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By Rush Greenslade

THE oil and gas lease is the basic contract of the oil and gas industry; it is the foundation stone upon which the producing industry, particularly, is based. As the industry is precarious and highly speculative, the foundation contract should be of the utmost integrity and certainty. But right there an anomaly exists; the oil and gas lease is the most obscure, most uncertain, doubtful contract in the realm of law today. That is a condition that must be considered when taking oil and gas leases, and when buying, selling, and holding them. It may fairly be asked why should this industry rest upon so insecure a foundation. Why should not the oil industry rest upon the contract that is the basis of all industry, the warranty deed? There are many contributing reasons, but the principal one is business expediency. The Anglo-Saxon idea of ownership of land is that every land owner owns from the center of the earth to the sky all that is above and all that is below-consequently the oil and gas are owned by the person who owns the surface. That idea is not exactly true with reference to oil and gas, for many states have adopted the doctrine that oil and gas are like wild animals; they are fugacious and migratory and belong to the man that traps them. But, except for that doctrine, we believe that oil and gas are owned by the owner of the surface, wherein we differ from the Latin-American countries where the mineral rights are owned by the government. The United States was settled largely by homesteading. The owners of land were, in the main, farmers, who did not have the means or the faith to drill for oil or gas. The operators or speculators did not want to buy the land on the mere possibility of finding oil; hence a compromise resulted by which the land owner gave the speculator or the operator what he called an oil and gas lease, or a right to go upon his land and drill for oil and gas. What is supposed to be the first oil lease placed on record reads as follows: Agreed this 4th day of July, A.D. 1853, with J. D. Angier of Cherrytree township in the county of Venango Pennsylvania that he shall repair up and keep in order the old oil springs on land in said Cherrytree township, or dig and make new springs, and the expense to be deducted out of the proceeds of the oil, and the balance, if any, to be

Jan 8, 1924

By Robert C. Stephenson

Large deposits of titaniferous magnetite occur associated with anorthosite and gabbro in the Lake Sanford area, Essex County, New York. The ore, gabbro, and anortbosite show consanguineous relations. Anorthosite grades through gabbroic anortbosite into gabbro but is locally intruded by gabbro. Structural and petrographic evidence suggests that gabbro was differentiated from anorthosite by filter pressing. Field and laboratory study of ore occurrences indicates that an ore residuum concentrated in the gabbro through magmatic segregation' by normal crystallization and flowage. Ore occurs as bands which grade into gabbro, and also as large masses which replace anorthosite. Ore in the gabbro is finer grained and richer in ilmenite than ore in anorthosite. Introduction The Lake Sanford area lies in the heart of the Adirondack Mountains, in the southeast portion of the Santanoni Quadrangle (Fig. I), and there are four ore bodies in the area immediately surrounding Lake Sanford. The area lies 30 miles by highway from the railroad at North Creek. The deposits were discovered in 1826, and from then until 1858 iron was produced in small quantities. They were idle from 1858 to 1906. Between 1906 and 1913, extensive development work was carried on. These early attempts to produce iron ore were thwarted by transportation difficulties and by the titanium content of the ore, which, ironically, has been the element responsible for the present development. In 1941 the National Lead Co., Titanium Division, developed the Sanford Hill ore body and is now producing ilmenite and magnetite concentrates.18 The Defense Plant Corporation is extending the railroad to the property from North Creek and is building a sintering plant to treat the magnetite concentrate. Investigations OF the Deposits* Early studies of the Lake Sanford titaniferous magnetite deposits were made by Emmons in 1842,l2 by Kemp, in 1897-98'0 and by Newland in 1908.22 Singewald26 and Osborne23 considered these deposits along with numerous other titaniferous magnetite deposits in 1913 and 1928, respectively. None of these reports entailed a detailed study of the ore occurrence in this area. The present study was begun in 1940. Seven months were spent in the field, and considerable time was spent in labora-

Jan 1, 1949

By Robert C. Stephenson

Large deposits of titaniferous magnetite occur associated with anorthosite and gabbro in the Lake Sanford area, Essex County, New York. The ore, gabbro, and anortbosite show consanguineous relations. Anorthosite grades through gabbroic anortbosite into gabbro but is locally intruded by gabbro. Structural and petrographic evidence suggests that gabbro was differentiated from anorthosite by filter pressing. Field and laboratory study of ore occurrences indicates that an ore residuum concentrated in the gabbro through magmatic segregation' by normal crystallization and flowage. Ore occurs as bands which grade into gabbro, and also as large masses which replace anorthosite. Ore in the gabbro is finer grained and richer in ilmenite than ore in anorthosite. Introduction The Lake Sanford area lies in the heart of the Adirondack Mountains, in the southeast portion of the Santanoni Quadrangle (Fig. I), and there are four ore bodies in the area immediately surrounding Lake Sanford. The area lies 30 miles by highway from the railroad at North Creek. The deposits were discovered in 1826, and from then until 1858 iron was produced in small quantities. They were idle from 1858 to 1906. Between 1906 and 1913, extensive development work was carried on. These early attempts to produce iron ore were thwarted by transportation difficulties and by the titanium content of the ore, which, ironically, has been the element responsible for the present development. In 1941 the National Lead Co., Titanium Division, developed the Sanford Hill ore body and is now producing ilmenite and magnetite concentrates.18 The Defense Plant Corporation is extending the railroad to the property from North Creek and is building a sintering plant to treat the magnetite concentrate. Investigations OF the Deposits* Early studies of the Lake Sanford titaniferous magnetite deposits were made by Emmons in 1842,l2 by Kemp, in 1897-98'0 and by Newland in 1908.22 Singewald26 and Osborne23 considered these deposits along with numerous other titaniferous magnetite deposits in 1913 and 1928, respectively. None of these reports entailed a detailed study of the ore occurrence in this area. The present study was begun in 1940. Seven months were spent in the field, and considerable time was spent in labora-

Jan 1, 1949

By David B. Dill, Edgar R. Lea

The zinc deposits of the Balmat-Edwards Division of the St. Joseph Lead Company in northern New York State provide some 10 per cent of the domestic zinc produced annually within the United States. These complex ore deposits are contained within marbles of the Precambrian Grenville series, in a repetitive sequence of dolomites and silicated units. The Balmat ore bodies are localized at various intervals throughout some 1800 feet of the stratigraphic column on the northwest side of a band of gneiss that has continuity to the Edwards area, some 10 miles to the northeast. The Edwards ore bodies are located to the southeast of this gneiss. The marble formations are thought to have included repetitive intervals of marine sedimentation that provided mineralized source "beds" and were subsequently folded, flooded, and injected with melts at great depth and were sheared, recrystallized, and reconstituted. Detailed structural and stratigraphic studies throughout the northwestern Adirondacks, in the Balmat-Edwards district, and at each mine in particular indicate the close dependence of the ore deposits on the enveloping structure whether it be local, district-wide, or regional in scope. Primary folding has developed a northeast regional trend with northwest dips. Secondary folding has been developed by an almost horizontal northeast-southwest-oriented shear couple in the plane of the regional trend. The secondary folding has produced crossfolds that intersect the regional northeast trend and plunge north to northwest at various angles. The ore bodies are found within certain stratigraphic horizons where repeated alternation of competent and incompetent beds encouraged unusually complex folding. Analysis of individual mine structures indicates that the location of each deposit is controlled by structural crossing of primary and secondary folding. The ore bodies, which are tabular, lenticular, or pod-like in form, have features that suggest parallelism to true bedding or modified flow banding, developed by northeast-southwest shearing stresses related to the development of the crossfolds. The ore deposits in general follow both structural and recrystallization trends within the wall rocks. Mobilization of the pre-metamorphic ore minerals is believed to have involved a combination of plastic flow under stress and solution of the sphalerite, minor galena, and pyrite. The ore fluids are thought to have been guided by secondary shearing and microbrecciation into structurally prepared areas where reprecipitation took place. The presumed premetamorphic mineralization now exhibits epigenetic high-temperature features related to late-stage metamorphism.

Jan 1, 1968

By M. H. Richman, W. D. Sproul

THE indexing of a field-ion micrograph is in many cases similar to the indexing of the poles of a stereo-graphic projection.* If one has a standard projection as a guide, the task of indexing is relatively simple. In this way, field-ion micrographs of bcc and fcc wires have been oriented from projections available in most any text on X-ray diffraction. These books always illustrate the projections for the bcc and fcc structures and even for a particular hcp structure. There is no "standard" hcp projection because the angles between planes depend on the c/o ratio of the unit cell. In order to index field-ion micrographs of hcp metals, one must compute the angles between various planes—a rather laborious task. In recent work,, we have had to identify the structure and index the orientation of field-ion micrographs of the compounds WC and W,C. To overcome the problem of computing angles by hand or calculator, a program was written in Fortran lV for use on the IBM 360, Model 50 which will compute all angles between planeswith indices (hlklll) and (17,k,l2) in the range from (447) to (444) for any given c/o ratio. The program, which is more specific than that of Camp and clum, was so written as to take advantage of the multiplicity of the hexagonal system, and, for the limits defined above, only 26,649 values out of a possible 265,721 values had to be computed. This is a 90 pct saving in time (and cost) and was accomplished in the following way. Because the lattice parameters of the hexagonal crystal system are defined such that: a = b * c [1] the I index does not enter into the multiplicity (i.e., it cannot be transposed with the h or k indices), and all possible values of h and I, from 4 to 4 must be used—a total of eighty-one combinations. The index h2 varies the most—it must assume values from - Ill,: to 3Ihl. The indices kl and k2 are always equal and vary

Jan 1, 1969

By M. F. Hawkes

Austenite grain size has long been recognized by metallurgists as an important property of steels because of its influence on toughness, hardenability, ma-chinability and creep strength. Much research has been carried out on wrought steels to develop methods for disclosing austenite grain size, and to, provide knowledge of the grain-size characteristics of steels produced and heat-treated in various ways. Much less work in these fields has been done on steel castings; partly because, owing to the variable and complex microstruc-tures of cast steels, it is frequently very difficult to obtain results that are not questionable. The object of this investigation, therefore, was to establish, for a wide variety of carbon and alloy cast steels, suitable methods for disclosing austenite grain size and some knowledge of the grain-size variations to be expected. The steel foundryman is interested in austenite grain size at two different stages in the manufacture of his products; one is just after the steel is cast, and the other is after any reheating operation carried out above the critical temperature range. In both, it must always be kept in mind that the grain size being sought is actually a previous austenite grain size, and that the austenite no longer exists once the steel has cooled to room temperature. The prob-lem of the investigator is always to use evidence obtained from the structure at room temperature to deduce this previous austenite grain size, which was established the last time the steel existed at a temperature above the critical range. Since most steel castings today are at least annealed or normalized, the measurement of austenite grain size established by heat-treatment will he considered first. More than 50 commercially produced cast steels rcpresenting a wide variety of compositions and melting practices were used in the study. For each steel, grain-size determinations were made after each of three widely varying heat-treating schedules namely, one hour at I550'F, one hour at I700°F, and six hours at 1700 F. The list of steels and results obtained on them will be found in the appendix. (See page 530.) A discussion of the knowledge gained on the applicability of various test methods and on grain-size characteristics of cast steels in general follows. MEASUREMENT OF AUSTENITE GRAIN SIZE ESTABLISHED BY HEAT TREATMENT Methods Suitable foR Determining Austenite Grain Size after Heat-treatment at Ordinary Temperatures and Times It was desired, as one of the results of this investigation, to be able to recommend to steel foundries a method, or methods, of disclosing grain size best suited to accurate

Jan 1, 1948

By M. F. Hawkes

Austenite grain size has long been recognized by metallurgists as an important property of steels because of its influence on toughness, hardenability, ma-chinability and creep strength. Much research has been carried out on wrought steels to develop methods for disclosing austenite grain size, and to, provide knowledge of the grain-size characteristics of steels produced and heat-treated in various ways. Much less work in these fields has been done on steel castings; partly because, owing to the variable and complex microstruc-tures of cast steels, it is frequently very difficult to obtain results that are not questionable. The object of this investigation, therefore, was to establish, for a wide variety of carbon and alloy cast steels, suitable methods for disclosing austenite grain size and some knowledge of the grain-size variations to be expected. The steel foundryman is interested in austenite grain size at two different stages in the manufacture of his products; one is just after the steel is cast, and the other is after any reheating operation carried out above the critical temperature range. In both, it must always be kept in mind that the grain size being sought is actually a previous austenite grain size, and that the austenite no longer exists once the steel has cooled to room temperature. The prob-lem of the investigator is always to use evidence obtained from the structure at room temperature to deduce this previous austenite grain size, which was established the last time the steel existed at a temperature above the critical range. Since most steel castings today are at least annealed or normalized, the measurement of austenite grain size established by heat-treatment will he considered first. More than 50 commercially produced cast steels rcpresenting a wide variety of compositions and melting practices were used in the study. For each steel, grain-size determinations were made after each of three widely varying heat-treating schedules namely, one hour at I550'F, one hour at I700°F, and six hours at 1700 F. The list of steels and results obtained on them will be found in the appendix. (See page 530.) A discussion of the knowledge gained on the applicability of various test methods and on grain-size characteristics of cast steels in general follows. MEASUREMENT OF AUSTENITE GRAIN SIZE ESTABLISHED BY HEAT TREATMENT Methods Suitable foR Determining Austenite Grain Size after Heat-treatment at Ordinary Temperatures and Times It was desired, as one of the results of this investigation, to be able to recommend to steel foundries a method, or methods, of disclosing grain size best suited to accurate

Jan 1, 1948

By Ed Van Eeckhout

As part of a U.S. Bureau of Mines-sponsored project on the utilization of "stiff" backfill to minimize potential rock burst hazards, a finite element study was undertaken to predict stresses and displacements around a stope mined up from the 5400 level of the Sunshine mine, Kellogg, Idaho. This stope was to be backfilled using a high-modulus fill. In preparation for that configuration, certain instrumentation was installed near the 5400 level to monitor stress changes. Due to untenable economics, only 2 cuts of the stope were ever made. This paper presents the results of the instrument readings taken during the first cut and compares them with the numerical predictions, as well as presents the modeling results of closure and fill stresses in the stope if it had been mined.

Jan 1, 1984

By A. Aly Selim

A computer model was developed to calculate the fragmentation cost for in situ leaching operations as a function of the blast design and deposit parameters. The model is based on blasting an ore zone only or an ore zone plus overburden by either a coyote blast or a vertical blasthole system. The model calculates the blast design parameters and the fragmentation cost based either on a user input powder factor value or on a powder factor calculated by the model as a function of the overburden height and the ore zone thickness. Examples of blast design parameters calculated by the model are the number and spacing of blastholes for a vertical blasthole system and the number and spacing of crosscuts for a coyote system. The model also calculates the total amount of explosives, the detonating cord length, and the number of primers. The cost of blasthole drilling can be calculated by the model based either on purchasing and operating a drill or on a user input value of the contracted cost of drilling. Application of the model to an example ore deposit showed that the vertical blasthole systems were more economical than the coyote system when there was no overburden and the deposit had an average ore thickness less than 45 meters. With no overburden and ore thickness greater than 45 meters, the vertical blasthole system was either more or less expensive than the coyote system depending on the number of levels used in the coyote system. With overburden, the coyote system was less expensive than the vertical blasthole system for blasting either the ore only or the ore plus the overburden. A coyote blast will usually produce larger particle sizes than a vertical blasthole system. Larger particle sizes can result in lower copper recoveries so that a less expensive coyote blast may not improve the overall economics of an in situ leaching operation. Blasting the ore zone only was generally less expensive than blasting the ore plus the overburden by either blasting system. Also, for the example considered, the coyote system costs were less sensitive to changes in overburden thickness and powder factor while the vertical blasthole system costs were less sensitive to changes in ore thickness.

Jan 1, 1977

By David B. Reger

Wildcat drilling for new supplies of gas and the expansion of previously discovered oil and gas pools were the principal petroleum activities in West Virginia .during 1942. Much of the new gas exploration is still uncompleted and still indecisive but various wildcats made substantial extensions to existing pools. Out of 53 wildcats drilled 27 resulted in commercial gas and 6 in commercial oil. Four of the oil discoveries also had commercial gas. No strictly new pools of oil or gas can safely be described as discovered but several scattered oil and gas wells previously drilled have been confirmed as the openers of definite pools; also, various completions closed wide gaps between apparent gas pools already discovered. The proved oil territory of the state was increased about 4850 acres and the proved gas territory about 51,000 acres. The new proved oil reserves should about balance withdrawals and the new gas may represent a substantial increase. Aside from the drilling in four rather lively pools, oil activity was slight because of unfavorable operating conditions and prices. Gas drilling also declined for reasons beyond the control of the operators. The account of operations, as gathered from trade journals and other reporting services, shows that 797 new wells were drilled, providing 119 new oil wells with 2762 bbl. of daily new production; 536 new gas wells with 1,228,501,000 CU. ft. of daily open flow: and 142 dry holes. Also... 76 old wells were drilled to deeper sands, with 71 bbl. and 26,034,000 cu, ft. of added production. On the new wells the oil average was 23.21 bbl. per well per day; and the gas average was 2,270,406 CU. ft. per well per day. On new wells the ratio of dry holes to completions was 17.82 per cent. On deeper drilling the ratio of failures was 21.05 per cent. Production of oil for the year was estimated by the Oil ad Gas Journal as 3,492,000 bbl., as compared with 3,378,000 bbl. in 1941. Production of natural gas for the year is estimated by the author as 220,000,000,000 cu. ft., as compared with the U. S. Bureau of Mines final figures of 207,000,000,000 cu. ft.* in 1941. General State op Industry Leasing of wildcat acreage increased considerably. The total land of all classes under lease may now exceed 5,000,000 acres. Taking into consideration completions, abandonments and corrected figures or estimates, Table I shows cumulative and late annual statistics. New Pools and Extensions Table 2 shows the principal areas of drilling activity during 1942. Various consolidations of territory, hitherto treated as separate pools, have been made. in addition to these active pools, extensive drilling was done in numerous other areas where pool boundaries can hardly be defined. Summary or Exploration Table 3 gives a summary of important wildcat or exploratory wells drilled during

Jan 1, 1943

By David B. Reger

Wildcat drilling for new supplies of gas and the expansion of previously discovered oil and gas pools were the principal petroleum activities in West Virginia .during 1942. Much of the new gas exploration is still uncompleted and still indecisive but various wildcats made substantial extensions to existing pools. Out of 53 wildcats drilled 27 resulted in commercial gas and 6 in commercial oil. Four of the oil discoveries also had commercial gas. No strictly new pools of oil or gas can safely be described as discovered but several scattered oil and gas wells previously drilled have been confirmed as the openers of definite pools; also, various completions closed wide gaps between apparent gas pools already discovered. The proved oil territory of the state was increased about 4850 acres and the proved gas territory about 51,000 acres. The new proved oil reserves should about balance withdrawals and the new gas may represent a substantial increase. Aside from the drilling in four rather lively pools, oil activity was slight because of unfavorable operating conditions and prices. Gas drilling also declined for reasons beyond the control of the operators. The account of operations, as gathered from trade journals and other reporting services, shows that 797 new wells were drilled, providing 119 new oil wells with 2762 bbl. of daily new production; 536 new gas wells with 1,228,501,000 CU. ft. of daily open flow: and 142 dry holes. Also... 76 old wells were drilled to deeper sands, with 71 bbl. and 26,034,000 cu, ft. of added production. On the new wells the oil average was 23.21 bbl. per well per day; and the gas average was 2,270,406 CU. ft. per well per day. On new wells the ratio of dry holes to completions was 17.82 per cent. On deeper drilling the ratio of failures was 21.05 per cent. Production of oil for the year was estimated by the Oil ad Gas Journal as 3,492,000 bbl., as compared with 3,378,000 bbl. in 1941. Production of natural gas for the year is estimated by the author as 220,000,000,000 cu. ft., as compared with the U. S. Bureau of Mines final figures of 207,000,000,000 cu. ft.* in 1941. General State op Industry Leasing of wildcat acreage increased considerably. The total land of all classes under lease may now exceed 5,000,000 acres. Taking into consideration completions, abandonments and corrected figures or estimates, Table I shows cumulative and late annual statistics. New Pools and Extensions Table 2 shows the principal areas of drilling activity during 1942. Various consolidations of territory, hitherto treated as separate pools, have been made. in addition to these active pools, extensive drilling was done in numerous other areas where pool boundaries can hardly be defined. Summary or Exploration Table 3 gives a summary of important wildcat or exploratory wells drilled during

Jan 1, 1943

By Charles Berkey

CONTENTS PAGE C. P. Berkey-Responsibilites of the Geologist in Engineering Projects (with discussion) 4 Kirk Bryan-Problems Involved in the Geologic Examination of Sites for Dams 10 0. E. Meinzer-Relation of Ground-water Conditions to Leakage of Reservoirs (with discussion) 19 Charles Terzaghi-Effect of Miner Geologic Details on the Safety of Dams (with discussion) 31 G. H. Matthes-More and Better Geologic Data for Use in Hydraulic Projects (with discussion) 47 L. W. Fisher and R. D. Ohrenschall-Geologic Examination of Dam Sites in the Tennessee and Cumberland River Basins 60 C. K. Wentworth-The Geology of Dam Sites (with discussion) 78 L. C. Glenn-The Geology of Dams and Reservoirs 97 H. T. Stearns-Success and Failure of Reservoirs in Basalt (abstract) 111

Jan 1, 1929

By THOMAS LEONBRD WATSON

I. INTRODUCTION. THE results embodied in this paper are based on a careful field- and laboratory-study of the lead- and zinc-deposits of the Virginia-Tennessee district, begun in the latter part of the summer of 1904 and completed in the spring of 1905, preparatory to the publishing of a State report .on them. A separate description of the individual deposits in Virginia is purposely omitted, since I have already described them in considerable detail in a State report. The Tennessee deposits are described here in some detail for the reason that no detailed record of them has yet been published. Practically, this paper summarizes the results obtained from a study of the geology of the ore-deposits of the district as, a whole. (I had the pleasure of visiting the deposits of Virginia and Tennessee with Dr. H. Foster Bain of the U. S. Geological Survey, in April, 1905. Figs. 21 and 22 are from photographs taken by Dr., Bail.) II. HISTORICAL. . The first authentic records of lead-mining .in Virginia date hack more than 150 years; and the old lead-mines at Austinville, on New river in Wythe county, V a., were the first to be worked. Colonel Chiswell, a native of Wales, and one of the earlier adventurers in southwestern Virginia, was one of the first operators of the Austinville mines. Chiswell's operations at Austinville commenced in the year 1750, and closed shortly after the beginning of the Revolutionary War, in the' year 1776, covering a period of about 25 years. From that time to the present, mining has been carried on almost continuously in the Virginia area. For many years after the Virginia mines were operated, mining was confined exclusively to the lead-ores. The zinc-ores

Mar 1, 1906

By Louis W. Huber

The Liberty tunnels extend through a very steep hill in Pittsburgh (locally called Mount Washington) for a distance of slightly over a mile. The two tunnels parallel each other and are 59 ft. apart, center to center (Fig. 1) They are for vehicular traffic, and in each there is ample space for two lines of vehicles. Northbound traffic, toward downtown Pitts- burgh, is confined to the east tunnel and southbound traffic to the west tunnel. The South Hills residential district is separated from downtown Pittsburgh by Mount Washington, a steeply rising escarpment south of and adjacent to the Monongahela River. The Mount Washington district immediately south of the Monongahela River has been reached, for many

Jan 1, 1927

By Robert H. Richards

(Pittsburg Meeting, March, 1910.) THIS is in part a review paper, indicating the various steps that have been taken in developing hindered-settling apparatus, some of the standard data that have been obtained, and some of the conclusions one is led to as to the effect of it in improving concentrating-methods and machinery, and in part it brings in some unpublished work. CAUSES OF LOSS IN ORE-CONCENTRATION. In making a study of the separation of valuable minerals from the waste gangue, particularly by water concentrators, it is necessary to define, first of all, what are the causes of-loss that are likely to interfere with the concentration. Having made this definition; we can then study to see in what way the machines make their losses, and plan remedies for them in an intelligent way. Losses may be stated to occur as included grains, as flat or long grains, as fine free mineral, and as absolute slime. We will take, these up one by one, as follows: Included Grains.-Fig. 1 shows by a set of diagrams how included grains may occur: first, where the heavy mineral grains attached to the quartz are of large size; secondly, where they are of small size ; and thirdly, where very fine particles of heavy mineral are included in the quartz. We have to decide in regard to included grains whether they are rich enough to go direct to, the furnace, or poor enough to throw away, or whether they lie between these two points and require recrushing as the only means of severing the values from the waste. This last case is the only one requiring special treatment at our hands. We will therefore consider that next. * By mutual consent, this paper has been presented also before the Colorado Scientific Society, and the Canadian Mining Institute, Montreal.

Feb 1, 1911

By Robert H. Richards

Tuns truly remarkable machine was built on a preliminary scale in May, 1895. The first full-sized table was built by Mr. A. R. Wilfley, and was used in his own mill in Kokomo in May, 1896. The first table sold for installation was placed' in the Puzzle mill, Breckinridge county, in August, 1896. The mill enthusiasts at first hailed it as the cure for all the ills that flesh is heir to in the milling line. A little later it was found to make losses which were serious, and on this account the table succeeded only to a limited extent in displacing the vanners of the gold-mills. Still later, mill-men in a number of districts throughout the country made special studies of the faults of the machine, and devised a number of ways of grouping supplementary machines to overcome as far as possible the losses, and at the same time retain the benefit of the extraordinarily large capacity accompanied by the production of clean concentrates for which the machine has become so justly famous. I hope to make an exhibit of some of these methods in an appendix to my book on ore-dressing which is now in preparation. These experimenters have not written up the subject, and if they possess all the facts they have not given them out for the benefit of the mining profession at large. The object of this paper is to obtain the facts and to pre¬sent them so clearly that their bearing can be seen by all. To this end two complete series-'of tests have been planned. One (the present paper), to study concentration of galena in presence of quartz; the other (to follow shortly), to study concentration of chalcopyrite in presence of quartz. Some authorities claim that the table does its best work when treating natural products; by this phrase I mean products which have been crushed to pass through a limiting

Jul 1, 1907

By Charles Barrett

SINCE 1925, when the preferred orientations in compressed aluminum were first determined1, 2 the orientations have been described as a fiber texture in which a face diagonal, [110], of the face-centered cubic lattice is parallel to the compression axis. Subsequent experiments have seemed to confirm this texture,3-5 and a number of theories (recently summarized in references 6 and 7) have been proposed to explain it and to relate it to the behavior of single crystals during compression. 3,8-11 The experiments reported in this paper prove that the orientations are not adequately described as quoted above-i.e., as a [110] fiber texture-although this is a first approximation to the actual texture. They also show that the texture cannot be thought of as a stable orienta-tion that is reached and maintained after a sufficient amount of deforma-tion. The actual texture, when studied in detail at successive stages of compression, indicates that a hitherto unsuspected range of orientations is present, both in the polycrystalline metal as a whole and in various individual grains in its interior, and that a state of dynamic equilibrium exists within this range. The reasons for the failure of previous theories to predict the actual texture become obvious when the heterogeneous nature of the flow is considered. In addition to the deformation texture, the manner of its develop-ment, and its theory, this paper presents data on the following related subjects: the identity of strain markings in aluminum; the orientation changes in aluminum single crystals during compression and a com-parison of these with the conditions in individual grains of a polycrystal-line specimen; the origin of asterism in deformed single crystals, which heretofore has been regarded as a distortion localized at the surfaces of slip planes; and the relation of plastic strain in individual grains in an aggregate to the strain of the whole.

Jan 1, 1939

By Charles W. Bloomquist

The profitability of miscible flooding in a hypothetical target oilfield is examined. The major costs, including Windfall Prof it Tax, are identified and their re1ative importance are discussed. The sensitivity of profit to important physical and economic variables is evaluated and discussed, including variance in oil recovery, oil price, injectant requirements, injectant cost, and capital requirements. Economic sensitivities to important development and operating decisions such as timing, Spacing, Slug size, and gas recycling are also analyzed. The Windfall Profit Tax (WPT) as it applies to gas miscible EOR projects is reviewed. The effect of WPT on each of the various project cases is analyzed and the effect of reduced WPT on remaining production from existing operations is evaluated. Tax implications are compared for integrated vs. "independent" controlled projects and the alternative of expensing vs. capitalizing tertiary injectants is also evaluated. The impact of the Net Income Limitation in reducing WPT. during early and late project life is determined and discussed.

Jan 1, 1982

By G. D. Marshall, D. K. Sarin, V. E. Hampton

Ground support at the Thompson Mine emphasizes scaling, rock bolting and wire mesh screening on the backs and walls of all underground stoping and development areas and also full column grouted cable bolting in the bulk mining areas. This paper describes the equipment for the point anchored rock bolts as well as the full column cable bolts. Modifications in design and testing of all components and procedures has ensured a safe and efficient method of ground support for the mining conditions existing at the Thompson Mine.

Jan 1, 1983

By L. Bombardieri, H. F. Mills

IRON KING mine, producing gold-silver-lead-zinc ore, is 10 miles east of Prescott, Ariz. At present the 1806 level is being developed. The echelon pattern of ore deposit continues at depth but is less pronounced, and the orebody is now more or less continuous over 2600 ft of strike length. with widths 5 ft to as high as 26 ft where overlapping of lenses occurs in one section of the mine. Better continuity of ore at depth has encouraged systematic mining and improved plant facilities to offset higher operating costs. With favorable persistence of ore at depth. the three-compartment No. 6 hoisting shaft appeared inadequate to handle increased tonnage from greater depths, and in 1952, a four-compartment steel and concrete shaft was started. This is now at a depth of 1906 ft, and shaft pockets and loading cartridges are being installed on the 1806 level. Ore from the new shaft, hoisted in 51/2 -ton Jeto bottom dump skips, is dumped into a 500-ton shaft bin, from which it is fed to a 16x30-in. gyratory crusher and conveyed 415 ft through an undersurface concrete gallery to the secondary crusher and conveying system supplying the 900-ton mill. Lead, zinc, and pyrite concentrates are floated, and the flotation tailings are cyanided after desliming. Waste from the new shaft is dumped into a 250-ton surge bin, fed from this bin to a 24-in. conveyor, and discharged into the glory hole above the block cave. The new shaft is served by a double-drum 400-hp hoist used for ore and waste; the No. 6 shaft conveys men and material To secure a cheap source of waste fill for stoping operations, a block cave area was undercut In the hanging wall near the north end of the mine above the 600 level. Waste from the block cave is drawn from any of three large drawpoints on the 600 level, and a series of hanging wall transfer raises with controls and bypasses on each level provide a fast low-cost material for fill. The block cave is worked vertically through to surface in the form of a steep-sided hole 350x250 ft and several hundred feet deep, the sides of which cave and provide fill material without any blasting. Fill is a mixture of caliche-cemented surface gravel and small particles of hanging wall schist. Level Development: An orebody 300 times as long as it is wide requires a lot of development work. Former practice consisted of driving a haulage drift about 30 ft from the ore in an andesitic footwall, a drift on the ore, and crosscuts from the haulage drift at 100-ft intervals. Crosscuts are about 90 ft long. At present, only the odd numbered levels are so developed, and on the even numbered levels only the haulage drift and crosscuts are driven. Little or no timber is used for this development. This change resulted in 20 pct reduction of development costs and 50 pet reduction of square set stoping required for removal of floor pillars. Elimination of ore drifts on alternate levels leaves

Jan 1, 1957