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The Colorado Society of Engineers, Cooper bldg , Denver, Colo C M Lightburn, Secretary. The official organ of the Colorado Society of Engineers is the Engineers' Bulletin, issued monthly. This magazine contains articles on a wide variety of subjects, as do most technical magazines. Several years ago the engineering societies of Colorado turned over to the Public Library of Denver their technical libraries and the Public Library now has a Technical Department serving engineers This library has been enlarged and is supported by the state as well as the engineering organizations of Colorado A bimonthly New Books List is sent out from the Technical Department to all engineers on the mailing list. Books will be lent for the cost of transportation The Technical Department endeavors to keep a file of all state and some foreign publications on mining, geology and engineering Effort will be made to borrow from other sources, any publications which are not on file. The Technical Department does research, compiles bibliographies and answers reference questions. Photostatic copies will be made, at a price, of any publications which can not be loaned Address The Public Library, The City and County of Denver, Technical Department, Denver, Colo Malcolm Glenn Wyer, Librarian.

Jan 1, 1933

By E. D. Gardner

Introduction Oil shale deposits have been exploited in various countries throughout the world, but generally with government aid. The oil-shale industry of Scotland perhaps is the oldest and best-known; the largest was conducted in Manchuria by the Japanese during World war 11 as a source of liquid fuels for military uses. In general, foreign oil-shale deposits that have been exploited are much lower grade than those in the western United States. Considerable interest began to be shown in western oil shales in 1916; the peak of activities was in 1923. The catlin operation, near Elko, Nevada, perhaps was the nearest approach in this country to an oil-shale enterprise on a commercial scale. Over 100 companies were formed, ostensibly for exploiting the oil shale; a large number of them, however, proved to be stock promotions only, which gave the embryo industry a black eye. The Bureau of Mines operated an experi-mental oil-shale retort plant near Rifle, Colorado, from September 1926 to June 1927 and again from April 1928 to July 1929, after which the plant was dismantled. By this time the East Texas oil fields had come ill and the country lost interest in substitute liquid fuels. During World War II the Nation again became concerned about the magnitude of its petroleum reserves. Congress (April 1944) directed the Bureau of Mines to build and operate demonstration plants to produce synthetic liquid fuels from coal, oil shales, and agricultural and other products; a five-year Program was authorized. *' a part of this program the Bureau of Mines has built, at Anvil Points near Rifle, Colorado, a retort plant and develOped an experimental mine to supply the plant with oil shale. An important part of the mining work at Rifle is to devise methods and select practices for mining the oil shale on a commercial scale at the lowest practicable cost. The product to be mined has a relatively low value, a fact that must be kept in in mind. The combined aim of those in charge of the mining and those in charge of retorting is to demonstrate that the shale oil can be produced at a cost per barrel corresponding to the current quotation for crude petroleum —or at least very close to it. Plans call for an uninterrupted flow of broken oil shale from the lace in the mine, through crushers, through the retorts and thence to the disposal dump. The disposal of the spent shale in the Ride area should present no unusual problem. Mining research has consisted so far of Paper studies of the general phases of the probleml determination of the widest Span that the roof Stone will stand safely unsupported, and drilling problems. underground development has not proceeded far

Jan 1, 1949

By E. D. Gardner

INTRODUCTION OIL shale deposits have been exploited in various countries throughout the world, but generally with government aid. The oil-shale industry of Scotland perhaps is the oldest and best-known; the largest was conducted in Manchuria by the Japanese during World War II as a source of liquid fuels for military uses. In general, foreign oil-shale deposits that have been exploited are much lower grade than those in the western United States. Considerable interest began to be shown in western oil shales in 1916; the peak of activities was in 1923. The Catlin operation, near Elko, Nevada, perhaps was the nearest approach in this country to an oil-shale enterprise on a commercial scale. Over 100 companies were formed, ostensibly for exploiting the oil shale; a large number of them, however, proved to be stock promotions only, which gave the embryo industry a black eye. The Bureau of Mines operated an experimental oil-shale retort plant near Rifle, Colorado, from September 1926 to June 1927 and again from April 1928 to July 1929, after which the plant was dismantled. By this time the East Texas oil fields had come in and the country lost interest in substitute liquid fuels. During World War II the Nation again became concerned about the magnitude of its petroleum reserves. Congress (April1944) directed the Bureau of Mines to build and operate demonstration plants to produce synthetic liquid fuels from coal, oil shales, and agricultural and other products; a five-year program was authorized. As a part of this program the Bureau of Mines has built, at Anvil Points near Rifle, Colorado, a retort plant and developed an experimental mine to supply the plant with oil shale. An important part of the mining work at Rifle is to devise methods and select practices for mining the oil shale on a commercial scale at the lowest practicable cost. The product to be mined has a relatively low value, a fact that must be kept continuously in mind. The combined aim of those in charge of the mining and those in charge of retorting is to demonstrate that the shale oil can be produced at a cost per barrel corresponding to the current quotation for crude petroleum -or at least very close to it. Plans call for an uninterrupted flow of broken oil shale from the face in the mine, through crushers, through the retorts and thence to the disposal dump. The disposal of the spent shale in the Rifle area should present no unusual problem. Mining research has consisted so far of paper studies of the general phases of the problem, determination of the widest span that the roof stone will stand safely unsupported, and drilling problems. Underground development has not proceeded far

Jan 1, 1947

The Institute conducts jointly with the American Society of Civil Engineers, American Society of Mechanical Engineers and American Institute of Electrical Engineers, certain activities as listed below, and is joint owner with them of certain properties situated at 29 West 39th Street in New York City United Engineering Trustees, Inc. When Mr Carnegie made his gift, "for the erection of a suitable union home" for the engineering societies, United Engineering Trustees, Inc (then United Engineering Society) was chartered un¬der Chapter 703, Laws of the State of New York, 1904, for "the advancement of the engineering arts and sciences in all their branches, and to maintain a free public engineering library " The Corporation was further empowered to acquire real and personal property and to use, maintain and occupy it, with the provision that any building erected by the Corporation shall be used perpet¬ually as a meeting place and headquar¬ters for the Founder Societies Thus the Carnegie gift realized the ideal of bring¬ing the engineering societies together under one roof, and the Corporation through its members nominated in equal numbers by the four Founder Societies had the necessary authority to act for the Founder Societies in their joint in¬terests in owning and operating for them not only Engineering Societies Building, but in the course of time, Engineering Societies Library, and The Engineering

Jan 1, 1952

By J. S. Aronofsky, R. Jenkins

A simple means of predicting the flowing well pressure history in a natural gas reservoir has been developed. The differential equation for unsteady radial flow of gases through porous media was solved by numerical methods using electronic punch card machines. The results obtained from these calculations are presented in a generalized form which is believed to be most convenient for engineering use. These results are compared with those presented in a paper by Bruce, et al4. An effective radius of drainage has been defined which permits the equation of steady state gas flow to be used easily to predict well pressures in gas reservoir depletion. An equivalent effective radius of drainage is defined for liquid flow systems and a comparison is made of the gas solution to the liquid solutions. INTRODUCTION This paper presents a numerical method for describing the transient flow of gases radially through a porous medium from which the production rate is specified. The results obtained from these calculations are presented in a generalized form which is believed to be the most convenient for engineering use. The principal application of these calculations should be to flow in natural gas reservoirs, in the interpretation of pressure drawdown tests, in the estimation of reserves, and in calculation of injection pressures required in gas injection and cycling operations. The evaluation of natural gas wells is based upon back-pressure tests in which measurements of production rate and flowing well pressure are made for periods of one, two, or more days. The flow is assumed to have stabilized at this time, and the observed values of pressure and production rate are used with standardized formulae to determine the well's allowable production rate. Furthermore, the results obtained from such a test of short time duration are extrapolated in such a manner to allow a prediction of what the well pressure will be at some future time for a specified (but possibly untested) flow rate. The manner of conducting such back-pressure tests suggests several questions as follows: 1. 'What is the definition of stabilized flow and what factors determine the length of time required for the flow to become stabilized? 2. How may the recorded values of pressure and rate be utilized? 3. As the well is produced and the reservoir pressure falls, how will the flowing well pressure change? Can this flowing well pressure be predicted from the back-pressure test? 4. Are the results obtainable from the test influenced by a particular procedure used in obtaining the results? 5. Is it possible to estimate the gross reservoir permeability from back-pressure data? It is not within the scope of this paper to provide solutions Or even to discuss adequately all the above questions. However. in considering such matters, the

Jan 1, 1955

By Clifford Frondel

THE aluminum oxide known as corundum has several varieties that have been used as gem materials since ancient times. These include the red variety called ruby, the blue variety sapphire, and the asteriated types of ruby and sapphire. Asteriated sapphire was known to the ancients under the name of astrios, and descriptions of this gem were given by Pliny and other early writers. The relation of these gem materials to each other as varieties of a single species, corundum, was first clearly established by Haüy in 1805 and J. M. Güthe' in 1809. Natural gem corundum is obtained principally in Ceylon, Siam, Burma, India, and Australia. Star sapphires and rubies always have been highly prized and in recent years have become particu- larly popular in the United States. Natural star rubies of large size and fine quality are extremely rare and rank with large and fine emeralds and diamonds as the most valuable of gem stones. Interest thus attaches to the recent success in commercially synthesizing star sapphires and rubies of a size and perfection unmatched by nature. Corundum was first synthesized as crystals in 1837 by A. Gaudin, who fused alum and aluminum oxide with potassium sulphate. Numerous other syntheses have been reported in more recent years. Summaries of this work are given in Doelter's Hand-buch der Mineralchemie, Mellor's Compreheizsive Treatise of Inorganic Chemistry, and other reference works. The methods employed include the reaction in the gaseous state at high temperatures of halogen compounds of aluminum with water vapor or boric oxide; the crystallization of aluminum oxide from fusion in potassium molybdate, potassium dichrom-ate or borax; and crystallization from highly aluminous silicate melts. Red, blue, or green colored varieties can be obtained by the addition of small

Jan 1, 1955

By Sherwin F. Kelly

Drilling in the Oligocene potash basin of Alsace prior to 1927 had shown important differences of level in the salt beds thus encountered. TO explain this a somewhat unsatisfactory hypothesis of faulting had been advanced. During the latter part of 1926 and the beginning of 1927 our firm was engaged by two organizations1 for the purpose of trying to supplement, by an electrical survey, the geological data this far collected. As a result of this exploration it was possible to affirm that salt dome structures were present in the Oligocene basin of the Upper Rhine, something heretofore absolutely unknown in that region. Two salt domes were actually outlined: one, near Meyenheim, was made the subject of a communication to the Academy of Sciences, by G. Friedel;2 the other, near Hetten-schlag, was briefly discussed by C. and M. Schlumberger3 before the same academy. The purpose of this paper is to indicate the stratigraphic and structural conditions of the area where these salt domes were found; to discuss the results of the electrical survey which led to the location of the domes; and to indicate the new geological outlookwhich such a discovery suggests. Stratigraphy In the southern part of the Rhine graben the Oligocene rests almost directly on the Middle Jurassic and consists, in ascending order, of: 1. Green marls, not salt-bearing, composed of fresh and brackish water deposits. 2. Middle stage, salt-bearing, consisting of lower-schistose marls and upper, variegated marls. 3. Blue marls, not salt-bearing, but including gypsum deposits; hence sediments laid down in a bay more or less connected with the sea.

Jan 1, 1929

The first record of coal anywhere in the Appalachian regions of which we now know is along the north fork of the Potomac River, above the mouth of Savage River, on a map entitled, A Plan of the upper Part of Potomack River call Cohongorooto Survey'd in the Year 1736. Benj. Winslow1 two "Cole-mines" are shown, one just above Green Island and the other just below Hopwood Run. Winslow was in charge of a surveying party to "Lay out the Bounds of the Northern Neck of Virginia," or Lord Fairfax's Grant, his party locating the liver above the mouth of the Shenandoah, while another party located it below that point, and then around Chesapeake Bay and up the Rappahannock River. The results of the two surveys were combined in a map called, The Courses of the Rivers Rappahannock and Potowmack, in Virginia, as surveyed according to Order in the Years 1736 & 1737, made by Wm. Mayo, which does not show the "cole-mines;" this map was used with the report of the boundary commission which was sent to London in the case before the Privy Council. The boundary line decided upon was surveyed on the ground in 1746, just ten years after the original one. The results of this work were shown on A Map of the Northern Neck in Virginia, According to an Actual Survey begun in the Year MDCCXXXVI, and ended in the Year MDCCXLVI, Drawn by Peter Jefferson And Robert Brooke, Surveyors, which is now in the Colonial Office in London. This map shows the "cole-mines" in the same location as on Winslow's map, and taken from his record, of course, as that part of the survey was not retraced. Faulkner, who examined all of these records in his review of the case in 1832, refers to the notes of the original survey as "No. 10. The original field notes of the survey of the Potomac River, and the mouth of the Shenandoah to the head spring of said Poto¬mac River, by Mr. Benjamin Winslow." While the notes of the 1746 survey are in the London records and photographic copies of them are in several libraries in this county, the notes of the 1736 survey cannot be found anywhere. (For Chas. J. Faulkner's report, dated Nov. 6, 1832, see Kercheval's History of the Valley of Virginia, pp. 160-173. Jas. W. Foster's Maps of the First Survey of the Potomac River, 1736-37, in Wm. and Mary College Quarterly History Mag., April, 1938, gives a complete history

Jan 1, 1942

World Petroleum Consumption. By V. R. GARFIAS AND R. V. WHETSEL. (Trans, vol 107). A tabulation showing world consumption of gasoline, kerosene, gas and fuel oil, lubricants, and miscellaneous petroleum products by counties in the years 1931, 1932 and 1933 , Totals are given; for instance, Cuba consumed 3,998,000 bbl of all petroleum products in 1933, in 1933; the world consumed 1,366,291,000 bbl. of all petroleum products, etc. Domestic Production. Annual Symposium of Petroleum Division, February Meeting, 1934 (Trans, vol. 107. 181 pages.) The symposium consists of reports on petroleum and gas developments and production in the producing states of the United States. This year the statistical information is presented in a new and far more comprehensive form. The reports on domestic production are as follows: Arkansas, by B C Craft; California, by V H. Wilhelm and H. W. Miller, Colorado, by C. E. Shoenfelt, Illinois, by A H Bell, Indiana, by W. N Logan and P. Simpson; Kansas, by Marvin Lee; Kentucky, Ohio and West Virginia, by V. C Smith; Louisi¬ana, by B C Craft, Michigan, by Theron Wasson; Mississippi, by B C Craft; Missouri, by F C Greene, Montana, by H. N Hickey, New Mexico, by C. E Shoen¬felt and D E Winchester, New York, by D. H. Newland, Oklahoma, by L. G. E. Bignell, J 0 Lewis and E. A Hanson, Pennsylvania, by G H Fancher, Tennessee, by L. C Glenn, Central Texas, by R B. Kelly and P R Martin, East Texas, by A R. Denison, Gulf Coast, by L P Teas, North Texas, by H B Fuqua and B. E Thomp¬son; North Central Texas, by J M. Armstrong, Panhandle, by R H Lynn and T. C. Craig, Southwest Texas, by 0. G. Bell; West Texas, by C W. Reith, Utah, by E S Shaw, Wyoming, by J G Bartram.

Jan 1, 1935

By P. E. Fitzgerald, J. C. Gindlesperger

1. The Acidizer (Trade Publication of Dowell Inc.): No. 1. Aspects of Acidizing. No. 2. Inhibited Acid. No. 3. The Value of Acidizing. No. 4. The Chemistry of Acidizing. No. 5. Jelly Seal in Acidizing. No. 6. Loosening Stuck Drill Pipe. No. 7. The Geology of Acidizing. 2. J. C. Albright: Acid Is Being Used for Cleaning Intake Wells in Water-flooded Areas. Oil Weekly (Sept. 23, 1935) 24. 3. D. H. Bancroft: Acid Tests Increase Production of Zwolle Wells, Miller County, Arkansas. Oil and Gas Jnl. (Dec. 22, 1932) 42. 4. A. H. Bell: Possible Areas for Acid Treatment in Illinois. Pub. of Illinois- Indiana Petr. Assn. and lllinois Geol. Survey (1934) 49. 5. N. A. Best: Treating Limestone Formations Consists of More than Pouring Hydrochloric Acid in the Well. Oil and Gas Jnl. (April 5, 1934) 54. 6. L. G. E. Bignell: Sealing Off Salt Water from Oil-bearing Formations. Oil and Gas Jnl. (Jan. 30, 1936) 59. 7. L. G. E, Bignell: Acidizing Upper Limestone Formation Facilitated by the Use of Jelly Seal. Oil and Gas Jnl. (March 5, 1936) 30. 8. L. G. E. Bignell: Bailing, Shooting, Tubing and Acidizing Have All Been Tried in Deep Test at Binger, Oklahoma. Oil and Gas Jnl. (May 10, 1934) 38. 9. L. G. E. Bignell: Dowel1 Incorporated Increasing Its Field Service for Acid Treatment of Wells. Oil and Gas Jnl. (June 7, 1934) 62. 10. L. C. Chamberlain, Jr. and P. E. Fitzgerald: Oil Well Acidizing in Michigan. Mich. Acad. Sci. Papers (March 1937). 11. M. E. Chapman: Some of the Theoretical and Practical Aspects of the Acid Treatment of Limestone Wells. Oil and Gas Jnl. (Oct. 12, 1933) 10. 12. C. E. Clason and J. G. Staudt: Limestone Reservoir Rocks of Kansas React Favorably to Acid Treatment. Oil and Gas Jnl. (April 25, 1935) 53. 13. W. F. Cloud: Cleaning and Reconditioning Oil Wells—Reconditioning by Use of Acid (Petroleum Production 1937), 389. University of Oklahoma Press, 1937,' 14. K. A. Covell: Developments in Eastern Production Practice. Acid Treatment of Michigan Wells. Amer. Petr. Inst. Prod. Bull. 213 (1934) 77; Oil and Gas Jnl. (May 31, 1934) 89; Oil Weekly (May 28, 1934) 17. 15. B. A. Cunningham: Acid Treatment of Lime Formations. Amer. Petr. Inst. Paper 901 (1933) 9D, 1-7. 16. 0. I. DeSchon: Pondera Production up 22,000 Barrels. Montana Oil & Min. Jnl. (Jan. 26, 1935) 1.

Jan 1, 1937

By W. H. Blauvelt

W. H. BLAUVELT, Syracuse, N. Y. (communication to the Secretary*).-I have read Mr. Howland's paper on Calculations with Reference to the Use of Carbon in Modern American Blast Furnaces with much interest, and believe that his method of analysis of the subject will be of material assistance in our study of the action of coke in the blast furnace. Mr. Howland quotes Professor Richards' statement that from the standpoint of the generation of the maximum quantity of heat in the furnace, Grüner was right in saying that all the carbon burned in the furnace should be first oxidized at the tuyères to CO and all reduction of oxides above the tuyères should be caused by CO, which thus becomes CO2. It is clear that the maximum quantity of heat is generated in the furnace when the greatest amount of carbon is burned to CO2 irrespective of whether it is burned at the tuyères or further up the furnace. So it would appear that Grüner's theory is sound regarding the maximum production of heat only because if all the carbon is burned to CO at the tuyères the reduction of the ores will have to be effected by the further oxidation to CO2. Whereas, if the reduction of the ores is effected in part by solid carbon, part of this carbon might be oxidized only to CO, resulting in a higher percentage of CO in the escaping gases than from Grüner's "ideal conditions.? But in studying the combustion of coke in the furnace, it is clear that the production of the maximum quantity of heat is not of the first importance in blast-furnace operation, or in the utilization of the fuel charged into the furnace. To my mind the production of a high thermal head at the tuyères is of the first importance, and the best coke is that which reaches the tuyères in proper condition to produce the highest temperature at the tuyères, and in just sufficient quantity to do the amount of work required there under the conditions produced by this maximum temperature. The combustion of a much larger amount of fuel at the tuyères, under conditions that will fall short of producing the highest possible temperature, cannot produce as good results, either in fuel economy or output. If this statement is correct, does it not correspond with Mr. Howland's statement that too much wind is inimical to low coke consumption? Nothing is more fatal to obtaining the highest temperatures than an excess of air for combustion. In the blast furnace an excess of air dilutes and cools the products of combus-

Jan 10, 1916

A 2-year moratorium on accreditation of curricula bearing new designations has been declared by Engineers' Council for Professional Development at its Executive Committee meeting on July 29, 1952. Reason: a more definitive description of what the contents of a curriculum should include to be appropriately designated as "engineering" is needed. This action was brought on by the Committee of Evaluation of the American Society of Engineering Education which had become perturbed over the extension of the name "engineering" to numerous fringe curricula. The 2-year period will permit time for the Committee on Evaluation to study the question and make a recommendation for further action by ECPD. ECPD action also provided that the following curricula should only be given provisional accreditation for one year upon either inspection or reinspection; such provisional accreditation to be extended annually for not more than two successive years pending the report: Engineering Physics, Engineering Mechanics, Geological Engineering, Geophysical Engineering, and Textile Engineering. There are 22 such curricula now accredited.

Jan 1, 1952

Mr. John J. Porter, Chicago Ill. (communication to the Secretary†):—Mr. Baker's account of his experiences with stock-distribution has been particularly interesting to me, as it

Jan 1, 1905

By P. F. Allen

WITH capacity of 51,000 tpd, the Morenci concentrator produces approximately 49,000 tons of tailing for final deposition. Disposal involves distribution of thickened tailing to dams in such a manner that solids can be used for dam construction and water can be impounded for reclamation. During early operation, although tonnage treated was lower, it was necessary to use orthodox disposal practices in the areas available for tailing. Trestles mounted on a series of dams, constructed of borrow material, carried the pipelines from which tailing were spigoted behind the dams. When adequate disposal areas were finally established, it became desirable to look for more efficient methods. The idea of placing the distribution pipe or manifold directly on the crest of the dam was advanced in 1945. After a period of testing, that procedure in modified form replaced the older trestle arrangement. Marked economies resulted, and time required to prepare dams for succeeding storage cycles was greatly reduced. The tailing disposal area for the Morenci concentrator lies south and southwest of the concentrator building. Ample storage space is available. A wide valley contains three sharply defined ravines lying on an average slope of 4 pct. The more central of these ravines, and the largest of the three, is known as Morenci canyon, which provides substantially more tailing storage area than the other two. Stargo canyon lies to the west; the other is appropriately named East canyon. Total area of the tailing disposal site is nearly 31/4 sq miles, or about 2000 acres. The storage area in use was somewhat more than 850 acres at the end of 1954, or 16 acres per 1000 tons of tailing to be stored daily. At the present time none of the east side dams are in regular use but they are available in emergency. There are five dams on the west side (in Morenci and Stargo canyons) as well as two auxiliary dams adjacent to No. 4 West and No. 5 West. This has made it possible to concentrate men and equipment in a smaller area with consequent savings in both manpower and machinery. Tailing Thickening: Tailing from the flotation process reaches the thickeners with a solid content of about 18 pct. The launder carrying this pulp is subdivided at a central point into seven launders carrying a proportional share to each of seven tailing thickeners, which are located in Morenci canyon close to the concentrator. Five of these thickeners are 300 ft diam and two are 325 ft diam. Thickeners are of the peripheral traction type and rakes travel at the rate of one revolution in 37 to 39 min. The entire installation provides 500,000 sq ft of settling area, or approximately 101/2 sq ft per ton of tailing to be thickened daily.

Jan 1, 1957

By S. J. CRAIGHEAD

IN 1912 the United States Smelting Refining and Mining Company made a large investment in a number of coal properties in Utah and in 1915 a subsidiary, the United States Fuel Co., was organized to take over these properties. Operations started in 1916 and the Company soon became, and remains, one of the major coal producers of the State. It now produces approximately one million tons of coal annually, which is about 22 per cent of Utah's output. The U. S. Fuel Co. owns large reserves of good coal and is in a position to expand operations with the industrial growth now taking place in the West. Traveling through the Western States, one is struck by numerous advertising signs portraying the picture of jovial Old King Cole of nursery rhyme fame. His rotund figure and beaming countenance are the symbols of Utah King Coal, the product of the King mine of U. S. Fuel Co. King Coal is a by-word of quality coal throughout all the Western States.

Jan 1, 1948

THIS issue is about Chuquicamata and the new sulphide plant. Chuquicamata is moving into a new cycle of productivity; she has begun to give up the sulphide copper which lies deep-seated beneath the oxide ore zones in large but yet unknown quantity. After forty years of production, Chuqui may be likened to a strapping youngster, with adolescence and maturity still ahead. Mining operations are being projected-not for decades -but for generations. Although there are still many years of open-pit mining ahead, planning of future underground mining has been started. The bottom of the orebody is still unknown, but enough work has been done to show that Chuqui is one of the largest known copper orebodies in the world. Until recently, only the oxide ores have been mined and these have been treated at the rate of 50,000 to 60,000 tons per day by leaching. Construction of the sulphide plant was timed to coincide with reduction in production of oxide ores. The new sulphide concentrator and smelter, designed in keeping with the magnitude of the orebody, will be brought on the production line at the rate of 30,000 tons per day. The capacity of the plant now planned can be expanded to treat 60,000 tons of sulphide ore. Little wonder that Chuqui is a name legendary in the remotest mining circles. But to those who have known her more intimately, and there is hardly a mining camp without a Chuqui graduate, she means much more. She is an orebody that has made engineers. Reposing at 10,000 ft on the western flank of the Andes in the arid northern reaches of Chile, water is scarce, common fuels absent, and volcanoes and earthquakes add drama and hazard. It is these natural difficulties which have created the fascination and challenge which have caused many engineers to devote their lives to unlocking this treasure house of nature.

Jan 1, 1952

By L. A. Morley, W. T. Parry

Engineering design problems encountered by mining engineers often depend on the properties of natural granular materials such as soil, poorly consolidated sediment, fault gouge, and hydrothermally produced clay. The physical properties of such granular materials frequently are determined by the properties of silicate clays. In most mining applications, the clays are in contact with water. Swelling of clay due to water infiltration can interfere with underground support and haulage systems. Water-saturated clay on fault, fracture, and bedding planes causes slope failures in open pit mines, roof falls and heaving of weak underclays in coal mines. Water may be removed and cementing agents may be produced in clays by electrical methods. When an electrical potential gradient is applied to a charged capillary by two electrodes, water moves toward the negative electrode.1 This electrokinetic phenomena is known as electroosmosis and has been used to successfully dewater clay minerals which lack strength because of water. A consolidation effect occurs when the flow of water is accompanied by a decrease in water content. Electrochemical changes in the clay result in cementing and irreversible hardening. Theory A mathematical basis of electroosmotic phenomena is presented by Helmholtz.3 Smoluchowski5 modifies Helmholtz’ model and presents Eq. 1 to describe fluid flow velocity due to electroosmosis. For this formula, the zeta potential can be measured experimentally. The Helmholtz-Smoluchowski model is reasonably valid for clay aggregates with large pores saturated with fresh water or dilute electrolyte solutions.° An assumption used for Eq. 1 (equations are given Table 1; terms are defined in Table 2) is that the thickness of the electrical double layer surrounding the clay particles is small compared with the pore radii. Because this is generally not the case, Schmid7 presents Eq. 2. The volume charge density in the pore may be approximated from cation exchange capacity and porosity measurements. Casagrande8 offers a semi-empirical relationship (Eq. 3) for volume rate of electroosmotic flow and finds that k, is relatively constant for most clays with an average

Jan 1, 1972

By C. E. Shoenfelt

There were 110 important discoveries of either oil or gas in Co1orado in 1935. There was, however, further development of the Price structure in southern Colorado and developments since the first of the year indicate. that an important oil field may be in the making. The discovery of oil in Price structure was made by the Oil City Petroleum Co. late ill Novem-ber, 1934, in its No. 2 Garnett in the northeast corner of lot 3 in the SW.¼ of sec. 25-33N.-2E. This well developed a good showing of oil in Dakota sand at 970 ft. The hole filled up 15 ft. with 40° gravity oil overnight and after standing for several days the oil level was 400 ft. higher. As a result of the discovery of oil by the No. 2 Garnett, three wells were drilled by the William E. Hughes Estate. Two of these wells had good showings of oil and may make good producers but it is doubtful whether they will produce the estimated capacity of 500 bbl. each with which they have been credited. Although the Hughes Estate wells have been completed for some time, they have not been given thorough production tests because of the isolated position of the field and lack of proper facilities. The. first well drilled by the Hughes Estate was located on the west side of the Navajo River on the downthrow side of a fault. It encoun-tered water ill the Dakota sand at 1285 ft, and was abandoned in green shales of the Morrison at 1405 ft. Well cuttings from the Dakota sand showed some evidence of once containing oil, so a 1ocation was selected for No. 2 Fee on the east side of the river and on the upthrow side of the fault. Oil was discovered in Dakota sands ill 1935 by Continental Oil Co. in its No. 3 Hoye, NW.NW.NE. of sec. 34-9N.-78W., on the South McCallum anticline in North Park, Jackson County, Colo., but on account of heavy flows of carbon dioxide gas under high pressure it has been impossible for the company to get an accurate gage of the oil production. The freezing action of expanding carbon dioxide makes the producing of the oil difficult and costly.

Jan 1, 1936

By C. E. Shoenfelt

There were 110 important discoveries of either oil or gas in Co1orado in 1935. There was, however, further development of the Price structure in southern Colorado and developments since the first of the year indicate. that an important oil field may be in the making. The discovery of oil in Price structure was made by the Oil City Petroleum Co. late ill Novem-ber, 1934, in its No. 2 Garnett in the northeast corner of lot 3 in the SW.¼ of sec. 25-33N.-2E. This well developed a good showing of oil in Dakota sand at 970 ft. The hole filled up 15 ft. with 40° gravity oil overnight and after standing for several days the oil level was 400 ft. higher. As a result of the discovery of oil by the No. 2 Garnett, three wells were drilled by the William E. Hughes Estate. Two of these wells had good showings of oil and may make good producers but it is doubtful whether they will produce the estimated capacity of 500 bbl. each with which they have been credited. Although the Hughes Estate wells have been completed for some time, they have not been given thorough production tests because of the isolated position of the field and lack of proper facilities. The. first well drilled by the Hughes Estate was located on the west side of the Navajo River on the downthrow side of a fault. It encoun-tered water ill the Dakota sand at 1285 ft, and was abandoned in green shales of the Morrison at 1405 ft. Well cuttings from the Dakota sand showed some evidence of once containing oil, so a 1ocation was selected for No. 2 Fee on the east side of the river and on the upthrow side of the fault. Oil was discovered in Dakota sands ill 1935 by Continental Oil Co. in its No. 3 Hoye, NW.NW.NE. of sec. 34-9N.-78W., on the South McCallum anticline in North Park, Jackson County, Colo., but on account of heavy flows of carbon dioxide gas under high pressure it has been impossible for the company to get an accurate gage of the oil production. The freezing action of expanding carbon dioxide makes the producing of the oil difficult and costly.

Jan 1, 1936

By John Charles

The Engineering Method. By John Charles Lou11sbul.y Fish. Stanford University Press. 1950. 186 P. $3.-This book is about the "professional habit often referred to . . . . as 'the scientific method' . . ." It formulates for students the system of logic and reasoning that is the mark of the practicing engineer. The three chapters are, "The Method of Engineering", "Application of the Engineering Method" and "Uncertainties in Engineering." They cover logic and reasoning, terms, nontechnical problems, practical conditions controlling the engineering method, inescapable uncertainties and the method of coping with them. The author is emeritus professor of civil engineering at Stanford. The material presented here formed chapters 9, 10, and 11 of The Engineering Profession, by Hoover and Fish, second edition 1950. Elements of Ore Dressing. By Arthur F. Taggart. John Wiley & Sons, Inc., New York, 1950. $10.- A modern and practical introduction to the subject by the noted author of the Handbook of Mineral Dressing. The philosophy that a mill and all its parts comprise a single treatment process is a continuing theme in the book. Professor Taggart covers hand picking, screening, filtration, and electrical concentration. After introducing sedimentation, he takes up acceleration in free-settling, hindered-settling, sink-float, jigging, film and trough concentrators and shaking concentrators. A discussion of organic chemicals in flotation is followed by a detailed treatment of flotation. Final chapters deal with primary crushing, secondary crushing, grinding, transport, and controls and flowsheets.

Jan 3, 1951