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By R. W. Stormont, F. Wald

The phase diagram of the Pseudobinary section PbTe-Fe was determined. It was found to contain a monotectic and a eutectic reaction, the latter one taking place at 14 at. pct Fe and 875° * 5°C. The solid solubility of iron in PbTe was found to be 0.3 at. pct by electronmicroProbe analysis. No solubility of PbTe was detected in iron. Slight deviations from true pseudobinary behavior were found to occur in the range of - 5 to 10 at. pct Fe. In the course of a general investigation of reactions of various metals with lead and tin telluride,' the lead telluride-iron system was reinvestigated. It had been established much earlier than iron does not chemically react with lead telluride but forms a eutectic with a melting point of 879" The eutectic composition or other related information has never been reported, but for a number of years iron has been in general use for contacting of lead telluride and lead telluride alloys for thermoelectric applications. It seems therefore desirable to clarify the exact constitution of the system to furnish a base for the long-term evaluation of bonds made between lead telluride and iron either by pressure contacting or by brazing methods. I) EXPERIMENTAL METHODS Lead telluride-iron alloys were prepared in 10-g charges, using premelted lead telluride. This material was prepared from high-purity, semiconductor-grade lead and tellurium obtained from the American Smelting and Refining Co. and described as 99.999 pct pure. The iron used was "Armco" iron; the major impurities found here were 0.02 pct C, 0.018 pct Si, and 0.015 pct Cr. All remaining impurities were less than 0.01, the total of all impurities not exceeding 0.15 pct. Charges were prepared in closed quartz arnpoules which were evacuated and in some cases backfilled with high-purity argon to retard excessive lead telluride evaporation and deposition in slightly cooler parts of the ampoule. For high iron concentrations, this can lead to total separation of the constituents, since the vapor pressure and the sublimation rate of PbTe are quite high.4 Nevertheless, since the ampoules are closed, no change in overall composition was expected and the nominal composition of all alloys was assumed to be retained. X-ray diffraction analysis, thermal analysis, and microsections were used in the evaluation of the alloys. The nature of the system was such that X-ray diffraction was not particularly helpful. It merely served to establish that at all concentrations PbTe and a! iron were in equilibrium at room temperature. Thermal analysis was carried out by taking direct temperature vs time curves on a Sargent recorder where a width of 10 in. was kept as 1 or 0.5 mv by use of an automatic bucking voltage network. Quartz ampoules with minimized dead space, coated with boron nitride and fitted with a thermocouple reentrant, were used as containers for the charge. At high temperatures and over long periods of time, boron nitride reacts with iron. For the thermal analysis runs, however, this was not significant. More significant was the fact that the vapor pressure of PbTe at some of the meas -uring temperatures apparently exceeded I atrn quite considerably. This, in some cases, caused the slightly softened quartz tubes to blow out if great care was not taken to contain them and minimize time and temperatures used. As containers pure nickel tubes were used which also served to avoid temperature gradients in the quartz ampoule. Nevertheless, the experimental difficulties at high temperatures were severe and the monotectic temperature could therefore not be determined accurately. In general, the accuracy reached by the thermal analysis setup in this case is *4"C as determined with gold, silver, and tin, under the conditions of analysis here. Inherently, the apparatus is capable of reaching accuracies better than i 1°C. Also, difficulties were encountered in microsection-ing. They were related to polishing, since it is rather difficult to avoid pulling the iron out of the weak and brittle lead telluride matrix. It proved best to follow a procedure where, after grinding to 600 grit on carborundum paper, a polish with 6 p diamond was used on nylon cloth. Finally, #3 "Buehler" alumina and an automatic polisher were used for -5 min only, to avoid relief. The best etching results were achieved with

Jan 1, 1969

By J. E. Gosline

In any theory of a hydrodynamic nature dealing with the vertical flow of gas-liquid mixtures in pipes, the two factors that present the greatest difficulty are the relative motion between the phases and the energy loss resulting from turbulence work. The former has generally been referred to in the literature as "slippage" and the latter as "friction." A third factor of importance is the nature of admixture between liquid and gas for both the relative motion between the phases as well as the turbulence work are functions of the type of mixture. Although much work of a general nature has been performed on the vertical flow problem, there have been very few attempts made to study experimentally the factors involved in the phenomenon individually. Of these, perhaps the most notable is the work of Moore and Wilde1 on slippage. Some writers on the subject have assumed that over a wide range of operating conditions the controlling type of mixture is one in which gas bubbles of uniform size are distributed throughout the liquid, and that the data obtained from experiments on the motion of single bubbles through various liquids may be used in evaluating the slippage. Ver-sluys2 has further assumed another controlling type of mixture in which the liquid occurs as a dispersed phase within the gas and applies data on the fall of drops of water in air to calculating the relative velocity. It was for the purpose of studying the applicability of data on single bubble motion to the slippage factor and to further observe the nature of mixtures that a research program was conducted at the University of California during 1932 and 1933. These experiments formed a basis for

Jan 1, 1936

By F. M. Lewis, J.F. Myers

The Tennessee Copper Company's operations are in the Ducktown Basin, in the extreme southeast corner of Tennessee. The ore is of the heavy sulphide type, the predominating sulphides being pyrite, pyr-rhotite, chalcopyrite and sphalerite. The gangue is a micaceous schist, with varying amounts of free quartz. The mining operation develops two classes of ore, each of which is concentrated by the flotation process in separate mills. Table 1 shows a typical analysis of the ore treated in each mill. The London mill was built in 1922, with a capacity of 400 tons per day. This was gradually increased to 600 tons by 1926, to 900 tons in 1928, and to 1350 tons in 1938. Fig. 1 shows the crushing and grinding flowsheet in 1928, when the capacity was 900 tons; Fig. 2, the crushing and grinding flowsheet that was developed by 1938, for the treatment of 1350 tons per day. A comparison of these flowsheets reveals that this increase in tonnage, with a subsequent improved operation, was accomplished with identically the same major equipment. Improving a concentrator's capacity, metallurgical results, and costs as time goes by is a commonplace practice, and is accomplished in various ways, depending upon the local conditions. The reason for presenting the data of how this was accomplished in the mills of the Tennessee Copper Co. is that a fast-running rod mill plays such an interesting role

Jan 1, 1943

By Stewart Coleman, Thomas W. Moore, H. D. Wilde

It is recognized that in the early days of the petroleum industry oil was produced with practically no scientific or fundamental knowledge of the laws and principles governing its extraction from the ground. Only a few, if any, of those exploiting the oil resources made any effort to collect accurate scientific information. There was little need for it, for as is frequently the case where the supply of a natural resource appears inexhaustible and is greater than the demand, large profits were possible from merely skimming the surface with little regard to the efficiency or thoroughness with which the oil was obtained. With this policy in force, great quantities of gas were wasted and when the reservoirs ceased producing by natural means they still contained a large fraetion of the oil originally in them. The present tendency in the industry is toward conserving existing oil reserves. In order that greater percentages of the oil present in the ground may be recovered, efforts are being made to improve production methods and to rework depleted fields. If the production methods are to be improved intelligently it is essential that the fundamental laws be known and understood, consequently large amounts of money and effort are being spent in gathering data that will serve to define and interpret these laws. A great deal of attention is being focussed on the study of the motion of oil through an oil-bearing sand, the forces that cause it to move and the factors that affect its motion. It is recognized that one of the important factors is pressure, but its quantitative effect is not known. In a given field the rate of production declines with time and so does the rock pressure. Furthermore, a comparison of different fields shows, as a

Jan 1, 1930

By Howland Bancroft

This article is not presented as a treatise on tin mines and mining in Bolivia. It deals primarily with the tin situation, and but fragmentary information is given regarding individual properties, generalizations being necessary in so short an article. Data on general subjects related to tin mining in Bolivia are necessarily abbreviated and very incomplete. It is believed that the references to be found in this article will help those interested to a more thorough under-' standing of the general conditions extant in Bolivia. Bolivia produces from one-fifth to one-fourth of the world's supply of tin. The United States consumes about one-half of the world's supply and produces practically none. Tin ore is not reduced in the United States. These facts are not generally appreciated by American mining men. Many conflicting data have been published regarding tin in Bolivia. The Transactions of the Institute contain practically no mention of this subject.1 I have made a study of mines and mining conditions in the west coast republics of South America and have been particularly impressed by the possibilities of the Bolivian field.2 In consequence the thought seems justified that the present meeting would, present a fitting occasion to bring the tin situation in Bolivia to the attention of American mining men.

Jan 9, 1913

By Frank Nicholson

Copper ore was first noticed in Ste. Genevieve County in 1563. The diswvery mas made by a German farmer named Simon Grass, who had occasion to make a road from his farm down the hill into the neighboring valley, and while so engaged noticed pieces of a green-colored mineral, some of which he collected. Not knowing the character of the ore he had found, and supposing it to be valua ble for its brilliant green color only, he carried a piece with him into the town of Ste. Genevieve and showed it around the various bar rooms as a curiosity. No special attention was paid to the matter until nine years later, when Mr. 0. D. Harris sent a specimen of the ore to Dr. Theodore Fay, of St. Louis, for analysis. This analysis, which was the first ever made of Ste. Genevieve copper ore, showed the specimen to contain : Copper,. .........17.75 per cent. Zinc,..........3.21 " Iron........... 24.50 " Sulphur ..........1.09 " Organic matter, silica, carbon, and oxygen,. .. 53.45 " 100.00 " From this analysis it is evident that the sample was taken from near the surface, and was probably recognized by its green color. The almost entire absence of sulphur proves it to be an oxidized form. There is on file, at the office of the Ste. Genevieve Copper Works, a paper* giving three arsays of the ore made in 1875 by Henry B.

Jan 1, 1882

By Morgan Walker

INTERMITTENT injection of gas in gas-lift pumping is a variation of the common practice in that the gas is' .delivered to the well for a short, period, called the "on time," followed by a period during which none is admitted, called the "off time," instead of being admitted continuously at a constant rate or by intermittent flowing in which it is occasionally delivered to the well in just sufficient quantity to flow off the accumulated head of fluid. The term "gas" is used throughout this discussion but it should be remembered that in so far as the operation is concerned either air or natural gas may be used. The equipment at the well is the same as commonly used in gas-lift installations and gas may be admitted to either the tubing or the casing. It seldom occurs that all the wells on a lease can be pumped economically by intermittent injection from one header. Wells that. have flow characteristics which permit their being handled together have their intake lines grouped at a central compressor station. Well groups may consist of two or more wells. The total volume of gas delivered by each group of compressors goes to one well at a time through a quick opening valve, each well connected to the header receiving its charge of gas in turn. Special cases may require a deviation from this arrangement. The distribution of the gas to the different wells is effected by an automatic timing device which operates quick-opening valves on the intake lines. The timing mechanism may be actuated by electricity, liquid or gas pressure. The essential factor in the operation of the timing mechanism is that as one intake valve is closed another must be opened.

Jan 1, 1928

By J. Norman Bulkley

As electrical power is used to a greater extent on the Rand than in any other mining center, it is thought that a short description of the methods used and results obtained may be of interest. In comparing Rand practice with that on other fields, several general factors should be borne in mind: First, the mines are all working on large tonnages of low-grade ore (average. $6.50). The annual crushing rate is about 27,000,000 tons. Second, the mines are all grouped udder the financial and engineering control of mining houses, so that the results of a group, rather than an individual mine, are open for study, and practice follows more uniform lines. Third, coal of fair quality (about 12,000 B.t.u.) can be obtained for $2 to $3 per ton., Good supplies of condensing water are, however, scarce, and have to be carefully stored. Power Supply Power is supplied by the Victoria Falls & Transvaal Power Co., Ltd., and its subsidiary, the Rand Mines Power Supply Co. Both companies, which are practically one from an engineering point of view, operate the following stations, all feeding into the same system.

Jan 2, 1916

By J. F. Myers, F. M. Lewis

The Tennessee Copper Company's operations are in the Ducktown Basin, in the extreme southeast corner of Tennessee. The ore is of the heavy sulphide type, the predominating sulphides being pyrite, pyr-rhotite, chalcopyrite and sphalerite. The gangue is a micaceous schist, with varying amounts of free quartz. The mining operation develops two classes of ore, each of which is concentrated by the flotation process in separate mills. Table 1 shows a typical analysis of the ore treated in each mill. The London mill was built in 1922, with a capacity of 400 tons per day. This was gradually increased to 600 tons by 1926, to 900 tons in 1928, and to 1350 tons in 1938. Fig. 1 shows the crushing and grinding flowsheet in 1928, when the capacity was 900 tons; Fig. 2, the crushing and grinding flowsheet that was developed by 1938, for the treatment of 1350 tons per day. A comparison of these flowsheets reveals that this increase in tonnage, with a subsequent improved operation, was accomplished with identically the same major equipment. Improving a concentrator's capacity, metallurgical results, and costs as time goes by is a commonplace practice, and is accomplished in various ways, depending upon the local conditions. The reason for presenting the data of how this was accomplished in the mills of the Tennessee Copper Co. is that a fast-running rod mill plays such an interesting role

Jan 1, 1943

By Paul Billingsley

IN THEIR course across Ecuador, the Andes fail to show the mineral wealth with which they abound in Peru, Bolivia, and Chile. This may well be due merely to the concealment of recent volcanic ash and dense tropical jungle, but at any rate Ecuador has lacked the stimulation to development and progress afforded to the southern countries by the mines of Cerro de Pasco, Potosi, etc. 1 There is, however; in Ecuador, near its southern border, one mining district that, in recent years under North American management, has become a steady producer of mineral. wealth and. a community in which the sanitary and mechanical elements of modern life are displayed, for ;the first time, to the Ecuadorians of the lowland forests. The mining district of Zaruma is .situated in the province of El Oro, near the southwestern corner of Ecuador, about 50 km. (31 mi.) from the coast. Pizarro's first landing on the mainland was at Tumbez, at the mouth of the river that drains the Zaruma area; and the gold so abundantly found in this Indian town was soon traced to its source. In 1549, Mercadillo, one of the original (band, reached Zaruma, having worked his way up-stream through canyons that .are now regarded as impassable. The Spaniards proved themselves efficient prospectors, finding practically every orebody in the district as yet discovered; and, working

Jan 10, 1925

By J. E. Gosline

In any theory of a hydrodynamic nature dealing with the vertical flow of gas-liquid mixtures in pipes, the two factors that present the greatest difficulty are the relative motion between the phases and the energy loss resulting from turbulence work. The former has generally been referred to in the literature as "slippage" and the latter as "friction." A third factor of importance is the nature of admixture between liquid and gas for both the relative motion between the phases as well as the turbulence work are functions of the type of mixture. Although much work of a general nature has been performed on the vertical flow problem, there have been very few attempts made to study experimentally the factors involved in the phenomenon individually. Of these, perhaps the most notable is the work of Moore and Wilde1 on slippage. Some writers on the subject have assumed that over a wide range of operating conditions the controlling type of mixture is one in which gas bubbles of uniform size are distributed throughout the liquid, and that the data obtained from experiments on the motion of single bubbles through various liquids may be used in evaluating the slippage. Ver-sluys2 has further assumed another controlling type of mixture in which the liquid occurs as a dispersed phase within the gas and applies data on the fall of drops of water in air to calculating the relative velocity. It was for the purpose of studying the applicability of data on single bubble motion to the slippage factor and to further observe the nature of mixtures that a research program was conducted at the University of California during 1932 and 1933. These experiments formed a basis for

Jan 1, 1936

By T. S. Fuller

VARIOUS phases of the embrittlement of solid copper containing oxygen by the action of reducing gases at high temperatures through the work of many experimenters are familiar to readers of metallurgical literature. In 1900, Heyn1 recorded observations of copper being heated in hydrogen with the development of fine cracks, the result of the formation of steam within the metal through the action of hydrogen on the copper oxide usually found in copper. Archbutt,2 in 1905, published the results of experiments, showing that all oxygen can be removed from copper by heating to redness, for several hours, in hydrogen. Intercrystalline cracks and extreme brittleness developed. Archbutt attributed the brittleness to the reduction of oxides present in the copper. Bengough and Hill,3 in 1910, encountered the now well-known embrittlement at the outset of their investigation and stated in their paper: It soon became evident that the effect of any heat treatment depended largely on the presence or absence of reducing gases in the atmosphere of the furnace, as well as on its temperature. Hence it became necessary to adopt a somewhat elaborate scheme of heat treatment. The authors found embrittlement in separate experiments due to both hydrogen and carbon monoxide and concluded that: "The gases ruin the alloys after being heated to about 650° C. in their presence."

Jan 2, 1926

By Owen Rice

CHANGES in coke hardness affect the working of the blast furnace, for soft coke is an obstacle to proper furnace operation. Soft coke is due to a low hydrogen-oxygen ratio in the coal charged; increasing this ratio increases the hardness of the coke. The best means of determining the hardness of coke is the combined tumbler and ball-mill. Soft coke is a great hindrance to proper blast-furnace operation and changes in coke hardness affect the working of the furnace. The best method of determining the hardness of coke is by using a combination tumbler-ball-mill. Soft coke is due to a low hydrogen-oxygen ratio in the coal charged. An increase of this ratio improves the hardness of the resulting coke. WHAT IS GOOD COKE? It is not always appreciated that the correct answer may be such a reliable forecast to the physical condition of the blast furnace, and incidentally its entire operation, that among the ordinary variations in other raw materials and also in operating conditions, it assumes a position of primary significance. Inasmuch as coke forms two-thirds of the total bulk of material charged, this assertion will not seem exaggerated, and in the subsequent discussion its applicability will be presented. Coke is the ideal blast-furnace fuel because it is strong and hard enough to resist the crushing and grinding effects of the furnace burden, and its porosity allows the ready passage of gas upward through the charge, and rapid combustion before the tuyeres. Coke deprived of its strength and with a cell structure physically frail and chemically susceptible to solution by carbon dioxide, has its chief asset eliminated. When the melting zones are approached the fluid cinder trickling toward the hearth will envelope the small pieces of coke and form a sticky mass that will retard the free passage of gas. Blast pressure will then rise, driving

Jan 1, 1921

By Frank M. Brewster

The handling of congealing oils and paraffin is a serious problem in the Appalachian fields, particularly because the small amount of oil produced per well makes the removing of paraffin a very costly operation per barrel. Few operators realize or have any means of knowing just how much production is lost on account of paraffin depositing over the face of the sand and plugging the pores of the sand; but where paraffin has been removed the production increases indicate that this loss has been considerable. Many operators believe that paraffining is confined to the tubing and pumping equipment, but it is evident that the most serious damage occurs on the face of the sand and a short distance back in the pores. This paper is an attempt to disseminate information on methods and processes in use in the Eastern fields for combatting losses of production and operating difficulties caused by deposition of paraffin in the pores, on the walls, on the tubing and on other pumping equipment. Mills1 covers this subject so thoroughly that excerpts, abstracts and quotations from his work have been used freely in this paper. Nature oF Paraffin Mills states: "The so-called paraffin that collects in oil wells, and in the pores of the producing sands immediately around the wells, is generally made up of amorphous wax or uncracked paraffin, asphalt, or other gummy hydrocarbons mixed with more or less water, oil and inorganic silt. Some of the samples of this paraffin collected from oil wells in different fields and examined by the Bureau of Mines contains as much as 20 per cent. by weight of water and inorganic silt, whereas other samples are composed entirely of waxy hydrocarbons and oil. The inorganic silt accompanying this 'paraffin' is mostly fine sand, clayey materials, common salt and finely disseminated precipitates of calcium and magnesium carbonates. Sulfates of calcium, barium and strontium are less common constituents of paraffin.

Jan 1, 1928

By AIME AIME

ROBERT F. MEHL was born in Lancaster, Pa., March 30, 1898 and graduated from Franklin and Marshall College in 1919. He then went to Princeton and was granted his doctor's degree in physical chemistry in 1924. Two years as head of the department of chemistry at Juniata College, followed by a like period as National Research fellow at Harvard, working with T. W. Richards and Albert Sauveuir, satisfied Bob's immediate affections for college and university life and prepared him to turn temporarily to other fields.

Jan 1, 1938

President MRS. ROBERT HURSH River Road, Silvermine Norwalk, Conn. First Vice-President MRS. THORNE E. LLOYD 14 Green Hill Road Morristown, N. J. Second Vice-President AIRS. JOHN PAUL DYER Short Hills New Jersey Third Vice-President MRS. FELIX E. WORMSER Acorn Lane Larchmont, N. Y. Fourth Vice-President MRS. JOHN J. LINCOLN Elkhorn, McDowell Co. West Virginia

Jan 1, 1942

By Howard S. Bryant

Kansas maintained its fourth position on the list of all oil-producing states, for the ninth consecutive year. Total crude-oil production during 1935, as reported by the Oil & Gas Journal, was 53,364,446 bbl. on 97 per rent tank table calculations. This represented an increase of 17 per cent over the production in 1934, which had been the all-time peak of production in Kansas up to that time. Many of the 51 new discoveries of the year, listed in Table 2, did not have a pipe line outlet until about January, 1936; therefore did not contribute to the 1935 production of the state. The potential of all wells in Kansas at the end of the year was 998,-000 bbl. per day, and the daily allowable was 143,000 bbl. per day, showing proration to the extent of 14 per cent of capacity, under the rules of the State Corporation Commission. Several important new pipe lines were built into western Kansas by extending older lines from east to northwest, providing additional outlets for new crude-oil production, and increasing the service facilities from the older oil fields. The crude-oil price level remained unchanged throughout 1935 as it did in 1934, the price of Kansas 36" gravity crude being quoted at $1 per barrel. However, on Jan. 9, 1936, the price of this gravity oil was raised to $1.10 per barrel. Following the trend of the past several years, drilling activity was largely in western Kansas, and showed a still farther westward push from last year. A relatively high percentage of successful wildcat wells at a relatively shallow drilling depth, combined with the expiration of leased acreage assembled before the depression, caused the rapid exploration and development campaign, begun in 1934, to continue. This has caused the opening of more new fields in 1935 than during any previous year in the history of oil production in Kansas. A summary of the results of drilling in western Kansas is given in Table 2. Eastern Kansas had considerable drilling, showed six new fields or extensions of oil fields, but in the limited space of this paper such developments cannot be described.

Jan 1, 1936

By Robert Mehl

METALLURGISTS are properly interested in papers dealing with subjects ranging from the theories of the metallic state to very practical details on the use of metals. A review of theoretical metallurgy naturally excludes papers concerned with the usefulness of metals and limits itself to those concerned purely with the science of metals. Even in this more limited field the reviewer is confronted with thousands of papers dealing with facts and theories of metallic behavior, from which he can select only a few hundred. The selection is necessarily highly arbitrary. Certain classes of papers definitely fall within the scope of this review. Thus, papers on the deformation of metals, on the structure of alloys, on recrystallization, to select only a few, are fully represented. Other subjects, which verge on what is generally accepted as the science of metals, such as the magnetic properties of metals, the less familiar electrical properties and theories, adsorption of gases by metal surfaces, and the like, are treated scantily. Particular attention is given to reviews of subjects that fall with in the groups chosen; in a summary such as this, which is largely in the nature of a progress report, capably written reviews are of importance, particularly since the monograph and text book literature is so meager in this field.

Jan 1, 1935

By Walter L. Maxson, Fred C. Bond

There is more information contained in a screen analysis than is ordinarily recognized, and there is an increasing need for methods of making this additional information easily available. As more comprehensive studies of crushing and grinding are made, and as the possibilities of decreased expense and increased extraction through a closer control of grinding are explored, methods of interpreting screen analyses assume an importance which they have not had heretofore. The information commonly desired, which can be determined from a complete and carefully made screen analysis, includes: (1) the size distribution of the material passing the finest screen, (2) the presence of a hard grinding fraction, (3) the location of natural grain sizes, (4) the presence of different materials with markedly different grinding characteristics, (5) the presence and amount of finely divided material such as clay, which is merely unlocked in grinding, and (6) the total surface area of the ground product. It is necessary to know the fundamental law of size distribution of a homogeneous material in order to correctly resolve a screen-analysis curve, and to understand the variations and anomalies that a sample may exhibit when compared with the ideal curve. This fundamental law was developed by Gaudin,1 who showed that when the logarithm of the per cent weight retained on any screen and passing the next larger screen in the Tyler standard screen scale was plotted against the logarithm of the screen aperture the resulting curve for the finer sizes of a homogeneous crusher or grinding-mill product would be a straight line. Gross and Zimmerley2 experimentally confirmed Rittinger's law, which states that the useful work done in crushing a homogeneous material is directly proportional to the new surface area produced; and showed that in the larger screen sizes resulting from impact crushing a

Jan 1, 1935

By Charles A. Ashburner

The Bradford Oil District lies in the northern part of McKean County, Pa., and the southern part of Cattaraugus County, N. Y. Although petroleum was first found in the producing sand in 1871, it was not until the early part of the year 1875 that a productive horizon was acknowledged to exist, even by those most largely interested in the production of the crude oil. It has been reported to me that the first well drilled in the valley of the Tuneangewant Creek (commonly called Tuna Creek) was drilled by F. E. Dean and brothers in 1865. This well was located on the Shepherd farm, near the present site of Custer City. One hundred and sixty feet of drive pipe was used, and the hole was drilled to the depth of 900 feet. The producing sand at Custer City is found about 1130 feet below the level of the railroad track. The Shepherd farm well was therefore abandoned over 200 feet above the top of the oil sand. The next well was drilled by the Dean brothers on the Clark farm at Tarport. Drilling was stopped at a depth of 605 feet, or over 400 feet above the top of the oil sand. In the year 1862 the old Bradford well, since known as the Barnsdall well, was drilled to a depth of 200 feet with a spring pole, and then abandoned. In the spring of 1866 the citizens of the village of Bradford concluded to club together and sink the Barnsdall well deeper. It was drilled to a total depth of 875 feet, or to within 150 feet of the Bradford producing sand. All of these wells were drilled with the expectation of finding the Venango County oil, and at

Jan 1, 1879