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On an average of at least once a year there comes to the attention of the Institute Headquarters the activities of some individual who represents himself as a member of the Institute, and by a hard-luck story or other means secures loans or advances of money which are never returned. On one or two occasions the Institute has been able to secure the arrest and conviction of these frauds. Recently some individual has been operating in California and defrauded several members of the Institute. He is described as a man of 5 ft. 7 or 8 in. height, decidedly slim, and his weight is about 140 lb. His hair and mustache are gray, eyes blue or gray and he claims to be near-sighted. He is also said to have had a keen, furtive, "Hang-dog" look and claims to have been raised in Bethlehem, Pa. He speaks with a German accent. If a man answering this description presents himself before any members and claims to be a member of the Institute it will be to the good of the profession if he can be caught making fraudulent representations and placed where his ability to defraud will be under control. The most effective means of apprehending persons of this character is the very prompt notification to Institute Headquarters of any persons claiming to be members of the Institute in hard luck. If such persons are asked to supply their signature or photograph or both to be, forwarded to Institute Headquarters for identification this will serve as an excellent check on their operations. Reluctance to comply with such a request is in itself a suspicious circumstance.

Jan 9, 1919

By H. L. Talbot, A. J. Hall, R. S. Young

A method for the chemical differentiation of oxidized cobalt from sulphide cobalt in complex mine and concentrator products is of considerable interest to a number of mining companies throughout the world. At Rhokana Corporation, in Northern Rhodesia, for instance, cobalt is found chiefly in the sulphide form, as carrollite, but a cobalt oxide mineral also occurs irregularly underground, and relatively small quantities in the mill feed from time to time are difficult to detect visually at the concentrator. The oxide cobalt is not amenable to the sulphide flotation process used at Rhokana and nearly all of it passes into the tailing. The occasional period when high tailing losses occur with no appreciable change in the cobalt content of the mill feed has naturally been disturbing to the concentrator staff, who had no means of determining whether an influx of cobalt oxide ore or laxity on the part of the mill flotation operators as responsible for these results. A procedure for determining oxidized copper minerals, based on their solubility in dilute sulphuric acid saturated with SO2, has been used for many years in the copper industry. In the presence of cuprite the procedure fails, but otherwise it gives results quite satisfactory for control pur- poses. Empirical methods for determining oxidized forms of zinc and lead have been proposed, but they are generally unsatisfactory except in isolated cases of a very simple ore. No published procedure for determining oxidized forms of cobalt or siinilar elements has come to the authors'notice. Experimental Procedure There are obviously two alternatives in attacking a problem of this nature. One is to employ a solvent for oxide cobalt that will not dissolve cobalt sulphide. The other is to find a substance capable of oxidizing the cobalt sulphide to sulphate, which of course is water-soluble and can then be leached from the water-insoluble oxide cobalt. A representative sample of Rhokana cobalt oxide ore was secured, ground to minus 200-mesh, and carefully rolled to furnish a standard sample for this work. The analysis of this material gave the following percentages: Co, 0.55; Cu, 1.64; Fe, 2.98; S, 0.08; SiO2, 41.42; Al2o3, 11.20; CaO, 13.82; MgO, 3.80. As a source of cobalt sulphide a similar large sample of carrollite was prepared, analyzing Co, 23.36 per cent; Cu, 27.32; and S, 31.13. This sample of course was not pure carrollite, but was the best obtainable in quantities sufficient for a standard intended for considerable work. It was a pure sulphide sample, microscopic examination showing only carrollite, a little bornite, and gangue, with no visible sign of oxidized ore present. A wide variety of reagents as used in an effort to selectively dissolve oxide cobalt or to oxidize sulphide cobalt to

Jan 1, 1949

By John F. Abel

At the spring meeting of the Open Pit Division of AIME's Arizona Section, I was asked a question which indicates the acceleration of technical advancement. The question was: "How does an engineer at a properly keep abreast of what is new?" The fact that some 200 Arizona AIME members were at the meeting is a testimonial to the desire of these men to do just that- keep abreast. There is a great deal of talk in academic circles about the built-in obsolescence of an engineering or scientific education, too. About 100 commencement speakers every spring are sure to admonish the graduates that education is a continuing thing. Mining engineers are a small fraternity. We keep informed by talking to one another. Talking shop is valuable but there is no substitute for reading.

Jan 1, 1970

CHARLES G. ROEBLING Charles Gustavus Roebling, president of the John A. Roebling's Sons' Co., of Trenton and Roebling, N. J., and of the New Jersey Wire Cloth Co., of Trenton, and vice-president of the John A. Roebling's Sons' Co., of New York, died at his home, No. 333 West State Street, Trenton, on Oct. 5, 1918. Mr. Roebling, who was born in Trenton, was a son of the John A. Roebling who finished the plans for the Brooklyn Bridge just before he died. The bridge was completed by his sons, Charles G. Roebling and Col. Washington A. Roebling. Upon graduation from the Rensselaer Polytechnic Institute in 1871, Charles Roebling became associated with the Roebling company as a mechanical engineer. He was engineer and builder of the suspension

Jan 12, 1918

By S. Feuerstein, J. M. Galligan

SURFACE effects in the deformation of metal single crystals have been noted by a variety of workers.&apos; A large majority of these experiments have used surface roughening or a second chemical constituent at the surface. We performed the following experiment to see how the presence of a fine polycrystalline layer influenced the stress-strain behavior of single crystals of zinc. Spherical single crystals oriented for single slip were acid-machined into cylindrical dumbbell-shape shear specimens having a gage length of 3.2 mm and a cross section of 20 sq mm. The crystals were then deformed varying amounts at the surface of the gage section with emery paper. Following this treatment, the crystals were heated for approximately 8 hr at 200°C. This resulted in a polycrystalline surface layer, with an observed grain size of approximately 1/10 mm in diameter. Deformation of these crystals was undertaken at 78°K in pure shear, the shear direction <1120> lying in the basal plane. The deformation apparatus has been described elsewhere.2 The presence of a polycrystalline layer markedly raises the first observed plastic deformation, as can be seen from Fig. 1. This yield stress is then followed by a region of low work hardening comparable to that observed in shear tests on similar untreated zinc single crystals. However, the extent of easy glide is quite seriously curtailed, and is followed by a more rapid increase in work hardening, reminiscent of Stage II observed in the deformation of fcc crystals. The higher yield can probably be attributed to the difficulty of penetrating the grain boundaries by dis locations from sources interior to the boundaries. If we associate this yield stress with this breakthrough, then we might expect that more dislocations would be trapped in the crystal than is normally the case. If there is an increased density of trapped dislocations, this could lead to an increase in the amount of trapping with increasing strain, giving a larger strain hardening in the crystal. Although other explanations can be given, it is quite tempting to characterize the region of increased work hardening as a manifestation of Stage II-type deformation. This seems reasonable if the polycrystalline layer is quite efficient in holding up a large number of dislocations. In zinc crystals, since it is well-known that the slip distance can be as large as the specimen dimensions, one would only expect to entrap a large number of dislocation with very large crystals or by applying surface layers. If this interpretation of increased strain hardening is correct, it might present a method of studying Stage II in single crystals of zinc. This research was supported, in part, by the Office of Naval Research (1959). The encouragement and stimulation given by Professor E. R. Parker is gratefully acknowledged.

Jan 1, 1965

By L. Guttman

LESTER GUTTMAN* The question of whether classical thermodynamics alone imposes any lower limit to solid solubilities was raised during a discussion among various members of the Institute for the Study of Metals. Although our conclusions are not new,1 they may be worth reiterating, since confusion on this subject seems to persist. In a binary system (A,B), the conditions for equilibrium, at constant pressure and temperature, between a solid solution and a liquid solution are µAs = µAl [la] µBs = µbl [lb] Here µ denotes the chemical potential either of component A or B, as shown by the subscripts, and the superscripts s and l refer to the solid and liquid solutions, respectively. These two conditions are just sufficient to determine the compositions of both phases. Suppose, however, that the solid phase is found experimentally not to contain any of component B; then we cannot evaluate µbs, which is defined by Here nAs and nBs are the number of mols of A and B, respectively, in the solid, whose free energy is Fs. Eq lb cannot be used, but it is no longer needed: we stated at the outset that the solid has the composition "pure A," and only the liquid composition need now be determined, from Eq la. All the equilibrium properties of the system can be derived from Eq la rigorously and simply. Hence there is no purely thermodynamic reason to exclude phase diagrams which show precisely zero solid solubility. Marsh2 has objected to such diagrams as implying that even the transformation of pure A begins at the eutectic temperature. In any case, the user of the diagram must have a certain minimum knowledge of how to interpret it, and it would seem simpler to remember the general rule that eutectic temperatures have no significance for pure components, rather than to show, say, by broken lines, on a scale which will often be exaggerated, a hypothetical solid-solubility about which we know only that it is less than a certain amount. The case of an intermetallic compound in equilibrium with a binary liquid solution does not require a separate treatment since nothing in the foregoing was dependent on the nature of the components. Therefore, thermodynamics alone does not exclude the possibility that (intermetallic) compounds may exist with compositions always precisely those given by their chemical formulas. With the aid of extra-thermodynamic methods, one may conclude that the solubility of one solid in another is never exactly zero. On the other hand, one would generally expect that the solubility will be small unless the components resemble one another (as do the metals), or form weakly-bound crystals. Therefore, it is useful to know that when there is no direct evidence for solid-solubility, one may neglect it without violating thermodynamic principles.

Jan 1, 1950

On the map of Europe the shield-shaped area included in the boundaries of Rumania appears too small to constitute a very important factor in the wold&apos;s oil production. The country has a total area of 122,000 square miles of territory, about one-fifth of 1 per cent. of the world&apos;s surface, from which about 21/2 per cent. of the world&apos;s oil was produced in 1929. This relatively small area also constitutes one of the known billion-barrel reserves of the world. Oil has been found in various localities in the foothills of the Carpathian Mountains, extending more than 100 miles in length at their base. It is rather unusual that, while the extent of prospective territory seems to be large, the area of the commercially productive pools is comparatively small. Oil accumulation in Rumania is closely associated with salt stocks. Shows of oil are encountered from the Pliocene down to the Cretaceous. Most of the production, however, comes from the Pliocene, the chief producing sands of which are the Dacic and the Meotic, although some oil is produced from the Levantic and the Pontic. The Meotic as a source of oil was known for many years, but the intensive output from this sand series is a comparatively recent development and accounts in a big measure for the steady increase in Rumanian production. In the early part of the summer of 1929 the Astra-Romano (Royal Dutch) completed a well at Moreni in what is thought by some to be a fourth Meotic sand (a new sand series) at a depth of 5200 ft. with an initial production of 2000 bbl. a day of 41" gravity oil. The development of this new horizon has been somewhat retarded by the disastrous fire which occurred at Romano-Americana&apos;s well No. 160 in Moreni, but its discovery adds materially to the future life of the Moreni area, one of the country&apos;s oldest fields. Rumania&apos;s production for 1929 is estimated at 35,556,000 bbl., a daily average of 97,400 bbl. This compares with the total of 31,542,000 bbl. for the previous year, a daily average of 86,180 bbl., or an increase of 12.73 per cent. Rumania now occupies seventh position in the world&apos;s oil picture, it having been replaced as the sixth in importance by the Dutch East Indies in 1929. Table 1 shows a comparison of production by districts and fields.

Jan 1, 1930

By John Birkinbine

In a former paper* attention was directed to the various forms of pumping machines employed for permanent work in mining and metallurgical processes. The following is simply a collection of memoranda of work done of a temporary character, and is presented by way of comparison with other work of similar nature. In close proximity to the charcoal fnrnace at Pine Grove, Cumberland County, Pa., is a large deposit of superior hematite iron ore, which has been worked for a number of years, and from which many thousand tons of ore have been taken by open pit workings. In July, 1874, the furnace was blown out and operations at the bank suspended, the machinery for draining being removed except a plunger pump, 18 inches in diameter and 66 inches stroke, operated by a steam-engine by means of rods. The pit was allowed to fill with water, and no steps towards its reclamation were taken until November, 1877. At that time the pit was a pond of water at the base of the mountain, having an area of about four acres and a depth of seventy feet. As the pumps, rods, etc., had been submerged for over three years, and partially buried by the mud washed down from the banks, and as it was determined to change the location of the pump for future operations and drive it by water-power, a temporary pumping apparatus was determined upon for reclaiming the pit and keeping it drained until the permanent arrangements could be completed. By opening an old adit about 10 feet of the water was removed, and the area decreased to three acres. The inflow of springs was found to be 250 gallons per minute, and the amount of water contained in the pit was computed to be 45,000,000 gallons. As the inflow would undoubtedly increase while the water sank in the pit, provision was made for removing at least 60,000,000 gallons, at the rate of 1,500,000 to 2,000,000 gallons per day. The company determined to employ a Heald and Cisco centrifugal pump driven by an oscillatinig engine by means of a belt. Steam was supplied by four plain cylinder boilers, each 36 inches diameter

Jan 1, 1879

By O. Nomland

The work of The Bahrein Petroleum Company, Ltd., on Bahrein Island consisted mainly in continuing development work and prospecting previously reported. The exploratory work, however, has been greatly minimized and new wells are being drilled, chiefly for the development of larger production; 20 wells had been completed by the end of 1935 and 8 were being drilled. In addition to what has been referred to as the &apos;&apos;main pay," two deeper productive horizons have been discovered, which apparently will greatly increase the potential of the field although the areal extent of this lower production has not yet been determined. The proven acreage of the "main pay" is more than 12,500 acres. Current production (principally from the upper horizons) is about 13,400 bbl. a day. The construction of a 10,000-bb1.-a-day refinery has begun and is to be in operation by July, 1936. It is expected that the capacity will be considerably increased at a later date. The construction of office buildings and a permanent camp has been almost completed. In Saudi Arabia the California Arabian Standard Oil Co., a wholly owned subsidiary of the Standard Oil Company of California, spudded in a well in April, 1935, near the village of Dammam, on the Persian Gulf coast of A1 Hasa. Although several important showings of high-gravity oil and considerable gas have been found, the well is not yet considcred a commercial producer. Dammam well No. 2 has been started farther south on the same structure. A great deal of reconnaissance and some detailed geological work has been completed during the last three field seasons. In order to overcome difficulties of transportation over the desert sand, unusual methods have been used. The parlies penctrating the interior by the use of automobiles and trucks have been supplied with gasoline and provisions by caravans of camels. Mail and supp1ies of lighter weight urgently needed have been carried to the field men by an airplane operated by the geological division of the company. Each party has been supplied with a radio receiving and transmitting set to keep in contact with the airplane as well as with geological headquarters at Jubail on the coast of A1 Hasa.

Jan 1, 1936

By W. D. Bennett

AN interesting effect has been observed in the vacuum etching of titanium in the high temperature ß phase. Using a high vacuum annealing furnace, operating at less than 2x10-6 mm with a tubular titanium liner, it has been found possible to etch polished metallographic specimens at different temperatures between room temperature and 1000°C without contamination or increase in hardness.&apos; Heat etching of titanium has been reported by other workers,&apos; but the following example is of interest as an experiment under high vacuum in the absence of any contamination. Two polished specimens of iodide-processed titanium are placed at different positions along the axis of the furnace corresponding to temperatures of 900" and 800°C above and below the a-ß transus. The specimens are then raised to these temperatures and annealed simultaneously for 3 hr under the same high vacuum conditions. After cooling and withdrawing the specimens, their surfaces are photographed without further treatment. Figs. 1 and 2 show the results for the 800" and 900°C specimens, respectively. Fig. 1, corresponding to a vacuum etch in the a region, shows a typical equiaxed structure with what appears to be a slight shift of grain boundaries. Fig. 2, corresponding to a vacuum etch in the ß region, shows an equiaxed type of structure with the growth of striations in certain grains. The striations are only superficial, as a light polish and chemical etch restores the clean equiaxed structure. The vacuum etch, occurring as it does above the a-ß transus, records the state of the metal in the ß phase by means of the surface relief produced by the selective evaporation of metal from different grains; the metal itself reverts to the equiaxed a on cooling. The nature of the ß etch" (Fig. 2) suggests that, in transforming from the close-packed-hexagonal a to the body-centered-cubic ß lenticular-shaped laminae are formed parallel to common planes of the two structures. This would explain why some grains appear to be unaffected by the etch. The technique has interesting possibilities in the investigation of the mechanics of high temperature transformation. Acknowledgment This note is published by permission of the Deputy Minister, Dept. of Mines and Technical Surveys, Ottawa, Ont., Canada.

Jan 1, 1956

By O. Nomland

The work of The Bahrein Petroleum Company, Ltd., on Bahrein Island consisted mainly in continuing development work and prospecting previously reported. The exploratory work, however, has been greatly minimized and new wells are being drilled, chiefly for the development of larger production; 20 wells had been completed by the end of 1935 and 8 were being drilled. In addition to what has been referred to as the &apos;&apos;main pay," two deeper productive horizons have been discovered, which apparently will greatly increase the potential of the field although the areal extent of this lower production has not yet been determined. The proven acreage of the "main pay" is more than 12,500 acres. Current production (principally from the upper horizons) is about 13,400 bbl. a day. The construction of a 10,000-bb1.-a-day refinery has begun and is to be in operation by July, 1936. It is expected that the capacity will be considerably increased at a later date. The construction of office buildings and a permanent camp has been almost completed. In Saudi Arabia the California Arabian Standard Oil Co., a wholly owned subsidiary of the Standard Oil Company of California, spudded in a well in April, 1935, near the village of Dammam, on the Persian Gulf coast of A1 Hasa. Although several important showings of high-gravity oil and considerable gas have been found, the well is not yet considcred a commercial producer. Dammam well No. 2 has been started farther south on the same structure. A great deal of reconnaissance and some detailed geological work has been completed during the last three field seasons. In order to overcome difficulties of transportation over the desert sand, unusual methods have been used. The parlies penctrating the interior by the use of automobiles and trucks have been supplied with gasoline and provisions by caravans of camels. Mail and supp1ies of lighter weight urgently needed have been carried to the field men by an airplane operated by the geological division of the company. Each party has been supplied with a radio receiving and transmitting set to keep in contact with the airplane as well as with geological headquarters at Jubail on the coast of A1 Hasa.

Jan 1, 1936

By Robert H. Richards

In the latter part of December a batch of amalgam was retorted and the tin in the retort uncovered while at a low red heat, and allowed to cool slowly to a temperature more suitable for ladling into moulds. It was then ladled and made what appeared to be nice, white, malleable block tin. On February 15th our attention is called to the fact that the tin is brittle, and on examination we find that the molecular condition of the pigs has changed to the extent of one-half its material. The change shows itself by an enlargement appearing on the surface something like crystallization, and comes in spots. The condition of the metal in these spots is very peculiar. It has changed from a malleable metal to a brittle one, with a structure somewhat resembling stibnite, and a color very considerably darker gray than tin. The analyses of the two parts of this tin pig showed the following results: Mercury. Tin. Specific Gravity. Crystalline part,.....2.62 97.24 6.175 Malleable part,.....2.38 97.50 7.387

Jan 1, 1883

By Bruno V. E. Nordberg

HOISTING is one of the earliest endeavors of man with machinery, for hoisting was probably used by the early Egyptians. Treadmills were used for general hoisting until early in the nineteenth century and it was a short step only to attach a Watt steam engine to the rope drum of a hoist. One of the earliest steam hoists was built for a coal mine at Frisne, near Valenciennes, France. It was a remarkable piece of engineering created by James Watt in 1811, using a wooden drum on a vertical shaft. This followed the crude hoist by Holtzhausen in 1803, which used a drum of wood on a horizontal shaft.1 In this country there were examples of crude mine hoists, which have been developed into the efficient machines in use today. African and Australian mines show examples of both extremes, and have an array of fine hoisting equipment exemplified in those built by British manufacturers. The influence of both English and American engineering in hoisting is interestingly evident in Canada. The information available to the writer does not reveal this to be true of South Africa, although American-built hoists have been furnished. Mining camps develop their own style of equipment, adapted to local conditions. For instance, the Butte mining district adheres to the straight drum with friction clutches, because of the great number of levels from which hoisting is done or to which men and material are lowered and the necessity for hoisting or lowering unbalanced. The north Michigan copper country uses both straight and cylindroconical drums and hoists continually in balance, so that the drums are not clutched to the main driving shaft. The Joplin mining district, Missouri, has its own peculiar small hoists. Other individual mines or localities in which a number of mines have been developed show individualistic types of hoists, depending upon their particular problems. In each instance, however, the particular problem must be carefully analyzed, as conditions are seldom so near the same that a number of identical hoists can be used to advantage.

Jan 1, 1940

By Ian J. Smalley

"Quickclay is an extreme case, it is by far the most mobile of all the common solid materials on the earth&apos;s surface. It has both a high water content and a mineral texture that allows it to flow with the utmost ease. A mass of quickclay that has lain undisturbed for thousands of years can be jarred into motion by any sudden shock." The quotation is from the paper by Kerr called, "Quickclay," which was published in Scientific American in 1963. This was probably the most widely read paper on quickclay ever published. It was reprinted by Fred Betz in his Benchmark collection on Environmental Geology (BM 25), A quickclay is an extremely sensitive soil. The sensitivity parameter is produced by dividing the undisturbed shear strength by the remoulded shear strength. If a value greater than 50 is obtained, then the soil can be classified as a quickclay. True quickclays are characterized by a very low remoulded strength of the order of 0.5 kPa. The classic quickclays are found in Scandinavia and Eastern Canada, but the 1964 Alaska earthquake revealed a considerable quick¬clay deposit underlying the town of Anchorage. This was discussed in a classic paper by Kerr and Drew in Engineering Geology in 1967. The Kerr views on quickclays were perhaps most clearly expressed in the paper with Liebling in Geol. Soc. Amer. Bull. in 1965. They suggested that the major critical conditions which contribute to quickclay movement are: substantial quantities of layer lattice silicates of colloidal size (about 40% or more by dry weight), sub¬stantial pore water (44%), a reduction in electrolyte concentration below 5 g/l of salt, and addition of a dispersant. There is still discussion and disagreement about the nature of quickclays and the mechanisms of quickclay slides; the "clay mineral"-based views favored by Kerr still find support, although an alternative "primary mineral" view suggests that it is the finely ground primary minerals

Jan 1, 1985

Take a look at the maintenance force in some of Wyoming&apos;s surface coal mines and you&apos;ll notice a significant change-the workers are younger than ever and many have had little or no prior experience. The change is quite a departure from industry&apos;s previous "experienced only" hiring policy. It results, in part, from a successful training program offered by Casper College in Casper. Wyo..

Jan 12, 1978

By AIME AIME

A separate room in the suite occupied by the American Institute of Mining Engineers on the ninth floor of the United Engineering Society Building, has been equipped with furniture and telephone extension for the temporary use of members of the Institute or of sister societies, or visitors suitably accredited. In addition to this general accommodation, another room has been similarly furnished as a business headquarters for a single person, and for a limited period. For the conditions of this privilege, inquiry should be made at the office of the Institute. In order that the benefit of this arrangement shall not be restricted to a few members only, the period of continued occupancy will be limited, and applications will be considered in the order of their receipt. A small fee will be required for the use of the facilities furnished.

Jan 1, 1908

By Maxwell Adams

CONSIDERABLE interest has recently been developed in sage-brush oil because of its possible utilization as a flotation agent in the mining industry. A list of some of its physical properties, together with the method used in its extraction, may prove of interest at this time. Something over a year ago, a study of the essential oils in desert plants was begun in the Chemical Laboratory of the University of Nevada. None of the oils so far studied possess properties of special interest to engineers, except the oil of sage, Artemesia tridentate, which has exceptional power as a flotation agent. This plant, known as common sage brush, also called black sage, is widely distributed over the semi-arid West, being found quite generally on most of the dry plains and mountains west of Missouri. The method of extracting the oil followed in these experiments is very simple. The leaves, twigs and small branches are placed in an airtight drum, having a capacity of about 27 cu. ft. Steam is admitted through a number of small openings at the bottom of the retort, and the pressure maintained at 20 to 25 lb. per sq. in. for 3 hr. The escape of the steam from the retort is regulated by allowing it to pass through a stop-cock into a condenser. The water in the receiver is drawn off from time to time and the oil, which is insoluble and floats upon the water, is thus collected. At the end of 2 hr. most of the oil has been driven out, though traces continue to come over for a much longer time. By raising the pressure, the time required could probably be shortened and the yield increased, but the lack of laboratory equipment has prevented the carrying out of this experiment.

Jan 9, 1916

By W. E. Thorne

The object of this graphic method is to estimate the weight of the casting, which is to be made from a given pattern, when the cross-section is not a uniform geometrical figure. Such an estimate is a very important guide to the foundryman, who would otherwise guess at the probable weight of a casting of new design, and, in trying to be on the safe side, would probably melt an unnecessary amount of iron. It is also an aid to the designer of a new car-wheel pattern, who must otherwise estimate from general experience the probable weight, have test-wheels made, and correct the pattern afterwards, so as to obtain the weight prescribed. For the method here described, an accurate drawing of the pattern is employed. This gives a closer result than a drawing of the wheel itself, for the following reasons: 1. Calculations based upon the actual dimensions of the wheel involve the erroneous assumption that the specific gravity of the casting is uniform throughout; and upon that basis the calculated weight would be wrong, because the amount of metal poured has shrunk in the mould, acquiring the highest density in the outside chilled portion, and growing less dense through the mottled to the gray portions. 2. Calculations based upon the dimensions of the pattern or " chiller " assume that the cooled metal will not have shrunk, but will have the volume of the pattern and a uniform density. These assumptions, though erroneous, counterbalance each other. For instance, the patterns and the chiller which give a wheel 33 in. in diameter when cold, are respectively 33.5 in. in diameter. This shows a shrinkage for wheel-iron of about & in. (ordinary gray pig is commonly assumed to shrink about 1/8 in.) per foot. Wheels cast in 33.5-in. chillers do not always have the

Jan 1, 1903

Discussion of the paper of Norman B. Braly, presented at the Butte meeting, August, 1913, and printed in Bulletin No. 80, August, 1913, pp. 1881 to 1906. GEORGE A. PACKARD, Butte, Mont.:-I would like to ask Mr. Braly if he has any information as to the relative efficiency of the sinking pump, using it as he refers to it, discharging the exhaust into the water column or otherwise. MR. BRALY :-I have never gathered any information on that point. It is a question of getting the work done. In driving the shaft, using that method, we find it easier on the men and everything else. In the bottom of the shaft, if you exhaust back into your column, it is a quiet. shaft. Another thing is the freezing: if you are sinking with air in your pump, you will find it is liable to freeze, and in that case as the air is still under compression it will not freeze the pump. The difference is very small if there is any. But, as might be expected, the pump is a little less efficient when exhausting the air into the column. MR. PACKARD :-I suppose all of us know what a pump in the bottom of the shaft is. My experience has been, although I have no figures, that the capacity of a pump is quite considerably decreased if you are pumping, say, from a depth of 200 ft. through a No. 7 Knowles pump, when you exhaust the air into a column, but, on the other hand, it is also my impression that we can raise the water to a little greater distance. I would like to get some figures from somebody who has made actual tests.

Jan 11, 1913

The entire War Minerals Relief Commission heard the case of the Chas. T. Pyrites & Chemical Company of Georgia on April 15 and 16. The Commission insisted on great detail with regard to the entire enterprise, although the main questions seemed to be of the amount involved. It is considered by the Commission that this claim comes unquestionably under the Act, it is one of the best examples that has been brought to the attention of the Government thus far. Testimony showed that operations were done on the property late in 1916 without request from the Government. Preparations were made to work the pyrites deposit on a comparatively small scale but , following a visit from a representative of the Secretary of Interior and a personal interview of the principal owner of the property and Secretary Lane, operations on a much larger scale were begun. The amounts expended prior to this interview were carefully separated from the expenditures thereafter. Testimony showed that it was the intention of the owners to transport their product by motor truck to the railroad-13 mi. away. This limited shipments to about 50 tons daily. Under the enlarged plan taken against the better business judgment of the owners, a railroad spur at a cost f nearly $200,000 was built to the mine. The operation included a concentrating mill with a capacity f 600 tons daily and an expensive dam to make possible the use of waterpower. With these improvements, the company was just beginning, operation under its enlarged program when the armistice was signed. This resulted in a greatly decreased demand and consequently lower prices, with all prospects indicating that the property could not operate profitably when Spanish pyrites begin to move.

Jan 6, 1919