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By Felix G. Berra, David H. Orr

The first large scale application of radio remote control equipment to standard gage railroad trains has been achieved at the Morenci mine of Phelps Dodge Corp. at Morenci, Ariz. Twenty or more ore and waste haulage trains are remote control operated at any one time, each with a one-man crew. Reduction of train crews from two men to one man has materially lowered the total cost of train operation. Elimination of brakemen has also resulted in an improvement in train efficiency brought about by a shortening of train haulage cycle times.

Jan 4, 1965

By W. E. Rice

The ceramic industry has to do with forming or molding articles of clay, and imparting to them their characteristic properties of permanence, strength and color by subjecting them to heat treatment in kilns. This heat treatment is commonly known as "firing" or "burning." The art of firing clay ware antedates the industrial use of coal; hence wood was the fuel first used, and the earliest kilns were built to burn wood. The majority of the clay ware produced today is fired in periodic kilns that are essentially enlarged structures similar to the earliest enclosed kilns; a kiln consists of a large chamber 16 to 32 ft. dia. (or rectangular) in which the ware is charged and fired either in direct contact with flame or hot gases from the fuel, or in saggers which shield the ware from direct contact with the gases. The fuel is burned in a number of small furnaces built in the thick wall that encloses the chamber; these furnaces are from 16 to 36 in. wide and from 3 to 5 ft. long; some of them have horizontal or sloping grates, but many have no grates; the last are called "dead-bottom" furnaces. The temperature necessary to mature the charge in the kiln varies for different clays; for some it is as low as 1800°, and for others as high as 2700" F. Wood was an ideal fuel for the low temperatures that were used in early kilns; it burns freely and produces a long, clean flame, which promotes uniform distribution of the heat in the kiln; it does not coke and so restrict the passage of air through the fuel bed; the ash does not melt in the fuel bed to form clinker; and the ash that is carried into the chamber and deposited on the charge does not contain iron and sulfur to discolor the clay. The extent of the ceramic industry now precludes the general use of wood in kilns, so that today this industry is one of the large users of bituminous coal, burning more than eight million tons annually in kilns. Manufacturing plants usually are at or near the source of clay, with deposits of coal suitable for kilns occurring near the clay. The cost of coal is the largest single item of expense in the manufacture of clay ware, and, because all coals are not equally suitable for the process, the careful selection of coal is important. In this selection the desidera-

Jan 1, 1932

By David R. Mitchell, R. M. Fleming

MANY trends were evident in the coal industry during 1951. Some were favorable for the industry; others were not. Probably those having the most far-reaching consequences are those affecting coal's markets. The rapid dieselization of many railroads and the continued trend toward oil and natural gas for home heating has caused serious dislocations in various mining districts. Mines have been forced to close down or to work on a reduced time basis. Conversely the increased activity in the metallurgical industries has increased the demand for coking and special purpose coals, and the growing production of electric energy has increased the demand in certain areas for steam coals. The increased demand for metallurgical coal and for steam raising by the large utilities is more than equal tonnage-wise to the loss of coal to railroad dieselization and conversions to oil and gas in the domestic market. Since much of the expansion is at captive mines of large corporations, many commercial operators supplying railroad and domestic users have had their markets curtailed without any compensating demand from other sources. Feverish activity was in evidence in many areas by commercial operators attempting to find new markets. The Norfolk and Western Railway is the, only major American railroad committed to the burning of coal. It has an exceptionally good cost record. During 1951, fifteen additional modern coal-burning steam switching locomotives were authorized for construction in the company's Roanoke shops at a cost of about $1,450,000. When the new order is completed the road will own a total of sixty locomotives of the modern-switcher type, including thirty acquired by purchase last year. The Norfolk and Western today is the only American railroad building its own motive power. All of these locomotives burn coal. Production Coal production in the year 1951 will approximate 570 million tons of anthracite, bituminous coal, and lignite. Of this, approximately 7 pet is anthracite. Total production is approximately 30 million tons more than in 1950 and reflects the increase in general industrial activity. Exports are expected to be close to 50 million tons. The industrial stockpile is close to 75 million tons, the highest it has been since 1943. With the exception of the usual local stoppages the year 1951 was unmarked by labor disputes. It was a year of good labor-management relations with a negotiated wage increase unmarred by a work stoppage. This may be the beginning. of an era of sensible negotiations to find agreeable settlements of disputes without the usual protracted bickering and industry-wide strike. The United Mine Workers of America has condemned wildcat strikes, stating that in nearly every, instance proper grievance procedures have not been instituted. Government defense organizations, perhaps profiting by their experiences during World War II, are pursuing a more enlightened program with regard to the fuel requirements of the nation. Many prominent officials have stated that wherever possible coal should be considered the primary source of fuel in all defense expansion. With the increased consumption of steel by defense projects, approval of transportation facilities for liquid and gaseous fuels have been refused where these fuels would enter a coal producing area. Liquid and gaseous fuel producers also have failed to provide satisfactory evidence that they have sufficient reserves and are capable of supplying their product in adequate amounts for the periods of time required. Realization has at last become prevalent that the hydro-electric power installations in several areas are insufficient to handle increased demands.' Steam generating plants are being constructed in these areas and equipped to burn coal. Most notable of these, is the TWA area whose supplemental steam power plants are expected to consume 10 million tons of coal per year when completed. The Pacific Northwest is another area which is expected to follow the same pattern. Nearly all new steam-power generating plants are being equipped to burn coal either as a primary fuel or as an emergency measure. Metallurgical Coal The steel and other metallurgical industries are expanding rapidly to meet increased industrial demands and defense orders. Since these industries are dependent on coke, coke has had a year of high production and can be expected to break all existing records when steel-plant expansions are completed. Most notable of the expansion projects is that of the Delaware River area where the iron ore will be received by ship from Canada and South America. U. S. Steel is only one of several steel corporations that are planning on putting integrated steel producing units in this area. The Defense Solids Fuels Administration announced in December that through. November 30, 1951. 29 projects in eight states, with a total cost of

Jan 1, 1952

By H. H. West

Modern mining is vitally concerned with the prompt, efficient movement of great quantities of bulk materials. It is not surprising, therefore, that intensive efforts are being directed toward improving effectiveness and reducing costs of materials handling systems. Historically, the operation of removing bulk material from a moving conveyor and depositing it in utilization or storage areas has been a high cost segment of the materials handling system. Since this operation is often performed by belt trippers, considerable attention has been focused on improvement of these devices. Frequently, the greatest opportunity for improving performance of these devices is the incorporation of remote or automatic control systems. This article describes tripper control systems developed by Kennecott Copper Corp. and explains the control philosophies used in designing these systems.

Jan 3, 1963

By Luis Elek

DEVELOPMENT of the cement industry in Mexico began some 40 years ago. It has gradually reached great importance in the economic life of the country and has contributed greatly to the technical and economical advances which have been so noteworthy, particularly during the last 15 years. From a modest start, the industry now comprises 18 cement-producing plants having a potential annual capacity of approximately 14 million bbl. About half the plants were built and equipped with second-hand machinery during the last world war when no new machinery could be procured. They will hardly attain full production before being modernized and reconditioned, a job now under way in several of the plants. At present, the yearly consumption is only about 8 to 9 million bbl but is steadily increasing. This is only a fraction of the cement consumed in the U.S.A., which is about 250 million bbl per year, although on the basis of consumption per capita per year, the figure is 1/3 bbl for Mexico and 1 2/3 bbl for the U.S.A. Cement consumption in Mexico is well above the average of all other Latin American countries, with the exception of the Argentine, and considering the potentialities and undeveloped riches of Mexico, the road construction and irrigation works, it is fair to assume that the Mexican cement industry will still prosper and expand in spite of temporary setbacks in the future caused by-local events of economic or political nature. Portland cement is manufactured by burning a mixture of raw materials, one of which is mainly composed of calcium carbonates and the other of aluminum silicates. The most typical materials answering this description are limestone and clay, both of which occur in Mexico in many varieties. To be usable for cement manufacture limestone should contain at least 77 to 80 pct calcium carbonate. Lower grade limestone can be used for cement manufacture only if the lime content is increased by the beneficiation process, which has not yet been adopted by the Mexican cement industry. Most of the limestone used by Mexican cement plants has a calcium carbonate content of 90 to 95 pct and therefore requires addition of one or several correction materials. A typical composition of raw mix for cement manufacture is 85 pct limestone and 15 pct shale, clay or volcanic materials. Occasionally it is necessary to add a smaller amount of sand or other siliceous material to increase the silica ratio in the raw mix. Likewise, it is sometimes necessary to add 1 or 2 pct iron ore to facilitate fusion in the kiln and to obtain proper relation between alumina and iron oxide. After calcining and

Jan 1, 1952

By J. W. Downey, A. E. Dwight, R. A. Conner

In a previous paper' we have reported the existence of a number of AB2 Laves phases in which A is a member of the scandium group (including the 1an-

Jan 1, 1967

SAN FRANCISCO SECTION W. H. SHOCKLEY, Chairman, PRANK H. PROBERT, Vice-Chairman, T. A. RICHARD, Sec.-Treas., 420 Market St., San Francisco, Cal. C. C. BRAYTON, J. F. NEWSOM. The San Francisco Section met on September 11 to discuss the problem of Labor in its Relation to the Mining Engineer. Mr. W. H. Shockley was in the chair. T. A. Rickard opened the discussion under four heads: The recognition of the union, the rustling-card, the sliding scale of wages, and the' contract system. He expressed his belief that collective bargaining cannot be ignored, and insisted that the mining company represented a collective bargaining of its shareholders with the men. employed in its mine. He held that the contract system was often used unfairly, but that used fairly it was the best check on labor tyranny. The rustling-card he held to be right in principle, in so far as it gave the employer the choice of employees, but he believed that it was often used in an irritating way to black-list refractory laborers. The sliding scale of wages was easy to establish in prosperous times, but it would inevitably lead to trouble when conditions went against the miner. His conclusion was that the quarrels of labor and capital were due mainly to a lack of the sense of fair play and of social justice. Albert Burch agreed with most of the foregoing, and insisted that 90 per cent. of the men were inclined to be just, but that the 10 per cent: made all the trouble. He stated that he had introduced the rustling-card in the Coeur d'Alene in 1899, as a means for getting rid of agitators. E. L. Foucar considered that labor was irresponsible. He described his experience in Peru, where the authorities promptly stopped a strike of Italian miners by threatening prompt punishment for any display of violence. Morton Webber also gave a bit of his own experience, to show that the chief trouble is that the men do not think for themselves, and are therefore easily led by fomenters of trouble. F. H. Probert described his experiences in Germany and. also in Arizona, and insisted that too often the men were not given a fair hearing. E. T. Blake argued that a manager must get the workmen's point of view, in order to control them effectively. He believed that young men who started life doing manual labor were in a better position to understand their fellow workers. George J. Young suggested that the mine owners should encourage the good men to lead the unions, and not leave the direction of the unions to the noisy element.

Jan 12, 1917

By N. A. Ziegler

THE present publication is a continuation of the work on gas analysis, described in a paper presented before the Institute of Metals Division a year ago.1 While that paper was largely descriptive in character, dealing with the various parts of the apparatus and method of operations, the present one gives numerical data obtained as a result of a series of experiments with iron-carbon alloys. The apparatus and the methods applied are essentially the same as previously described, changes being only in minor details. Attention should be called to the fact that in the present work we are dealing with the gaseous mixtures obtained as a result of vacuum melting of various ferrous alloys. It should be understood that when the terms "degasified sample" and "products of degasification" are used, they refer to the sample remaining after the vacuum fusion of the alloy and the gaseous products removed therefrom, respectively. The writer does not wish to create the impression that the metallic products of this process are absolutely free from any gaseous elements, nor that the gases obtained are present as such in the original sample. These two points are not yet definitely known and are subjects for future investigation. The point, however, which has been established beyond doubt, is that all the gases dealt with come from the metallic charge and are present either in the charge as such, or are produced as a result of chemical reactions going on within the charge. The suggestion that the gases are due to the reactions between the metallic charge and the refractory materials has no valid basis.

Jan 1, 1929

By M. M. Fidlar, Ralph E. Esarey

A marked decrease in drilling during 1937 in Indiana seemed to have no undesirable effect upon the oil and gas industry. Instead, production figures for oil showed a small increase over those for the preceding year, although not so much gas was marketed as in 1936. Drilling activity was centered in proven areas, and the proportion of dry holes to the number of wells drilled decreased somewhat. During 1937, including old wells drilled to deeper horizons, 134 wells were completed in Indiana, of which 39 were oil wells, 39 gas wells, and 56 dry holes. Nearly 75 per cent of the holes were drilled in proven areas. Of the 36 wells drilled in wildcat areas, only four found commercial production. Wildcat wells were especially numerous in Vigo, Pike, Perry and Spencer Counties. Exploratory drilling activity in Vigo County resulted in part from the drilling of the discovery well in the new Prairie Creek field. In Pike County, wildcat wells were drilled in the search for new supplies of gas to meet the demand in the southwestern portion of Indiana. Drilling in both proven and wildcat areas in Perry and Spencer Counties continued to be heavy, because of the presence of shallow Missis-sippian sands and the resulting low cost of drilling and equipping. At the end of the year, 42 of the wells started in 1937 were not completed. Only a few locations were drilled in the old Trenton field, but the wells, many of them 40 years old, continued to furnish a small supply of gas for domestic consumption. Oil production in the Jay County portion of the Trenton area was nearly twice that of 1936, owing in part to a vacuum system installed on several leases. The Harrison County (Laconia) gas field is being developed northward to offset water encroaching from the south. This water in the black shale threatens to put an end to the steady production that this field has furnished for many years. During 1937, the Oaktown gas field again furnished more gas than any other field, but production in that area showed a marked decrease over the marketed gas for 1936. During the early months of the year, seven wells were completed in the Oaktown field to bring the total number of producing wells to over 40. At present, all the operators in the area are

Jan 1, 1938

By T. A. O’Hara

SINCE May 1948, when tungsten carbide bits were introduced at the Flin Flon mine, they have been popular with the miners because of their fast drilling speed and low gage loss. The high cost of commercial carbide bits and tipped drill steel, however, prevented their use except for the hardest rock. In an effort to extend the use of tungsten carbide on a basis economically competitive with detachable steel bits, experimental work was begun in 1950 to test the feasibility of making tungsten carbide tipped drill steel in the mine drill steel shop. This work showed that tipped drill steel could be made locally at less than half the cost of the commercial product. The performance of the local tipped drill steel was comparable to that obtained with commercial carbide bits and tipped drill steel and the cost per foot drilled was much lower.

Jan 3, 1954

By R. D. Hagni

The following is a case study illustrating the use of thin sections and polished sections of crude ore to predict metallurgical response. By examining polished sections of the metallurgical products, the textural and mineralogical reasons for unsatisfactory separation can be explained. An area of oxidized Negaunee Iron-Formation located south of Negaunee, Michigan, in the Marquette Iron Range, has been considered for roast reduction-magnetic separation. Preliminary metallurgical studies and subsequent pilot plant testing produced varied results. These results prompted this microscopic study which began with an examination of 126 thin sections and 82 polished sections prepared from 126

Jan 1, 1967

By Renato G. Bautista, KNona C. Liddell

A model of the reaction of chalcopyrite, CuFeS2, with Fe3+ and with 02 is considered. Homogeneous solution phase reactions are assumed to be always at equilibrium throughout the dissolution of the mineral. The dissociation of USOb- and several complexation reactions involving cu2+, Fez+ and Fe3+ are incorporated in the model equations. The relative importance of Fe3+, 02, and H+ as oxidants and the role of solution equilibria are assessed and the implications for leaching practice discussed.

Jan 1, 1981

By Cyril Stanley Smith

The method of thermal analysis, so important in the development of metallographie science, has of recent years been falling into disuse owing to the development of other physical methods which give result's easier of interpretation and which can be used for the study of either equilibrium or transitional conditions because they do not require a continuously changing temperature. Nevertheless thermal analysis remains useful in the study of reactions that take place rapidly, and the simplicity of the experimental technique and the general availability of the apparatus involved are point's in its favor. Theoretically, thermal analysis is capable of giving specific and latent hat measurements and therefore should permit the study of reactions on a more fundamental basis than any other method. It is, however,difficult or impossible to obtain quantitative heat measurements from cooling curves obtained in the usual way. Even if the furnace containing the sample is cooled or heated at a linear rate, or if a gradient furnaec is employed to maintain a constant rate over a large range of temperature, the heat flow from or to the specimen depends on its previous history, for the difference of temperature between the specimen and its surroundings varies. The emissivity of the specimen surface, moreover, is unlikely to be constant. The able mathematical analysis by Russrll,1 although it prevent,s misinterpretat,ion of data, has an effect rather the reverse of that intended, and leaves the reader doubtful of the possibility of ever obtaining quantitative results from thermal curves. Nothing can be done to apply thermal analysis t'o the study of equilibrium conditions of reactions that arc not completed at rates of temperature change above about 1° C;. per minute, and this unfortunatetly excludes most solid transformations in alloys.† For the determination of liquidus

Jan 1, 1940

By Cyril Stanley Smith

The method of thermal analysis, so important in the development of metallographie science, has of recent years been falling into disuse owing to the development of other physical methods which give result's easier of interpretation and which can be used for the study of either equilibrium or transitional conditions because they do not require a continuously changing temperature. Nevertheless thermal analysis remains useful in the study of reactions that take place rapidly, and the simplicity of the experimental technique and the general availability of the apparatus involved are point's in its favor. Theoretically, thermal analysis is capable of giving specific and latent hat measurements and therefore should permit the study of reactions on a more fundamental basis than any other method. It is, however,difficult or impossible to obtain quantitative heat measurements from cooling curves obtained in the usual way. Even if the furnace containing the sample is cooled or heated at a linear rate, or if a gradient furnaec is employed to maintain a constant rate over a large range of temperature, the heat flow from or to the specimen depends on its previous history, for the difference of temperature between the specimen and its surroundings varies. The emissivity of the specimen surface, moreover, is unlikely to be constant. The able mathematical analysis by Russrll,1 although it prevent,s misinterpretat,ion of data, has an effect rather the reverse of that intended, and leaves the reader doubtful of the possibility of ever obtaining quantitative results from thermal curves. Nothing can be done to apply thermal analysis t'o the study of equilibrium conditions of reactions that arc not completed at rates of temperature change above about 1° C;. per minute, and this unfortunatetly excludes most solid transformations in alloys.† For the determination of liquidus

Jan 1, 1940

By Lucien Eaton

THE accuracy with which detachable bits can be sharpened and gauged by grinding has made possible refinements in design that cannot be attained by forging. This applies particularly to gauging, where accuracy is of the greatest importance. Gauge changes of 1/32 in., and even 1/64 in., are now feasible, whereas 1/16 -in. changes are about the limit in accuracy for forged bits. These small changes in gauge are feasible, however, only with certain fundamental principles of design. Within reasonable limits the depth to which a hole can be drilled is dependent primarily upon the loss in gauge, or diameter, of the bit. In drilling there is always a certain amount of "overdrilling"-the bouncing of the bit in the hole and its rotation wear away the walls-so that the actual diameter of the hole is greater than the diameter of the bit. The amount of this overdrilling depends upon the kind of rock being drilled, and is sometimes sufficient to permit the use of the same diameter of bit for the full depth of the hole. If, for instance, a 1 3/4-in. diameter bit overdrills 1/32 in. in diameter, and loses 1/64 in. in gauge in drilling 2 ft. of hole, the bottom of the hole is still 1/64 in, larger than the original diameter of the bit, and a new 1 ¾ -in. bit can be used to drill the next 2 ft. If, however, the overdrill is less than the loss in gauge, the next bit must be of smaller diameter. The first requisite in reducing loss of gauge in drilling is to have the points and corners of the wings of the bit cut circles of the same diameter, thus producing a reaming surface with continuous bearing on the wall of the hole. The greater the reaming surface, the less the gauge loss that is to be expected. If the reaming surface, however, is too large, it may impede the rotation of the bit through excessive friction. This principle was probably first recognized in the design of the Carr bit (Fig. 1), a bit with a single cutting edge of wide angle, a definite reaming edge, and a large center hole. The same idea was followed in designing the double-taper cross bits, which are now standard almost everywhere.

Jan 1, 1939

By J. M. Lohr

THE characteristics and uses of thermocouples of platinum and the platinum alloys being so well known, this paper will be confined to base-metal couples. During the past decade, there has developed a strong demand for thermocouples made of metals cheaper than the platinum alloys, and suitable for industrial heat measurements. Much research has been clone but only a very limited number of alloys have been found to possess the necessary characteristics for general technical use. In the development of thermocouple alloys it is necessary to consider the following points: The electromotive force and temperature relations; permanency or constancy; reproducibility; manufacturing difficulties; durability; and accuracy in use. The electromotive force developed by the thermocouple should increase with the rise of temperature according to some definite law. It is desirable that the electromotive force should vary directly with the temperature difference of its junctions, in other words, giving a curve linear or nearly so. It is also desirable that the resulting electromotive force be as large as possible for any given range of temperature, thereby insuring greater accuracy of readings.

Jan 9, 1919

SEC, 1, This Institute is incorporated under the Membership Corporations law of the State of New York; its corporate name is American Institute of Mining and Metallurgical Engineers, Inc,; and its objects are such as are stated in its Certificate of Incorporation. ARTICLE II MEMBERS SEC. 1. The membership of the Institute shall comprise four classes, namely: 1. Members; 2. Honorary Members; 3, Associates; 4, Junior Associates. All members shall be equally- entitled to the privileges of membership, excepting that Honorary Members, Junior Associates, and Members and Associates whose residences shall be outside of the United States, Mexico, and Canada shall not be entitled to vote. Members and Associates residing within the United States of America, Mexico, and Canada, and not in arrears for dues, shall be entitled to vote in person at the meetings of the Institute, or, as hereinafter provided for, by letter ballot, SEC. 2, Members shall comprise all those persons who on the third Monday of February, 1918, were members of the Institute, and in-addition thereto, all those thereafter elected or transferred into the class of Members. A person to be eligible for election or transfer into the class of Members must be at least 27 years of age and must have had at least six years', employment in the practice of engineering, mining, geology, metallurgy or chemistry, during at least three years of which he must have held positions of responsibility in one or more of these fields. Graduation from the scientific course of a college, approved by the Committee on Membership,' shall be considered equivalent to two years' employment, as required in the previous sentence, Employment as -a teacher of engineering, mining, geology, metallurgy or chemistry, if in direct charge, may be considered a position of responsibility as specified in the second paragraph. Persons employed in research or any scientific literary work or in teaching in the scientific departments of colleges, approved by the Committee on Membership, who at the same time are engaged in consulting or in the active practice of mining, geology, or metallurgy, shall be entitled to consider the time so spent in active practice as equivalent to an equal length of time of employment in positions of responsibility, provided the work done or the positions held seem to the Committee on Membership to warrant the equivalency. The requirement of three years' employment in positions of responsibility may be waived by the Committee on Membership in the case of persons who have done notable original work in mining, geology, or metallurgy, or have won distinction by research or investigations, in one or more of these subjects.

Jan 1, 1928

Both drilling and production in Rumania showed increases in 1934 over 1933. The drilling totaled 1,138,000 ft. and production 63,500,-000 bbl., being increases of 50 and 15 per cent, respectively. During the year production gradually increased from 155,000 bbl. per day in January to 180,000 bbl. in September, and then declined slightly to the end of the year. The increases were largely due to competitive drilling in the Gura Ocnitei field (including west extension to Viforata). Wells completed during the year totaled 238, of which 215 were oil producers. The outstanding development of the year was the discovery by Steaua Romana of what appears to be a major field at Bucsani. Other important discoveries were a three-mile west extension of the Gura Ocnitei fault to Viforata and a five-mile east extension of the Moreni field to Calinesti. Strictly speaking, the latter cannot as yet be called an extension. Oil sands have been corded in the Meotic, and in all probability production will be established in 1935. The Calinesti discovery greatly restricts the unproved area between Moreni and Baicoi, and the probabilities of

Jan 1, 1935

By James R. Evans

Forecasting demand is an art as well as a science, and much personal judgment is required. National forecasts made for sand and gravel, crushed stone, and/or aggregate may be misleading or unhelpful locally. This is because of significant variation in demand within different geographic and/or political areas in the US, and/or the use of an inadequate data base and forecasting methodology. The best forecasts may be made for local or regional market areas, irrespective of geographic or political boundaries, provided a proper data base is available.1 The Bureau of Mines compiles detailed statistics on commodities sold or used in the construction industries and, therefore, is in an advantageous position to make national aggregate demand forecasts.

Jan 1, 1979

By Warren B. Weeks

Continued development in the deeper fields discovered during 1937 and 1938 was largely responsible for the 16 per cent (2,913,400-bbl.) increase in production, bringing the 1939 output to 21,376,230 bbl., the largest for South Arkansas since 1929. The older settled fields continued to decline and Rodessa was added to this classification. Magnolia field accounted for much of the increase, with Schuler field showing only a slight increase. There were 248 wells drilled during 1939, five more than during the previous year. Of 198 wells drilled in proven fields, 21 were dry; 46 of the 50 wildcats drilled were dry. The old depth record of 8332 ft. was increased to the present record of 9028. Trend of Prospecting Production from the porous " Reynolds " oolite zone of the Smackover limestone continued to be the objective of prospecting. During the year 20 seismograph, 3 gravity meter, 1 magnetometer, 1 soil analysis and 1 electromagnetic crews were reported in the state. The geophysical work was largely concentrated in three southern counties: Columbia, Lafayette and Union. As indicated in Table 2, the same three counties received most of the important drilling tests. At the end of the year only three seismograph crews remained in the areas. The area for prospecting Smackover limestone was greatly narrowed during the year by the failure of two "fault zone" wells to find satisfactory permeability in the oolite zone, and by the relatively thin sections of porosity found in wells drilled in townships 18 and 19 South. Geology Most of the wells listed in Table 2 afforded additional control on structure of the lower beds, but gave little new information on stratigraphy. Of the 248 wells drilled, 3 ended in Tertiary, 34 in Gulf, 1 in Paluxy, 29 in Glen Rose, 15 in Travis Peak, 15 in Cotton Valley, 139 in Smackover, 2 in Eagle Mills and 10 in Carboniferous. The age of the beds between the Travis Peak formation and Carboniferous is still questionable. Most

Jan 1, 1940