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By J. J. Brown

The ore-hearth was the earliest type of furnace used in smelting Mississippi Valley lead-ores, which are very pure, and low in silver-content. The first smelters made no attempts to recover lead from the smoke; and since about 15 per cent. of the lead in the charge escaped in this manner, early practice with the hearth was decidedly wasteful. At most of the large smelting-plants blast-furnaces with auxiliary roasters were substituted for the hearths long ago. But, upon the introduction of the Lewis and Bartlett bag-process for collecting fume, the ore-hearth was used by companies engaged in the manufacture of pigments, simply on account of the large percentage of fume made by it. In fact, the extraction of lead mas kept down by the use of hot blast and other devices. During recent years, however, several smelting companies have realized that the preliminary roasting of galena for the blast-furnace is not economical, and have, therefore, replaced the roasting-furnace with a modification of the old Scotch hearth, in which a large percentage of the lead in a charge is

Jan 1, 1912

By Edward S. Cook

For several years past, dating particularly from the days of serious "ore-dirt" complications at the Warwick furnace, I have been desirous of providing some safe, quick and easy method of relieving the tuyeres of slag, when the cinder- and iron-notches are chilled through loss of heat in the clucible or when, from dropping or jumping of stock, the molten slag is forcibly driven into the bellyand leg-pipes. Various methods were proposed, but objections of one kind or another always presented themselves, and the subject was postponed to a more convenient season. In the summer of 1887, while running on anthracite alone, 1 found the various expedients in use to be so utterly valueless, that the importance of a practicable tuyere slagging-valve impressed me more forcibly than ever. The holes left in the cast-iron jacket at one side of the bottom of the water-blocks were found to be of no value whatever. The swinging or hinged cap on the elbow of the belly-pipe, while convenient to permit the removal of lag after the belly-pipe was partially or wholly filled, could not be adapted to discharge the slag before solidifying, except at great risk to the men and loss of time just when the constant running of the engine and the keeping of blast on the furnace was of the utmost importance. By removing keys from the caps and holding them in place with props, the slag could be discharged through the tuyeres and belly-pipes, with the engine running, by knocking the props away at a given signal. This method is extremely hazardous to life and limb, and I have always hesitated to make use of it. When the furnace is in such condition as to require the adoption of some method of the kind, the stoppage of the engine, cooling the blast and the contents of the crucible, always aggravates the trouble. When the caps are blown open and the slag is discharged by removal of the props, it is necessary to stop the engine to replace them. An hour or more will elapse before this can be done, as the slag must be partly removed before the tuyeres can be approached by ordinary mortals, and the caps handled and fastened in place again. Any movement of the stock is liable to burn the workman, as he stands, securing the cap in front or at one side of the open belly-pipe.

Jan 1, 1889

(The following list contains the names of those members of the Institute of whose connection with military service. we have only recently become acquainted; it also includes the names of a few who have recently been promoted or transferred. A complete list was published in the Year Book, issued as a supplement of the Bulletin for March, 1918.) ADAMS, HENRY, Major, Assistant to Department Engineer, North-eastern Dept. ALINE, P. A., Co. C, 316th Supply Trains. * Low-cost cottage construction in America; a study based on the housing collection in the Harvard Social Museum, by Winthrop A. Hamlin. Cambridge, Mass., Harvard University, 1917. (Publications of the Department of Social Ethics, No. 7.) 30 pp., 4 charts. Illus.

Jan 5, 1918

By Jerry M. Thornton, Richard W. Cannon, Don C. Rotherham

The orebodies of Gibraltar Mines Ltd. (N.P.L.) are located on the western slope of Granite Mountain, central British Columbia. The area in and around Gibraltar Mines has a moderate topographic relief with elevations between 3500 and 4100 ft. The property is 95% covered by overburden which varies in depth from a few feet to 230 ft. Early History and Geology The present Gibraltar Mines property before amalgamation consisted of the Pollyanna property (Duval-Canex) and the Gibraltar property (original Gibraltar Mines) as well as some Coast Silver and McLeese Lake Copper claims.

Jan 9, 1972

By L. M. Clarebrough, A. K. Head, G. W. West, M. E. Hargreaves

RECENTLY Welber and Webelerl reported that during the annealing of fatigued copper no energy was released, but that energy was absorbed in the range of temperature 250" to 400°C. In view of the fact that strain hardening occurs during the fatigue of copper, this result was surprising and it seemed desirable to check the measurements. This note describes measurements made by a different technique which indicates that energy is stored during the fatigue of copper. Two test bars with gage length ¾ in. in diameter and 6 in. long were machined from OFHC copper and annealed in vacuum for 1 hr at 600°C. These were fatigued to fracture in an Avery pulsator at a frequency of 2000 cycles per min. The first specimen fractured after 0.25x10 cycles under a push-pull

Jan 1, 1956

By D. Roberts

SUMMARY In order to accommodate a new plant in a limestone quarry in the Mendip Hills, it became necessary to excavate a potentially unstable disused face of the quarry. A simple two-dimensional graphical method was used to analyse a failure, which occurred during a period of exceptionally heavy rain in 1968, and the results of this analysis were used in estimating the stability of the proposed excavation. The presence of water in vertical fissures and tension cracks was found to be a dominant factor in determining the stability of these faces. The results of this approximate analysis were used as a guide in deciding upon the final slope design and the purpose of presenting this example is to illustrate how the various factors involved in arriving at this design were weighed to arrive at a compromise between theoretical recommendations and practical considerations. INTRODUCTION The successful outcome of a geological and geochemical survey to prove adequate re- serves of high quality limestone, suitable for producing burnt lime, led to planning for the installation of the necessary plant at Amalgamated Roadstone Corporation's Batts Combe Quarry at Cheddar in Somerset. Topographic and property boundary limits added to restrictions which were likely to be imposed by any forthcoming planning consents and restricted the choice of plant location to one site. The particular site is, in fact, the main floor area of the original quarry which, like many hillside quarries, had been worked with just one face. Before a benching scheme had been introduced on higher ground, the original face had attained a height of 230 ft. and sloped at angles of 58º to 64º. Fig. I shows the present configuration of the disused quarry face and the present working area above. The floor area below the disused face accommodates the existing crushing, conveying, and screening plant. The new facilities for lime burning are to be in addition to the existing main line business of producing roadstone and concrete aggregates and, although a new aggregate production plant would be included in the new installation, no disturbance of current production was to be contemplated.

Jan 1, 1972

By L. K. Smith, E. M. de Kock, J. van der Walt

A unique and systematic approach for analysing alternative methods of ventilating and cooling large hot mines is presented. The important factors that have a bearing on ventilation and cooling requirements and practices, such as air flow through the mine, geographical distribution of heat loads, micro ventilation considerations etc., are dealt with. Analysis of these leads to the definitive ventilation and cooling strategies, air and water process design, detail specifications and design of associated plant and equipment.

Jan 1, 1982

By M. F. McCarty, R. S. Olson

New organic flocculants of high-molecular weight are replacing lime, glue, and starch in liquid-solid separation. Of these synthetic materials, poly-acrylamides are outstanding. Polyacrylamides form a class of compounds varying widely in composition and activity. Separan 2610, one of the first of these flocculants' released to the mining industry in 1954, is described' as a high-molecular weight polymer of acrylamide with or without a copolymer material and with some replacement of amide by carboxylic groups. MECHANISM OF FLOCCULATION In practice, flocculation makes solids settle faster and filter better. But two opposing factors control it. The random motion that causes particles to collide favors Van der Waals' forces, which hold the particles together. The effect of zeta potential opposes this contact, and particles are mutually repelled. Flocculation can be achieved by reducing the magnitude of the zeta potential; this is the mechanism of flocculation by lime addition. The way in which polyacrylamides accomplish flocculation is not fully understood, but the action is undoubtedly comp1ex and probably varies considerably depending on the system. To begin with, the active groups of these compounds have an extremely high affinity for solid surfaces, probably by hydrogen bonding." Initially some active groups of the molecule attach themselves to the solids with a large portion of the molecule extending into the solution. Two particles can become tied together by long flocculant molecules in the following ways—by bonding between the active groups of two flocculant molecules on different particles, or by an extended molecule from one particle attaching itself directly to the surface of the other particles." These flocculant bridges prevent the particles from moving apart through random motion, but when such motion moves them together other active groups on the flocculant bridge bond to the solids, holding them in the closer position. This process is repeated until the particles are close together. Although bridging is probably a major flocculation mechanism, it is not the only phenomenon involved. Relatively neutral acrylamide flocculants reduce the magnitude of the zeta potential by increasing the viscosity of solution in the immediate vicinity of the solid surface which contains the mobile counter ions of the double layer. In other words, it moves the shear surface which bounds the zeta potential out into the solution containing counter ions which tend to neutralize the zeta potential. This effect is probably more pronounced during the initial adsorption period, before the flocculant molecules are pulled close to the solid. In some cases the slight charge of the polyacry-lamide molecule tends to neutralize a zeta potential. However, this is not a primary flocculation mechanism, as evidenced by the fact that the polyacrylamides will flocculate solids with either positive or negative zeta potential. Adsorption of polyacrylamide flocculants by a solid is substantially an irreversible reaction. Since the flocculant molecule is attached to the particle surface by many active groups of high bonding strength, desorption would require the simultaneous breaking of many bonds—an unlikely occurrence. UNIQUE PROPERTIES The irreversible adsorption of certain polyacrylamides, the flocculant's high affinity for solid surfaces and its rapid adsorption make it effective, but these unique properties require special techniques to achieve maximum flocculation. If flocculants of this type are added to a pulp as a relatively concentrated solution, the solids in the

Jan 1, 1960

WE the undersigned, being all persons of full age and citizens of the United States, and a majority residents of the State of New York, desiring to form a corporation pursuant to the provisions of the Membership Corporations Law for the purpose of incorporating, as provided in Section 6 of Article I. of said law, the existing unincorporated association known as American Institute of Mining Engineers, do hereby make, acknowledge and 6le this Certificate for that purpose, and do Certify as follows: I. That the American Institute of Mining Engineers is an unincorporated association organized and existing with the object of promoting the arts and sciences connected with the economic production of the useful minerals and metals and the welfare of those employed in these industries by means of meetings for social intercourse and the reading and discussion of professional papers, and to circulate by means of publications among its members and associates the information thus obtained. 11. That the persons duly appointed or designated to manage the affairs of said association are designated by the rules thereof Members of its Council; that the under- signed are all members of said Council as the same was constituted on the 29th day of December, 1904.

Jan 1, 1939

By R. R. Hoffman

The name L'brush,l as applied to the parts to be briefly considered in this paper, is not clearly descriptive of the design and function of those parts when the usual definition of the word is applied. In a general way, the brushes to be considered here are the parts employed on certain types of electrical equipment to facilitate the transfer of electrical current between a rotating or moving element and a stationary element. These machines are generally motors and generators of both the slip-ring and commutator types, rotary converters, battery charges, etc. Parts that serve a similar purpose on relatively slow or intermittently moving devices such as rheostats, switches, controllers, etc., are generally referred to as contacts. A few special applications involve the use of current-carrying washers, rollers, bushings, etc. As may be inferred, therefore, the design of these brushes and allied parts is dictated by both electrical and mechanical considerations. In most cases these factors are closely interrelated, and unfortunately many of them are not subject to exact scientific or mathematical analysis. Special Advantages Since brushes operating on direct-current machines must carry the load current, resist destructive action from voltage induced in imperfectly compensated armature coils, and in addition act as a bearing material, maintaining intimate contact with the commutator at peripheral speed, which may be as high as 70 miles per hour it is difficult to obtain in one brush the ideal properties necessary for perfect functioning under all operating conditions. The engineer-designer, therefore, when selecting a brush for a specific application, must choose a grade that possesses the characteristics most adequate to meet the conditions involved. In many cases a characteristic that makes a specific grade of brush the ideal selection for one type of machine may be of secondary importance to some other property when the brush is applied on another machine. Frequently different grades of brushes must be applied to the same type of machines when they operate under different or unusual atmospheric conditions. Completely satisfactory brush operation depends on freedom from appreciable sparking, minimum electrical and mechanical losses, negligible commutator or slip-ring wear, uniform film over the commutator or slip ring, quiet operation and good brush life. The ability to produce special structures, and to combine in widely varying proportions materials that are incompatible, through conventional melting and alloying procedures has been the basic contribution of powder metallurgy to the solution of problems involving brushes and allied parts. This is especially true where current-carrying capacity is a major factor, owing to the limitations of all carbon or all graphite brushes in that respect. Metal-graphite Brushes With very few exceptions, friction between moving elements. across which

Jan 1, 1945

By R. W. Raymond

In June, 1906, I delivered to the graduating class of Lehigh Cniversity an address upon this subject, the substance of which, with sundry omissions and additions, was subsequently repeated, in October of the same year, in an extempore address before the Schenectady branch of the American Institute of Electrical Engineers. The latter, as stenographically reported, was published in the Proceedings of that society for November, 1906, and was referred to by President John Hays Hammond in his address at the Chattanooga meeting of October, 1908. Requests have been received from various quarters for the repub-lication of this address by the Institute. This I do not regard as necessary or proper; but I yield to that demand so far as to reproduce in the Transactions a summary of my views, as expressed in the two addresses above mentioned.

Jan 1, 1911

By Byron E. Eldred

Generally speaking, the practical study of combustion has been made mainly from the stand-point of the steam engineer. This narrow view-point has left open a large field for scientific research on the application of combustion in other arts, where the conditions of heat-utilization are widely different from those presented in the steam-generator. The great economic importance of the boiler and the ease of measuring its performance, together with the comparative uniformity of conditions in the steam-generator, is, probably, quite largely responsible for the practical neglect of the study of the use of fuels in other arts save only on the basis of their thermal value. yet these other arts show quite plainly that a thermal-value basis alone is not sufficient. For example, in burning lime, under ordinary conditions of firing, a cord of wood will do as much work as a ton of coal, though the latter affords more than twice the number of heat-units. Similar results are evidenced in burning brick, in the roasting of certain ores, in reheating billets, and in many other, arts where heat is to be applied over extended areas to fragmental masses of more or less refractory materials. In these arts much is to be gained by a

Jan 1, 1911

Payloader The Frank G. Hough Co. has made available another four-wheel drive tractor-shovel. It has a 1 cu-yd bucket with 60 hp Diesel or 54 hp gasoline power optional. The use of large pneumatic tires, same size all around, and drive on all four wheels gives this new Payloader traction to work effectively in sand, mud and snow, and travel on pavements with- [ ] out injuring the surface. Rear wheel steer with power booster plus short wheel base makes it easy to operate and highly maneuverable. Four speeds in both directions insure fast travel speeds for transport and fast operating speeds on shuttle loading or similar operations. Bulldozer blade, crane hook, fork lift and snow plow attachments are available, quickly interchangeable with the bucket to further increase its multi-purpose usefulness. Circle No. 1

Jan 1, 1952

On Sept. 22 to 26, the Institute will hold its 120th meeting in Chicago. The program arranged provides for technical sessions on: Mine Taxation, Non-ferrous Metallography, Coal and Gas, Milling, Oil, Industrial Organization, Geology, Non-ferrous Metallurgy, Mining and Local Resources, Iron and Steel, Symposium on Sulfur Coals, Symposium on Pyrometry. Inspection trips have been arranged to: Gary Steel Plant. La Salle District: Zinc smelters, coal mines, cement works, America's first permanganate plant, many varied industries, scenic trips. North Chicago and Milwaukee: Mining-machinery manufacturing plants, tungsten and molybdenum reduction plants. East Chicago and Whiting: Lead refinery, oil refinery. Franklin and McCoupin: Coal fields. Chicago: Nearly every kind of metallurgical and manufacturing industry. MONDAY, SEPT. 22d Morning Registration, Non-ferrous Metallurgy, Coal and Gas. Afternoon Coal and Gas Milling Industrial Geology, etc. Evening Smoker. TUESDAY Morning Gary. Afternoon Gary. Iron and Steel. Evening Oil, Iron and Steel.

Jan 9, 1919

By M. L. Brashears, R. G. Slayback

The host dolomite of the Pine Point lead-zinc ore is a prolific ground-water aquifer that occurs locally under watertable and artesian conditions. Mining schedules and severe climate require rapid and thorough dewatering of open pits. Pumping-test methods, common to ground-water supply studies, were applied to dewatering design for a model ore pit in 1968. Procedures for testing and design at other ore bodies were established and have been carried out successfully by mine personnel. At the inception of ground-water studies, parts of ore bodies were below prevailing ground-water levels by 35 to more than 150 ft. Movement of ground water through the coarsely recrystallized dolomite occurs largely through fractures and solution openings. Because the overburden deposits consist mainly of glacial till, it is estimated that the recharge to the aquifer is about 25% of the 13-in. annual precipitation. Natural groundwater flow is northeastward toward Great Slave Lake. Background data included extensive diamond drill hole logs and cores and static level data for a number of ore pits. An ore pit, known as N-42, that required 40 ft of dewatering was selected for the initial application of the pumping-test method. Production wells, cased with 14in. pipe, were drilled to a depth of 300 ft on the rim of the ore pit. A suitable pattern of observation wells was obtained by lining 21/8-in. diamond drill holes with perforated electrical conduit. A two-stage pumping test

Jan 1, 1973

By David S. Cahn

Pilot-plant and laboratory tests were made on blends of steel plant flue dust and portland cement to determine whether the flue dust could be pelletized for use as a source of iron in dry process cement manufacture. Strength and setting time results showed that an acceptable agglomerate can be made with a Type II portland cement binder. Abrasion-resistant and well-sized pellets were made in a horizontal drum, using a simulated closed circuit, with a binder content of 7.5% and a moisture content below 15%. Pellet quality was found to be relatively insensitive to changes in binder concentration above 5%. Simulations of stockpiling and weathering indicate that little difficulty would be encountered with use of the flue dust pellets in cement plants.

Jan 1, 1972

By R. A. Generes, H. C. H. Darley

Laboratory tests showed that at elevated temperatures a reaction takes place between all metal hydroxides and clay muds, which results in a thickening or solidifying of the mud, the extent of which depends on the nature of the ingredients. Calcium hydroxide gave the strongest solidification whereas barium hydroxide only caused a mild thickening, indicating that the use of barium hydroxide muds instead of lime muds would be a good way of preventing high-temperature solidification. It was found possible to prepare barium mud in the laboratory with caustic soda and a thinner in the same manner as lime muds, and these barium muds had the same or better toleration of high solids content, resistance to salt contamination, and low gel strengths as the corresponding lime muds. Three field trials have been made with barium mud. The principal difficulty encountered was in determining the correct proportions of the tourly treatments required to maintain low gel strengths. A satisfactory systern was finally developed, and low gels were maintained throughout the third test. The wells on which the trials were made were not carried deep enough to test the resistance to solidification adequately, but oven tests at 350°F were made periodically and no tendency to solidification was noted except immediately after severe cernent contamination had introduced excessive amounts of calcium into the system. Although barium hydroxide costs considerably more than lime, the total mud costs were as low, and on the last well significantly lower, than the average cost of lime mud wells drilled in the vicinity. INTRODUCTION The advantages of repressing dispersion and hydra-tion of clay cuttings carried in the mud, particularly when drilling through thick clay formations, are well recognized. This repression is generally achieved by the use of lime, and lime muds have in consequence the desirable characteristics of high toleration of solids, low thixotropy, and good resistance to contamination. They have, however, the disadvantage of high-temperature solidification. This phenomenon has been described in detail by Gray et al, who have shown that it is the result of a chemical reaction between the hydroxides and the clay minerals. The work described in this paper was undertaken to find a substitute for lime which would not cause this solidification. LABORATORY EXPERlMENTS The principal positive requirement for a substitute for lime is that it should repress the hydration and dispersion of clay. It is well known that monovalent cations promote hydration while polyvalent cations repress it. Therefore, a few representative polyvalent salts and hydroxides were tested to determine whether they could be used as substitutes for lime. Their efficiency at repressing hydration and dispersion was measured by means of the clay-volume test. It has been shown elsewhere' that this test is a good measure of degree of dispersion of clay in suspension and that hydration accompanies and correlates with dispersion, so that measuring one measures the other. The test is made by centrifuging a 1:100 mixture of mud and 1-N NaCl and observing the volume of sediment—the greater the volume, the greater the dispersion. The tendency to caux solidification was measured by heating the muds in pressure vessels for 16 hours at 150°F and 370°F. An approximate quantitative

Jan 1, 1957

By John K. Dienes

The permeability of sands and soils seems to be adequately de- scribed by Darcy's law, but the permeability of rocks is complicated by a number of factors related to the probability of crack intersections. During the last few years we have developed a statistical theory of fragmentation which has been successful in explaining the observed behavior of rocks. In this paper, a theory of permeability is developed which draws on the concepts employed in previous work. The permeability involves three factors, the average fluid flux per crack, the number of cracks per unit area, and the fraction of cracks that are not isolated. Probabilistic ideas are used in connection with the hydrodynamic theory of flow through a single crack to develop an integral expression for permeability. The result has the form of Darcy's law for anistropic media. Although the current work is motivated by the need to develop optimized oil-shale retorts, we believe that the theory can be applied to a variety of other problems.

Jan 1, 1982

By Leendert de Witte

Conventional resistivity logs consisting of a short normal, a long normal, and one or more long lateral curves do not give data that allow a complete quantitative interpretation in beds thinner than 20 ft. Reservoir rocks usually exhibit zones of continuous homogeneity of quite limited thickness where the long lateral curves become useless because of adjacent bed effects and boundary phenomena. If the beds are 12 ft or thicker, the short and long normals may be used for qualitative interpretation, which can be streamlined by the application of simplified departure curves. For beds of a thickness less than twice the long normal spacing, this procedure breaks down. The combination of the limestone curve, the later-olog or guard electrode log, and the microlaterolog permit quantitative interpretation for beds that are at least 10 ft thick, provided the mud resistivity and the hole diameter are known with sufficient accuracy. For beds thinner than 10 ft, combinations of the microlaterolog with short spaced laterologs and pseudo laterologs appear to be promising. Interpretation of these curves again requires the application of simplified departure curves. Resolution of various possible combinations was analyzed using departure curve data calculated on the Whirlwind I computer at the Massachusetts Institute of Technology. A field example is shown using the microlaterolog-microlog combination, and the combination of a 6-in. modified laterolog plus a 6-in. pseudo laterolog. INTRODUCTION For the purpose of quantitative interpretation of resistivity logs in porous formations, we want to obtain two essential quantities from the logs, namely, the true resistivity of the undisturbed formation, Rt, and the resistivity of the part of the formation invaded by mud filtrate, Rt. The apparent resistivities of all conventional logging devices are functions of these two parameters and are also influenced by a third unknown parameter, the diameter of the invaded zone, d. It has been shown' that from the normal curves alone it is impossible to arrive at a unique solution for the three unknowns, Rt, R1, and d1. In very thick homogeneous beds, if invasion is not too deep, we can obtain a fair approximation to Rt from the long lateral curves and then use the two normal curves to find Rt and d1 Even under the most favorable conditions, the resolution of this system is not very good. The short normal does not give a reasonable approximation to R1 unless invasion is very deep (dl>16 hole diameters). For very deep invasion, however, the long laterals no longer approximate Rt. For bed thickness between 20 and 40 ft, the long laterals are affected appreciably by the adjacent beds; and the curves are distorted by boundary anomalies to the extent that they lose their quantitative usefulness in most cases. For the same bed thicknesses, the normal curves still function reasonably well. Although it is impossible to find unique solutions Lor R1 and Rt using the normal curves alone, we can obtain a reasonable approximation for the ratio R1/Rt through the use of simplified departure curves. This fact was brought to our attention by A. J. de Witte, geologist with Continental Oil Co. As the magnitude of Rl/Rt is a major clue to the presence of oil in formations, this method can be used to good advantage for qualitative analysis and will be discussed in somewhat greater detail. With the aid of suitable bed thickness corrections, the analysis of the normal curves may be used for bed thicknesses larger than 12 ft. For thinner beds, the method rapidly loses its resolution; and we have to resort to different types of resistivity logs if we want to attempt to analyze the curves quantitatively. The inadequacy of conventional resistivity curves in thin beds is far more serious than generally realized. Fig. 1 shows a conventional E. S. with a 16-in. and 64-in. normal and a 16-ft lateral through a section of Lansing-Kansas City lime, in comparison to a guard electrode survey through the same section in a neighboring well. The porous zones, which show up as low resistivity breaks on the guard electrode log, are completely masked by adjacent bed effects and boundary anomalies on the conventional curves. Even the short normal shows most of the porous Zones only as Vague deflections and in many cases fails to register Their

Jan 1, 1955

By H. Vance

In 1932, as in 1931, the East Texas area outside the Gulf Coast exerted ' its influence over the entire petroleum industry. Practically 60 per cent of the oil wells completed in the United States during 1932 were in this area, development being chiefly confined to the East Texas oil field in Upshur, Gregg, Rusk, Smith and Cherokee counties. This East Texas area is geologically an interior salt dome basin, along the western edge of which are located the fault line fields as represented by Mexia and Powell. Production occurs on salt domes in the interior of the basin as represented by Boggy Creek and possibly Van, although no salt has actually been discovered in drilling at Van. Shore line conditions on the east side of this basin along the flanks of the Sabine uplift have been responsible for the East Texas oil field. Many known salt domes in the center of this basin have been tested but as yet have failed to produce oil in commercial quantities. The main producing horizon throughout the area is lowermost upper Cretaceous and is known locally as the Woodbine sand. The East Texas Oil Field Development.—Approximately 6000 producing wells were completed during the year in the East Texas oil field. No accurate estimate of the total initial production of these wells is available because few initial production tests were made as the wells were completed. The writer estimates the average initial production of these completed wells at 2500 bbl. per day while flowing wide open through tubing. Based on this estimate, the total initial production of the wells completed during the year is 15,000,000 barrels. At the close of 1932 there were approximately 9500 completed wells in the East Texas field. Of this number 176 were without pipe line connections. The oil produced from these unconnected wells could be marketed for $0.30 per barrel while the price paid for oil run from the connected wells was $0.75 per barrel.

Jan 1, 1933