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By Lawrence Wright

THE occurrence of gold, gold-silver, silver-lead-zinc ores in the post-Cambrian sediments in the Black Hills of South Dakota, and their genetic relationship to the Tertiary intrusives, is well known and accepted, but the occurrence of gold in the pre-Cambrian rocks at the Homestake mine, which underlie this Tertiary gold mineralization, has given rise to differ-ences of opinion as to the period of major gold introduction into the older rocks. Fig. 1 illustrates. the distribution of mineralization along the axis of the Tertiary uplift in both pre-Cambrian and post-Cambrian rocks. The following possibilities have been presented: 1. The Homestake gold deposit was formed in pre-Cambrian time and the deposits in the overlying Cambrian sediments formed during Ter-tiary time. 2. The Homestake lode existed at the beginning of Cambrian time, but was enriched by the passage of Tertiary auriferous solutions. 3. The Homestake lode was represented by pre-Cambrian quartz-chlorite sulfide mineralization, very low in gold content and the gold superimposed on the older nearly barren mineralization during the Ter-tiary metallogenic epoch. 4. The sulfides and sulfarsenides as well as gold were deposited in both pre-Cambrian and post-Cambrian rocks during the Tertiary period. Those favoring the first proposition feel that the question is pretty well settled, while the proponents of the second theory are more flexible in their view, feeling that the amount of gold introduced in either period is still an open question. The third and fourth theories, with some modifi-cations, are supported by the proponents of the Tertiary theory, who feel that the evidence strongly favors that period. The following pages are intended to present the evidence and to give the reaction of various observers with my own comments and conclu-sions; also, the accumulated facts of observation gathered over a period of close association with the area under discussion, beginning in 1919.

Jan 1, 1936

By Grant Buma

The purpose of this paper is to present arguments and evidence that there are natural processes at work which tend to minimize the impact of solution mining on the environment. The contaminants have two sources. First are elements which were present in the roll-front deposit in insoluble compounds, for example, uranium in uraninite and coffinite, molybdenum, arsenic, iron, cobalt, nickel, etc. in sulfide minerals, vanadium in micas and clays, etc. Second are elements introduced by the leach liquor. Precipitation of reduced compounds, scavenging of heavy elements and absorption by quartz and clays, can all reduce the amount of heavy elements in solution. If a roll can be demonstrated to be actively precipitating uranium and heavy metal elements, then the presence of precipitants (pyrite and carbon) can be assumed. Criteria for recognizing an active roll are described.

Jan 1, 1979

By B. P. Canning

In recent years much attention has been given to comminution theory and the design of crushing and grinding installations in large plants. The day of the small plant is not over, however, and we will attempt to analyze some cost aspects of conventional plant design, particular to their smallness. Small plants generally have the same design requirements as large plants, however, certain additional restraints are imposed which generally reduce efficiency and availability. The engineer must take particular note of these restraints in order to properly design crushing and grinding installations for these plants. Whatever equipment is selected for small plant crushing and grinding circuits, it is more costly on a per-ton capacity basis than for a large plant. Circuit Design Small crushing and grinding circuits of recent design usually are of one-line concept utilizing simplified flowsheets. This is the logical outcome of a cost evaluation excluding special considerations and is the basis of the circuit design discussion and cost evaluation which follows. Objections to the one-line concept have been voiced with arguments claiming little flexibility, low availability, higher disaster risk, etc., however, experience has proven these arguments not to be convincing. Equipment of sufficient capacity is available on the market for all normal applications up to the 4000 mtpd plant size here considered and the engineer has complete freedom of choice. Where separate treatment of ores is required, the single-line plant concept requires adequate ore storage be provided with facilities for clean-out between campaigns on one or the other ores. It is very difficult to justify parallel crushing and grinding sections for small plants as material handling is more difficult with small flows involved, and equipment costs become significantly higher. Cost Evaluation Criteria In order to evaluate the small plant comminution circuit on a cost-effectiveness basis, a test model is here established for a comparison basis. Although it is recognized that the parameters chosen will fit only certain metal mining applications, the cost trends should provide useful information for other applications. The test model used is a one-line comminution circuit which considers maximum space utilization in an all-enclosed plant. Plant feed is assumed to be 90 percent passing 12 in. with nominal maximum rock size

Jan 1, 1982

By Sidney Powers

CONTENTS PAGE Distribution of fields 4 History of development 6 Origin of oil 7 Structure, accumulation and migration 8 Reservoir rocks 9 Methods of drilling and exploration 10 Oil-field statistics : 12 Description by regions: United States: Appalachian region ; 12 East-central states 17 Kansas 18 Oklahoma : 19 Texas : 24 Arkansas : 32 Louisiana 33 Mississippi ....... 34 Rocky Mountain region : 34 California 37 Canada 41 Mexico 43 Cuba 46 Bibliography 46 THE purpose of this brief account- of the occurrence of petroleum in North America is to make available to those who have a knowledge of geology, but who are not engaged in the petroleum industry, a few salient facts about the location of oil and gas fields, their productivity, the important structural types of accumulation and the age of the rocks containing petroleum. A few useful data and statistics are furnished, yet not complete statistics that are available elsewhere. Geology has been treated in simple terms because the reader is presumed to have little interest in the names of formations and of oil sands. Mineral deposits are more or less analogous. Whether oil or metals, minerals are found in rocks, largely in sedimentary rocks which carry water or have at one time carried it. A genetic or accumula-

Jan 1, 1931

By Oliver C. Ralston

This paper reports the results of the use of salt in some research work carried on during the past 3 years at the Salt Lake City Station of the Bureau of Mines, which is quartered in the University of Utah, whose Metallurgical Research Department cooperates with the Bureau. Only the work involving the use of salt is described. The authors wish equal credit given to J. F. Cullen, C. L. Larson, C. Y. Pfoutz, C. E. Sims, H. C. Neeld, R. W. Johnson, F. G. Moses, N. C. Christensen, and G. H. Wigton, who have all in some way contributed toward the success of this work, while connected with the station in one way or another. Lead Metallurgy Popularly Supposed to be Without Problems In lead metallurgy it is difficult at first to find metallurgical problems, as the prevailing conception has been that lead is so easily concentrated in its various ores and so easily reduced to its metallic form that the only progress possible is that involved in cheapening methods of mining and of reduction. Most of the problems usually considered are of minor nature and do not involve radical metallurgical changes. During the three years of work of the Salt Lake Station, the following classification of problems in the metallurgy of lead has been made: Oxidized Ores. 1. Ores containing only lead. 2. Ores containing lead and silver or gold. 3. Ores containing lead and zinc, with or without silver. Sulphide Ores. 1. Ores of pyrite carrying some lead. 2. Ores of complex zinc-lead-iron sulphides. 3. Complex sulphides containing precious metals.

Jan 1, 1918

By Burton H. Boyum

GREATER depth of exploration drill holes and increasing cost of drilling have been principal factors in reviving interest on the Marquette Iron Range in controlled directional drill-hole deflection. This deflection is obtained by the application of the Hall-Row wedging technique. Modifications were made in the technique and equipment in the effort to simplify and strengthen the procedure. The practice is similar in many respects to the oil well type of deflection with a whipstock.

Jan 1, 1947

By Sidney Powers

Contents Page Distribution of fields..................................................... 490 History of development.................................................. 492 Origin of oil............................................................ 493 Structure, accumulation and migration..................................... 494 Reservoir rocks......................................................... 495 Methods of drilling and exploration....................................... 496 Oil-field statistics........................................................ 498 Description by regions: United States: Appalachian region.................................................. 498 East-central states............................................. 503 Kansas............................................................ 504 Oklahoma.......................................................... 505 Texas........................................................... 510 Arkansas........................................................... 518 Louisiana.......................................................... 519 Mississippi......................................................... 520 Rocky Mountain region.............................................. 520 Cahforn~a ......................................................... 523 Canada.............................................................. 527 Mexico.............................................................. 529 Cuba............................................................... 532 Bibliography........................................................... 532 The purpose of this brief account of the occurrence of petroleum in North America is to make available to those who have a knowledge of geology, but who are not engaged in the petroleum industry, a few salient facts about the location of oil and gas fields, their productivity, the important structural types of accumulation and the age of the rocks containing petroleum. A few useful data and statistics are furnished, yet not complete statistics that are available elsewhere. Geology has been treated in simple terms because the reader is presumed to have little interest in the names of formations and of oil sands. Mineral deposits are more or less analogous. Whether oil or metals, minerals are found in rocks, largely in sedimentary rocks which carry water or have at one time carried it. A genetic or accumulative

Jan 1, 1931

By G. W. Brock

Experiments in the form of aging of overstrained tension specimens and elevated temperature tension testing, have been carried out on recrystallized arc-cast molybdenum. The aging behavior of molybdenum was found to be strongly dependent on the degree of plastic strain present in the lattice: the reason for this being the low solid solubility for the common interstitial elements in molybdenum. GEORGE W. BROCK, formerly Research Associate, Department of Theoretical and Applied Mechanics, University of Illinois, Urbana, III., is Research Associate, Department of Engineering Sciences, IBM Research Center, Yorktown Heights, N. Y. Manuscript submitted January 19, 1961. IMD THE term strain aging is familiar in connection with the recovery of the yield point in mild steel after tensile overstraining, and there are other instances where it is known to exert an appreciable effect on mechanical properties. For example, steel exhibits a greater tensile strength at mildly elevated temperatures than at room temperature and serrated stress-strain flow curves occur under certain conditions. It has been known for a number of years that the phenomenon of strain aging is directly connected with the presence of carbon and nitrogen in the lattice; and extremely small amounts of either element are sufficient to produce the effect. In this study, the aging behavior of overstrained tensile specimens of recrystallized molybdenum has

Jan 1, 1962

By A. E. Gorum, J. Washburn, E. R. Parker

Experimental evidence was obtained in support of the idea that cleavage fracture can be initiated by dislocation pile-up. The high ductility of MgO crystals when tested in bending comPared to their relative brittleness in tension was explained on the basis that large pile-ups are more likely in a tension specimen. CLEAVAGE fractures have been a problem of major concern for many years. A number of large steel structures have failed in a brittle manner, usually suddenly and without warning; often the failures occurred for no obvious reason and at nominal stress levels well within the generally accepted range. A great deal of data have been collected about factors that contribute to failures,1 but the physics of the fracture process has never been revealed. cottrel12 has recently developed a theory of brittle fracture in ductile materials which was based upon the concept that dislocations moving on two intersecting planes can unite to form a crack nucleus. This theory accounts for the known effect of grain size and for the effect of testing temperature. There has, as yet, been no experimental evidence published that would substantiate this or the earlier theories based on stress concentrations due to piled-up dislocations. The study reported herein was conducted to obtain information that would either substantiate or disprove the

Jan 1, 1960

By Schrade F. Radtke

The future of lead and zinc, as with any material, will relate directly to their capability to remain competitive; that is, to demonstrate cost-performance ratios that are superior to those of competing materials. These cost-performance ratios are not static; therefore, it is necessary to develop improvements in products or processes to maintain present markets or to penetrate other markets. Perhaps the surest way to achieve these goals, if they can be achieved at all, is through research. The world lead and zinc producing industry established ILZRO as its cooperative research function to carry on both fundamental and applied research and development efforts aimed at the stated objectives. Current research efforts in the fields of die casting, galvanizing, finishing, chemicals, architectural applications, ceramics, and batteries are reviewed and potential impact assessed, some projections are given of possible new areas of research. Environmental research and its impact on future uses of lead and zinc are also discussed.

Jan 1, 1977

By W. F. White, W. R. Beloff, B. C. Dorwart, G. W. Jaworski

INTRODUCTION The rigid inclusion stressmeter is a relatively low-cost instrument developed by Hawkes and Bailey (1973) and was originally intended to monitor stress changes in mine pillars subjected to uniaxial stress changes. In this regard, this instrument has found considerable use by the mining industry. More recently, there have been attempts to use the stressmeter for determination of more general changes of the in situ rock stress. This paper reports on a study to characterize the performance of the rigid inclusion stressmeter for this application and presents results on the effect of anisotropic stress changes. These stress changes must be accounted for to properly analyze general changes of the in situ rock stress. BACKGROUND INFORMATION The rigid inclusion stressmeter is an instrument designed to measure variations of the in situ stress around a borehole. The stressmeter studied in this work, is manufactured by Irad Gage, Div. Creare Products, Inc. Lebanon, New Hampshire. It consists of a stiff hollow steel gage body that is preloaded across a borehole diameter. The preloading is activated by sliding a wedge between an upper platen and the gage body. Changes in the in situ stress result in slight deformations of the gage body. These deformations affect the stress in a highly tensioned wire that

Jan 1, 1982

By Moshe Sheinkin, Douglas E. Julin

Large tonnage operations face many problems in adequately planning ahead for future years production. In order to maintain desired levels of production, such problems as source of tonnage, man- power and equipment requirements, tailings disposal and water requirements must be anticipated. Of course, before any of these problems can be analyzed, daily tonnage requirements and its source must be determined. Looking ahead for one year or even two or three is usually not sufficient time to adequately prepare an area for production. Because of the sequence of mining and the multilevel nature of the 42,000 tpd Climax mine in Colorado long-range planning must be on a ten-year basis. By using a ten-year base, adequate time is allowed to gain access and prepare a new level for production. Usually eight years will be required for this phase of the initial mine preparation. Once production has been started on a level and access to the area is available, three years is usually sufficient to prepare a new block for production as long as it follows in the normal sequence of mining.

Jan 4, 1967

SIDNEY ROLLE, Chrome, N. J.-I should like to ask if Mr. Bach does not think it rather harmful to let the amen depend entirely on the company, whether it would not be a good plan to let the men aid a little in the support of these organizations? Also whether he has had any experience with utilizing the Y. M. C. A. in this connection. E. E. BACH, Ellsworth, Pa.-That question is always raised whenever there is discussion upon this subject. So far as we are concerned that would not help a bit; our people do not have that feeling, because .we have a company which these men recognize has a corps of very sympathetic officials in every way. I remember the assistant general manager lived out in one of these mining towns for a while. His difficulty was that every man, no matter what, who or where he was, if he had, or thought lie had, a, complaint, had the right of way to his office, and didn't have to stop at all. That is the spirit that predominates all through it. This is also the spirit of the mine foremen, two of whom were trained in our own night school, and it is the spirit of the fire boss and the general spirit of the people. They do not feel that we are trying to feed them with a spoon. As to the Y. M. C. A., we feel that it would be impracticable for us. R H. VAIL, New York, N. Y.-It would be very interesting if Mr. Bach would tell a little more about the control of the dispensing of intoxicants. There are many communities where the state intends to do that but does not succeed very well, and as Mr. Bach has spoken of the speakeasies on the environment of these towns, it would he well to know more about the problem of eliminating those.

Jan 4, 1918

By R. M. Brick

AN increased demand for information in regard to the effect of gaseous elements in steel has accompanied the recognition of the importance of grain size. Attempts to correlate grain-size characteristics with gas con-tent, particularly oxygen in solution or in the form of included metallic oxides, have not been universally successful. Certain definite effects of dissolved gases are recognized; specifically, the role of hydrogen in causing internal cracks or "flakes" and that of nitrogen in preventing excessive grain growth of ferritic chromium steels. When irregular behavior or properties are found in a well-known steel and no definite cause for the abnormality may be assigned on the basis of chemical and metallographic tests, dissolved gases are frequently blamed as the culprits. The solubilities of hydrogen1 and nitrogen2 in pure liquid iron are known but of the ternary systems, iron-alloying element-gas, only the Fe-Si-N3 and Fe-Cr-N systems have received attention and here the study was confined to liquid alloys. Krivobok4 published a curve show-ing the solubility of nitrogen in liquid Fe-Cr alloys but gave no informa-tion on the experimental procedure employed. The considerable experimental work reported on the Cr-N binary alloys has been reviewed by Hansen.5 It is generally agreed that the nitride CrN is a stable phase although the existence of nitrides within limited temperature ranges of stability, viz., Cr3N2 and Cr2N, has been disputed, Adcock6 and others7 have reported a eutectic between Cr and CrN at 1580°C., although the supporting evidence is not complete.

Jan 1, 1940

By George E. Kruger, William F. Butler

The less developed nations maintaining a free enterprise economy (to which this chapter is addressed) have real and substantial opportunities to lay a foundation for general economic progress by using their mineral resources. Most of these nations have mineral resources which could be developed. By seizing these opportunities, nations seeking rapid economic development can secure a source of foreign exchange earnings to finance the imports needed for growth and, at the same time, increase the technical knowledge and well-being of an important part of their population. History clearly shows the manner in which most of the currently industrialized nations have used mineral resources to support their development. Indeed, few nations have managed to achieve a high level of income without a firm base of mineral resource development. The main exceptions appear to be the Netherlands, Switzerland, Denmark, and New Zealand, and the last two have based their prosperity on a highly efficient agriculture. Economic growth in the United States, the United Kingdom, Canada, France, Germany, and Russia was importantly based on the use of indigenous mineral resources. Despite this record of accomplishment through mineral development, many of the currently less developed nations are not taking advantage of the opportunities available in the mineral field. Restrictive laws or practices in many such nations operate effectively to prevent development of mineral resources. This failure to grasp real opportunities for development is based on a series of arguments that the mineral field offers few substantial and attainable advantages. Among these, the following propositions appear the most important:

Jan 1, 1964

By G. S. Hume

IN. THE autumn of 1922, British Petroleums Ltd. found oil of 14° Baumé in a sand 17 ft. thick in its. No. 2 well at Wainwright, 120 miles southeast of Edmonton. This greatly encouraged drilling in the Wainwright-Irma area and this past summer several wells were started, three of which are now completed and the others still being drilled. Of the three completed, No. 4 British Petroleums contains oil; No. 3 British Petroleums gave a show of oil but so far has not given much hope, of becoming a commercial producer; and No. 1 Maple Leaf Co., as now finished, is a. gas well with a daily flow of gas of about 2,500,000 cu. ft. at a closed pressure of 700 lb. An oil sand is reported to have been encountered below the producing gas horizon in the Maple Leaf well but has not been tested. Operations on this well have been suspended for the winter. The Geological Survey of Canada this past summer undertook a geological investigation of this area with the object of defining the structures with which the oil and gas are associated. The structure underlying this portion of the plains was supposed to be a terrace with the western edge dipping into the Alberta syncline and with a monoclinal structure to the east. By accurate leveling on known geological horizons on this terrace, a number of gentle folds were located and -it is in these folds that the oil and gas are found. At the British Petroleums Nos. 2 and 4 oil wells, the western flank of the fold has a gentle dip of only a few feet to the mile to the southwest whereas the strata on the eastern flank dip to the northeast about 40 ft. in ½ mile, the strike of the fold being northwest and southeast. How far oil will be found down the gentle southwest dip is unknown but probably the productive part of the fold will not exceed 1 mile in width, and possibly less. No. 3 British Petroleums well is on the strike of the fold 1 mile southeast of the two oil wells. The sand that was productive in Nos. 2 and 4 wells was not present in this well or, if present, was very thin and unproductive. Two other sand horizons, however, were encountered. The upper of these

Jan 3, 1925

By Jack Washburn, E. R. Parker

Kinking in zinc single-crystal tension specimens was observed under conditions of low stress and high temperature. Kinking is discussed in relation to other plastic bending phenomena on the basis of dislocation theory. Experiments on the stress-induced motion of small angle boundaries are reported. KINKING was first reported by Orowan1 as a new deformation mechanism. He observed the phenomenon in cadmium single crystals loaded in compression. Glide lamellae in a local region of the rod were observed to snap over suddenly to a tilted position, resulting in a sudden shortening of the specimen. Between the tilted portion and the rest of the crystal there were fairly sharp boundaries, with the slip plane assuming approximately mirror image positions on opposite sides of these boundaries. Orowan considered the boundaries to be regions where dislocations had concentrated. Hess and Barrett' observed the formation of kinks in critically oriented zinc compression specimens. It was found that the sudden snapping over of the tilted region was not an essential part of the kinking phenomenon but rather was associated with the method of loading. Kinking was explained on the basis of the accepted mechanisms of slip and flexural glide. It was also suggested that a kink can be considered as a special type of deformation band. During a recent investigation of the effect of surface condition on creep of zinc single crystals," a similar phenomenon was observed in crystals which were loaded in tension. The specimens were 0.4 in. diam cylindrical rods with a free length of 4 in. between end connections. All of the crystals were tested at a constant load. adjusted to give an extension rate of approximately 0.05 pct per hr. Kinking, as shown in Fig. 1, occurred in some of the tests performed at temperatures above 200°C. Kinking was observed in specimens varying widely in initial orientation, scattering about a 45" angle between the slip plane and the specimen axis. The condition leading to kinking in tension appeared to be non-uniform distribution of flow along the gage length combined with the restraint imposed by the tensile load. At low temperatures and fast strain rates, the distribution of strain throughout the midsection of tension specimens was generally quite uniform; therefore, bend planes developed only near the ends as described by Miller.4 However, at high temperatures under creep conditions it was difficult to obtain specimens in which the distribution of flow was uniform. Some of the factors which may have caused differences in flow stress along the length of the crystals are: Nonuniform distribution of impurities, accidents of growth (lineage structure), slight bending or other damage during handling, surface conditions, and strain-aging characteristics due to dissolved nitrogen." Plastic flow, once started in a local region, often continued to a relatively large strain before other parts of the gage length became active. Under these conditions a series of kinks, such as those in Fig. 1, were produced. Fig. 2 illustrates how a nonuniform distribution of slip produces bending moments which- are responsible for kink formation. If no plastic bending were to occur while the rod extended by pure slip in two separate sections of the rod, it would assume a shape such as that in Fig. 2a. A specimen having this shape and being subjected to a tension load would have concentrations of stress at the concave surfaces C and lower than average stress would exist at the convex surfaces D. Therefore a bending moment is superimposed on the average stress in the regions between C and D. The positions of potential bend planes under these conditions are shown as dotted lines. Actually no such shape as Fig. 2a develops because plastic bending in the region C-D occurs simultaneously with pure slip in the intervening regions. The observed structure of a tension kink is indicated by Fig. 2b. Perhaps the best approach to an understanding of kinking as well as other related plastic bending phenomena, such as the bend planes discussed by Miller,' cell formation studied by Wood et al.,6 and polygonization,7 is consideration of the dislocation model of a bent lattice. Current theories of the slip process postulate generation or multiplication of dislocations at certain lattice imperfections. The mechanism proposed by Frank and Read8 results in continuous generation of concentric dislocation loops which spread out

Jan 1, 1953

By R. V. Whetsel, V. R. Gargias, J. W. Ristori

WoRld consumption of petroleum and its substitutes in 1941, the amount of which obviously is largely conjectural, is estimated at 2,066,653,000 bbl. This is 48,689,000 bbl. more than the previous year and is an all-time high. Except for the United States, this figure does not include consumption for military purposes. Consumption in the United States also reached an all-time high during 1941, totaling 1,492,000,000 bbl., or 158,230,000 bbl. more than the previous peak year of 1940. On the other hand, it is estimated that civil consumption in countries outside of the United States decreased 109,541,ooo bbl. as compared with the previous year. Demand for military purposes and/or additions to stocks in countries outside of the United States is estimated at 304,507,000 bbl. during 1941, compared with 209,635,000 bbl. in 1940. This increase was due largely to blitzkrieg warfare on several fronts. especially Russia; entailing large expenditures of petroleum by both sides because of the immense area covered by the fighting forces, the long supply lines necessary and the intensity of the fighting. It is interesting to note in this connection that Axis-controlled countries, excluding Japan, had an estimated production of approximately 89,000,000 bbl. of petroleum and its substitutes in 1941. The peacetime consumption of these countries in 1938, for example, was about 183,000,000 bbl. It is believed that the minimum to which civil consumption could possibly be re-duced in wartime is 20 per cent of that of peacetime, which would call for a minimum consumption of 37,000,000 bbl. in these countries in 1941 for civil purposes. This

Jan 1, 1942

By V. R. Gargias, J. W. Ristori, R. V. Whetsel

WoRld consumption of petroleum and its substitutes in 1941, the amount of which obviously is largely conjectural, is estimated at 2,066,653,000 bbl. This is 48,689,000 bbl. more than the previous year and is an all-time high. Except for the United States, this figure does not include consumption for military purposes. Consumption in the United States also reached an all-time high during 1941, totaling 1,492,000,000 bbl., or 158,230,000 bbl. more than the previous peak year of 1940. On the other hand, it is estimated that civil consumption in countries outside of the United States decreased 109,541,ooo bbl. as compared with the previous year. Demand for military purposes and/or additions to stocks in countries outside of the United States is estimated at 304,507,000 bbl. during 1941, compared with 209,635,000 bbl. in 1940. This increase was due largely to blitzkrieg warfare on several fronts. especially Russia; entailing large expenditures of petroleum by both sides because of the immense area covered by the fighting forces, the long supply lines necessary and the intensity of the fighting. It is interesting to note in this connection that Axis-controlled countries, excluding Japan, had an estimated production of approximately 89,000,000 bbl. of petroleum and its substitutes in 1941. The peacetime consumption of these countries in 1938, for example, was about 183,000,000 bbl. It is believed that the minimum to which civil consumption could possibly be re-duced in wartime is 20 per cent of that of peacetime, which would call for a minimum consumption of 37,000,000 bbl. in these countries in 1941 for civil purposes. This

Jan 1, 1942

By J. F. Kemp

CONTENTS. [ ] INTRODUCTION. THE saying that " of all the known regions of the universe, the most unsafe to reason about is that which is under our feet,"* might well be the motto of the present paper, in view of the writer's profound appreciation of the difficulties and uncertainties of the subject. In such a field, the temptation is very strong to announce a probable proposition, and then to defend it with a loyalty insensibly graduating into partisanship. Conscious of this danger, the writer has endeavored to maintain an impartial and candid form of statement, though others may feel that he has not been wholly successful. The subject, as here considered, falls naturally into two di-

Jan 1, 1902