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E. L. BLOSSOM, New. York, N. Y.-That this paper deals with a real problem is illustrated by a statement made to the speaker a few months ago by the manager of a silver-lead property: "Our ore contains 60 per cent. silica on which the smelters are penalizing us heavily, and they are not able to take all our stuff even then. We have simply got to find some method other than smelting for getting the silver and lead out of our ores. We have had experts down here and have investigated flotation, leaching and volatilization, of which processes the latter is by far the most promising. We are continuing investigation." I was somewhat concerned in certain chloride volatilization experiments which we carried on in Denver in 1903, working on a carload of ore from Butte. Now being connected with the Cottrell process, by which method the fumes will undoubtedly he recovered if they solve the volatilization problem, I have looked into the matter again, and believe it can be developed into a commercial process. On a laboratory scale, working With silver-lead ores, experimenters have obtained a volatilization of over 90 per cent. of the total values in 30 to 60 min, on quantities of 1 to 5 lb., using a roasting dish and a muffle. That looks very good, and would be entirely commercial. On attempting to duplicate these results in a reverberatory furnace, they found that it is more likely to take 8 hr. firing to yield 75 per cent. extraction, which is not commercial at all, as it requires too much time, labor, and fuel, and the whole process is too slow. Of course it can be done, because we have done it in the laboratory.

Jan 1, 1918

By W. M. Myers

Certain minerals possess inherent color and other properties that make them suitable for the pigmentation of paints, mortar, plaster, concrete, face brick, and other materials. Their production is one of the most ancient of mineral industries and their use by primitive man is well known. These natural pigments have some economic factors in their favor, particularly wide geographic distribution, low cost of production, ease of preparation, chemical stability, and permanence in use so that they continue to form the basis of a small but useful industry. When used in paints such pigments act as a filler and supply body and opacity in addition to color. Natural mineral pigments are prepared for the market by the comparatively simple operations of washing, grinding, blending, and calcining. Any one, or all of these processes may be applied to a single pigment. The development of synthetic pigments and the use of by- product materials have introduced competition with the products of nature and are having a growing influence on the economic position of the mined minerals.

Jan 1, 1949

By S. Shapiro, R. G. Ames

Background Research on the respiratory health of coal miners has focused predominately on the relationship between coal mine dust exposure and ventilatory function impairment (Lapp et al., 1972; Jacobsen, 1976), on the prevalence of coal workers' pneumoconiosis (Lainhart et al., 1969; Morgan et al., 1973), and on coal miner mortality (Ortmeyer et al., 1974; Rockette, 1977). Lesser attention has been paid to the effects of other mining exposures. For example, underground exposure to diesel exhaust emissions (Reger et al., 1980; Ames et al., 1982,1984). An omission in US coal mining research, however, has been identified by the US Office of Technology Assessment (OTA) as the failure to study the effects of inhaled polyvinyl chloride (PVC) thermal decomposition and combustion products (Seltzer, 1979). These products may be released in the mine environment by cable fires, cable explosions, smoldering cables, and conveyor belt fires. In addition to the OTA concern, recent findings of chronic respiratory conditions and other health complications resulting from exposure to PVC decomposition and combustion products in firefighters (Peters et al., 1974; NBS, 1980; NIOSH, 1982; Wallace, 1982), and in survivors of several large scale PVC-fueled fires (Dyer and Esch, 1976; Wallace, 1981, 1982), add immediacy to the concerns. PVC decomposition and combustion PVC decomposition is initiated at temperatures far below ignition (Hartstein and Forshey, 1974; Wallace, 1981). Hence, exposures to decomposition products from smoldering cables may be important health hazards in addition to cable insulation combustion products. Hydrochloric acid (HCL) appears to be the principle toxic substance from the thermal decomposition of PVC since up to 60% by weight is released as HCL (Barrow et al., 1979). HCL is released both as a gas and as an adsorbant on soot particles (Stone et al., 1973), thus allowing penetration of respiratory defenses. In addition, laboratory results indicate that phosgene (carbonyl chloride), a potentially lethal gas, may be produced in significant quantities from electrical arcing of wires covered with PVC insulation (Woolley, 1971; Brown and Birky, 1980). Health concerns related to PVC Toxic effects resulting from high level exposures to PVC pyrolysis and combustion products in animals (Cornish and Abar, 1969) and in humans (Wallace, 1981) is beyond question. Analyses have reported acute, or short-term, health effects resulting from exposure to PVC decomposition and combustion products (Peters et al., 1974; Polakoff et al., 1975). Recently, however, several studies have found that acute effects are often followed first by apparent healing, and then by delayed chronic effects. This pattern of consequential respiratory involvement among persons involved in major PVC-fueled fires has been noted in firefighters, specifically the 1975 New York Telephone Exchange fire (Dyer and Esch, 1976; Wallace, 1982), and the survivors of the 1977 Beverly Hills Supper Club fire (Wallace, 1981). An obstructive syndrome (low FVC and FEV1) was seen in 15% of workers three months following fighting a PVC-fueled fire (Colardyn et al., 1976). Long-term respiratory symptoms seen in studies of survivors of PVC-fueled fires include the bronchitis symptoms of cough and phlegm, and lung dysfunction (Wallace, 1981). Additional support for the thesis of longer-term respiratory effects resulting from PVC-fueled fires is derived from the finding that four persons who initially survived the Beverly Hills Supper Club fire died within nine months of the fire of severe respiratory impairment (Wallace, 1981).

Jan 1, 1986

By V. I. Purcell, S. C. Sun. R. E. Snow

A study including effects of 7) pH value, 2) fatty acid collector, 3) fuel oil, 4) interfering ion, 5) particle size, and 6) operational variables. Test results indicate feasibility of fatty acid flotation under certain restrictive conditions. FATTY acids have been used as standard collectors for floating the matrix1-8 but not the leached zone phosphate ores. After a series of investigations, Davenport9 and Tarbutton10 concluded that the Florida leached zone ores tested were unamenable to fatty acid flotation and must be upgraded by floating the siliceous gangue with Armac-T as collector. The cationic flotation was estimated11 to cost almost ten times as much as a fatty acid process that would ideally give the same flotation grades and recoveries of phosphates. Mineralization: Extensive deposits of leached zone aluminiferous phosphate occur in Florida."= The ore sample used for this work was obtained from the Virginia-Carolina Chemical Corp., Clear Springs area, Florida. The ore is a potential source of uranium and aluminum as well as phosphorus. Since the uranium and the recoverable aluminum are contained in some of the phosphate minerals, an upgrading of phosphate results in a corresponding enrichment of both uranium and aluminum. The phosphate minerals in the ore are primarily pseudo-wavellite, millisite, and carbonate fluorapatite, with a minor amount of wavellite. Quartz and clay are the common gangue minerals, quartz being predominant. Others present in small amounts are ilmenite, hydrated iron oxides, staurolite, monazite, and zircon. Experimental Procedures: After being dried to less than 1 pct surface moisture the material was dry-ground in a Hardinge conical ball mill to —6 mesh. The ground product was classified into 6/20, 20/200, and —200 mesh size fractions. On the basis of Table I, the coarse and fine size fractions were considered as phosphate concentrates, because of their high phosphorus contents. In contrast, the 20/200 mesh fraction, which was low in phosphorus, was used as the flotation feed. All the flotation tests, unless otherwise stated, were performed in a laboratory Fagergren machine under the following conditions: 1) 400 g of solid feed for each test, 2) 2000 rpm impeller speed, 3) 8.9 pH and 4-min conditioning, and 4) 3-min flotation. The procedure used for the quantitative bubble pick-up tests has been described previously.18

Jan 1, 1958

By Howland Bancroft

AMERICAN investment in foreign mining interests today faces its greatest task. U. S. dollars must make possible the. steady procurement of the minerals our defense effort consumes in huge quantities. The two most vital factors involved in foreign procurement are time and the continued good will of the nations from which minerals are purchased. The Point IV program was formulated to care for the second item, but it has failed to do the job. Its lack of success has not been from intent or from basic failure in formula. Foreign Investment, Four Eras Foreign mineral development, in so far as participation by private capital from the United States is concerned, may be divided into four main chronological categories: First: The period prior to the first World War when people, capital and products moved with relative freedom across international boundaries, and London was the recognized mining seat of the world. By the end of 1919 the United States direct investments abroad amounted to $3.9 billion of which some $900 million were in mining and smelting and $600 million in petroleum. Investment climate throughout most of the world was excellent. Second: The period between the end of World War I, when the international economy had been shaken from its foundations, and the beginning of the great depression of the 1930's, which still further disrupted the world economy. By that time the world mining center had moved across the sea and the United States direct investments abroad had increased to $7.7 billion of which mining and smelting accounted for $1.2 billion and petroleum for $1.1 billion. Investment climate was good in most parts of the world. Third: The period of the depression of the 1930's and the beginning of World War II during which foreign trade was still further disorganized and the international economy collapsed. Nazi barter agreements were initiated in many parts of the world, and Soviet propaganda commenced to make its, influence felt in many countries. During this period United States direct investments abroad decreased to $7.3 billion. Mining and smelting investments during the same period decreased some $200 million, though direct investments in foreign petroleum areas increased an equal amount. Investment climate became less and less hospitable in all parts of the world affected by economic nationalism. Fourth: The period since the beginning of World War II during which total direct investments abroad increased from $7.3 to $13.7 billion. Of this sum, at the beginning of 1950 investment in foreign mining and smelting is reported to have been $1.2 billion-back to where it was in 1929, and in petroleum to have reached $3.7 billion. Investment climate remained favorable in the countries respecting contractual obligations and fair in their treatment of invested capital. [ ] As noted above, the relative freedom of passage across international boundaries by people, capital and products ended with World War I and the situation remains unchanged in a greater part of the world. While this same war upset international economy, the depression of the 1930's caused the collapse of world trade, and exports from all countries fell to an alarmingly low figure. Some countries almost ceased to export. Chile, for example, reported a drop of 88 pct in exports. Countries with

Jan 1, 1952

By Joseph E. Pogue, F. G. Coqueron

Prior to 1934, published information covering expenditures by oil companies for properties, plant, and equipment and the residual investments in the various segments of the petroleum industry was not readily available. This paper presents an analysis of the funds invested by a selected group of oil companies during the years 1934 through 1942, based on an extensive study of the individual records of 30 oil companies. The sources, disposition, and characteristics of the capital employed by this group of companies are traced through a series of combined statements and appropriate charts, covering financial and operating data. The analysis of these statements not only constitutes a record useful for comparative purposes but also serves as a basis for a number of broad conclusions, as follows: 1. The petroleum industry generates the capital needed for its expansion almost entirely from its own operations and is therefore a singularly self-contained economic unit. 2. The long-term debt contained in the financial structure of the industry is small relative to the total capital employed, is less than the net working capital, and has increased but slightly during the period under review. 3. The capital expenditures of the group of 30 oil companies for 9 years amounted to 6.1 billion dollars, 58.3 per cent of which went into crude-oil producing facilities. The trend of this segment of expenditures has been downward since 1937. In 1942, expenditures for refining facilities increased sharply and for marketing facilities declined drastically. 4. The net working capital of the group increased 380 million dollars over the period, and the industry is in a favorable position of liquidity. The ratio of combined current assets to current liabilities was 3.21 at the close of the period. 5. The net income of the group displayed an upward trend for the period but with rather sharp cyclical fluctuations. 6. In 1942, Government funds entered the industry for the first time in substantial amounts and were utilized for the provision of war facilities needed for emergency use. 7. The group has paid out a relatively low percentage of net income in the form of dividends. For the period the average was 55 per cent of net income. 8. The rate of return on invested capital for the group averaged 6.4 per cent for the

Jan 1, 1944

By Joseph E. Pogue, F. G. Coqueron

Prior to 1934, published information covering expenditures by oil companies for properties, plant, and equipment and the residual investments in the various segments of the petroleum industry was not readily available. This paper presents an analysis of the funds invested by a selected group of oil companies during the years 1934 through 1942, based on an extensive study of the individual records of 30 oil companies. The sources, disposition, and characteristics of the capital employed by this group of companies are traced through a series of combined statements and appropriate charts, covering financial and operating data. The analysis of these statements not only constitutes a record useful for comparative purposes but also serves as a basis for a number of broad conclusions, as follows: 1. The petroleum industry generates the capital needed for its expansion almost entirely from its own operations and is therefore a singularly self-contained economic unit. 2. The long-term debt contained in the financial structure of the industry is small relative to the total capital employed, is less than the net working capital, and has increased but slightly during the period under review. 3. The capital expenditures of the group of 30 oil companies for 9 years amounted to 6.1 billion dollars, 58.3 per cent of which went into crude-oil producing facilities. The trend of this segment of expenditures has been downward since 1937. In 1942, expenditures for refining facilities increased sharply and for marketing facilities declined drastically. 4. The net working capital of the group increased 380 million dollars over the period, and the industry is in a favorable position of liquidity. The ratio of combined current assets to current liabilities was 3.21 at the close of the period. 5. The net income of the group displayed an upward trend for the period but with rather sharp cyclical fluctuations. 6. In 1942, Government funds entered the industry for the first time in substantial amounts and were utilized for the provision of war facilities needed for emergency use. 7. The group has paid out a relatively low percentage of net income in the form of dividends. For the period the average was 55 per cent of net income. 8. The rate of return on invested capital for the group averaged 6.4 per cent for the

Jan 1, 1944

By R. A. Haney, S. J. Gigliotti

Over the past ten years, analysis of the acceptability of face ventilation systems has been based on numerical criteria rather than solely a study of air flow and methane patterns in the face area. This type of analysis has become possible primarily because of the instrumentation and mathematical models developed by the Ventilation Division, Pittsburgh Health Technology Center, Mine Safety and Health Administration (MSHA). To properly use these mathematical models, large amounts of methane and airflow data must be collected in the face area during mining activities. To supplement underground testing of face ventilation systems, a full scale model of a face area was built. This model includes a full scale model continuous miner, a face ventilation system, a gas release system, and a remote methane detection system. The remote methane detection system consists of an array of twelve methane sensors located throughout the face area. Data from the sensors are transmitted to strip chart recorders. Methane, air quantity, and other data collected during a test are entered into a computer for analysis. This paper presents the data entry system, the models used for data analysis, the test results, and the application of these results to a face ventilation system.

Jan 1, 1983

W. ROWLAND Cox,* New York, N. Y. (written discussion?).-The process described by Mr. Malcolmson undoubtedly represents a great stride toward conservation of our natural resources. Without discussing the subject from an economic standpoint, I wish further to emphasize the fundamental principles of the Smith process in order that its economic value may be fully appreciated. The process is essentially a means of producing an ideal fuel, as regards its combustion qualities, by the removal of the so-called volatile matter from the coal, in the form of byproducts, which have value for other purposes far in excess of their fuel value. In other words, coals which contain. large amounts of gas, tar, and ammonia, and are not suitable for domestic or industrial fuel, or for treatment in byproduct coke ovens or gas retorts; because they possess poor coking qualities, can he prepared for commercial use by the. Smith process with a very high degree of efficiency. Much work has been done along this line, both in this country and in Europe, in developing a means of preparing coal, as the economic advantages have long been recognized. To the best of my knowledge, the Smith process is the only one that has proved its commercial adaptability. Distillation of coal at 900° to 1000° F. (480° to 540° C.) yields a large amount of tar and oils. The residue of the distillation, however, is a very friable semi-coke, wholly unsuitable for use as a fuel, unless it can be charged directly into a byproduct gas producer. The problem which confronted the inventor was then to convert this carbon residue into a commercial product, and it is in this step that the Smith process has overcome the obstacles which prevented a number of other methods from becoming commercially practicable.

Jan 10, 1918

By Robert S. Schecter, Mark P. Walsh, Michael J. Humenick

In recent years in situ leach mining has emerged as a viable technology for the recovery of uranium from strata in South Texas which contain relatively low concentrations of uranium ore. Because the ore bodies lie within ground-water aquifers, a significant determinant in the economics is the requirement that such aquifers be protected from contamination. Since ammonia is one of the constituents of the leach solutions now being field tested, one environmental problem to be resolved is the removal of ammonia at the end of mining. A second related question is the fate of the ammonia which is not removed by the restoration procedure. This paper considers the displacement and migration of ammonium in a flowing electrolyte with concomitant ion exchange. The ion exchange is an important feature since, during the solution mining phase, ammonium saturates the mineral exchange sites and must be removed from these sites. A mathematical model is used to simulate this process and the model is tested against the results of laborator.y experiments. It is found that the simulations are adequate if an appropriate selection of parameters is made. The model is then used to investigate the effect of cation composition and concentration of the restoration medium as well as dispersion on the overall effectiveness of the process. It is concluded that increasing the concentration of monovalent ions in a solution containing a mixture of both monovalent and divalent ions decreases the adsorption selectivity of the divalent ions with respect to all monovalent ions including ammonium. Thus increasing the ionic concentration of a restoration fluid by increasing the concentration of a nonselectively adsorbed (with respect to ammonium) ion may have a very limited benefit.

Jan 1, 1979

By Charles H. Fulton

THE Engineering Education group began its sessions Tuesday morning, Feb. 16, as a Committee and wound up the day as the Institute's fifth " Division." C.II. Fulton presided. The first paper for discussion was entitled "Teaching Management in Engineering Schools,"' by Eugene McAuliffe, president of the Union Pacific Coal Co., space for which may be found later in these pages. In it, Mr. McAuliffe argued that an engineering student should be taught the knowledge of men, much as a medical school teaches surgery. He then went on to indicate, out of the wealth of his administrative experience, the problems an executive needs to be equipped to handle, and said that every student engineer should look on himself as a potential manager.

Jan 1, 1932

By H. A. Schwartz, Wolfram Ruff

The spheroidal form of the temper carbon nodules in malleable cast iron and of the graphite mottles of "mottled" cast iron suggests that in both all the graphite in a given mottle or nodule grew from a single center of crystallization or nucleus. $ There is, however, a distinct metallo-graphic difference between the mottle and the nodule; the area of mother metal impoverished in combined carbon by the crystallization of graphite in a mottle is practically coextensive with the ramifications of the graphite, while the impoverished zone of metal corresponding to a given nodule is always larger, and usually much larger, than the approximately spherical mass of graphite crystals forming the nodules. Furthermore, the mottle probably is formed during freezing and the nodule almost always at a considerably lower temperature. Assuming that the nodules or mottles can be used as a measure of the existing nuclei (capable of germination) we propose to record certain observations as to the graphitizing reaction in the light of the number and habits of growth of these nuclei. The present authors, in cooperation with others'-', have reported upon various cognate aspects of the problem. The fact that temper carbon is a mass of flakes and not a solid granule has become well recognized since the introduction of an improved polishing technique8, 9, 10 for cast iron. The problem of deriving from the circular planar intercepts of a mass of spheres of varying sizes their number and size distribution in space has also been satisfactorily solved12, 13 Growth of Nuclei in White Cast Iron It has already been shown1, 3 that the progress of graphitization with time is usual1y consistent with the assumption that nodules grow in size

Jan 1, 1936

By Wolfram Ruff, H. A. Schwartz

The spheroidal form of the temper carbon nodules in malleable cast iron and of the graphite mottles of "mottled" cast iron suggests that in both all the graphite in a given mottle or nodule grew from a single center of crystallization or nucleus. $ There is, however, a distinct metallo-graphic difference between the mottle and the nodule; the area of mother metal impoverished in combined carbon by the crystallization of graphite in a mottle is practically coextensive with the ramifications of the graphite, while the impoverished zone of metal corresponding to a given nodule is always larger, and usually much larger, than the approximately spherical mass of graphite crystals forming the nodules. Furthermore, the mottle probably is formed during freezing and the nodule almost always at a considerably lower temperature. Assuming that the nodules or mottles can be used as a measure of the existing nuclei (capable of germination) we propose to record certain observations as to the graphitizing reaction in the light of the number and habits of growth of these nuclei. The present authors, in cooperation with others'-', have reported upon various cognate aspects of the problem. The fact that temper carbon is a mass of flakes and not a solid granule has become well recognized since the introduction of an improved polishing technique8, 9, 10 for cast iron. The problem of deriving from the circular planar intercepts of a mass of spheres of varying sizes their number and size distribution in space has also been satisfactorily solved12, 13 Growth of Nuclei in White Cast Iron It has already been shown1, 3 that the progress of graphitization with time is usual1y consistent with the assumption that nodules grow in size

Jan 1, 1936

By W. I. Duvall

A brief review of the resonant frequency and ultrasonic pulse methods for obtaining elastic constants of rock samples shows that the equations for an iso-tropic elastic solid commonly used to calculate Young's modulus, modulus of rigidity and Poisson's ratio can result in appreciable error if the rock is even slightly anisotropic. Consideration of the equations that relate bar velocities and free medium velocities to elastic constants for orthotropic, transversely isotropic and isotropic solids shows that a combination of the two methods can be used to determine average elastic constants for a single sample of rock. The determination of elastic constants in different directions requires a large number of tests on oriented samples. The use of both the resonant frequency and ultrasonic pulse methods is recommended so that the determination of both Young's modulus and modulus of rigidity is independent of the determination of Poisson's ratio. The dynamic elastic constants of rock can be determined in the laboratory from measurements on small samples which may be in the form of right circular cylinders (diamond drill core). Either the resonant frequency6 or ultrasonic pulse method1 can be used to determine the longitudinal and shear velocities in the same specimen. The resonant frequency method provides a measure of the longitudinal bar velocity, V,, and the torsional bar velocity Vt; whereas the ultrasonic pulse method provides a measure of the free medium longitudinal velocity, Vp, and the free medium shear velocity, V, . The elastic constants (Young's modulus E, modulus of rigidity G, and Poisson's ratio v) are calculated from the density of the specimen, p, and one of the pairs of velocities by means of equations from isotropic elastic theory. For the resonant frequency method the equations are: It should be noted that Eq. 5 is derived from Eq. 4 and 6 and the relation between the elastic constants for an isotropic solid as given by the first part of Eq. 3. The in situ determination of dynamic elastic constants is accomplished by generating a complex seismic pulse in the rock and measuring the arrival times for the longitudinal and shear phases of the pulse at two distant points.5 From these travel times and the distance of the travel path both Vp and Vs are determined. The density of the rock is determined from samples in the laboratory, and Eq. 4 to 6 are used to calculate the elastic constants. These three methods involve the assumption of isotropy and perfect elasticity, and require the use of the relation v = (E/2G) - 1, which holds only if the elastic constants are the same in at least two directions. The calculation of v by means of Eq. 3 introduces considerable error, as a 1% error in V, and V, results in a 20% error in v. If frequencies for samples with a length-to-diameter ratio greater than four and a length greater than 8 in. are measured carefully, the experimental error can be kept to 1%. However, it is not unreasonable to expect that the variation in Vb and Vt with direction may exceed 1%. Thus, for even a small percentage of anisotropy the use of Eq. 3 can result in considerable error in v. The calculation of v by Eq. 5 also involves some uncertainty as a 1% error in Vs and Vp can result in a 6% error in v. By means of the pulse method both

Jan 1, 1965

By E. N. Harshman

The Wind River Formation of Eocene age is the host rock for large high-grade uranium deposits in the Shirley Basin. The major deposits are in a northwest-trending belt of sandstones that were deposited in stream channels and that were lithologically favorable for uranium accumulation. Paleotopography influenced the character and position of the belt. The major deposits within the belt are at, or near, the margins of large tongues of altered sandstone formed in the most transmissive parts of thick sandstone beds. At least two tongues of altered sandstone are present in the belt, one of which is 5 miles long, 3 miles wide, and 70 feet thick; the other tongue is somewhat smaller. Ore bodies consist of a few hundred tons to several hundred thousand tons of material containing from 0.10 to about 2.00 per cent U3O8. The ore mineral is uraninite associated with pyrite, marcasite, hematite, and calcite. Deposition is believed to have taken place when neutral to slightly alkaline, oxidizing, uranium-bearing ground water, on entering the basin, encountered a reducing environment. The reductant may have been H2S of biogenic origin. Geology played an important role in discovery, exploration, and development of ore in the Shirley Basin.

Jan 1, 1968

Said Plutarch a long time ago, ?To appreciate a man's work at the full, it is well to know the man himself, his circumstances and the incidents of his career." He might as truly have said "gift" instead of "work." Ambrose Swasey, engineer, collaborater with scientists, promoter of engineering research, patron of Engineering Foundation, advancer of the good of mankind, modest gentleman and generous giver, is, happily, well known to a great many engineers, who will therefore more fully appreciate his recent additional gift, for the use of the Engineering Foundation, which; purpose is "the furtherance of research in science and engineering, and the advancement of the profession of engineering and the good of mankind." But full appreciation of a gift of money necessitates more than acquaintance with -the giver and knowledge of the amount. Its timeliness; its inspiration; the character and continuity of its benefits, all must be comprehended. But whose imagination, though far-visioned as the great telescopes Mr. Swasey has built, can see the limits of benefit of such gifts as he has made to the Engineering Foundation, attracting-as they will-other gifts and evidences of, devotion to a great cause-? Every such gift lays responsibilities upon the recipients. Will American engineers grasp not merely, their pecuniary value but also emulate the spirit of fraternity and desire for harmony which have accompanied them? Shall we not work together and with Ambrose Swasey to advance still further the good of mankind, thus to demonstrate an acceptance of our obligations to humanity which is a counterpart in a democracy of the noblesse oblige of aristocratic tradition?

Jan 12, 1918

By W. D. Robertson, H. Conrad

Incremental loading creep tests were conducted on magnesium single crystals in tension and direct shear at 78" to 364°K. The creep curves were transient in character and exhibited waves or periodic behavior, especially at small strain rates. A sigmoidal curve was frequently observed following the first occurrence of creep. Repeating of segments of a master curve was observed at all temperatures indicating that identical conditions for flow existed after various stress and strain histories. A logarithmic time law with a independent of temperature whs observed at 78°and 203°K, while a parabolic (power) time law was approximated at 298" and 364°K. The departure from logarithmic creep was attributed. to recovery, which was observed at 298" and 364°K. The temperature independence of a represents a serious objection to the theory of low-temperature creep based on the intersection of dislocations. IN a previous paper1 it was found that the initial creep rate of magnesium single crystals, y, following the addition of a stress increment in the range of 78° to 364°K, was given by the expression ? = C exp - {?H/kT} exp {B(T- h ?)} [1] where B and C are constants, AH is an activation energy of 10,300 cal per mole, T is the applied stress, ? is the total strain at the time of the stress increment, and h is the strain-hardening coefficient. The present paper is concerned with certain other features of creep behavior observed during this investigation; namely, the form of the creep curves, time laws for creep, recovery, and microscopic and X-ray observations of the structural manifestations of the creep flow. To the authors' knowledge the temperature range of the present investigation (0.08 Tm to 0.40 Tm) has not been covered previ-

Jan 1, 1959

By J. B. STEWART

T HE position of each hole of any series of holes was carefully located by the surveyor, plotted in plan and elevation, and numbers assigned to them. The second series was staggered halfway between the first and so on for each succeeding series. Two and a, half to three months was frequently required to grout a series of holes calculated to insure safety for sinking a distance of 10 meters or say 33 ft. Naturally the initial operation called for drilling and grouting two series of holes but thereafter each sinking campaign required only one series of holes as shown in Fig. 8. The pump handling about 75 gal. per minute corresponds to 46 tons of grout or 6 tons cement delivered as a fair over-all average for the 24 hours. Thus 600 to 800 tons of cement was used for a single section of 33 ft. depth of shaft. One campaign used nearly 1100 tons of cement. Some holes were effectually sealed with as low as 30 tons, while many required 60, and some 80 to 90 tons.

Jan 1, 1926

By P. A. Boeck

Discussion of the paper of P. A. BOECK, presented at the San Francisco meeting, September, 1915, and printed in Bulletin No. 104, August, 1915, pp. 1539 to 1550. LAWRENCE ADDICKS, Douglas, Ariz.-It does not seem to me that the role played by carrying heat away from one surface to another has been brought out. A cellular construction prevents the motion of air currents. Also in the installation on the top of a reverberatory furnace, that Mr. Krieger mentions, where it stopped the cooling, there is besides the question of overheating. Another complex question, entirely apart from the necessity of not carrying a brick above a certain temperature, is that of not allowing acids and bases to come together at too high a temperature. J. W. BECKMAN.-What cements together the individual cells in the insulating material? Also, how does the material behave in the presence of acids and alkalies, both strong and weak? A. H. KRIEGER, New York, N. Y.-The material is formed or composed of myriads of lace-like skeleton remains of diatoms visible only -under a powerful microscope. The diatom lives in salt and fresh water. On the Pacific Coast there must have been an abundant life of the diatom, because the beds, still in existence in Southern California, are fully 1,000 ft. through, and are hard and strong, standing a pressure of more than 400 lb. per square inch. The beds must have been many ages in forming and the diatoms have become firmly packed together. The samples shown are typical of the entire deposit as it was formed at the bottom of the sea. Once this structure has been destroyed, it is impossible to reconstruct it without artificial bonding materials. With the exception

Jan 12, 1915

By AIME AIME

THE Institute of Metals Division of this Institute held a joint meeting with the American Foundry- men's Association on Oct. 5-9, at Syracuse, N. Y. The registration at this meeting was about 150. There were four meetings in all, three of which were in con- junction with the American Foundrymen's Association. This combination works out very nicely and gives the I Division a number of practical foundry papers that it would not get otherwise. The sessions were well attended and the discussion was active. The session on Monday morning was of a general nature and consisted of the following subjects : " Refractory Problems in the Non-ferrous Electric Furnace Casting Shop, " "Temperature Control of Non-ferrous Alloys," "Atomized Coal System of Non-ferrous Melting," "Material Handling in a Brass Foundry." On Tuesday morning, the session was on "Aluminum and Its Alloys." The paper on permanent mold castings created a large amount of discussion, in fact so much that it had to be renewed after the close of the regular program. Aluminum is assuming a more important place every year and adds greatly to the program as a whole. One of the most remarkable meetings that this Division has ever had was held on Tuesday at noon in the form of a Round Table discussion, headed by G. K. Elliott, chairman of the Division, Cincinnati, Ohio. Mr. Elliott divided the members present, numbering about 80, into groups as they were seated at the tables. Each of these groups suggested a topic for discussion. They were as follows : "Fluxes on Market ;" "Simplification of Alloys;" "Pyrometric Control;" "Effect of Gas- sing Metal and Control;" "Barium Sulfate Added to Electric Furnace to Create Slight Oxidation to Remove Aluminum and Silicon;" and" Nickel in Brass."

Jan 1, 1925