waste rock to the waste dump. 3-Hauling mill tailings to the tailings dump. 4-Hauling supplies from, and finished products to Danville. Main line tracks are permanent, but those within the pit and on the dumps have to be relocated constantly to follow the mining face and dump edges. Tracks within rock areas in the mine are laid on steel ties and can be moved by a bulldozer. Standard mechanical track shifters move tracks in dirt areas in the mine and on the dumps. Train-movements, both within the mine and over the out-lying tracks are controlled by a dispatcher located at the southwest rim of the pit. Steam locomotives haul all stripping, waste rock, and ore from the mine to the gathering yard at the northwest rim of the pit. Normally, two trains per operating shovel are used, with adjustment for optimum loading. In the event of shovel loading on the bottom level or in good stripping, service may be increased to three or four trains per shovel. From the gathering yard a 100 ton diesel-electric locomotive hauls the mill rock to the mill slips, a distance of about three miles. Electric or steam locomotives haul the waste rock and stripping to the waste dump located about two and one-half miles from the mine. Stripping cars are sprayed with a chloride solution and "gravelled" to prevent wet stripping from freezing in the cars during the cold months. Cars pass under a shaking screen which distributes an even

Jan 1, 1952

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

By F. Julius Fohs

With portions of two coal basins within its borders and a few scattered fields already developed, the question arises: What is the future of Kentucky as an oil-producing State? Is the long list of failures due to lack of commercial pools, or unintelligent prospecting? A study of its beds and irregularities of structure points not only to a large waste of development money on unpromising areas, but also to the presence of a few structures well worthy of development. The surface rocks of Kentucky show in succession more than 4,000 ft. of Paleozoic sediments and more than 2,000 ft. of Cretaceous, Tertiary, and more recent deposits. Folding and erosion have brought these beds to the surface, where they have been observed and studied in detail by my associate, James H. Gardner, myself, and others. This has given opportunity to observe the beds offering suitable reservoirs and having the proper impermeable covering; also the mapping of outcrops and outcrop lines, taken in conjunction with available well records, indicates that certain areas are worth testing, and with even greater definiteness shows areas which should be excluded, as devoid of possibilities. West of the Tennessee River, Cretaceous, Tertiary, and Quaternary sediments occur so that all trace of ancient folding is obliterated, the sediments overlapping unconformably Mississippian rocks. This area embraces 2,000 square miles, or one-twentieth of the area of the State, the Paleozoic rocks covering the remainder. Since there is nothing upon which to base the location of tests for oil and gas in the Cretaceous-Tertiary beds of Kentucky, the Paleozoic area will be chiefly considered. The distribution of Paleozoic rocks in Kentucky is centered about the north-northeast striking Cincinnati geanticline, bringing to the surface on the Jessamine dome the oldest rocks exposed in the.State, those of the Devonian, Silurian, and Ordovician systems. On either flank of this great earth-arch are the Mississippian rocks, sloping gradually beneath the coal-measure basins to the west and to the east. West of the western coal basin, and. between it and the Cretaceous-Tertiary rocks further west, is a high area of Mississippian rocks. Crossing the State

Jan 1, 1915

By Julius Pohlman

Considering the truly wonderful natural resources of the United States, and the variety and extent of uses for hydraulic cement at the present day, it seems strange that the manufacture of the artificial product called Portland cement has not been introduced here. Possibly the reason may be we have in different States of the Union rock deposits from which a cement can be obtained that is as good, and some claim even better, because of a more uniform quality, than the English product after it has been subjected to transportation across the ocean. One of these natural cement-rock deposits is found in the northern part of the city of Buffalo, and its manufacture has been carried on successfully for the past eleven years by the Buffalo Cement co., Mr. L. J. Bennett, President. The quarries cover an area of about two hundred acres, of which only twenty-five acres have been exhausted up to date; and the supply is assured for years to come. One acre yields on an average 80,000 barrels of cement; hence 12,000,000 barrels is a low estimate of what these quarries will yield before they are exhausted. According to the Geology of New York this cement-rock deposit is called the Water-Lime group, and forms in this section the uppermost member of the Upper Silurian. Its outcrop can be traced along the base of the second limestone terrace of Western New York, but at Buffalo a very large part of the overlying Corniferous limestone has been removed by natural agencies, leaving only about eight feet (six feet of rock and two feet of clay) on the top of the cement-rock, and thus furnishing the conditions for successful quarrying at a minimum expense. This rock is really an impure limestone, a mixture, as it were, of the underlying shales of the Onondaga Salt group with the overlying

Jan 1, 1889

The separate outputs of Burma and India in 1937 were 274,664,365 gal. valued at £4,474,147 and 75,657,857 gal. valued at £1,030,591, respectively. The corresponding figures for the year 1938 were 263,823,-265 gal. valued at £3,766,810 and 87,082,371 gal. valued at £1,234,563, respectively, which is a slight increase in total quantities but a fall in value for the combined outputs of Burma and India. The appreciable increase from India in 1938 is due to an increase of over 11 million gallons from Attock and a little from Digboi, while the decrease from Burma is due to a fall of nearly 9 million gallons from Yenangyaung, over 3 million gallons from Yenangyat (and Lanywa) and half a million gallons from Minbu (Table 1). The 'amount' of gasoline produced from natural gas during the year 1938 was 10,587,291 gal. in Burma and 496,163 gal. in the Punjab.

Jan 1, 1940

The separate outputs of Burma and India in 1937 were 274,664,365 gal. valued at £4,474,147 and 75,657,857 gal. valued at £1,030,591, respectively. The corresponding figures for the year 1938 were 263,823,-265 gal. valued at £3,766,810 and 87,082,371 gal. valued at £1,234,563, respectively, which is a slight increase in total quantities but a fall in value for the combined outputs of Burma and India. The appreciable increase from India in 1938 is due to an increase of over 11 million gallons from Attock and a little from Digboi, while the decrease from Burma is due to a fall of nearly 9 million gallons from Yenangyaung, over 3 million gallons from Yenangyat (and Lanywa) and half a million gallons from Minbu (Table 1). The 'amount' of gasoline produced from natural gas during the year 1938 was 10,587,291 gal. in Burma and 496,163 gal. in the Punjab.

Jan 1, 1940

By L. C. Snider

During the past few years a number of large and highly productive oil fields have been discovered in the United States. The immediate oversupply which has resulted, together with the circumstances under which the new fields have been operated, has created exaggerated impressions of the importance and magnitude of these fields. Statements as to the many years during which individual fields could supply the entire demand of certain areas, as to the overwhelming effect of these fields on the industry, and as to their greater size compared with any of the older fields have become so common as to attract little attention. For example, East Texas is commonly considered as the "greatest oil field" and a review of the development of the field for 1931 is so headed in one of the leading trade journals.' East Texas is unquestionably a very great oil field. However, some students of the field have estimated its ultimate recovery at about one billion barrels, and the Bradford field discovered in 1875 is also estimated, by competent engineers, to have about a billion barrels still recoverable by water drive, in addition to more than 300,000,-000 bbl. it has already produced. If East Texas should produce the two or three billion barrels assigned to it by more optimistic estimators, it will, though considerably greater than Bradford, still fall far short of it in importance to the industry. A reasonable doubt also exists as to whether East Texas will exceed the Midway-Sunset field which has produced about 720,000,000 bbl. and still has important reserves. Again, in importance to the industry, Midway-Sunset has been greater than East Texas can ever be. Relative Importance of Oil Fields The principal purpose of this study is to compare, on the basis of their importance to the industry, a considerable number of the major fields which have been developed in the United States. Some remarks are also made as to the estimates of reserves in certain fields now in course of development, since the writer believes that the conditions under which these fields are operated lead to estimates of recoverable reserves which

Jan 1, 1933