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[Separates of all the Technical Publications published in 1928 are available at Institute headquarters. All the papers are on file in public, university and technical libraries, and when so indicated in the list, may be found either in the TRANSACTIONS or in the special volumes issued by the Institute.; METAL MINING TECH- NICAL TRANS. PUBLI- TITLE AUTHOR MEETING VOLUME CATION AND PAGE* No. 50 The Eötvös Torsion Balance D. C. Barton New York Method of Mapping Geologic Feb., 1928 Structure 52 A Cartographic Correction for the C. A. Heiland New York Eötvös Torsion Balance Feb., 1928 61 Liquid-oxygen Blasting at Chuqui- H. C. Schultz, New York camata, Chile F. K. Middleton Hunter Feb., 1928 76, 108, 123 64 Working Methods of Practical Geo- Hans Haalck New York physics Feb., 1928 65 Experiments with Eötvös Torsion P. W. George New York Balance in the Tri-State Zinc and Feb., 1928 Lead District 74 Gravity Surveying in Great Britain H. Shaw New York Feb., 1928 75 The Computation of Eötvös Gravity E. Lancaster-Jones New York Effects Feb., 1928 82 Earth-resistivity Measurements in W. O. Hotchkiss, New York the Lake Superior Copper Country W. J. Rooney, Feb., 1928 James Fisher 83 Mining Methods and Records at the Roy W. Moore New York 76, 56, 90 United Eastern Mine Feb., 1928 98 Recent Results in Electrical Pros- Hans Lundberg New York specting for Ore Feb., 1928 101 Relation between the Oxygen Bal- G. St. J. Perrott, New York ance and Propulsive Strength of N. A. Tolch, Feb., 1928 Eight Gelatin Dynamites J. E. Crawshaw 102 Effect of Oxygen Balance of Gelatin G. W. Jones, New York Dynamites on the Gaseous Prod- G. St. J. Perrott Feb., 1928 ucts of Detonation 108 The Financial Report of a Min- Henry B. Fernald New York ing Company-Its Content and Feb., 1928 Meaning 116 What Duty to Support the Surface R. G. Bosworth New York Does a Subsurface Owner Owe? Feb., 1927 136 Comparison of Branch Raise and C. A. Mitke Los Angeles 76, 93, 103 Combined Shrinkage and Caving Sept., 1928 Methods 141 A Mining Company Balance Sheet G. F. Wolff New York Feb., 1928

Jan 1, 1927

By D. G. Brubaker

IN the history of geophysical exploration by the electromagnetic method many procedures and types of equipment have been used. Source arrangements for surveying on the ground have included long wires grounded at both ends, large loops laid on the ground, small horizontal loops, and vertical loops of moderate to small sizes. Receivers have ranged from simple direction-finding coils to combinations of coils and a bridge circuit to measure quantities related to both amplitude and phase of the received signal. Primary considerations in choosing a survey method are effectiveness, speed, and economy. In work on the ground in which locating and outlining conducting bodies is the objective, methods using a vertical coil and a simple direction-finder have been found the most satisfactory. Mason1 and his associates applied such a method by setting up a vertical source loop, fed with low frequency alternating current by an engine-generator set. With a direction-finding receiver they surveyed lines along the ground in the plane of the loop, taking measurements at each station of the azimuth and inclination of the magnetic field direction. Deviations of this direction from the normal direction, that is, from horizontal and perpendicular to the traverse line, indicated a conducting body. Recent advances in design of light-weight generating equipment have encouraged using this and similar methods. In 1950 W. H. Westphal and the present writer developed a variation of this method and the apparatus for carrying it out. Their ideas were also based on experience with the Boliden Mining Co. method, which uses a small source coil and a vac- uum tube oscillator. The new procedure uses a small vertical source coil, powered by a vacuum tube oscillator, apd a direction-finding receiving coil. Source and receiver are kept a fixed distance apart and move as a unit along the survey lines. At each receiver station only the inclination of the magnetic field created by the source is measured. Source Unit: The source coil and a small vacuum tube oscillator together weigh about 45 lb. The source coil consists of about 60 turns of 10-gage

Jan 1, 1958

By L. Adler

Analysis of a mine roof can be based on fixed-end beam behavior. The author here analyzes the effects of zero restraint at deflecting beam supports. Formulae are given for determining permissible support deflections. Analysis of a mine roof in a bedded deposit usually follows the assumption that the behavior of the roof is analogous to a beam with both ends fixed. Yet it is recognized that the end restraint itself varies with the thickness of cover, so that at shallow depth the restraint is minimum, and at great depth, maximum.' Consequently, an analysis on the basis of fixed ends or full restraint represents only one extreme in the possible range of conditions. Since the actual amount of restraint is difficult to ascertain, a more rational approach is to consider the two extreme cases of end restraint. Such situations regarding uncertainty of the restraining effects of supports are not uncommon in structural analysis, and are handled in a like manner.' Since previous studies9)4 have dealt with full restraint, this paper will analyze the effects of zero restraint at deflecting beam supports. In such a case a mine roof with several intermediate supports becomes analogous to a uniformly loaded continuous beam on simple supports, as shown in Fig. 1A. Such a structure is statically indeterminate to a degree equal to the number of intermediate supports, n. Therefore, with the three equilibrium equations, n additional equations are needed. A number of methods exist to analyze this problem, but The Theorem of Three Moments is Simplest. The continuous beam is divided at each support into a sequence of simply supported single span beams, with the unknown end moments, as appears in Fig. 1B. Continuity requires that the common ends of adjacent beams have the same slope (Fig. 1C). eiB= B(i+l)~= ei(i+l)and MiB= Mti+I)A= Mi(i+i). [1I A Glossary of all terms is given in Table I. Furthermore, if we first consider that the supports do not deflect, the slope at a support is the sum of the slopes due to each of the individual loads shown in Fig. 2, yielding:

Jan 1, 1961

By R. F. Shurtz

This paper relates geostatistical doctrine to classical statistical and mathematical concepts. It is not a contribution to geostatistics; it is a contribution about geostatistics. It uses descriptive and pictorial arguments to assist interested readers in forming an intuitive grasp of the recondite and difficult mathematical issues involved. The method chosen is to cite authoritative literature references from the two fields and trace connections between them. Four broad conclusions appear: first, geostatistics comprises a relabelled subset of concepts detached from classical statistics and mathematics; second, this relabelling artificially isolates geostatistics from the classical fields and restricts its scope; third, the classical fields still have much to offer to the mining industry but will remain fallow unless artifcial communication barriers are removed; and fourth, the unique advantages asserted for geostatistics are neither unique nor necessarily real. These findings should not be regarded as iconoclastic but rather as Pointing the way to a wider and more productive scope for those who evaluate mineral deposits.

Jan 1, 1983

By Paul Billingsley

IN THEIR course across Ecuador, the Andes fail to show the mineral wealth with which they abound in Peru, Bolivia, and Chile. This may well be due merely to the concealment of recent volcanic ash and dense tropical jungle, but at any rate Ecuador has lacked the stimulation to development and progress afforded to the southern countries by the mines of Cerro de Pasco, Potosi, etc. 1 There is, however; in Ecuador, near its southern border, one mining district that, in recent years under North American management, has become a steady producer of mineral. wealth and. a community in which the sanitary and mechanical elements of modern life are displayed, for ;the first time, to the Ecuadorians of the lowland forests. The mining district of Zaruma is .situated in the province of El Oro, near the southwestern corner of Ecuador, about 50 km. (31 mi.) from the coast. Pizarro's first landing on the mainland was at Tumbez, at the mouth of the river that drains the Zaruma area; and the gold so abundantly found in this Indian town was soon traced to its source. In 1549, Mercadillo, one of the original (band, reached Zaruma, having worked his way up-stream through canyons that .are now regarded as impassable. The Spaniards proved themselves efficient prospectors, finding practically every orebody in the district as yet discovered; and, working

Jan 10, 1925

By Eldon Dunlap

RECENTLY the producing branch of the petroleum industry has shown a considerable and growing interest in the quantitative determination of the water, oil, and gas content of cores as it relates to estimation of reserves, to providing a, basis for judging as to the feasibility of applying various secondary-recovery and pressure-maintenance processes, and in general to the operation of producing properties. For years it has been known that oil, gas and water coexisted in the pores of many semidepleted oil measures. It is now generally believed that oil-bearing beds contain connate water in amounts varying up to 50 per cent of the pore space. However, only lately has reliable direct evidence of the extensive occur-rence of connate water in oil sands been published. Very little work has been done to ascertain the effect of this water on the productivity and ultimate recovery of oil from wells. It was the intent of this research to study the influence of this indigenous water on the flow of oil through unconsolidated sands, with the hope that the results could be applied qualitatively to the flow of oil in underground reservoirs partly saturated with water. Obviously, ultimate recovery estimates based on the void volume of the reservoir will be in error unless a, conscious or unconscious correction is made for the volume of water occupying a portion of the effective pore volume of the reservoir- Evaluation engineers in the past have applied arbitrary saturation and recovery factors that may inadverently have compensated for the failure to consider specifically the water content. Nevertheless, the evidence available indicates that these factors need revising if each is to be independently correct and truly representative. Although the mere fact that the connate water renders part of the pore volume of the reservoir incapable of containing oil is of primary importance to the operator, it is also of interest to know whether and to what extent the presence of varying amounts of interstitial water influ-ences the permeability of the sand to oil.

Jan 1, 1938

By Arthur Knapp

The petroleum industry is confronted with the problem of conservalion. This is not a simple problem in view of a wide difference of opinion among authorities as to whether conservation is necessary and the specific direction that it should take. Many writers accuse the petroleum industry of wasting the natural resources of the country. Others link the consuming public with the industry in this waste. Let us define our terms; agree, if possible, on where and when waste occurs in connection with either the recovery or use of petroleum and select such plans for conservation as appear most practical. A plan for conserv3tion which appears to be logical today may not meet the problem tomorrow. The conservation of petroleum is closely linked with the advancement of marly arts and sciences and as these advance, the plan of conservation has to change. The need for conservation does not necessarily rest upon the elimination of waste. There is not necessarily a fixed connection between waste and conservation. Conservation may be necessary or desirable although there is no waste. Definitions Waste: Useless or unnecessary expenditure. Conservation: The preservation of the natural resources for economical use. Both definitions contain adjectives the interpretation of which is extremely difficult. It is the determination of what expenditures are "unnecessary" or what uses are "economical" that will require study and agreement. If one lets his automobile engine run in cold weather in order to keep it hot, it is difficult to measure that necessity. If an automobile is driven two blocks, when the driver is physically capable of walking, what is the measure of necessity. This question is in the realm of one of the oldest of sociological problems, "What is a luxury?"—a problem which has not been solved. The history of society indicates that the measure of a man's wealth has been the measure of necessity. What he can afford to buy without stinting himself in some other direction, is not a luxury to him and, if it fulfills his desires, may be considered his necessity.

Jan 1, 1927

By N. J. Keys, B. Barlin

Operating properties of Bancroft Mines Ltd. are in the Western Province of Northern Rhodesia, just south of the Katanga border and at the north- western end of the Rhodesian Copperbelt. The concentrator, above, was commissioned in January 1957 to treat 150,000 tons per month of ore derived from the nearby Kirila Bomwe South orebody, and the Konkola orebody eight miles away. The Konkola orebody is comparatively low grade and mining was discontinued there in early 1958. Development work on the new mine at the Kirila Bomwe North orebody commenced in 1959. Today, the plant treats approximately 150,000 tons of ore per month from the Kirila Bomwe South orebody and development ore from the north orebody. Ultimately, 100,000 tons of ore per month will be produced from the north orebody.

Jan 9, 1963

TO THE BOARD OF DIRECTORS OF THE AMERICAN INSTITUTE OF MINING AND METALLURGICAL ENGINEERS Gentlemen -The following report covers briefly some of the more important activities of the Institute during the year 1923 In my report for the year 1922, I drew attention to the falling off in membership of the Institute due to the depressed condition of the mining industry in several lines and the inability of many of our members to find profitable employment in mining or its associated branches. A number who were unemployed during 1922 established connections during 1923, but a still greater number have been forced to resign or drop their membership during 1923. Fortunately, the number dropped is not so great as in the previous year. The Employment Service conducted by the four Founder Societies bears witness to the trend in business For the young men just out of college, there are plenty of opportunities at small salaries, there are plenty of opportunities for them as laborers, but for the mature members, those of experience, there are few calls. During the last eighteen months, our Employment Service has been able to place only six of our members out of every hundred engineers for whom it has found work. Another loss which this Society has suffered, but which is not felt so keenly by our sister societies, is in its foreign members The A. I M E has always had a large foreign membership, but of recent years exchange has been so heavily against many European and South American coun¬tries that a large number of members residing abroad have been compelled to relinquish their membership. Almost invariably these members express keen regret because of the necessity that confronts them, and almost invariably the writers express hope that present conditions will not last long and that they will soon be able to ask for reinstatement. Having stated the darkest side of the picture first, it may now be drawn to your attention that in spite of these losses the number of persons applying for membership was decidedly encouraging. From the quality point of view, the membership has not gone back¬ward. The Membership Committee has declined to recommend many

Jan 1, 1923

By Hoyt Gale

RECENT work on borate deposits near Kramer, in the extreme southeast corner of Kern County, California, is of special interest to those who are making a study of the mode of origin of the borate minerals colemanite and ulexite. A valuable clue to the mode of origin of colemanite in its present known deposits is given in a paper by W. F. Foshag1, of the United States National Museum. Colemanite is found in or near original deposits of ulexite, from which it is supposed to have been derived by a change in the rate of movement or the character of the ground water. Indications that an alteration of this sort had produced colemanite were first recognized by the writer' in specimens collected in the Kramer district in 1920, and sent to W. T. Schaller, at U. S. Geological Survey, for identification. The identity of the two borate minerals in these specimens was not at once determined, but the relations of the minerals as seen in the specimens afforded a manifest clue to the origin of the deposits. Similar specimens were obtained by the writer from deposits in death Valley soon after he had examined the deposits near Kramer. After studying the specimens submitted to him Dr. Schaller wrote as follows: "I have finally positively identified the boron minerals you sent me with your letter of Sept. 27. The `white fibrous mineral like ulexite' is ulexite; the harder nodules' in the clay are colemanite, apparently formed from the ulexite as a result of leaching, with recrystallization in place-a theory that Foshag is working on." The present paper is a report on the facts observed at. the deposits near Kramer, and some general observations on the geological relations noted, which, unfortunately, still form only a very incomplete record.

Jan 2, 1926

By G. W. Phelps

The field of industrial minerals is concerned with both sieve size and distribution of sub-sieve particles. A great deal of work has been reported on the techniques designed to provide information of this work. The term sub-sieve is here considered to include particular material that will pass a 325-mesh testing sieve. Plant men require rapid, precise and simple testing techniques that are, if possible, inexpensive with respect to equipment and manpower. A number of particle-size procedures have been developed, based on the Stokes equation for streamline movement of a particle of diam D, moving at velocity V through a liquid of viscosity n. 1 Particles are considered to be rigid, smooth spheres, completely dispersed at low concentration and moving at low velocity through the suspending medium with no slippage between particle and liquid. In particle size determinations the particle moves either from natural gravitational forces or those provided by centrifugal means. The diagram of Fig. 1 shows a spherical particle of density S and diam D moving downward at velocity L/T (or V) through a liquid of density So and viscosity n. The forces of gravity G (natural) or Gc (centrifugal) cause the particle to move through the liquid, thereby creating a viscous drag F or Fc. Within the streamline flow

Jan 1, 1967

By L. R. Budrow, R. T. Mishler

The Lucky-Tiger mine is a silver-gold property, situated at El Tigre, in the northeastern part of Sonora, Mexico, at an elevation of 6000 ft. in the Sierra Madre Mountains. It is 30 miles by wagon road from the Esqueda station on the Nacozari railroad. Since its discovery in 1903, the mine has produced forty million ounces of silver. The ore has averaged 40 oz. silver and 0.25 oz. gold per ton. Copper, lead and zinc have been of minor importance, having averaged 0.4 per cent., 1.1 per cent., and 1.5 per cent., respectively. The richness of the ore, combined with its occurrence in narrow veins, required the use of the more expensive methods. of mining. Geology Wall Rock The wall rock is rhyolite and rhyolite tuff, both of Tertiary age. In rare instances, post-mineral andesite dikes have been intruded along the veins. In the upper part of the mine, the walls were fairly solid. On the lower levels, the walls are usually cither kaolinized and soft or silicified and fractured, both conditions requiring closely filled stopes or much timber. Veins The veins have been deposited along fracture planes in the volcanics. There are three principal veins, about 600 ft. apart, all striking nearly north-south and dipping steeply to the west. Table 1 records the approximate dimensions and assay of the veins. Although the average

Jan 1, 1925

By John Lovejoy

As the Seminole area, Seminole and Pottawatomie Counties, Okla., appears to be the chief danger zone of overproduction in the United States, it may be of interest to review the production records of the various pools which make up this area; also to dis-cuss the future prospects of these pools, together with the structurally "high" points which may develop into new pools. It is also of interest to appraise the effect of the curtailment program in this general area, which was agreed to in principle by the various Seminole op-erators at a meeting held on May 23 at the offices of W. C. Teagle in New York. There are four large pools in the greater Seminole area. They are, in the order of their importance Seminole City, Bowlegs, Earlsboro, and Searight pools. A glance at the accompanying general map of the area will show their relative situation. The detail maps show the extent and area of these prolific spots. Seminole production comes from the Wilcox sand of Ordovician age, found at a depth of 3900 to 4300 feet. Semninole City Pool:-This pool was discovered in Wilcox sand in July, 1926. By Jan., 1927, there were 123 wells completed, making 146,000 bbl. per day. The field reached its peak of 253,000 bbl. per day the last week of Feb., 1927, with 211 completions and a per well average of 1200 bbl. On July 4 there were 304 wells completed, producing 102,000 bbl., with a per well aver-age of 336 bbl. per day. This pool will cover an area of approximately 3500 acres. It has produced approxi-mately 38,000,000 bbl. to. July 1. Estimates of total ultimate production are around 55,000,000 bbl. or somewhat better than 15,000 bbl. per acre. Some of the individual leases have already yielded 30,000 and 40,000 bbl. to the acre. Bowlegs Pool:-This pool shows 175 drilling wells and 131 completions making 180,000 bbl. per day, with an average per well production of 1380 bbl. It appears that this pool will develop into nearly as large an area as Seminole City. The wells, however, do not give up

Jan 8, 1927

By A. B. Stevens, C. J. Coberly

The absolute porosity of a rock or sand may be defined as the volume of the interparticle space expressed as a percentage of the total rock volume. The effective porosity as contrasted with the absolute porosity is the volume of the interparticle spaces which intercommunicate with passages of sufficient size to permit the entrance or recovery of gas or oil, also expressed as a percentage of the total rock volume. A knowledge of effective porosity is of prime importance in estimating the ultimate recovery to be expected from oil and gas-bearing formations. The determination of the effective porosity of a rock includes the measurement of two values: (I) the volume of the rock as a whole, and (2) the volume of the grains and sealed pore space. This paper deals with a new apparatus which has been called a "hydrogen porosimeter" for determining the volume of the grains and the sealed pore space. This volume is determined by means of the pressure relations established in the instrument by the introduction of a known quantity of hydrogen. The Hydrogen Porosimeter The apparatus used in this work consists of an upper chamber for measuring the gas, a lower chamber for holding the sample to be tested, a gage for measuring the pressures, a tank of hydrogen, and the necessary connections. (Figs. 1 and 2.) Of the several gases that might be used for this work, hydrogen has been chosen for three reasons: (1) it deviates less from the gas laws than most gases; (2) it readily penetrates the sample; (3) it is absorbed less than most gases by the solids and liquids with which it may come in contact. Method of Operation After placing the sample to be tested in the lower chamber, the apparatus is thoroughly flushed with hydrogen to remove all air from the system, which is then brought to atmospheric pressure Po. The valve connecting the two chambers is next closed and the pressure in the upper chamber is brought up to a pressure PI by admitting gas from the tank.

Jan 1, 1933

By Peter Nalle

12.3-1. Reporting. NEED. It seems almost unnecessary to comment on the need for reporting research and development results and activities, and yet much of the difficulty and misunderstanding surrounding a Research and Development (R&D) group results from poor or nonexistent reporting. Certainly no evaluation can be made without reports of results or plans. It is as important to report accurately and fully for the department's own use as it is for external use. Research unreported might as well be considered research undone. This section will discuss, in part, the need for reporting, the general types of reports which may be generated to satisfy the need, and finally, the evaluation of a project as judged by various commonly used standards. PURPOSE. Some specific observations might be appropriate concerning the reporting of R&D results. The requirements and background of the group receiving the report must be considered. A particular report is usually directed towards the background of a particular group, such as ((technical," "operational," "financial," or "marketing." It is essential that the emphasis and coverage be geared to the training of people receiving the report. It should be obvious that the financial department will be less interested in the technical details of the process and more interested in the capital funds and tax implications involved in the project. Operating personnel will be greatly interested in the effects of a new method on mining plans, and so on. This does not mean that the reporting in any way should slight pertinent details, nor should a patronizing attitude be assumed by the writer. However, it is essential that the needs of the reader be recognized. For reports that might have large and varied distribution, it is often feasible to group, either as sections or appendixes, the special details and information of interest only to certain functions within the organization. A

Jan 1, 1968

By Fred Wright

IN A recent paper1 a detailed discussion is given of the possibilities. of using polarized light in the examination of opaque substances. The factors underlying the problem .are there treated from the viewpoint of the electromagnetic theory of light and the presentation is necessarily mathematical in form. The practical methods resulting from the discussion are, however, relatively simple and promise to be of value in the determination of certain ores and metals when studied in reflected light under the microscope. The results of the theoretical investigation referred to may be summarized by stating that in general the optical constants, such as refractive indices and absorption indices, cannot be satisfactorily ascertained on small, random, polished sections; that the use of polarized light enables. the observer ordinarily to determine whether the crystal plate is isotropic or anisotropic, and also to ascertain the degree of anisotropism; that for this purpose methods based either on the contrast in intensity between the two reflected components of non-polarized light, or on the amount of rotation of the plane of polarization, on reflection, of vertically incident, plane-polarized light, may be employed; that methods based on the phase difference between the two reflected components are in general of little value because of the small differences in phase which ordinarily result for a relatively large change in birefringence or biabsorption. The measurement of the optical properties of transparent minerals, even in minute irregular grains, is a simple task with modern petrographic microscope methods and is accomplished by petrologists as part of their ordinary routine work. But the determination of the optical constants of opaque substances is difficult and is rarely attempted; all observations are necessarily made in reflected light and are restricted commonly to the determination of color, of hardness, of the character of crystallization, and

Jan 2, 1920

By W. C. Bednar

In all, 127 producing oil wells, 8 producing gas wells and 212 dry holes were drilled during 1936 in the Central Texas area; 76 wells in Bexar County, 62 in Caldwell County, 44 in Guadalupe County, 22 in Williamson County, 20 in Navarro County and 20 in Frio County. Less than 20 were drilled in each of the other counties and none at all in Ellis, Hill, Bosque, Coryell, Lampasas, Burnet, Llano, Kennedy, Mason, Real, Kinney and Uvalde Counties. The Pearsall-Austin chalk field in Frio County and the Zoboroski field in Guadalupe County were the only new discoveries and there were no important extensions to old fields. In this report Corsicana, Mildred (Elm Ridge), Angus-Edens-Hodge, Burke, and Rice-Oil Ridge, all shallow Navarro County stripper fields, are grouped together under the name of Corsicana. This grouping follows that of the Railroad Commission of Texas, thus facilitating the gathering of production data. A map showing the location of the oil and gas fields in the Central Texas Area was published in Volume 114 of the A.I.M.E. TranBactions, page 380. New Fields Pearsall-Austin Chalk.—The Amerada Petroleum Corporation completed 13 Austin chalk wells during 1936 on the large Amerada-Rycade block in Frio County. Other companies drilled two dry holes to the Austin chalk in this vicinity. Not enough wells were drilled to give control of the structure but it appears to be a nose plunging in a west-southwest direction. A second deep test is being drilled in the Pearsall area and at this writing has cemented off a show of oil and gas in the Edwards limestone. The Humble Oil and Refining Co. is building a 6-in. pipe line from Lytle, Tex., to serve the Pearsall field. Zoboroski.—Actual discovery of the Zoboroski field was made by W. J. Walton et al. in 1931. The discovery well, Anton Zoboroski No. 1, was a small producer making but from 3 to 5 bbl. per day, which was used locally for fuel oil. The discovery of the Darst Creek Extension in

Jan 1, 1937

By J. E. Gosline

IN any theory of a hydrodynamic nature dealing with the vertical flow of gas-liquid mixtures in pipes, the two factors that present the greatest difficulty are the relative motion between the phases and the energy loss resulting from turbulence work. The former has generally been referred to in the literature as "slippage" and the latter as "fric-tion." A third factor of importance is the nature of admixture between liquid and gas for both the relative motion between the phases as well as the turbulence work are functions of the type of mixture. Although much work of a general nature has been performed on the vertical flow problem, there have been very few attempts made to study experimentally the factors involved in the phenomenon individually. Of these, perhaps the most notable is the work of Moore and Wilde1 on slippage. Some writers on the subject have assumed that over a wide range of operating conditions the controlling type of mixture, is one in which gas bubbles of uniform size are distributed throughout the liquid, and that the data obtained from experiments on the motion of single bubbles through various liquids may be used in evaluating the slippage. Ver-sluys2 has further assumed another controlling type of mixture in which the liquid occurs as a dispersed phase within the gas and applies data on the fall of drops of water in air to calculating the relative velocity. It was for the purpose of studying the applicability of data on single bubble motion to the slippage factor and to further observe the nature of mixtures that a research program was conducted at the University of California during 1932 and 1933. These experiments formed a basis for

Jan 1, 1935

By T. R. Armstrong

During the year 1939, Mexican production totaled 42,479,000 bbl.; a daily average of 116,381 bbl. or a little over 2 per cent of the estimated world production. The Mexican Government operates 100 per cent of the refining branch of the industry, 100 per cent of the domestic distribution, 96 per cent of the crude production and 92 per cent of the total exports. No discussion of the Mexican petroleum industry in 1939 is adequate without reference to the "expropriation" of the foreign-owned oil properties in Mexico by executive fiat on March 18, 1938. The forcible seizing of the properties culminated a long series of efforts on the part of the Mexican Government to obtain control of the oil properties developed through foreign initiative and with foreign capital in Mexico. The heart of the issue is whether the Mexican nation or any nation may with impunity confiscate the legally acquired properties of American citizens. The Department of State of our Government has in its communications to Mexico emphasized the fact that its "expropriation" of American properties was confiscatory because Mexico had failed to make "adequate, effective and prompt compensation"; that the taking was no less confiscatory "because there may be an expressed intent to pay at some time in the future," and that, consequently, "Mexico has assumed and continues to assume to exercise a right without compliance with the condition necessary to give such exercise a recognizable status of legality." Mexico has professed its willingness to pay for the oil properties but at the same time through its Supreme Court it has declared that the owners or lessees do not have the exclusive right to extract and dispose of the oil in the subsoil. This is a reversal of the Mexican position with respect to oil as set forth in the Mexican mining laws, affirmed by Mexican Supreme Court decisions, and as clarified in the Warren-Paync and the Morrow-Calles agreements, as well as in diplomatic correspondence. Efforts to Settle the Controversy Responding to suggestions from the State Department, representatives of the principal oil companies undertook in 1939 to effect a direct

Jan 1, 1940

By John C. Calhoun, F. W. Gooch, J. P. Everett

The results of two sets of displacement experiments are reported. In the first set of experiments various solutions of sugar in water were displaced by other solutions of sugar in water. In the second set oils were displaced by water. Each set of experiments was performed on a linear system made of cemented silica sand grains. These displacement tests were made to evaluate the behavior when the ratio of fluid viscosities between the displacing and displaced phases was varied. A further consequence of the test results is a comparison between displacement behavior when the displaced and displacing phases are miscible as with sugar solutions and when they are immiscible as with oil and water. INTRODUCTION Buckley and Leverett1 have presented a theory for the displacement of oil by gas or water based upon the relative permeability concept. This theory presents the displacement of oil as occurring in two phases, an initial or primary phase preceding the breakthrough of the displacing phase and a subordinate or secondary phase during which both oil and the displacing phase flow simultaneously through the same porous section. These authors gave the results of calculations to show that the percentage of oil displaced during the primary phase by water drive would be dependent upon the ratio of the viscosity of the oil to that of the water. No experimental evidence was reported by these authors to substantiate their theory. Qualitatively, however, it has been found to be in agreement with many observed field results. Laboratory investigators have been in general agreement in reporting for air or gas drive2,3 a small primary phase of production and a large secondary phase. Reported investigations on water drive3,4,5 have shown instances where both primary

Jan 1, 1950