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By H. J. Wasson, E. B. Hopkins

Throughout 1928, production of oil from Venezuela steadily increased, and at the close of the year, the output was at the rate of nearly 400,000 bbl. a day. The total for the year was approximately 106,500,000 bbl., representing an increase of about 66 per cent. over the 63,000,000 bbl. produced in 1927. Venezuela now stands next to the United States as the second largest oil-producing country in the world; and there is abundant evidence to suggest that this relationship will endure for a number of years. Reserves were notably increased in the Lake shore fields, and the potential output of the Maracaibo Basin is much greater than the current production. In spite of this, the percentage of production increase was comparatively moderate, and the rate of this increase continued to fall off slightly, as has been the case for the last three years. This does not suggest that further annual increases in Venezuelan output will not materialize; only that the rate of these increases appears to be on the decline, and that with every succeeding year the future tendency will be in the direction of a stabilized level of output. The following table shows the production trend of the country since 1925: 1925 increase over 1924, 132 per cent. 1926 increase over 1925, 80 per cent. 1927 increase over 1926, 75 per cent. 1928 increase over 1927, 66 per cent. Many factors will work to prevent a reversal of this trend, but the principal ones are strong ownership in large-acreage units, and the probable indisposition of the world market to absorb a more rapidly increasing Venezuelan output at prices profitable to the producers. The distress oil element is not a factor in Venezuela; also, any unforeseen jump, such as results in the United States from the discovery of a Seminole or a deep sand at Long Beach, or Santa Fe Springs, is impossible in Venezuela, on account of lack of means for transporting a sudden surplus of oil, and the slowness with which additional transportation equipment in the form of shallow-draft tankers can be obtained.

Jan 1, 1929

By E. V. Murphree

CREATION of atomic energy, aside from its influence on war or peace, has posed these basic questions for the world: How soon can energy from atoms be harnessed to do man's daily work? How much of this power will there be, to what degree will it supplant present fuels, and what does it imply for the future of civilization? Answers to these questions may be found in part in analysis of just what atomic energy is and how far its development has come. The answers are encouraging. One of the first questions encountered in considering the application of atomic reactions is whether such reactions can be controlled. Fortunately, this has been adequately demonstrated by the operation of the Government plutonium plants at Hanford, Wash. Here nuclear reactions are carried out on a large scale involving liberation of about a billion B.t.u. per hour. This hourly heat liberation is equivalent to that obtained from about 7100 gallons of fuel oil. It has been possible to operate these plants day in and day out with the reaction controlled at the intensity desired. There should therefore be no question that, under proper conditions, reactions involving nuclear fission can be controlled.

Jan 1, 1946

By Walter W. R. May

FOR more than 25 years a few business men who represent virile private enterprise in the Pacific Northwest have been trying to awaken the community to the potential benefits of an open Columbia River. No threat of government com- petition then hung over the industry, which was adjusted to state regulation. Numerous sites were engineered and the findings were laid before the operators of heavy industry in the East, Middle West, and South -even of Europe. These engineering data became, if not the basis, the inspiration upon which the U. S. Army Engineers eventually were to "build the Columbia River Bible" - their great document known as House Document 103, the report on the Columbia River and minor tributaries.

Jan 1, 1940

Industrial minerals enjoyed a fairly successful year in 1978, despite the sluggish economy, inflation, and environmental restrictions. A glance at US Bureau of Mines statistics shows that, in general, production of industrial minerals increased from + 1% (salt) to as much as 26% (sulfur, other than Frasch or recovered). A few industrial minerals showed a decline; fluorspar production, for example, registered a 23% decrease in 1978 from 1977 due to the closing of three domestic mines. Bromine, natural sodium sulfate, Frasch sulfur, and vermiculite also had production decreases of 2-6% in 1978.

Jan 5, 1979

By N. S. Stoloff, M. Gensamer

The effects of temperature, grain size, and magnesium content on the strength and ductility of cadmium were studied in the range -269° to 23 °C. A sharp drop in ductility between -140° and -190°C marked a transition in fracture mode from ductile shear to inter gvanular fracture. The addition of up to 15.35 wt pct Mg in solid solution raised the transition temperature, and for two compositions produced basal cleavages. The relatively high ductility of unalloyed cadmium at cryogenic temperatures is attributed to temperature independence of the yield stress and the absence of dislocation locking. ALTHOUGH numerous studies have been made of the mechanical properties of cadmium single crystals,1-5 no comprehensive investigation of deformation and fracture in polycrystalline cadmium has been carried out. This investigation was initiated to determine the mechanisms of deformation and fracture in polycrystalline cadmium, and to attempt to correlate these mechanisms with the behavior of other metals of hexagonal close-packed structure. A second objective of this work was to determine whether the slip systems and mode of fracture of polycrystalline cadmium could be altered by reduction of the axial ratio, which is 1.886, through alloying. Dorn and co-workers' have been able to induce prismatic slip in magnesium through alloying to reduce the axial ratio. Single crystals of cadmium are so highly ductile that glide strains of 400 pct are observed at room temperature, and 80 pct at -269°c.l Failure in every reported case is by necking down and shearing off of the crystal. Cleavage in cadmium single crystals has never been observed. Magnusson and aldwin reported a ductile to brittle transition for polycrystalline cadmium at about —160 C for specimens tested at a strain rate of 0.05 in. per in. per min in tension. However, even at -196° substantial ductility was retained. The transition temperature was strain rate dependent, impact loading at 19,000 in. per in. per min raising the transition temperature to about -85°C while leaving the low temperature ductility unchanged. No information was given on microstructures or fracture mode, nor were stress-strain characteristics reported. In the present investigation, tensile tests were carried out on polycrystalline cadmium and solid solution Cd-Mg alloys to determine flow stresses, work-hardening behavior, fracture strength, and fracture ductility. Variables employed included temperature, alloy content (and c/a ratio), and grain size.Some compression data also have been obtained for comparison purposes. I) EXPERIMENTAL PROCEDURES A) Polycrystalline Cadmium. Two purities of cadmium were employed in this investigation. Cadmium of 99.95 pct purity was supplied by Belmont Smelting and Refining Co. Cadmium of 99.99+ pct purity was supplied by American Smelting and Refining Co. Threaded cylindrical tensile specimens were machined to give approximately a 1/2 in. long straight gage section with a reduced diameter of about 0.110 in. Specimens were heat treated in evacuated pyrex capsules in the range 140" to 290°C to produce desired grain sizes. All specimens were polished in a solution containing 320 g Cr03 and 20 g NaS04 in 1000 cc of H20. Occasionally this solution caused staining of the specimen, in which case a further polish with a solution of one part HN03 and two parts H202 in two parts ethyl alcohol was employed.' Tensile testing was carried out on a screw-driven Instron machine, at a constant rate of crosshead movement, which for most tests was 0.01 in. per in. per min. Load vs time, and therefore load vs total strain, were recorded. Temperatures from -196" to -40°C were obtained by passing nitrogen gas through a copper coil immersed in liquid nitrogen, and then feeding the gas into a jacket around the specimen. Tests at -269°C were carried out in a helium cryostat, at a crosshead rate of 0.1 in. per in. per min, with specimens of 1 in. gage length. Compression specimens were tested in a jig similar to one designed by ilman. The jig was mounted on the under side of the Instron crosshead. Load was transmitted by means of a rod connected to a movable part of the jig at one end, and the load cell at the other end. A downward movement of the crosshead applied a compressive load to the specimen.

Jan 1, 1963

By R. H. Sweetser

THERE are SO many conditions affecting blast-furnace results that it is hard to get satisfactory comparative data on the working of two furnaces, and much more difficult to get comparable results from the use of two entirely different fuels. The several advantages of charcoal over coke as a blast-furnace fuel have doubtless been apparent to many managers; but probably the conditions for comparative tests of the two were never so favorable as during the year 1905, at the works of the Algoma Steel Co., Sault Ste. Marie, Ontario, which comprise two modern blast-furnaces, well equipped, though of comparatively small capacity. For four consecutive months one of these furnaces was run with charcoal and the other with coke. Then the charcoal-furnace ran for a while with part charcoal and part coke; and, still later, with coke only. The ore-mixtures were about the same in the two furnaces, and, of course, all the climatic conditions were identical. The dimensions of the two furnaces, and their work with the different fuels, are given in Table I.

Jan 5, 1908

By Wilbur S. Burbank, Robert G. Leudke

The impressive western San Juan Mountains of Colorado were carved by Pleistocene and Recent erosion from a thick blanket of Tertiary volcanic rocks that rests upon a basement of metamorphic, sedimentary, and igneous rocks ranging in age from Precambrian to Tertiary. These rocks record a long, complex, and fairly complete sequence of geologic events that have affected the region through much of geologic time. The geologic history of the region includes several periods of deformation, erosion, and igneous activity; closely associated with two of these periods were two periods of mineralization. The older of these was related to Late Cretaceous-early Tertiary (Laramide) intrusive activity, and its deposits occur in the older sedimentary units. The younger, of later Tertiary age and related to the widespread middle Tertiary extrusive and intrusive activity, is the chief concern of this paper. Tertiary volcanism built a great plateau surrounding the San Juan volcanic depression, a complex of subsided crustal blocks in the vent areas. The Silverton and Lake City cauldrons, nested within the larger depression, were domed by resurgent magma that created keystone grabens along the distended crests of the domed floors and many postcauldron radial and concentric fractures, dikes, and intrusive plutons within and marginal to the cauldron sites. The postvolcanic evolution of large quantities of gases, chiefly carbon dioxide and water, propylitically altered the rocks in and around the volcanic depression prior to the younger period of ore deposition. The ore deposits, localized mainly in the radial and concentric fractures about the cauldrons and in the associated graben faults, include fissure veins, chimneys, replacements, and disseminations in volcanic and underlying basement rocks. Fissure veins, constituting the major economic source, yielded precious- and basemetal ores. Most veins are compound with sphalerite, galena, and chalcopyrite; some veins contain silver-bearing arsenical sulfosalts and free gold. These minerals occur in predominantly quartz gangue. However, gangues composed of several manganese silicates and carbonates and relatively· barren of metals are abundant locally and probably originated by alteration of rocks at roots of faults and fissures during evolution of carbonatic solutions. The bulk of the ores are hypogene and probably had their source in deep parent magmas of the shallow eruptive rocks. Total production since the early 1870's has exceeded half a billion dollars in recovered metals, with a ratio of precious- to base-metal values of about 3 to 2. Since 1930, improvements in metallurgical treatment and mining techniques have increased the base-metal yield.

Jan 1, 1968

By P. Nicholls

THOUGH the burning of fuels extends far back into antiquity, and though fuel beds are the most common and widely distributed example of chemical actions and engineering practice, there has been little attempt to group fuel beds by types or to define the principles associated with them. This paper does not profess to cover completely the subject of fuel beds. It suggests some of the over-all principles of the two more com-mon types. No new investigational data are included, but the deduc-tions are largely based on a recent publication of the U.S. Bureau of Mines1. DEFINITION OF TYPES There are three primary types of fuel beds: (1) Underfeed, in which the fuel and the air move in the same direction; (2) overfeed, in which the fuel and the air move in opposite directions; (3) crossfeed, in .which the fuel and the air move at right angles to each other. The principle that fixes the type is the relation between directions of the flow of fuel and of air. Fig. 1 shows the three types diagrammatically. All other types are compounded of these three in a simple or more or less complex manner. It does not follow that these three type designations are limited to the methods used in representing them in Fig. 1; they may be turned in any direction, and as long as the relative directions of the fuel and air are the same the type is not changed. For example, A as shown resembles a pot-type stoker, but the air and fuel can move downward as in the so-called smokeless heating boiler furnace. Also, C can be placed hori-zontal, as in chain-grate stokers. For this reason, the terms used to designate the three types are not all that could be desired; more logical ones could be coined, but those used probably are satisfactory until the discussion of fuel-bed types becomes more common.

Jan 1, 1935

By Herbert J. French

ALLOY steels have become essential to industry in meeting the rigid requirements on materials imposed by our, advanced technology. In comparison with the total ingot capacity of the steel industry, the volume of alloy steels is relatively small although for many years annual alloy-ingot tonnage has, been in seven figures. However, the monetary value of the alloy-steel production is exceedingly high and the benefits derived from the products are relatively great. The trend in total ingot production since 1932 has been generally upward with only two major interruptions. That of the year 1938 was due to a decrease in general business activity whereas that of 1946 resulted largely from work stoppages. Traditionally, the tonnage of alloy-steel ingots produced was in the neighborhood of 5 to

Jan 1, 1948

By Shiro Ban-ya, John F. Elliott, John Chipman

The activity of carbon in Fe-C austenite at 1150°C has been determined for concentrations up to about 2.1 pct C using the equilibrium: C + COz = 2CO; equations have been derived expessing the activity as a function of carbon content on the basis of twelve mathematical models. Several of these represent the data satisfactorily. ACCURATE information on the thermodynamic properties of austenite in the binary system Fe-C is needed as a basis for studies of transformation and precipitation in steels of all sorts, alloy as well as plain carbon. The many attempts to approach this problem through statistical thermodynamics require sound and dependable experimental data in order to evaluate the several models which have been suggested. In this paper we are concerned with the experimental determination of the activity-composition relation in austenite at the temperature of its widest range of stability, approximately the eutectic temperature (1153°C). Accurate investigation of the activity of carbon in austenite may be said to have begun with the work of Dunwald and wagner.' A more detailed study was carried out by R. P. smith2 on the two equilibria: More recent work on these two equilibria has been reviewed by Chipman,3 who pointed out the experimental hazards associated with studies of Eq. [I]. Studies of this reaction involve rather small values of the ratio these are susceptible to errors due to traces of moisture in the apparatus according to the reaction: Ellis, Davidson, and Bodsworth4 evaluated K, for their experimental temperatures and used desiccants to control water vapor pressure. While they were able in this way to obtain consistent values for K1 it cannot be said that all of the uncertainties of the method have been overcome. Results by both methods reported by Schurmann, Schmidt, and wagener5 appear to be consistent except at very low carbon content. Reaction [2] was employed in the experimental work reported here. It is to be recognized, however, that it is not applicable to projected studies of certain alloy steel compositions involving stable oxide-formers.

Jan 1, 1970

Jan 1, 1916

By Henry Sturgis Drinker, Rossiter W. Raymond

Jan 1, 1914

By Edward W. Parker

(Toronto Meeting, July, 1907.) NOTE.-The material from which this paper has been prepared was collected for the U. S. Geological Survey Bulletin, Contributions to Economic Geology, 1906, and appears also, though in somewhat more extended form without illustrations, in that publication. ALTHOUGH the briquetting of coals and lignites has been carried on for many years in Europe, and has reached a particularly high state of development in France, Belgium, and Germany, it has made comparatively little progress in the United States. The causes for the backwardness of the United States in this regard are several, and first among them has been the abundant supply of cheap raw fuel with which the manufactured article has to compete. With our millions of acres of coal-productive territory, from which the product can in most cases be cheaply extracted, it has appeared in many districts more economical to waste the slack or culm, which con¬stitutes a considerable percentage -of the product, than to attempt to save it at the additional expense required for briquetting. It is for this reason that the view in all sections of the anthracite-region of Pennsylvania is marred by the unsightly culm-banks which encumber the ground, and that in some of the bituminous-districts one sees huge piles of unmarketable- slack allowed to burn up in order to get rid of them. When the coal is of a coking quality, or when the slack can be used for steaming-purposes, these losses are not sustained, but many thousands of tons of what might be converted into usable fuel have been wasted every year simply because of the increased expense involved in its preparation.

Sep 1, 1907

By R. M. Howe, J. Spotts McDowell

Preparation and Use.—Magnesite is an important refractory in open-hearth, heating, and electric furnaces for steel-making and in many of those employed in the metallurgy of copper and lead. It is sold in the form of brick, finely ground "furnace magnesite" for bricklaying, and dead-burned grains for making and repairing furnace bottoms. The latter are a mixture of granules varying in size from pieces of about 5/8 in. (1.6 cm.) diameter to very fine but sandy particles. Dead-burned magnesite results from calcining the crude or lightly burned mineral at a temperaturc that will not merely drive off practically all the CO2, but will also cause sintering of the particles. During this process the pieces shrink considerably and become hard, dense, and inert to atmospheric moisture and CO2; under-burned material, on the other hand, will hydrate on exposure to the air. A small percentage of ferric oxide seems to be necessary for the production of a satisfactory sinter; from 4.5 to 8 per cent. in the dead-burned grains is considered the most desirable amount. Dolomite has been little used for brickmaking in the United States, but it is prepared for use in the granular condition calcined or "double-burned" and is the principal ingredient of several materials offered for sale under various trade names for refractory purposes. Dolomitic refractories are almost wholly confined to the open-hearth and electric furnaces, where they are used for fettling and as substitutes for magnesite. Much more magnesite and dolomite are used for basic open-hearth steel-making than for all other refractory purposes. The hearth of the furnace is usually built up of magnesite brick and dead-burned grain magnesite so laid that the brick base is protected by a working bottom of the granular material. The latter is sintered into place in layers 1/2 to 1 in: (1.25 to 2.5 cm.) thick to a total depth of 12 to 18 in. (30 to 45 cm.) at the center of the furnace. After each heat, burned dolomite is thrown against the banks as high as it will stick, and all holes in the bottom are Glled. At most plants such holes, at the end of each week, are also carefully filled with dead-burned grain magnesite. For temporary

Jan 1, 1920

By FRANK FIRRISTONE

Ix the summer of 1842 my father, William Firmstone, was engaged by Charles Jackson, Jr., of Boston, to examine the conditions in the Lehigh valley as a site for blast-furnaces using anthracite for fuel. In consequence of his report, he was further engaged by Mr. Jackson to build a furnace for him and his partners on the Lehigh canal, 2 miles above the mouth of the river at Easton. Work was begun in the fall of 1842, and the first furnace blown-in in 1844. The history of the works, therefore, from 1844 to 1887, when my own connection with them ceased, covers only four years less than the whole period of the rise, culmination, and commencement of the decline in the smelting of iron with anthracite in America, the beginning of which, in a commercial sense, may be put in 1839.' Although this paper, as the title indicates, is concerned almost exclusively with the furnaces at Glendon, still what was done there was more or less influenced by current opinion in the dis¬trict, and even reflects, to some extent, the changes in opinion and practice with mineral fuel the world over. No. 1 Furnace was built of red brick, on four piers, had three tuyeres and fore-hearth and tymp, as was universal with furnaces using mineral fuel until the introduction of Liirmann's cinder-tuyere. The dimensions and profile are shown in Figs. 1 and 2. The first hearth (Fig. 1) was of sandstone; all after were of fire-brick (Fig. 2). The profile was no doubt derived directly from Gibbons's furnace,2 for it appears from W. Firmstone's note-books that in October, 1840, he visited ." Gibbons' new furnaces building at Corbyn Hall," and I have an old drawing,\

Sep 1, 1909

By T. A. Rickard

The key-note of good writing, as of good manners, is B natural. Sincerity is the first requisite for effective writing. When a man says what he knows or believes, he is likely to be interesting, because each human being possesses an individuality, a point of view, or a range of sympathy that makes him different from his fellows. To say or to write what you do no6 think, for the mere sake of talking or writing, is a verbal exercise that must be performed with extraordinary skill if it is to be attractive. Affectations are rarely attractive, rarely effective. To be natural is to be yourself, not a poseur; to give the reader the best of yourself, instead of re-warming the baked meats of yesterday. Quotations-which are second-hand thoughts-will serve occasionally when the thing you want to say has been said so well by another that it would be waste of energy to try to say it better; but, as a rule, the utterance of the writer himself is more interesting than the quotation, because the writer brings something of himself to bear on the subject, and for the moment is more in touch with the reader than any dear departed author. Therefore, say things as best you can in your own way, neither in borrowed words nor in the phraseology that mimics another. Write as if you were speaking to a person whom you desire to persuade or convince. You will then write better than you speak, because, in the first place, you can be more deliberate, and, secondly, you can revise what you have written. Speaking and writing are similar mental acts, with a difference: the difference between eating food raw and eating it cooked. Some kinds of food gain nothing by being cooked; likewise some kinds of utterance are not bettered by being written down first; but most expressions of thought, especially

Jan 1, 1931

By U. F. Kocks

The flow stress in some latent slip systems of aluminum and silver crystals after various deformations in single slip was investigated by transverse compression and supplemented by experiments on overshoot of the compression axis and the stability of corner orientations. Work hardening was found to be remarkably isotropic, the ratio of the flow stress in the latent system to that in the primary system being between 1.0 and 1.3. The strain-rate dependence was not significantly larger in the latent system. This low anisotropy suggests that specific dislocation interactions are not the direct cause of work hardening. Either the obstacles are essentially impenetrable so that only their distance enters, or a fairly random distribution of dislocations of all systems is. in fact. formed during single slip. The latter seems to he excluded by the observations on the strain-mte dependence and on the amount of secondary strain. The amount of seconzdary strains occurring in single slip was determined by shape-change mensurements and by a new method connected with the latent-hardening experiments. It is definitely less than 1/300 times the strain in the primary svstem. WORK hardening is due to dislocation interactions; this is a hypothesis, and possibly the only one, on which all present work-harden ing theories agree. About a dozen specific interactions have been considered, and it is unlikely that any essential one has been missed. Different work-hardening theories differ to a large extent in the specific interactions which are deemed most important. The presence or absence of any particular interaction, and its degree, depend on the geometrical relationships between the two dislocations interacting. Let us enumerate some examples. Two dislocations may react, with a varying reaction energy, to form a third dislocation, and this reaction product may be sessile or glissile. Two dislocations may intersect and a jog may be formed on both, on one of them, or on neither; this jog may be sessile17Z or glissile and it may, if moved nonconservatively, lead to the production of vacancies or interstitials. Finally, a dislocation may bypass another one and thus interact only with its stress field. All these interactions depend on the specific relation between the Burgers vectors and line directions of the two dislocations. Any dislocation generated during plastic deformation of fcc crystals belongs to one of twelve slip systems. Taking any one dislocation, its relationship to each of the other eleven can fall, by symmetry, into one of only five classes. These relationships are enumerated in Fig. 1 and Table I. Each slip system is represented in the stereo-graphic projection by two triangles, namely those in one of which the specimen axis would have to lie if the specimen were to deform in single slip on this slip system in a given sense, in a tension test. Let us represent the primary slip system by the shaded triangles. The other slip systems are classified only with respect to their relationship to this primary system. The code letters (initials of established names* in German) are explained in Table I. Three specific interactions are also listed in cases where they may be strong: the product of a reaction, the formation of jogs in either system, and the elastic bypass stress. The last column relates to the types of experiments reported in this paper and summarizes their results. To decide experimentally between the relative importance of the various interactions one would like to produce a group of dislocations in one slip system and then measure the stress necessary to force another group of dislocations of a specific second system through them. Hopefully, one can produce the first set of dislocations by plastically deforming the specimen in single slip. Then one can try to achieve single slip in a specific, previously latent system and measure its flow stress. If it is different from the virgin flow stress, there has been "latent hardening". Some types of latent-hardening experiments will be discussed in the next section. The strain-rate and temperature dependence of the flow stress is an indication of the importance of dislocation intersections. By extending an investigation of this dependence to the latent systems, one can determine how much more important forest contributions are here. seeger3 has used the as-

Jan 1, 1964

Jan 1, 1957

By Harry P. Hohenadel

DURING the past few years the amazing developments of the chemical industry have inspired so much publicity that the feature writers assure us that we are entering a "Chemical Age," industrially as important as the "Steel Age" and the "Electric Age," so-called. Whether or not these assurances are overstatements, it is a fact that the expansion of the chemical industry during the past 25 years has been enormous. The Chemical Bureau of the War Production Board calculates the value of chemicals produced during 1944 at $8,300,000,000, no small sum even in inflated dollars. As concerns us of the Southwest oil and gas country, four significant trends of the chemical industry are most important. (1) Many of the recently developed chemical products are new creations, not substitutes,. as new and original as the invention of the light bulb, and with a field for exploitation almost as wide. (2) Many of these chemical products will enter the mass consuming markets, which require enormous tonnages of products, and such markets are setting up an industrial demand for chemicals on a mass volume basis, compared to the relatively high-priced low-volume basis ordinarily considered as the chemical outlet of the past. (3) Most of the processes involved in producing these chemicals are adapt. able to the use, all or in part, of natural gas, oil, or refinery gases as raw mate-

Jan 1, 1945

By G. C. RIDDELL

THE metallurgist, chemist, and physicist are blazing trails that lead far afield. Pushing on into an "Alloy Age" they see a non-ferrous era over- taking iron and steel. Delving into the nature of the physical world, they break down a supposedly indivisible element, hydrogen. Not content with terrestrial problems, they peer back along the cosmic ray into iaterstellar space, glimpsing forces that are, apparently, still busy with the task of atom-making. Mastering and organizing the material and physical, they advance steadily toward that borderland of science where the concept of matter itself seems abandoned, and force is the substance left.

Jan 1, 1930