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By S. L. GILLAN

OF the forty or more excursions provided for the delegates to the World Engineering Congress at Tokyo, the trip to the Ashio copper mine stands out as one of the most enjoyable. In every detail looking to our comfort and pleasure the Furukawa company, our hosts, were admirable. This company operates five other copper mines, also gold and coal mines. Ashio is the largest with an annual production of about 14,000 tons of copper. It has been continuously worked since 1620, and doubtless was one of the sources of copper used in the gigantic statues of Buddha of many hundred years earlier date.

Jan 1, 1930

By Roger K. Clifford, Gary W. Hudiburgh

The amine flotation of feldspar from a magnetite concentrate produced at a domestic concentrator was investigated using zeta potential measurements, Hallimond tube flotation tests, and laboratory-scale flotation tests. The point of zero charge of six feldspars (microcline, orthoclase, albite, anorthite, anorthoclase, and oligoclase) range from pH 1.4 to 2.5. Hallimond tube flotation tests using amine flotation reagents were performed on these feldspars and on gangue material (quartz, albite, and microcline) from the magnetite concentrating plant. Laboratory-scale (623 g and 2500 g) flotation tests were performed on the magnetite concentrate to float the feldspar. The effects of three different collectors, two levels of collector concentration, three pH levels, starch, HF acid and regrind were investigated.

Jan 1, 1977

By O. F. Thornton, D. L. Marshall

Results of the determination of the inter stitial water content of several core samples from oil reservoirs are presented. Data obtained by the capillary pressure method, which has recently been developed, are compared with water saturations measured in cores cut with oil-base mud and with values calculated from the electrical resistivity of the formation. The agreement between the capillary pressure and other methods, combined with the fact that similar agreement has been obtained by others, indicates that the capillary method properly applied yields results sufficiently accurate for most engineering purposes. In some cases, it may be possible to extend the utility of data obtained with the capillary pressure method by correlation of interstitial water saturation with more easily measured physical properties of the media. Introduction Several methods are in use for determining or for estimating the interstitial water saturation at given points within oil and gas reservoirs. The direct measurement of the water content of cores obtained with nonaqueous fluid in the hole is believed to be an accurate method under most conditions. The water saturation may be calculated by use of the resistivity curves of the electric log,' although this method is not applicable under conditions that exist in some reservoirs. Recently, a method has been developed and described3.' wherein the interstitial water saturation of cores is measured at a capillary pressure such that conditions existing in the reservoir are simulated. The purpose of this paper is to present data obtained by use of this latter method, and to compare the results obtained with determinations made by other means. Method The theory underlying the capillary pressure method applied to petroleum reservoirs has been discussed adequately in the literature by Garrison,2 Leverett,5 and Others.3,6,7 Briefly, and simply, capillary pressure is defined as the difference in pressure between two contacting fluid phases, such as oil and water. For the simplified sand, water and oil system illustrated in Fig I, the pressure difference can be stated as follows:6 where Pc is the capillary pressure in pounds per square inch, ? is the interfacial tension between oil and water in pounds per inch, r1 and r2 are the radii of curvature of the interface between oil and water in inches. Capillary pressure varies in a given reservoir with depth because of the greater density of the water phase as compared with oil or gas. The following equation expresses the difference in pressure between two points: p1- p2 - h?p/144 [2] where p1 — p2 is the capillary pressure difference in pounds per square inch, h is

Jan 1, 1947

By D. L. Marshall, O. F. Thornton

Results of the determination of the inter stitial water content of several core samples from oil reservoirs are presented. Data obtained by the capillary pressure method, which has recently been developed, are compared with water saturations measured in cores cut with oil-base mud and with values calculated from the electrical resistivity of the formation. The agreement between the capillary pressure and other methods, combined with the fact that similar agreement has been obtained by others, indicates that the capillary method properly applied yields results sufficiently accurate for most engineering purposes. In some cases, it may be possible to extend the utility of data obtained with the capillary pressure method by correlation of interstitial water saturation with more easily measured physical properties of the media. Introduction Several methods are in use for determining or for estimating the interstitial water saturation at given points within oil and gas reservoirs. The direct measurement of the water content of cores obtained with nonaqueous fluid in the hole is believed to be an accurate method under most conditions. The water saturation may be calculated by use of the resistivity curves of the electric log,' although this method is not applicable under conditions that exist in some reservoirs. Recently, a method has been developed and described3.' wherein the interstitial water saturation of cores is measured at a capillary pressure such that conditions existing in the reservoir are simulated. The purpose of this paper is to present data obtained by use of this latter method, and to compare the results obtained with determinations made by other means. Method The theory underlying the capillary pressure method applied to petroleum reservoirs has been discussed adequately in the literature by Garrison,2 Leverett,5 and Others.3,6,7 Briefly, and simply, capillary pressure is defined as the difference in pressure between two contacting fluid phases, such as oil and water. For the simplified sand, water and oil system illustrated in Fig I, the pressure difference can be stated as follows:6 where Pc is the capillary pressure in pounds per square inch, ? is the interfacial tension between oil and water in pounds per inch, r1 and r2 are the radii of curvature of the interface between oil and water in inches. Capillary pressure varies in a given reservoir with depth because of the greater density of the water phase as compared with oil or gas. The following equation expresses the difference in pressure between two points: p1- p2 - h?p/144 [2] where p1 — p2 is the capillary pressure difference in pounds per square inch, h is

Jan 1, 1947

By H. E. Mussey

When the American Institute of Mining Engineers visited the Birmingham district in May, 1888, the four Ensley furnaces (Fig. 1) then completed were referred to as monumental.' Their dimensions are givcn in Table 1. Mr. Gordon stated, with considerable satisfaction, that on the preceding day one furnace had produced 165 tons. The blast was

Jan 1, 1925

By Chester A. Fulton

SUPPLYING as it does a necessity for healthy animal and vegetable phosphate production is a most important industry. We human beings also are animal as this war so surely proves. Unlike many other elements no substitnite is available for phosphorus or its compounds. Marvelous as are modern plastics none can lake the place of phosphorus in making hone structures. As meassured in these times the phosphate industry is not a large industry. Output of phosphate rock, the original source of our agricultural and ,chemical phophates amounts to only some twelve million long tons per annum in the entire world. Phosphates are compounds of phosphorus, which is always found in nature combined with other elements. It never occurs in nature as such. The first choice of the element phosphorus is tie itself strongly to oxygen and then to water moisture - thus becomeing phosphlic acid. This phosphoric acid in turn hunts around for a base such as lime for instance and together they make phosphate of lime.

Jan 1, 1944

By C. R. Keyes

Discussion of the paper of C. R. Keyes, presented at the Chattanooga meeting, October, 190S, Bulletin No. 26, February, 1909, pp. 119 to 166. E. R. BUCKLEY, Flat River, Mo. (communication to the Secretary*) :-Some statements in the paper of Mr. Keyes relative to the nature and formation of the Ozark lead- and zinc-deposits seem to me erroneous and misleading, and I respectfully present the following criticisms, placing Mr. Keyes's original statements in quotations. Referring to the Ozark dome: (P. 127.) "It is a region that has been repeatedly upraised and planed off, until in the middle portion the oldest known' rocks only are exposed." Does he mean that the St. Francois mountains, which have always been considered as lying on the eastern flank of the Ozark dome, are the middle of the dome? Or does he mean that the Cambrian rocks of the generally-accepted middle are the oldest known rocks ? Certainly not the latter, and if the former, his idea of the middle of the dome is not in accord with that of others who are familiar with the region. (P. 138.) " . . . the ore-deposits are definitely associated with, or localized by, geologic structures of some kind that .produce in effect basins in which' the underground waters are impounded, or their flow retarded." This statement does not appear to be altogether consistent with the facts, since the ore- bodies of the Joplin district, as the rule, occur in those parts of the Mississippian formation which have a tendency to accel¬erate the flow of ground-water rather than retard it. I might name the open, breeciated ground near Joplin, Webb City, and Oronogo as especially noteworthy illustrations. The ore-bodies, everywhere, occur in positions where there must have been a free and copious circulation of dilute lead- and zinc-solutions in the presence of reducing constituents. The inequalities in the distribution of the ore-deposits are

Oct 1, 1909

By H. A. Pearse

NORMALLY, the Britannia ore mixture contains chalcopyrite and pyrite as the chief sulfide minerals, together with minor amounts of gold and silver and a low zinc content. Reduction is accomplished by jaw crushers underground, followed at the concentrating plant by Symons cone crushers, rolls, and ball mills. The standard flotation practice, evolved during several years of experimentation, provided for bulk flotation of the two sulfides, after primary grinding to only approximately 35 mesh, followed by regrinding of the bulk concentrate, with subsequent separation of the chalcopyrite and pyrite to make a marketable concentrate of each mineral. This so-called standard milling practice has previously been described in detail in U. S. Bureau of Mines Information Circular 6619. A modification will he discussed here. In the face of a constantly increasing world surplus of copper and a steadily falling price during 1930 and 1931, it was obviously undesirable to continue unprofitable production of large quantities of this metal. On the other hand, company officials were

Jan 1, 1934

By C. R. Hayward

CARLE R. HAYWARD.-I do not want it understood that I think that the conclusion that the time of tempering temperature is immaterial has been definitely proven, but since these are the first definite figures put out, I thought before continuing on more work ourselves, it would be well to present them as progress and for information. J. A. MATHEWS, Syracuse, N. Y.-I think that if Prof. Hayward would consult the paper of Profs. Barus and Strouhal,1 1885, he would find about 250 pages, mostly figures, on this subject, in which they investigated the tempering effect by electrical and magnetic methods. There are so many figures in the paper that it is very difficult reading. One point particularly brought out was that even at a low temperature, such as the boiling point of alcohol, about 60° C., there is a tempering effect, increasing up to 4 hr. One reason they obtained those results, with which the present authors are at variance, was that they started with a high-carbon steel which hardens thoroughly, whereas the steel Prof. Hayward and his collaborator used was a comparatively mild steel which does not take a great deal of hardening. About 3 years ago Mr. Stagg and I published 2 a few figures bearing on the same subject, but we used .a low-carbon alloy steel of high tempering qualities and found a great deal of improvement, particularly in ductility, by continuing the drawing up to 4 hr. We used a chrome-vanadium steel showing after heat treatment 250,000 tensile strength. On short drawing, we got almost no ductility, but by continuing to 4 hr., we raised it to 12 per cent. I believe Prof. Hayward's results are due to using comparatively mild steel, whereas Prof. Barus used drill rod and carried out a, wonderfully exhaustive

Jan 4, 1917

By L. Thomassen, N. Spooner, J. M. Thomas

NI-CR and some Ni-Cr-Fc alloys, when used as electrical resistance heating elements in reducing atmospheres, at times suffer rapid breakdowns due to so-called "green rot." These reducing atmospheres are most frequently used in bright annealing and heat-treating furnaces which are kept for long periods of time at 1500' to 1800°F. The green rot is a preferential oxidation of the chromium in the alloy to such an extent that the remaining metal frequently becomes ferromagnetic. The Curie point (magnetic transition point) at room temperature for a pure Ni-Cr alloy is known to be at about 7 pct Cr.¹ This represents a severe loss in chromium for one popular grade of resistance alloy, which is nominally 80 pct Ni-20 pct Cr. The formation of oxides along the grain boundaries makes the ribbon brittle and gives the fracture a green, earthy appearance—hence the name. The authors have studied this phenomenon, simulating the industrial conditions by heating resistance ribbons in various reducing atmospheres, such as moist hydrogen or the atmosphere specified in the ASTM test.² This atmosphere contains 16 pct H2, 10 pct CO, 4 pct C02, 1 pct CH1, 1.5 to 2.5 pct H2O, balance N2. Little success was had in producing severe corrosion with the commercial 80 pct Ni-20 pct Cr alloys. It had been noticed, however, that 90 pct Ni-10 pct Cr alloy wires deteriorated very rapidly when placed in the bottom of narrow thermocouple protection tubes. The bottoms of the tubes with the wires were heated in air. This took place both in porcelain tubes and in Inconel* tubes either with the cold end open or loosely stoppered with asbestos. On examination the wires showed microstructures which would be classified as green-rot corrosion. Subsequent investigations with various alloy wires confirmed the observation that corrosion occurred in some wires, including 80 pct Ni-20 pct Cr alloys, much more rapidly in such tubes than had occurred previously in test atmospheres mentioned above. When 90 pct Ni-10 pct Cr alloys are oxidized with an abundant air supply, the oxide coat consists of both nickel and chromium oxides. In this case thermodynamic equilibrium between the oxides is not established. However, when oxidized 90 pct Ni-10 pct Cr alloy specimens were heated to 1500" to 1800°F inside small diameter tubes, the oxide coat transformed to a bright metallic outer layer of nickel or nickel-rich alloy, beneath which appeared a green oxide, followed by intergranularly attacked metal. The obvious explanation is that in the narrow tubes, thermodynamic equilibrium is being established according to the equation NiO + Cr (in alloy) ? Ni + Cr2O3 This reaction is favored due to the fact that the oxygen pressure over nickel oxide is more than 10"' times the oxygen pressure over the green chromium oxide. The initial oxygen in the tubes is depleted very rapidly by oxidation of the wire and of the tube, if it is metallic. A confirmation of the occurrence of the reaction, reduction of NiO by the chromium in the alloy, was obtained by putting oxidized nickel foil into an evacuated quartz tube along with a piece of bright 90 pct Ni-10 pct Cr alloy ribbon, and heating the tube at 1820°F for a number of hours. The nickel oxide on the foil was completely reduced to pure nickel, leaving a bright foil. The 90 pct Ni-10 pct Cr alloy became strongly magnetic and showed the typical green-rot structure. Weights of the samples before and after testing showed the weight loss of the foil to approximately equal the weight gain of the ribbon. Evidently the bottom of long, narrow protection tubes, stoppered or not, may under certain conditions act just as the sealed quartz tubes in respect to being a confined space in which oxygen is not freely replenished. This condition of oxygen depletion can be prevented by introducing a small amount of air into the bottom of the tube. Many conditions becloud the green-rot phenomenon, such as carburization, sulphidization, and the presence of other corrosive agents. However, these experiments have shown that the basic reaction is a case of internal oxidation which can occur simply by adjusting the oxygen pressure to a low enough level so that the atmosphere will leave the nickel intact and oxidize the chromium. The action of the other agents in commercial atmospheres can then be taken up as individual cases. From these and numerous other tests completed to date or still in progress, it is believed that a more critical evaluation of electrical resistance alloys for their resistance to green-rot corrosion can be made. A much better understanding of the mechanism for this type of corrosion should also result. A more complete report on these experiments will be published later. In the May 1953 issue: TP 35213 Discussion: Solubility of Carbon and Oxygen in Molybdenum by W. E. Few and G. K. Manning, discussion by N. A. Gokcen: p. 747, first column, the fifth, sixth, and seventh lines should be the first, second, and third lines, followed by the present first, second, third, fourth, eighth, ninth, and tenth lines.

Jan 1, 1954

By Joachim J. Hauser

William F. Hosford, Jr. (Massachusetts Institute of Technology)—Dr. Hauser has used a very interesting method to study the interaction of dislocations on different slip systems, but it should be pointed out that the analysis of the experiments is subject to a serious criticism. He states that "the effect of the compression can be adequately described by one slip system." The effect of frictional constraint during the compression makes this quite unlikely. When a block of metal is compressed its lateral expansion requires a sliding of the metal over the compression platens. The role of friction in the interface between the deforming metal and the platens is to increase the normal force required for the compression. Analyses1213 have shown that, in general, the additional force, p, required for the compression is a function of l/h where is the coefficient of friction, I is the length of the speci- men in contact with the platens. For a constant COefficient of friction, isho' shows that P should increase exponentially with pl/h for both plane strain and axially symmetric compression. For a compression specimen, Fig. 7, whose cross section perpendicular to the compression axis is a rectangle whith one dimension L, much larger than the other W, a much larger force would be required for appreciable flow parallel to L than for flow parallel to U7. Therefore lateral strain in the W direction, EW, should be much greater than the lateral strain in the L direction EL. Since L/H = 14.5 for Dr. Hauser's crystals, and since no lubrication was used, it seems questionable that appreciable lengthening of the crystals could occur. Because the theories of frictional constraint have been derived for isotropic polycrystalline materials, it was decided to make experimental measurements on a single crystal. A section 3.590 in. long was sawed from an aluminum single crystal with a square section of 0.249 in., so that L/W= 14.4. This crystal was tested in compression between dry ground steel platens. Fig. 8 shows the orientation of the crystal and the axis of compression. The face for compression was chosen so that the operation of the single-slip system which would be predicted in the absence of friction would lead to a larger strain in the length direction than in the width direction. The dimensional changes of the width and length as well as the height were measured frequently during the compression with micrometers. Width strains were calculated from the average of readings near each end and at the center. A plot of the length strain, EL, against the width strain E w is given in Fig. 9. The slope indicates that the EL amounted to only 2.5 pct of cw. Other compression tests on similar crystals with shorter lengths also showed severely limited elongation. Even for a crystal with L/W = A.0, EL was only about 26 pct of cw. Because of the frequent interruptions of the tests for dimensional measurements should have decreased the frictional constraint by allowing a reseating of the platens, even smaller elongations under continuous testing seem probable. These tests on long narrow crystals show that essentially plane strain conditions prevailed. We may assume that Dr. Hauser's crystals deformed similarly. That the compression can be described by the

Jan 1, 1962

By H. M. Chance

Jan 1, 1886

By H. H. Power

THE PETROLEUM DIVISION of the A.I.M.E. continued with its diversified activities during 1.935. Sessions at the New York meeting in February were devoted to production engineering, domestic and foreign oil production, and petroleum economics. The symposiums on domestic and foreign production proved their increased usefulness. The data accumulated for 1935 were added to those published during prior years in "Petroleum Development and Technology." A joint session on the use of metals in the petroleum industry was held by the Institute of Metals, Iron and Steel, and Petroleum Divisions. W. S. Farish, chairman of the board of the Standard Oil Co. (N. J.), was the principal speaker at the annual dinner. The October meeting, held in Hous¬ton, was characterized by an excellent program and large attendance. Four sessions were devoted to problems in estimating reserves, reservoir energy, properties of drilling muds, electrical logging, water flooding, and other subsurface studies. Foreign representatives of the Anglo-Persian Oil Co. presented a paper on surface tension and specific gravity of crude oil under reservoir conditions. The address by President Buehler, the dinner at San Jacinto Inn, a trip to various lo

Jan 1, 1936

By Charles Will Wright

The application of the camera as an adjunct to topographic mapping began practically with its invention, and it has been employed with varying success since that time. With the exception of the camera to be described, the plate-camera has been universally used in this work, thus giving a projection of the area photographed on a flat surface. From such projections or photographs, by the rules of geometry and of perspective, points defining topographic features and seen from at least two camera-stations may be projected upon a ground-plane—the map.' In 1904 I employed the plate-camera for this purpose in Alaska, but found that the labor necessary to plot the maps, even in a general way, was long and tedious. In 1905 a small Eastman panoramic camera was fitted with spirit-levels, a sight-alidade and a transparent scale, introduced inside the camera to register the degree-points in the sky-line of the film-negative ; also, arrows to indicate the horizon-line. This was, on the whole, successful; but the details in the topography were not brought out in the views with sufficient clearness, aid the photographs were too small. These difficulties were overcome by obtaining a larger and more carefully constructed instrument, which was satisfactorily employed in the field during the year 1906. A panoramic view is made up of an integral number of perspective views upon flat surfaces, and logically is the most accurate and direct means to obtain an impression of a field of * Published by permission of the Director of the U. S. Geological Survey. Stanley, H. M. Photographic and Co-ordinate Surveying, Bans., xx., 740 to 766 (1891). Also, Flemer, J. ,4. Phototopographic Methods and Instruments, Report U. 8. Coast and Geodetic Survey, pt. 2, app. 10, pp. 619 to 735 (1897).

Jan 1, 1908

By S. H. Ash, J. J. Forbes

Probably the newest thing in mining safety, or safety for mines, is the apparent dissatisfaction on the part of the mineral industries, as represented by both management and labor, and the general public of the Nation, with the safety record of the mining industry. This is reflected by published comments and papers in the technical press;l-9 in labor periodicals,10,11 in popular journals and periodicals,l2, 13 and in the daily press; also by discussions of the Safety Committees sponsored by the National Safety Council,9, 14-15 the American Mining Congress,l.l6 the American Institute of Mining and Metallurgical Engineers,2,4 the Mine Inspectors' Institute of Amerthe Coal Mining Institute of America,5 19 the American Standards Association, and others.20.21 Mining safety is a joint problem of management and the individual workman. Safety is not attained and will not be attained solely by laws, decrees, and commands because, if it could be done in this manner, acceptable mining safety would have been achieved long ago by the individual states in our Nation and by the nations abroad. The best safety performance is found at plants where management provides a safe environment for the workers; where supervision is efficient and super- visors, others concerned with promoting safety, and the individual worker know through training, experience, and personal contact the safe and unsafe practices of their field; and where the trained individual worker has become safety-minded by experience, quiet influence, unconscious suggestion, and personal guidance. Despite what may be said to the contrary, progress has been and is being made in mining safety. This is shown in Fig 1 to 4. It is beyond the scope of this paper to give possible reasons for the valleys and peaks in the fatal-injury rates. Some recent factors that appear to be contributing to the improvement in these rates are briefly discussed. Aside from mining equipment, "what's new in mining safety" for some mines has been in effect or was tried by others long ago. A safety pro- gram is a living thing; as such, it must be vitalized and continuously fed with enthusiasm, constructive action, and improvements. Because safety is concerned with human conduct, it is necessary to practice safety at all times; if not, it is soon forgotten, and accidents occur. Mining-safety Records The large employment and production concerned with anthracite contribute much to the mining-safety records of the mineral industry. Approximately 81,000 persons are. employed in this industry having mines concentrated in an area of 480 square miles in northeastern Pennsylvania. Because of the achievement of the anthracite industry in safety during 1948, the other branches of the mineral industry can profit by a study of what has been done to achieve that record. Where one mineral is produced by other large groups having methods of mining that are similar in many respects to the anthracite-mining methods, an achievement in such a large industry is important. Salient factors concerned with safetye in the anthracite industry are: no radical change has occurred in the mining-safety regulations pertaining to anthracite mines. Because anthracite mining is a branch of the coal-mining industry,

Jan 1, 1950

By Ian Wark

IN an earlier paper1 measurements of contact angles due to the effect of xanthates on mineral surfaces were reported. The solutions in which these measurements were made differed widely from those of modern flotation circuits. It is intended, however, by introducing, one at a time, the other principal reagents of flotation, to approach gradually the solu-tion composition of flotation liquors. The work now described is an attempt to determine the effect of one of the most important of these reagents-namely, sodium cyanide-on the establishment of air-mineral contact. The work has been carried out for the following companies: Broken Hill South, North Broken Hill, Zinc Corporation, Electro-lytic Zinc of Australasia, Mount Lyell Mining and Railway, and Burma Corporation. Since the effect of cyanide is inseparably connected with the alkalinity, the results cited below deal with the mutual effects of alkalis and cyanide. Alkalis alone exert a significant effect on the air-mineral contact but comparatively large amounts are required. Since the addition of a small amount of cyanide greatly decreases the degree of alkalinity necessary for the suppression of contact at surfaces of any of the minerals experimented with (except galena) and since alkalis are rarely used alone in practice, little attention has been paid to cyanide-free solutions. It was shown in the previous paper that, excluding the dixanthogen effect, whenever contact was practicable at all in an ethyl xanthate solution the angle of contact was 60°. There is, therefore, less necessity to measure equilibrium contact angles; in fact, the experiments herein described have generally been conducted with a view to determining whether contact is possible and not to measuring the actual value of the contact angle. The separations which have generally to be effected in dealing with complex sulfide ores are: (1) galena from sphalerite, pyrite, etc.; (2) sphalerite from pyrite and/or gangue minerals; (3) copper minerals from pyrite and gangue minerals; (4) pyrite from gangue minerals; (5) chal-

Jan 1, 1933

By Richard L. Stowe, Donnie L. Ainsworth

The static, rapid, and shock-loading response of rock is of interest to many in the field of rock mechanics. For example, the effects of loading rates on strength and stress-strain characteristics of rock are quite important in defining input loading for use in the design of underground protective installations. Response data on rock subjected to shock loading over a wide range of pressures are also vital in the field of underground nuclear testing. In addition, material response is needed in design of shock-absorbing liners. A number of investigators have reported that ultimate compressive strength of rock increases with increased rates of loading.1-6 Wuerker3 stated that modulus of elasticity, obtained from sonic determinations, increased in some rocks by a factor as high as 4.5. It appears that only a limited amount of work has been done on comparing static modulus and modulus obtained from impact testing.6 Phillips4 showed that with increased rates of loading the deformation decreased. More recent work by Atchley and Furr5 showed that when moderate-strength concrete is stressed with increased loading rates, the axial strain at failure increased. One would expect this to occur if we think in terms of purely elastic materials. For example, if E is constant and maximum strength [amax], increases, the axial strain would also increase. However, in rock testing thus far we have worked almost exclusively with nonhomogeneous and inelastic rocks. From this fact alone the increase in axial strain with increased load application is noteworthy.

Jan 1, 1972

By Fitterer, G. R.

The impact of the work of Herty "et al" on modern liquid steel technology can only be evaluated by first setting the stage as it existed in 1926. It is important to briefly review not only the steel making process and viewpoints regarding methods of refining, but also to describe the tools which were available for research at the time. One must recall that only 15 years before the beginning of this program, the open hearth production exceeded that of the Bessemer in the United States. Many open hearths were still operating on producer gas (a very inefficient fuel), although some plants were converting to the use of natural gas and very few to oil. Continuous rolling of wide strip started this year. The Faraday Society in England held a World Conference on Physical Chemistry in Steel Making in 1925 and the contributions to this work created considerable interest throughout the world and it appeared that physical chemistry might convert the art of steel making into a science. These papers, however, attempted to solve the problems through the use of the older physical chemical concepts such as Nernst's numbers, etc. and considerable data were missing. In 1923, Lewis and Randall had published their book Thermodynanzicsl and this was later to establish and standardize the steps which are now accepted for the calculation of physico-chemical equations. At the time this research work was started, there were no small high frequency induction furnaces. Northrup had just invented his high frequency furnace and a few large units had been instilled in plants. The vacuum fusion method lor the determination of oxygen in steel was

Jan 1, 1957

By Carl Heinrich

I HAVE read with particular interest that portion of the discussion by Anton Eilers referring to the high-lime (and also high-alumina) slags made by August Raht in 1881, while smelting the Horn Silver ores at Franklin, Utah. The two analyses of such slags, furnished by Mr. Raht to Mr. Eilers are: Horn Silver Slags Oxygen(b) Oxygen(b) Average of I and. II Slag I percentage Slag II percentage Oxygen Si02 33.9 18.1 .35.0 18.7 34.50 18.40 FeO 26.8 6.0 25.4 5.7 26.10 5.80 CaO 26.1 7.5 24.9 7.1 25.50 7.30 BaO 3.2 (a) 0.3 3.2 0.3 3.20 0.30 A1203 10.8 5.1 9.3 4.4. 10.05 4.75 100.8 37.0 97.8 36.2

Jan 10, 1916

By Samuel Hoyt

THE writer has long been interested in seeking an explanation of the upper heat effect in the copper-tin alloys over the a + ß range, first described in 1913. These notes are offered, not at all as the final explanation of this heat effect, but rather to indicate certain progress which has been made toward establishing what happens over this temperature interval. While working on the thermal analysis of the copper-rich kalchoids (copper-tin-zinc alloys), it was noted that those alloys containing major portions of tin and minor portions of zinc exhibited two marked heat effects, one at about 520° C. and the other at about 600° C., instead of the single effect which is generally observed in either of the two binary series. This matter was discussed with Dr. Guertler, who suggested that a heat effect at about 600° C. in the pure copper-tin alloys might be expected. This led to a more searching examination of the thermal critical points in the pure copper-tin alloys, with the result that a marked, although somewhat weak, heat effect was located at about 600°. Somewhat later, this upper heat effect was discussed with Dr. Burgess, and it was requested that the Bureau of Standards make heating and cooling curves of one of these alloys for the purpose of removing any possible doubt as to the actual presence of the heat effect. Results obtained by the Bureau are given in Plate I. In an earlier paper1 differential curves were published showing that the heat effect occurred at constant temperature over the a + ß range and increased in magnitude with the amount of a up to a point somewhat above 20 per cent. tin. No heat effect was noticed at this temperature in the eutectoid alloy. The existence of this heat effect seems to require a modification of the present copper-tin diagram in the a + ß field, and it has been the object of the work here presented to secure the evidence upon which such a change should be based.

Jan 12, 1918