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By Gilbert P. Moore

Bolivia does not yet have any production which is being marketed. It does have a potential production, however, from wells which have been completed by the Standard Oil Co. of Bolivia, a subsidiary of the Standard Oil Co. of New Jersey. No other company is active in drilling and development work to date. The total potential production from wells now completed is about 6000 bbl, daily. Wells Completed Completions during 1928 and their initial daily productions. if any, were as follows: Camatindi No. 1, 350 to 1000 bbl.: Camiri No. 1, 500 bbl.; Sanandita No. 3, 100 bbl.; Tatarenda No. 1, dry hole, and Bermejo No. 2, deepened 50 ft. made 1000 barrels. The most striking development of the year was the Camiri No. 1 well which, after just entering the sand, made 500 bbl. per day of 52" B. oil. This well is the northernmost good producer which the Standard has brought in to date. Oil from this well is used without refining in the tractors and trucks of the company. A small topping plant has been installed from which high-grade gasoline is obtained for use in motor cars and some is being produced for the use of air plants stationed at Villa Montes. The results for Sanandita No. 13 were somewhat disappointing since Sanandita No. 2 was rated at about 3000 bbl. Tatarenda NO. 1, located on a large unbroken structure, was drilled to 4000 ft. and abandoned as a dry hole. Bermejo No. 2 was deepened 50 ft. to 2085 ft.. and on a 10-day test averaged 1000 bbl. per day. This well is on the border between Bolivia and the Argentine. Wells Drilling The wells drilling are Camiri No. 2, Sanandita No. 5, Machareti No. I and Bermejo No. 5. This is the smallest number of drilling wells which the Standard has had for several years but is principally due to

Jan 1, 1929

G. M. TAYLOR,* Colorado Springs, Colo.-The ore treated at the United Eastern is primarily a gold one and is cyanided-the counter-current decantation method being employed. One of our employees visited this plant a few months ago and, on his return, reported that the moisture in the tailing was carrying 20 c. per ton, which would appear to be somewhat high. As this type of plant has been advocated by one of the recognized cyaniding engineering firms in the country, and a number of these plants are in successful operation, it does not seem to me that the dissolved loss could be so high, and I would like to know if any one can give any definite information on this point? J. V. N. DORR, New York, N. Y.-I am very glad that Mr. Taylor has raised this question. When I first read Mr. North's paper and saw his statement, that they had an actual dissolved loss of 21.5 c. per ton, I was very much puzzled at this high loss which appeared avoidable by another decantation or the addition of a rotary filter. Reading it again, however, I noted that the actual dissolved loss of 21.5 c. given was evi-dently obtained by multiplying the assay of solution discharged from Z. thickener by the tonnage. On the basis of 283 tons milled per clay, this means $56.54 going to the clam. He states, however, that he returns from. the dam into the system, 70 tons daily assaying 40 c. per ton or $28 per day, so it would seem reasonable, unless I have overlooked something to regard the actual dissolved loss as $56.54 less $28 or $28.54, equaling 10.8 c. per ton. Even this loss, however, is much higher than good practice elsewhere, and can be accounted for largely by the tonnage being handled, which I believe is 30 per cent. above the capacity planned.

Jan 12, 1919

By Thomas M. Drown

In the course of some experiments on the analysis of pig iron, I heated, in a platinum crucible, some borings of a graphitic pig iron with sodium carbonate. When the crucible was at a full red heat and the carbonate was thoroughly fused, I noticed a lively ebullition of the mass, and an escape of gas, which burned on the surface. On investigation this gas proved to be carbonic oxide, and on examining the borings in the bottom of the crucible after an hour or two, they were found to be perfectly malleable, although unchanged in general form and appearance. Analysis showed that the carbon was completely removed. I then repeated the experiment, to ascertain whether the silicon and phosphorus were affected, and found that these elements too were largely removed, and could be .found in the fused mass as alkaline silicates and phosphates. In order to ascertain whether the removal of the silicon and phosphorus was merely a surface action or whether the reaction really extended into the mass of the iron, I tried the following experiments : A number of bars of pig iron were cast about one foot long and planed down 'accurately to one inch section. These were immersed in a large wrought-iron pot full of molteu sodium carbonate made by fusiug the commercial bicarbonate of soda. Through the kindness of Mr. Frank Firmstone, Superintendent of the Glendon Iron Works, Easton, I was enabled to keep this pot at a reasonably constant high temperature for a long time in one of the hot-blast ovens. One of the bars was removed from the pot every twenty-four or forty-eight hours, according to the rapidity of the action, and after cooling mas broken and the fracture examined. The change from pig iron to malleable iron was progressively inwards and always sharp and easily recognized, the rate of progression being in a decreasing ratio with the time. The temperature of the oven had evidently

Jan 1, 1879

By John V. Beall

They let the whole world know again that not only could we do it, but we make it look easy. The great crews before Scott, Irwin and Worden of Apollo 15 have all blended warm humor, informality and dexterity to put on a good show: but it keeps getting better and the last one was the best. Scott's rendition of Galileo's experiment using a hammer and a feather--not just any feather, but a falcon feather after the name of the LEM-was priceless. One generation of school kids will never forget that lesson. The final touch was in the "would-you-believe''" category, Now if English astronauts had been performing the mission, the sign-off would have been typically low key. Something like; "well its tea time, chaps; we'll have to toddle along." Apollo 15 surprised and thrilled spectators by blasting off to the Air Force song "Off we go into the wild blue yonder" and leaving a camera behind to photograph their own ascent. Now that is what we call showmanship. There is another aspect to our space show and that is that it cost billions of dollars to put on. With that kind of backing, the world for an audience and in the face of grave personal risk, one would expect the space explorers to be all business. Instead they did their jobs with limpid buoyancy. Our older readers will recall and contrast a movie of the thirties and the tense atmosphere when they had to talk that kid up there (Franchot Tone) down through the zero ceiling. A feat of considerably less difficulty than docking LEM. but nevertheless the gut tightening drama was absent in the latter event. In another example, few of us can visualize reporting back after a business mission to one of the old barons such as J. P. Morgan in any but the most sedate and business-like terms. In fact we don't have to go that far back, as we can think of a few pepper-pot bosses we have had to whom one always played it straight.

Jan 1, 1971

Reserves of Lake Superior Manganiferous Iron Ores Appendix-to paper by CARL ZAPFFE, presented at the Cleveland Meeting and issued, as Pamphlet No. 1664-C, with MINING AND METALLURGY, May, 1927. The author has made several test calculations on the basis of manganese units that are and may be involved. These are summarized here, as follows: On the basis of ore produced since 1902, the average annual requirement of manganese units would be 91,000 tons; on the basis of the production of the past 4 or 5 years, the requirement would be 145,000 tons; on the basis of the year 1925 only, the requirement would be 155,000 tons. Applying the percentage of increase for the next 20 years, as determined by the plat shown as Fig. 3, the total requirement for 20 years would be 3,254,000 to 3,572,000 tons, if one used either 145,000 tons or 155,000 tons as a starting point. We have the following interesting facts: (1) The Michigan ores contain only about one-half the manganese that the Cuyuna ore does; (2) the Cuyuna district now produces one-half the ore required; (3) the known tonnage of Cuyuna reserves is greater than the speculative reserve offered for Michigan; (4) at the present rate of production considered by tons, Michigan ores ought to be exhausted in 20 years or less while Cuyuna ores would last up to 44 years. We should now reduce the estimated reserves to a basis of manganese, units. Using the tonnages listed in Combinations 2, 3, 4 and 5, the reserves total 3,118,225 tons, 3,781,995 tons, 5,041,995 tons and 5,560,342 tons, respectively. Therefore, needing at the most 3,572,000 tons, as shown above, either Combination 3, 4 or 5 will not only suffice but will leave an excess-enough for 1 or 2 years for Combination 3, 9 or 10 years for Combination 4, and 12' to 13 years for Combination 5. This means that for Combination 5, without using tonnages obtained from beneficiating or from mixing poor ores, the reserves are ample for about 33 years.

Jan 5, 1927

By John Primrose

TUBE stills having demonstrated their usefulness for refining operations, the later developments in their design have been in the direction of improved thermal efficiency: The earlier designs operated with low furnace temperatures and large volumes of furnace gas because the fuel was burned with much excess air. It was quite possible to provide sufficient heating surface to lower the temperature of the flue gas to within 150° of the temperature of the inlet oil, or when inlet-oil temperatures were high to have the flue gas escape at 300° or 350° F. by using the heat remaining in the flue gas from the still to preheat the air supplied for combustion. But even so, the thermal efficiency was low because of the large quantity of air used for combustion. The large quantity of excess air was required to burn the fuel in the furnace at a temperature low enough to prevent overheating the furnace walls and overheating of the oil. Supplying heat to the tubes of the heating surface at a rate beyond the capabilities of the oil to absorb, except with a considerable difference between the temperature of the inside of the tube and oil passing through, would result in overheating the tubes and the oil in contact with them. For these reasons it was very necessary in the older types of tube stills to burn the fuel with large quantities of excess air, resulting in low thermal efficiency despite the low flue-gas temperature. Neglecting loss by radiation, the thermal efficiency could be improved only by burning the fuel with less excess air, but it was necessary to accomplish this without upsetting the furnace temperature conditions existing when large quantities of excess air were used. There are several methods of bringing this about, such as controlling the furnace temperature by returning a proportion of the flue gas to the furnace, or by exposing direct to the fire a heat-absorbing surface so located and proportioned that sufficient heat will be absorbed by radiation to prevent excessive furnace temperatures.

Jan 1, 1928

By C. A. Edwards

Following a brief introduction, an outline is given of the four main conditions in which gases may be associated with metals; namely, (1) adsorbed gases, (2) dissolved gases, (3) gases in chemical combination, (4) gases entrapped in blowholes or cavities. Adsorption is essentially a surface phenomenon and is regarded as the attachment of outside molecules or atoms to the exposed free valencies of the atoms comprising the surface layers. In many cases where adsorbed films of gas are formed this is accompanied by a process of diffusion of the gas into the metal itself. This is particularly true in respect to iron and hydrogen, and experiments have shown that there is no difference between the rate at which hydrogen diffuses through a single crystal of iron arid through the same material after it has been recrystal-lized into a mass of small crystals. This does not prevent a somewhat greater concentration of gas at the boundaries of adjacent crystals, nor does it mean that the effect of the gas will be the same at the boundaries as it is within the body of the crystals. Indeed, under certain conditions, iron is rendered very brittle at the crystal boundaries, as shown in experiments by Pfeil with samples of almost pure iron. Much work has been done by many investigators concerning the temperature and conditions under which dissolved hydrogen, in particular, can be at least partially removed from different metals. With iron, the hydrogen that has diffused into the metal as a result of acid attack by pickling or by electrolytic deposition of the gas on the metal is partly removed by exposing the metal to the atmosphere at ordinary temperatures. Considerably more can be eliminated by raising the temperature, and even greater quantities by jointly raising the temperature and reducing the pressure. Annealing at suitable temperatures completely removes the bad effects of excessive mounts of hydrogen dissolved in or associated with iron. This is shown by the data plotted in Fig. 1, giving values for electrolytic iron sheets after annealing at temperatures between 250" and 950" C. The hydrogen brittleness is rapidly diminished at

Jan 1, 1935

By Charles H. White

+1HARVARD UNIVERSITY, CAMBRIDGE, MASS. The equipment of a laboratory in which students are to be trained for practical work in metallurgical chemistry presents many difficulties not encountered in the fitting up of a commercial or works laboratory. At an industrial plant the chemical work required usually demands the frequent repetition of a comparatively limited number of methods. In a steel-works laboratory, for instance, by far the larger part of the work consists in making determinations of the usual impurities found in iron and steel; at a smelter the great bulk of the work is confined to the analysis of ores, slags, mattes, and fuels, which involve the frequent application of perhaps not more than a dozen different methods. In a laboratory of this character, therefore, those operations most frequently applied may each have a certain section set apart and fitted permanently with such apparatus as best facilitates the carrying out of this one operation. The work of a commercial or custom laboratory is perhaps more varied than that of a works laboratory, but the couditions are similar in these respects, that there is usually no great need for economy of space, and that a few skilled workmen are employed to carry the determinations through from beginning to end without interruption. On the other hand, the laboratory of a technical school should be planned on such a scale that a comparatively large number of students may work at the same time, and each desk should be equipped for general metallurgical analysis. In most institutions for technical education the student's program is so arranged that his day is divided among several subjects in the course of study; only a few consecutive hours being devoted to one subject, or spent in one laboratory. Therefore, those appliances should be provided that render possible the safe continuation of such processes as

Jan 1, 1905

By Michael J. Messel

W. P. MOULD*—Has consideration been given to the problem of retreating the 4,000,000 ton tailings pile to recover the very considerable amount of asbestos fiber that was lost over the years due to insufficient operation and poor recoveries? Also, what was known about the possible content of chromite and the sulphides of nickel and cobalt? M. J. MESSEL (author's reply)—Consideration was given to the problem but nothing concrete has been done up to this time. W. P. MOULD—I am certain the tail- ings contain a very considerable quantity of fiber, not all of which is in the shortest lengths, because in the milling of talc rock from a neighboring location having a common origin with the asbestos bearing serpentine source of the tailings pile, a concentrate carrying 15 pct Ni and Co in complex sulphides and constituting about 4/10 of 1 pct of the talc rock was recovered. In the belief that the tailings also contained an appreciable content of chromite (then in demand, 1937) it was suggested to the management of the asbestos company that a truck load of the current tailings be sent to the flotation plant of the talc company where it would be put over the concentrating tables in an effort to discover the presence and roughly the percentages of chromite, nickel, and cobalt. Preparations for the test were woefully inadequate and the test was completely snarled up by the surprisingly large quantity of asbestos fiber from 1 in. long down to very short fiber, all of which matted up and plugged launders and pumps with disastrous effects and practically the total loss of the sample. If anything was indicaded by the test, it was that a wet process for milling asbestos was worthy of very serious consideration. M. J. MESSEL—A wet milling process for tailings retreatment only, is at present under study at our plant. One asbestos mining company in Canada has constructed a fairly large test plant for this purpose, but as yet no definite results have been obtained other than in a small test unit plant which were in some respects quite encouraging.

Jan 1, 1950

By M. A. Hunter

This paper gives the results of an investigation of the specific resistance and temperature coefficient of the electrical resistance of nickel and its important alloy, monel metal. For most of the pure metals, the temperature coefficient of resistance is approximately 0.004 per degree centigrade at 20" C. Nickel and iron, however, are exceptions. This property is important as it gives us good material for the construction of thermometers and other instruments involving electrical control. A summary of information on this subject has been publishcd by the Bureau of Standards.l The present experiments antedate this publication by several years and as the information obtained is not contained in it, the results of the experiments arc published as additional information. Electrical Properties of Pure Nickel It is generally conceded that the lowest values for electrical resistance are obtained in the purest metal. In the case of nickel, the best material obtainable is electrolytic nickel, which contains approximately 99.80 per cent. nickel, 0.15 per cent. iron, and 0.05 per cent. copper. Any cobalt that may be present is included in the nickel figure. If the elcctrolStic sheet has been deposited without intermission, it is possible to cut a section from the sheet and roll it into wire without melting. By this means a nickel wire may be obtained that is uncontaminated by any of the impurities always taken up by nickel during melting. Two samples of nickel wire obtained from different electrolytic nickels had the follolving electrical resistance and temperature coefficient of electrical resistance: Specific Temp. CofEE. Sample MateRial ReSISTance peR Deg. C. NO. 1 Electrolytic nickel.................... 7.55 0.00550 NO. 2 Electrolytic nickcl ................... 7.60 0.00553 * Rensselacr Polytechnic Institute. Director of Research, Driver-Harris Co. Russell Sage Laboratory, Rensselaer Polyt,ecllnic Institute. 1 U. S. Bureau of Standards, Circular 100 (March, 1921).

Jan 1, 1923

By Meredith Johnson

THE year 1924 saw little change in the production of oil and gas it either Pennsylvania or New York. In the early months of the year the price of Pennsylvania crude oil, $4.00 to $4.50 a barrel, was sufficiently high to cause operators to lay plans for rather extensive drilling opera-tions. But when, in August, the price dropped to $2.85 a barrel, there was no inducement for new work and drilling was curtailed. In spite of the curtailment, however, the combined production of the two states for the year showed a slight increase over 1923, the production being 8;859,000 bbl. in 1923, and 8,901,000 bbl.1 in 1924. The increased production was due entirely to. the continued development of flooding operations in the Bradford field, all other oilfields showing a decline for the year. TABLE 1. Production of Crude Oil in Pennsylvania and New York for the Last Ten Years a Production, Barrels Production, Barrels Year Year Pennsylvania I New York Pennsylvania I New York 1915 7,838,000 888,000 1920- 7,438,000 906,000 1916 7,593,000 874,000 1921 7,418,000 988,000 1917 7,733,000 880,000 1922 7,425,000 1;000,000 1918 7,408,000 809,000 1923 7,609,000 1,250,000 1919 8,137,000 851,000 1924 7,535,0006 1;366,0006 a U. S. Geological Survey figures. b Estimated. Much of the drilling in the southwestern part of Pennsylvania was done in search of gas. Natural gas in Pennsylvania is fast being recognized at its true worth and the increased prices allowed 'the gas companies for their product induced quite a bit of new work. The relative importance of natural gas compared with manufactured gas is shown in Table 2.2

Jan 3, 1925

By M. A. Mallinger

A series of laboratory tests was conducted to determine the limits of practicability in regulating the weights of various cement slurries. It was found that slurry weights of 12 to 19 lb per gallon could be obtained by adding bentonite to decrease the weight and barytes ore to increase the weight. It was also found that barytes ore was not usable in all cements. LIGHTWEIGHT CEMENT SLURRIES INTRODUCTION During the drilling and completion of oil wells the magnitude of the hydraulic pressures exerted on certain formations is critical. In many cases considerable care must be exercised to prevent drilling mud weights from becoming too high, and in those wells where loss of circulation is a problem, the use of normal weight cement slurries will generally result in lost returns during casing cementing operations. While mud weights can easily be controlled, it is necessary to exercise care in the selection of weight reducing additives for cement slurries in order that slurry weights may be reduced sufficiently to prevent the loss of a large portion of the cement to the thief formations without seriously affecting the setting properties of the cement. EXPERIMENTAL RESULTS An extensive search revealed that a large number of materials .that might have been otherwise practicable as a weight reducing additive were not acceptable for use with oil we cements because the imposition of pressure on the slurries caused the additive being tested to be compressed or to absorb water from the slurries, resulting in negligible decrease in the slurry weight. This search for lightweight additives disclosed that bentonite, a material very commonly used for reducing the weight of drilling muds and cements, produced the best results without undue harmful effects on the properties of oil well cements. It was found that there was a limit to the amount of benton-

Jan 1, 1950

By R. C. Canby

The difficulty of exact neutralization by ammonia of the acid solution obtained in the determination of arsenic by the method of fusion with carbonate of soda and nitrate of potassium, led me to try the effect of neutralization by oxide of zinc. I obtained most satisfactory results, and found a great saving of time. The oxide of zinc being added in excess, there is no delicate testing with lit? mils paper and tedious alternate adding of dilute ammonia arid acid until the proper point is reached. The excess of oxide of zinc, too, seems to hold, from the filter, the gelatinous silica and alumina, which are usually precipitated upon neutralization, and thus to render the washing of the precipitated arseniate of silver almost invariably much more rapid. Except the substitution of the neutralization by oxide of zinc for the more tedious method by ammonia, the details of the process are practically the same as those published by Mr. Richard Pearce, of Argo, Colorado (Proceedings of the Colorado Scientific Society, vol. i.), who shows what very accurate results can be obtained by the fusion process. I have made numerous tests of comparison between the two methods of neutralization, and find that those by the oxide of zinc agree almost exactly with the old method. Increasing the quantity of nitric acid, even to considerable excess, to be neutralized by the oxide of zinc did not affect the precipitation of arseniate of silver. The process may be outlined as follows : Take 4 to 1 gramme finely pulverized ore, and mix in a porcelain crucible with eight to ten times its weight of a mixture of equal parts of carbonate of soda and nitrate of potassium (Kerl. Metallurgische Probirkunst gives 4 to 5 nitre to 14 soda). Gradually bring to fusion and keep so, three to five minutes. Cool. Disintegrate in hot water. Filter and wash with hot water. Acidify the filtrate with nitric acid, and boil to expel carbonic acid and nitrous fumes. Cool. Add an excess of an emulsion of oxide of zinc. The bottom of the beaker should have quite a layer of oxide of zinc, after stirring.

Jan 1, 1889

By H. P. Reid

Portland cement is manufactured under either of two general processes, the wet or the dry. The raw materials in general consist of limestone, shells, marl, cement rock, clay, shale, blast-furnace slag, etc., so proportioned that when calcined the desired composition will be obtained. In the wet process the combined raw materials are ground to extreme fineness in the presence of water, to a resulting slurry of from 30 to 50 per cent moisture content. The moisture of the slurry may be reduced by thickening or filtering processes for feed to the cement kiln or the slurry may be fed to the kiln with its full percentage of water. The dry process differs from the wet in that the surface moisture of the raw materials is removed prior to grinding. For the drying of these materials heat is required and in most cases is produced by burning of raw fuel either on grates or stokers before the dryers or in suspension in the form of pulverized coal, oil or gaseous fuel. The power required for making the cement is sometimes purchased from outside sources; sometimes it is generated from the heat in the waste gases leaving the cement kilns, or generated at the plants direct from raw fuel. We have, then, as the possible requirements of fuel in the cement industry: (1) fuel for power generation, (2) fuel for drying raw materials, including coal before pulverizing, and (3) fuel for burning the raw materials to cement clinker. There is no essential difference in quality required in fuel for burning the materials by the wet and,dry processes. Fuel fob Power Generation As there is nothing peculiar to steam generation in a cement mill power plant as compared with other power plants this use classification of such fuel will be found in other reports of the Technical Committee. Fuel for Drying Raw Materials and Coal Any fuels capable of producing moderate temperature gases may be used for drying raw materials. There is no problem of material contamination from fuels at this part of the cement manufacture to be guarded against.

Jan 1, 1932

By Milton Lissberger

MILTON L. LISSBERGER, ? New York, N. Y.-Solder is a mechanical mixture of tin and lead, a fact which is susceptible of very simple demonstration. A bar of solder of a grade even as low as 30 per cent. tin and 70 per cent. lead, passed through a buffing machine, will show a surface practically identical with that of a bar of second-quality or reclaimed tin. The buffings, on chemical analysis, will prove to be almost pure lead. According to the best practice, solder is made in the following manner. Virgin pig lead is first melted, and when it is thoroughly liquefied, virgin pig tin is added, together with a small amount of flux; the latter is for the purpose of bringing to the surface the so-called "liver," consisting of impurities that may have remained in either the lead or the tin as a result of incomplete refining. The combined material, when completely liquid, is thoroughly stirred for some hours, and is then cast into small pigs. Just before casting, and continuously during this operation, the molten metal yields dross, consisting largely of the oxides of lead and tin; this should be carefully skimmed off. After the pigs have cooled, they are taken to a smaller kettle, remelted, and cast into the desired shape for use; or if wires, ribbons, etc., are to be made, the solder is cast into slugs suitable for extrusion and rolling. During this second operation, the skimming of dross should be even more carefully done than at first. Hand mixing has proved to be the only reliable method for the production of the best quality of solder, irrespective of its percentages of lead and tin. The best quality of solder is not necessarily that which contains the highest percentage of tin, but rather is that composition which performs best on the required piece of work. In order to produce

Jan 12, 1918

By John E. Udd

Introduction During the very long period in which man has mined minerals from the crust of the earth, falls of ground and collapes of under- ground workings have been the causes of a significant part of those accidents which have resulted in either death or in injury. At present, because of improvements in the approaches to the design of underground structures, in equipment, and in attitudes towards accident prevention, the proportion of accidents due to instability of rock is probably far less than it was historically. Nonetheless, in spite of the many advances which have been made, instabilities still account for about one-quarter of all fatalities, and one-tenth of all of the injuries, in the minerals industry. The means must be found whereby both the numbers of accidents and the accident rates due to falls of ground can be reduced to the lowest levels possible. At the outset it should be stated that, short of suspension of all mining activity, it will probably never be possible for us to eliminate accidents completely. Most human enterprise involves unknowns and risks, and mining is no exception. A certain number of accidents, then, must be viewed as the inevitable consequence of our attempting to work with unknowns and to make decisions that involve uncertainties. However, in retrospect, many instabilities can be attributed to factors which could have been within our control. The preventable accident must be eliminated. It should be our goal that we make every effort to direct our skills and technology to the creation of a safer working environment and should be constantly striving to

Jan 1, 1983

INTRODUCTION Engineering studies of many near surface coal deposits that are amenable to strip mining can be enhanced and expedited by the application of computer techniques for defining coal reserves and overburden and intraburden yardage and their stripping ratios. The case study discussed herein could be from the western coalfields of Colorado, Wyoming, or Montana; the lignite deposits of the Dakotas or Texas, or from the strippable coal seams of the midwest. Because the techniques can be applied so universally, the actual map locations are not identified. The same computing principles apply to one seam or multiseam deposits, and the capability of the computing programs and plotting routines to display the coal seams in plan and sections provide excellent base maps for further engineering planning and mine layout studies. MANAGEMENT OF DRILL HOLE DATA Drilling for coalfield information is usually done at much wider centers than for other mineral deposits. The geologic logs of the holes are generally quite simple, and frequently record only major lithologies and depths to the top and bottom of the coal seams, together with hole collar survey information. A header card is prepared for each drill hole showing: Hole ID Northing Fasting Elevation Azimuth Dip The header card can be followed by any number of downhole lithologic intercept records: [Hole Depth Lithology Hole ID From-To Coal] Less data errors occur if the computer cards are punched directly from drill hole logs, thus eliminating opportunities for mistakes in transcribing data. All arithmetic manipulations should be left to the computer to avoid as much human error as possible. The SURVEY program is run over the raw data file and all lithologic intercepts are computed and defined in XYZ space. BOUNDARY SURFACES-COAL SEAMS AND LITHOLOGIC UNITS The most useful computer program for defining coal seams in 3D space is a linear inter-

Jan 1, 1980

By Charles E. Weaver

Discussion of the paper of CHARLES E. WEAVER, presented at the San Francisco meeting, September, 1915, and printed in Bulletin No. 103, July, 1915, pp. 1419 to 1427. MILNOR ROBERT, Seattle, Wash.-A year ago at this time, 12 wells were being drilled for oil in western Washington. Some excitement attended the operations; many thousand acres of land were leased to oil companies and stock was widely advertised. The location of the wells may be described by referring to the conclusions in Dr. Weaver's paper, in which the State is divided into four areas. In the area described first, which includes the Cascade Mountains and eastern Washington, where conditions are decidedly against the existence of commercial oil fields, no new drilling was reported. In the second area, the Puget Sound Basin, where conditions are unfavorable, but to a less degree, five wells were being drilled. The third region, covering certain parts of southwestern Washington, contained four drilling wells and several others projected or beginning operations, in spite of the absence of petroleum seepages. None of the wells mentioned is fully active today. On the western side of the Olympic Peninsula, along the Pacific Ocean, are three wells which have been the scene of operations for the past two to three years. The region they are prospecting contains seepages of light oils and is the fourth area described in the paper. The difficulties of transporting both men and supplies to the well sites have delayed operations and brought the costs up to high figures. The drilling of these three wells is interesting on account of the presence of oil in nearby seepages and its occasional appearances in the material penetrated. A. C. McLAUGHLIN, San Francisco, Cal.-The most important part of Washington is on the Olympic Peninsula. The geological conditions on the Peninsula are not similar to the conditions in California, and it would not prove to be a continuous belt of oil-bearing territory from there to here if oil should be found at either end.

Jan 12, 1915

This study of engineering education arose out of the action of a joint committee on engineering education, representing the principal engineering societies. The committee had gathered so much material that it decided the work could best be carried out by some one trained in applied' science, who would devote his entire attention to the study.. The Carnegie Foundation therefore asked Prof. Charles R. Mann, of the University of Chicago, to undertake the work. After making a thorough study Prof. Mann has made a most comprehensive report. In it he says: The engineering schools of the United States began their work upon a definite teaching plan and one that had at least pedagogic consistency. But during the past half century the course of study has been overlaid with many special studies intended to enable the student to deal with the constantly growing applications of science to the industries. As a result, the load upon the student has become so heavy that there is a feeling that the students fail to gain a satisfactory grounding in the fundamental sciences and do not fulfil the expectations of engineers in d manufacturers in dealing with the practical problems with which they are confronted on leaving school. At present 60 per cent. of those who enter the schools fail to graduate, still many of them persist in engineering and make a success of it. It is evident, therefore, that the present systems of admission are not satisfactory. If a group of schools will take up the careful study of their entrance systems and experiment with objective tests and records of the students' youthful interests and achievements, the percentage of elimination can be reduced to at least a fourth of its present size, with an enormous saving of time, energy, and money for both student and school. The number of required credit hours per week should be less than eighteen, preferably sixteen. The few experiments that have been made indicate that college students do their best work when not more than five subjects are studied at a given time.

Jan 1, 1919

By J. M. Ohm, C. M. Bunker

Two special tools for recovering gamma-ray probes and logging cable from drillholes have been designed by Ohm and Bunker and constructed by Ohm. Though intended specifically for U. S. Geological Survey equipment, they may be used with other equipment of the same general type. Fishing Tool for Probes: A fishing tool of the overshot type (Fig. 1) was designed to retrieve logging probes (sondes) that become disconnected from the logging cable and are trapped in the drillhole. When the tool slides over the top of the gamma-ray probe, studs on the bottom engage the shoulder near the top of the probe (Fig. 2), which is then pulled to surface. The barrel can be constructed from brass or steel tubing. Wall thickness is not a critical dimension, but the tool should be heavy enough to sink through mud or water in the drillhole. The internal length of the tool must be enough to prevent interference with the upper end of the probe head as the tool slides over it. The design of the probe head used by the USGS required a minimum free space of 2 1/2 in. inside the fishing tool, which was made 7 1/2 in. long to increase the weight. The lower end, which engages the shoulder of the upper end of the probe, contains three studs placed at 120" around the circumference of the tool and held in the engaging position by the tension of a spring wire. The studs can be made of any metal, such as steel, having high tensile strength. As the tool slides over the probe the studs are pushed outward from the center against the spring tension, allowing the tool to slide into position below the shoulder of the probe head. The spring tension forces the studs inward into the engaged position after they pass the shoulder. When the tool is raised the studs stop against the shoulder, preventing the tool from sliding up over the top of the probe. Once it engages the shoulder of the probe it cannot be freed until both probe and fishing equipment are recovered from the drillhole.

Jan 1, 1960