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By Charles S. Larkey

Numerous papers have been published on the use of graphic methods for determining the best curve for estimating the production decline of oil wells but, as far as the writer has been able to ascertain, nothing has been published showing how curves may be worked out mathematically that will conform most closely to the production data under consideration in any given instance; hence the writer has endeavored to show just how such application can be made. Among the valuation engineers, two types of curves are in current use for the representation of the decline in production of oil wells. One may be represented by the equation, y = krx; this is sometimes known as a percentage curve, for the production for any period is multiplied by a constant rate or percentage to obtain the production for the succeeding period. It appears as a straight line on semilogarithmic cross-section paper. The other curve may be represented by the equation, y = kxn, and is shown as a straight line on logarithmic cross-section paper. In each equation, y represents the number of barrels produced in a given period of time, and x the successive periods of time. The other letters are constants to be determined for each well, or group of wells considered in arriving at the most probable curve to represent the rate of production for a given property. From this the underground reserves may be estimated by extrapolation, or by extending the curve beyond the last known period of production to show the most probable production values for the future. Application to the Burbank Pool Fig. 1 relates to a property in the Burbank Pool, Osage County, Okla. The production is shown as an average per well per month, is plotted to the vertical scale of barrels on the left-hand margin and to the horizontal scale of months at the bottom of the chart. In column y, the number of barrels is listed beginning with May, 1922, as the first month on which to base a decline curve. The type of curve used is of the form, y = krx, or, expressed in logarithms, log y = log k + x log r, in which log k and log r are constants to be determined so that the curve will most closely approximate the production data given.

Jan 1, 1925

Jan 1, 1925

By W. W. Adams

luring the past two years the Bureau of ?,lines has been receiving from 100 to 150 coal mines in various States a report of each accident causing death, permanent total disability, permanent partial disability, or temporary disability lasting beyond the remainder of the day or shift on which the accident occurred. For each 100 accidents in these groups, there are perhaps from 35 to 45 accidents that do not disable the employee beyond the remainder of the day, and of these fraction-of-a-day accidents the Bureau has compiled no statistics. Information revealed by the reports is to the effect that falls of roof and coal in bituminous coal mines are responsible for 28 per cent of the temporary injuries to underground workers and 33 per cent of the days lost from all temporary injuries underground; they also indicate that falls caused 59 per cent of the deaths from all causes underground. Figures compiled by R. N. Hosler, of the Pennsylvania. Mine Rating Bureau, and covering accidents in bituminous; minis in that State, chow that 61 per cent of the deaths underground during the years 1917-1921 wore due to falls. Neither of these percentage figures includes deaths in major explosions; figures for all bituminous mines in the United States during the five years 1920-1024, inclusive of deaths in major explosions, show that 52 per cent of the deaths underground and in shafts were due to falls of roof and coal.

Jan 1, 1925

By K. W. Fritzsche

The prosperity of any nation depends, to a large extent, on its natural resources such as oil, coal, 'metal, timber, waterpower, and fertile soil. Each one of these resources forms the basis of a huge industry. The mining and smelting industry ranks among the first since it paves the way for a number of other industries. The mines and smelters provide a market for electric power, coal, timber, and agricultural products: other industries in turn provide a market for metals and non-metals. The real pioneering, however, is done by the prospector who goes into the wilderness to search for the ores from which the metals are to be extracted for the use of men. Prospecting is an interesting and fascinating occupation. There are many difficulties and hardships in the way but the lure of gold and the vision of finding an outcrop that may develop into a large bank account, within a reasonably short time, will urge the prospector forward. Thus, on the outskirts of this northern hemisphere hundreds of prospectors are searching and toiling and of whom nothing is known or heard until they reach civilization and announce a new discovery. Then a mad rush takes place and everybody who can afford to go will take a gamblers chance and plant stakes in the neighbourhood of the new discovery, or wherever an outcrop of mineralized rock can be found, with the hope of winning a fortune.

Jan 1, 1925

A filled stope is one in which the support for walls and men and, at times, for the back of ore, is furnished by waste rock or sand tailings. The filling may be rock sorted out in the stope or from the walls, develop-ent, or the surface. The orebody is mined in sections, each practically an open or timbered stope, filled wholly or in part before adjacent ground is attacked. As a rule, the filled-stope method is limited to overhand flat-back, stepped-face, or rill stopes. The examples given are Copper Range, Iron Cap, Verde district, Zaruma district, Lucky Tiger, and Silver King Coalition.

Jan 1, 1925

By Rudolph Emmel

The mines operated by the South American Development Co. are located in the Zaruma mining district of southwestern Ecuador. They are near the old mining town of Zaruma, which is the only important city in the canton of the same name. The district is situated in the upper end of a valley lying between two spurs of the Cordillera, one of which may be considered the Coast Range and the other an intermediate range. The mining camp proper, known as Portovelo, and the plant are 2.4 km. south of Zaruma, on the north bank of the Amarillo River, a tributary of the Tumbes River, which flows southwestward through Peru to the Pacific. Portovelo is difficult of access; it is reached from Guayaquil by means of river steamers and muleback. 'Embarking at Guayaquil, the route is down the Guayas River, across the Jambeli Canal, and up the Santa Rosa River to Santa Rosa, a distance of 177 km. From Santa Rosa, the road or trail follows the Santa Rosa River, then across the summit of the Coast Range into Portovelo, a distance of 74 km.—a two-day trip on muleback. The mining property of the South American Development Co. comprises 297 lode claims and 142 placer claims. The combined lode claims cover an area, roughly rectangular in shape, 9000 m. long from north to south by 4000 m. wide; the northern edge of the rectangle is about 3000 m. north of the central plaza of Zaruma. Mineral lands in Ecuador are held by virtue of an annual tax per claim paid to the central government, no surface rights being included. HiSTOry The Zaruma mine has been worked by white men since 1549, probably before that it was worked by Indians. The followers of Pizarro, led by traces of gold in the sands of the Tumbes River, followed that stream to its source, worked the gold veins that they found and established the city of Zaruma. Among the mines worked by them were th Sesmo, Leonora, Viscaya, and Mina Grande. Only the soft ores at the outcrop were

Jan 1, 1925

The timber township of Powelltown, Victoria lies N.E. of Yarra Junction, 60 miles east of Melbourne and in the site of the mill of the Victorian Hardwood Company Proprietary Ltd.A lift gauge railway owned by the company connects Yarra Junction on the Warburton line, with the township through two or three smaller mill centres on the way.The company has been operating for some 12 years. In the divide, about four miles from Powelltown, between the Little Yarra and Latrobe rivers, cutting was continued with material being handled by winch and double incline haulage over the divide. A small bush locomotive dealt with the traffic between the divide and the cutting site.In order to reduce costs, which were heavy at the haulage, the company decided to make a continuous railway from Powelltown to the bush by means of a tunnel through the divide.Hand bore holes were put down on the proposed line of tunnel and showed that the divide at this point consisted of decomposed depth of about 100 ft. towards the eastern or Latrobe side - and that the undecomposed granite summit lay to the west of the surface summit.The bores also served to locate the underground water line, this was afterwards found to rise and fall with wet and weather.To avoid tunnelling in hard and heavy water, the grading of the was laid out with the summit of the hard granite the point in the line.

Jan 1, 1925

By Jacob W. Young

A casual reading of the geological literature extant to-day would give one the impression that carbon is an element which by some chance or another always existed at or near the surface of the earth, and was never of a magmatic origin. The carbonaceous matter in shales is said to be of vegetal derivation; petroleum is stated to have been derived from vegetable matter or from marine animal bodies; if carbon or bituminous matter is found in igneous rocks or associated with metallic ores, the statement is made that deeply buried carbonaceous sedimentaries were undoubtedly the source from which such carbon or bituminous matter was derived. This, I do not consider a reasonable or common sense view of the matter. Carbon is one of the elements of which the earth is composed. In the table giving the periodicity of the elements it comes sixth in the order of increasing atomic weights. It is an element formed like all the rest were formed, and must be as common to the interior of the earth as the rest of the eighty-odd elements so far discovered. The spectroscopic analysis of light from the sun, and the stars, shows the presence of carbon in the sun and in the colder stars. Thus with carbon, an element, found throughout the universe as well as on the earth, it is entirely reasonable to consider it as present in the interior of the earth with the other elements. Such being the case, the magmatic origin for the various forms of carbon in rocks and ores is a rational and logical conclusion. If but a small fraction of thought and effort was made along these lines, which is made in fostering the idea of the organic origin of the carbon found in the earth's crust, untold advances in this phase of geological science would result.

Jan 1, 1925

By A. J. Lyon, J. B. Johnson, Samuel Daniels

The wrought alloys of aluminum with small amounts of copper and of magnesium have, with the development of the automotive and aircraft industries, sprung into prominence through the medium of duralumin; but the cast alloys remained in the background because their possibilities in the heat-treated condition were either not recognized or not fully investigated. In 1919, the Bureau of Standards published a preliminary survey1 of this field, which pointed out that, in general, the ultimate strength and the percentage of elongation of the alloys of aluminum with and without magnesium could be improved by so simple a treatment as heating at 932' F. (500" C.) for 2 hr., cooling in air, and aging at room temperature for several days. British investigators, too, working with chill-cast material, found that" considerable improvement in the mechanical properties of copper-aluminum alloys may be obtained from suitable heat treatment applied to castings."' Jeffries and Gibson8 made the first contribution to the literature dealing exclusively with the heat treatment of sand-cast aluminum-base alloys, describing the effect of small additions or of combinations of copper, magnesium, and iron on the response to a short heat treatment comprising heating at 932" F. in a nitrate bath for 1 hr., quenching in fish oil, and reheating at 300' F. for for 1 hr. Their results disclosed the facts that the ultimate strength and the percentage of elongation of sound alloys were usually, and quite uniformly, improved by heat treatment; that with the iron content ranging between 0.36 and 0.88 per cent. and the silicon content between 0.24 and 0.60 per cent. the effect of increasing the copper content (Tables 10

Jan 1, 1925

By E. P. Polushkin

This work has for its purpose the establishment of a new method for determining the structural composition of alloys. The area occupied by a constituent on a few representative photomicrographs of the alloy is measured, by a planimeter, especially designed for metallographic work, and the volume and proportional weight of the constituent calculated. Experiments have shown that the results are accurate enough to justify the application of the method to many problems in metallographic research instead of chemical analysis. The advantage of the method is the possibility of determining the amount of the constituents without separating them from the alloy; their composition may also be determined if the ultimate chemical analysis of the alloy is known. Suppose Fig. 1 represents a part of a photomicrograph on which the total area of the black figures is to be found. By a system of parallel lines drawn short equal distances apart all figures may be divided into trapezoids. As the area of a trapezoid is equal to its median multiplied by its altitude, the relation between the total areas of the black and the white figures comprised within each strip is equal to the relation between the sums of medians for these figures respectively. This is also true for the whole area of the photomicrograph. Therefore, to determine the total areas of the black and white figures we must first find the proportion between the sums of the medians and then divide the area of the whole photomicrograph in the same proportion.

Jan 1, 1925

By Edward O’Toole

THe Pocahontas district occupies the extreme southern end of West Virginia, principally McDowell, Mercer and Wyoming counties, and a part of Tazewell county, in southwestern Virginia. The first record of the coal field is a report by Prof. J. P. Lesley, of Pennsylvania, about 1880, in which he mentions a coal opening at the upper end of Abbs Valley, Tazewell county, Va. C. R. Boyd, a mining engineer of Wytheville, Va., published a series of articles in 1881, mentioning coal on Indian Creek, Tazewell county, and on Horse Pen creek, which coals, he stated, extended toward the Ohio River. He also mentions the Abbs Valley coal reported by Lesley. In 1881, F. J. Kimball (who became president of the Norfolk & Western R. R. in 1883)) after examining the Scott mine in Abbs Valley, went northward across Abbs Valley Mountain to the place now known as Pocahontas, where he located what has since been called No. 3 vein of Pocahontas coal. In November, 1882, Jed Hotchkiss and others prepared a cross-section of the Flat Top Mountain coal measures, some notes on which were published by Mr. Hotchkiss, between 1880 and 1892, under the title of " The Virginias.' In May, 1881, the Norfolk & Western R. R. was organized through the purchase of the Atlantic, Mississippi & Ohio R. R., an old line running from Norfolk, Va., to Bristol, Tenn., with branches from Petersburg to City Point and from Glade Springs to Saltville. At that time, charters had been granted for three railroads tributary to the New River Valley, but their proposed routes would indicate that the promoters were concerned with minerals, timber, and a connection with the Chesapeake & Ohio R. R., rather than the development of any coal in the Pocahontas district. One of them was projected to extend up Bluestone River a short distance, but not far enough to reach the coal in the Bluestone Valley, and a little grading was done for a narrow-gage road between New River Station and a point in Giles county, Virginia, near the West Virginia line. All charters and railroads in this district were acquired by the Norfolk & Western R.R.

Jan 1, 1925

By S. W. Parr, F. B. Hobart

Studies relating to the behavior of coal toward oxygen may have for their purpose the determination of the fundamental factors that underlie spontaneous combustion, weathering and deterioration, and the general topic of storage, as well as those properties that have to do with the underlying principles of carbonization. There is also involved the possibility of developing information relating to the constitution of coal, or at least the chemical properties inherent in the type substances of which the coal is composed. It is the purpose here to record certain results bearing on this latter idea of the chemical properties that characterize the main constituents of bituminous coal. The avidity of freshly mined coal for oxygen has long been known. What happens to the coal or to the oxygen is not so clear. Is the oxygen absorbed or chemically combined, and what are the conditions as to time, temperature, texture, or components that are most involved in the phenomenon? If we subject a weighed quantity of coal maintained at a constant temperature to a current of oxygen, we may obtain three factors of interest—the weight increase of the coal, the weight of the water, and the weight of the carbon dioxide formed in the reactions involved at that

Jan 1, 1925

By Harry M. Roeser

As a result of the publication, several years ago, of some articles on determining the constants of empirical formulas, the determining the constants of types of curves used for estimating the production decline of oil wells was brought to the writer for study. Methods requiring the minimum of time and labor and the maximum of rigor were sought, as it appeared that the nature of the data from which such curves are computed and the relative uncertainty of occurrence of the events predicted from them did not justify close adherence to the theory on which the solution of such problems is ordinarily based. The technical deficiencies of the solutions presented in this paper, from the standpoint of the method of least squares, are readily apparent to those familiar with that method, but their presentation in detail here is irrelevant to the subject matter. However, it is the author's conviction, after a rather exhaustive study of the problem, that the value of the solutions lose little by the approximate application of the conventional theory. It must be understood by those who use these formulas that the solutions herein given, and the formulas based on them, are merely facilities to aid the valuation engineer in forecasting future events. It is assumed, also, that before application is made of them, prescient judgment based on the circumstances in each case, shows that the forecast has some probability of realization. On this basis only will these formulas be found useful.

Jan 1, 1925

Briefly, an open stope is one in which the ore is taken out and no filling is put in; the only support for the walls may be posts or pillars of ore. Such a method is limited to orebodies with strong walls and ore strong enough to stand unsupported over the back of the stope. Details vary and depend on the dip of the vein, mode of breaking ground, method of handling broken ore, and so forth. The examples given are the Beat-son, Birmingham district, Mineville district, and Cornucopia.

Jan 1, 1925

By C. C. Griggs

From its inception, a limestone quarry or mine should be under the direction of a capable engineer. Before it becomes a reality, he should outlinc the future results, plan the most economical methods for moving the materials and the most efficient equipment, and pilot the undertaking along the narrow pathway of success, avoiding the pitfalls of uneconomical production and the precipitous walls of scanty profits. Inspection of successful limestone properties shows that all have had difficult engineering problems, the solution of which have required keen engineering ability. In approaching a subject of this nature, it is logical to follow the progress of the limestone operation from its inception to the end, as reflecting the engineering required. There are four major divisions: Investigation, equipment, development, and operation. Investigation On the reliability of the engineer's estimates and the soundness of his judgment depend the success or failure of the enterprise. When one visits a prosperous concern, realizes that the limestone is of a constant chemical composition, sees the mechanical devices installed, and watches the output leave the plant in trains of railroad cars or fleets of vessels, he may overlook the fact that in the remote past this great creation was born in some man's brain and evolved through competent engineering. Many factors must be considered before a promoter could procure the money necessary to launch such an enterprise, for a conservative banker will only recommend a successful producer while the promoter must provide funds on his own and his engineer's judgment. An engineering investigation must be made preliminary to expenditure for actual operation, which, for a limestone deposit, would' naturally embrace such subjects as : ' Readily available. 1. Tonnage available........ Possibly available. Chemical analysis.

Jan 1, 1925

By R. W. Bowers

In order to hoist the ore according to grades, stope samples are taken. Three equidistant grooves are picked across the breast at right angles to the dip of the ore, the part removed being caught in the hand and then put into a small bag. When there is broken ore in the breast, the lines are continued down the pile and a small amount taken at intervals of the length of the sampler's pick handle. The quantity of sample from each breast will be between 2 and 3 Ib. If there are two grades of ore, bessemer and non-bessemer, there are two sets of brass checks for each chute, each check stamped with the number of the chute; one set of checks has the word "bessemer" and the other "non-bessemer." Before any ore is removed from the chutes, it is the duty of one man to see that the proper set of checks is at each chute in the mine. As each motor car is loaded, a check is attached to it. When the train reaches the shaft, the sample man removes the check on the first car, notes the grade, and directs the motorman to spot it over the proper pocket. The check is then hung on a hook with the number corresponding to the chute from which the ore came. The sample man throws a short rope with a knot in the end over the car and at the point where the knot falls a standard scoopful is taken. This is placed in a large bag that hangs directly under the hook containing the checks for that particular chute. These chute samples represent a check on the grading of the various contracts and by counting the tags a check is obtained on the miner's tally of the ore going into each chute; the total of the checks represents the hoist. During the stocking season, a standard scoopful is taken from each top tram car. This sample is taken in the same way as the chute samples at the plats underground. Top-of-car Samples These samples are taken by using a rope, preferably a clothesline, knotted each 18 in. of its length, and a hammer and a scoop. The standard scoop measures 31/2 by 21/4 by 11/4 in. and holds about 1/2 Ib. of ore. The rope, as applied to the usual railroad cars at the mine, is knotted into fifteen sections. It is placed diagonally over the car from

Jan 1, 1925

[ASSETS Equity in Engineering Societies Building $491,642.36 Books in Library 40,000.00 Investments: Life Membership Fund $ 16,381.18 James Douglas Library Fund 99,999.36 Robert W. Hunt Fund 7,497.33 J. E. Johnson, Jr. Fund 3,000.00 James Douglas Medal Fund 3,250.00 General Reserve Fund 13,896.75 144,024.62 Cash 47,467.02 Paper on hand 5,253.83 Accounts Receivable 1,124.49 Supplies on hand 163.84 $729,676.16] [ ]

Jan 1, 1925

"The largest variety of asphalt and related bitumen deposits in this country is found in Utah. Utah is one of the few places in the world where the hydrocarbon minerals, gilsonite or uintaite, wurtzilite (trade name elaterite) and ozokerite are produced. These bitumens occur in an area embracing nearly 10,000 square miles in eastern Utah near the Colorado line. This area is largely in the western part of the Uintah basin. The bitumens are in the Tertiary horizon in the various divisions of the Eocene series.Gilsonite is an asphaltite derived from petroleum, wurtzilite is an asphaltic pyrobitu¬men derived from petroleum, and ozokerite is a native mineral wax resulting from the met-amorphosis of paraffinaceous petroleum.Gilsonite is produced by the Gilson Asphaltum Company, a subsidiary of the Bar¬ber Asphalt Company, at Watson, Utah. A narrow guage railroad, seventy miles in length and with a 7 1/2 percent grade over the Book Cliffs on Baxter Pass, was constructed by the company from the Denver & Rio Grande Western railroad main line in order to open up the gilsonite deposits. The veins range from narrow upward to 18 feet in width. The Rainbow vein at the present wokings is eight feet wide, vertical, and has sandstone walls. This vein has been opened up for a distance of about three miles and in some places four hundred feet deep. Forty men usually are employed with a production of eighty tons per day."

Jan 1, 1925

"For many years it has been known that large bodies of iron ore existed in Iron and Washington counties in Utah. The ore is chiefly hematite—both hard and soft—though some magnetite is found. No definite and complete estimate of the iron ore reserves of the state have been made. The U. S. Geological Survey estimated that 40,000,000 tons of ore were disclosed by development work averaging only 35 feet below the surface of the ore. The ore is found along an area about one and a half miles wide by twenty miles long, and for the most part on the eastern and southern slopes or foothills of Three Peaks, Granite Mountain and Iron Mountain. Later estimates by others have gone as high as ore in sight 164,000,000 tons, probable ore 300,000,000 tons and possible ore 1,000,000,000 tons. Whether this last estimate is too great or not there is sufficient iron ore in Utah to justify the starting of an iron industry.Two companies are now mining iron ore in Utah, the Columbia Steel Corporation and the Utah Iron Corporation. The mine of the Columbia Steel Corporation is at Iron Springs a few miles west of Cedar City. About 650 tons, of ore a day is being shipped to the blast furnace at Ironton. The ore is mined by the glory hole method. After being drilled it is blasted to the bottom of the several glory holes and is dropped through chutes into cars on the ore haulage level below. It is then hauled by electric locomotives to the crushing plant, where it is crushed to blast furnace size before going to storage bins. Some of the softer ore is brought to the chutes by Fresno scrapers."

Jan 1, 1925

[YEAR OF ELECTION 1913. FRANK DAWSON ADAMS Montreal, Canada. 1921. WILLIAM CUTHBERT BLACKETT Sacriston, Durham, England. 1923. GELASIO CAETANI Washington, D. C. 1920. HENRY STURGIS DRINKER Merion Station, Pa. 1921. .FERDINAND FOCH Paris, France. 1922. FEDERICO GIOLITTI Torino, Italy. 1888. HATON DE LA GOUPILLIERE Paris, France. 1906. SIR ROBERT A. HADFIELD London, England. 1921. FRANK WILLIAM HARBORD London, England. 1921. HEINRICH O. HOFMAN Cambridge, Mass. 1917. HERBERT HOOVER Washington, D. C. 1915. JAMES FURMAN KEMP New York, N. Y. 1905. HENRI LECHATELIER Paris, France. 1921. C. MCDERMID London, England. 1913. EZEQUIEL ORDONEZ Mexico City, Mexico. 1909. ALEXANDRE POURCEL Paris, France. 1911. ROBERT H. RICHARDS Cambridge, Mass. 1907. CHARLES D. WALCOTT Washington, D. C.] [ ]

Jan 1, 1925