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By Benjamin Gi ldersleeve

Uniquely colored, thin-bedded quartzite is quarried between Crossville and Crab Orchard in Cumberland County, Tenn. It is produced in all sizes up to the limits of transportation from beds usually ranging in thickness from less than 1/2 in. to 6 in. The stone is very resistant to wear and weathering and is marketed throughout the country for many different purposes in exterior and interior construction. The annual production exceeds 36,000 tons, valued at nearly $1,000,000.

Jan 1, 1950

By Benjamin Smith Lyman

THE importance of topography to geology is so commonly underrated as to deserve to be pointed out again and again. The relation of topography to the different branches of geology may be seen best by a glance at them all. Geology is well understood to consist of the observation of facts about rocks as materials of the earth (geognosy ), and the explanation of those facts (geogeny). The facts to observe are: I. GEOMETRICAL, as (1) structure, including the dip and strike at different points, the size, shape, and position of basins and saddles; (2) vertical section, that is, the thickness of rock groups and of their parts ; (3) horizontal or geographical position. II. PHYSICAL, such as texture, whether sedimentary or crystalline ; and, if crystalline, whether granitic, porphyritic, amygdaloidal, globular, or concretionary; whether compact or granular; coarse or fine; pervious or impervious; hard or soft; firm or tender; with cleavage or without; massive or thin; the microscopic structure; also whether magnetic or not; soluble or insoluble; fusible or infusible; and the constituent minerals. III. CHEMICAL, that is, the composition of the rocks and of their minerals and their affinities. IV. PALÆONTOLOGICAL, as what kind of fossils are in the rocks,

Jan 1, 1873

STANDING COMMITTEES Executive-A. R. LEDOUX, chairman. Membership-GEORGE C. STONE, chairman. Finance-J. V. N. DORR, chairman. Library-E. GYBBON SPILSBURY, chairman. Papers and Publications-BRADLEY STOUGHTON, chairman. Nominations-POPE YEATMAN, chairman.

Jan 7, 1919

ONE of the perplexing problems that face the translator of an old technical treatise is the question of terms for units of weight and measure. We have used an English word only when it is linguistically equivalent to the Italian one and is a unit of approximately the same size. Libbra and oncia thus become pound and ounce, for the actual weights were within 10 per cent of the modem Troy weights. On, the other hand, the length measures braccio, palmo, and dito, which could be rendered literally as arm, palm, and finger or digit, respectively, have no good English metrological equivalents and it has seemed best to retain the Italian words. The exact transfer of Biringuccio's weights and measures into modern terms is impossible because of the uncertainty as to his standards. Even as late as 1803, when the metric system was first introduced into Italy, practically every city had its own standards. There were, for example, at least eight different palmi, varying from 22.3 to 29.2 centimeters. The values listed below for the various units mentioned by Biringuccio are the Florentine ones, which were also used in Siena and Tuscany: [ ]

Jan 1, 1942

STANDING COMMITTEES Executive-SIDNEY J. JENNINGS, chairman. Membership-KARL EILERS, chairman. Finance-J. V. N. Dorr, chairman. Library-E. GIBBON SPILSBURY, chairman. Papers and Publications-BRADLEY STOUGHTON, chairman. Nominations-R. V. NORRIS, chairman.

Jan 1, 1919

By P. R. Hanes

A description of the methods used in driving two tunnels, 2 miles long each, one a 9-ft. and the other a 19-ft. diameter section, for the Owyhee Irrigation Project, Oregon. One heading of the smaller tunnel was driven 1315 ft. in 73 shifts in one month and 10,966 ft. of this section completed in ll½ months using two shifts for eight months and three shifts the rest of the time. This is a good illustration of the proper use of a mechanical shovel and the importance of careful selection of supplernentary equipment to secure best results. Large cars, speedier and heavier locomotives, 36-in. gage track of 45-lb. rail, and a good switching method increased actual shoveling time and cut down muck removal period about 45 minutes from average. The larger tunnel, after trying out standard electric revolving shovels of both the rail mounting and caterpillar tread types, was excavated with a mechanical mucker. This is the first time that a tunnel of so large a section has been handled this way. This record work was accomplished without drill carriages.

Jan 1, 1934

F. G. CLAPP, New York, N. Y. (written discussion *).-Whatever processes of appraisal have been found most correct and feasible in one field or group of fields will generally prove most adaptable in others. So far as the California fields are concerned, Mr. Requa's paper appears to outline the most up-to-date processes of appraisal. It remains, then, to discuss and adapt these and to make such revisions in methods and processes of calculation as will give us results elsewhere. The trouble about most attempts to place a value on oil lands, whether in this country or elsewhere, has been that many of the so-called "experts" called upon to express an opinion either have not possessed the requisite engineering and geological knowledge to make an accurate appraisal of the lands, or that they were not furnished with sufficient information for the purpose in hand. The Independent. 011. Producers' Agency of California, for whom Mr. Requa's original report was prepared, had many advantages in this respect not generally available to engineers making reports, as all existing information seems to have been at the experts' disposal within the limits of a large number of properties, practically commensurate with the extent of the fields in question. Hence the report could be and was more accurate than any similar report for a single company is likely to be in other fields. Very few companies are so exempt from competition that all the data on neighboring leases of other companies will be freely turned over to them. In many companies, certain available data are concealed from the engineer who makes the reports, particularly if the properties are supposed to be worth less than their apparent value. In the case of other companies, having the best of intentions, the data are insufficient to help the engineer greatly in his appraisal, simply because the oil business has been so, unsystematic in most fields that only the largest and wisest companies have kept accurate figures regarding runs and gravity of oil from individual wells and from different depths. In many wells, which ran wild for clays or weeks in the older fields, there was a waste which is not recordable with exactness. These and many other difficulties confront even the most experienced expert in actual practice outside of the California fields. We may justly say, therefore, that an engineer in other fields of the United States and in the European, South American and Asiatic fields, must not only begin where the Independent Oil Producers' Agency

Jan 4, 1918

OFFICERS AND DIRECTORS For the year ending February, 1934 PRESIDENT AND DIRECTOR FREDERICK M. BECKET NEW YORK ,N . Y. PAST PRESIDENTS AND DIRECTORS ROBERT E. TALLY JEROME ARIZ SCOTT TURNER WASHINGTON D. C.

Jan 1, 1932

STANDING COMMITTEES Executive-A. R. LEDOUX, chairman. Membership-GEORGE C. STONE, chairman. Finance-J. V. N. DORR, chairman. Library-E. GYBBON SPILSBURY, chairman. Papers and Publications-BRADLEY STOUGHTON, chairman. Nominations-POPE YEATMAN, chairman.

Jan 6, 1919

STANDING COMMITTEES Executive-A. R. LEDOUX, chairman. Membership-GEORGE C. STONE, chairman. Finance-J. V. N. DORR, chairman. Library-E. GYBBON SPILSBURY, chairman. Papers and Publications-BRADLEY STOUGHTON, chairman. Nominations-Pops YEATMAN, chairman.

Jan 8, 1919

OFFICERS AND DIRECTORS For the year ending February, 1932 PRESIDENT ROBERT E. TALLY JEROME, ARIZ. FREDERICK W. BRADLEY SAN FRANCISCO, CAL. WILLIAM H. BASSETT,P WATERBURY, CONN KARL EILERS NEW YORK N. Y.

Jan 1, 1929

H. RIES, Ithaca, N. Y.-The part of Mr. Fiske's paper that interests me especially is that portion dealing with the raw materials, and the tests that were applied to the raw materials in order to determine their value in advance, if possible, because that, I believe, is a step in the right direction. For a number of years I have done my best to persuade different consumers of clay to develop standard methods for testing raw materials. We have in this country a large variety of clays which can be used for a great many different purposes, but in many cases the consumers either have no standard methods for determining the value of those clays in. advance, or if they have they do not publish them; consequently it often puts the clay miner at a disadvantage. If, for example, manufacturers of different types of refractory materials would state publicly just what physical tests their raw materials have to meet, it would, I believe, help them to find more easily the materials that they are looking for, and the clay producer would also be benefited. It would also encourage him to have his clays tested in advance, so that samples could be accompanied by certificates of physical tests that would be of convenience to the manufacturer. At the present time, in this country there are certain types of clay which seem to be rather scarce. There apparently are not many deposits of clay that are exactly suited for the manufacture of zinc refractories. So, too, there are not many deposits of clay that are suited for the manufacture of glass-pots, or the blocks for glass tank furnaces, or clays that can be used for graphite crucibles. Now, in many cases, no standard series of tests has been developed. I am also gratified to see that Mr. Fiske considers the tensile strength. tests of value. Some years ago the American Ceramic Society appointed a committee to draw up a series of recommendations covering standard tests. These recommendations were especially for the use of State geologists and the U., .S. Geological, Survey. Among the tests that were considered was the tensile-strength test, which Mr. Fiske has mentioned in his paper. Unfortunately, a majority of the committee turned it down, and the test was therefore not officially approved, but two of us, who formed the minority, believed in it. Since then the other members of the Committee have come to see that that is an important test to make and Mr. Fiske has emphasized it in his paper.

Jan 1, 1918

By P. A. Beck, M. V. Nevitt

All binary and a number of ternary u alloys formed by first long period transition elements were examined and found to be ferromagnetic at low temperatures. The Curie temperatures for these alloys were measured. It was found that the correlation of the Curie temperature with composition may be described qualitatively in terms of the contributions of the various component atomic moments to the saturation moment of the alloy. Ternary Fe-Cr-Mo u phase alloys were also found to be ferromagnetic, with a Curie temperature dependent on the iron content and largely independent of the unit cell dimensions. Similar relations were found for the Co-Fe-Cr and the Co-Cr-Mo a alloys, where the Co + Fe content appears to determine the Curie temperature. RECENTLY, it has become increasingly evident that the u phase is some kind of an "electron compound." Several papers1-' discussed the empirical correlation between the composition of the various u phases in alloys of the transition elements and the distribution of electrons in the partially filled d-levels of the component atoms. However, a picture of the latter can be formed only in a more or less intuitive manner, as in the Pauling theory," and the rigorous treatment of these problems is at present prevented by lack of adequate knowledge of the electronic structure of the transition elements in the metallic state. It appeared reasonable to expect that investigation of the magnetic properties, which are related to d-shell electrons, may help in clarifying the physical nature of the foregoing empirical correlation. Qualitative tests of samples of various compositions have shown that certain u alloys become ferromagnetic at liquid nitrogen temperature." The present investigation was undertaken to determine whether or not low temperature ferromagnetism is characteristic of a large variety of u alloys and to establish how the Curie temperatures of ferromagnetic u alloys are influenced by changes in composition and in lattice parameter. In the first portion of the in- vestigation, Curie temperatures were measured for a series of u alloys containing either vanadium or chromium with one or two of the elements manganese, iron, cobalt, or nickel. In the second phase of the work, data were obtained on the Curie temperature of ternary (Fe, Co, Cr)a, (Fe, Cr, Mo)a, and (Co, Cr, MO)U alloys, as a function of composition and of interatomic spacing. Experimental Procedures High frequency vacuum melting in high purity re-crystallized alumina crucibles was employed in the preparation of the u alloys, using metals whose lot analyses are given in Table I. Approximately two-thirds of the alloys were analyzed chemically, the analytical results being in acceptable agreement with the intended compositions, as seen in Tables I1 and 111. The specimens were annealed for homogen-ization in an atmosphere of purified 92 pct He and 8 pct H, mixture or in evacuated and sealed Vycor tubes at temperatures from 780" to 1300°C, depending on the temperature range of the u phase field for the particular composition. The annealing temwerature and time for kach alloy are given in Tables 11 and 111. Curie points were determined by an induction method; the change with temperature of mutual inductance between two coils was observed when the i-u specimen was inserted into the flux path between the coils. The transformer consisted of three coils each containing 1200 turns of 0.0050 in. diam enameled copper wire. The center coil, P in Fig. 1, served as the primary coil, and was linked magnetically with each of the two secondary coils, S, and S? which were connected in series opposition. The primary coil, P, was energized by an audio-oscillator, set at a frequency of 500 cycles per sec, while the signal from the transformer secondary circuit,

Jan 1, 1956

STANDING COMMITTEES Executive-A. R. LEDOUX, chairman. Membership-GEORGE C. STONE, chairman. Finance-J. V. N. DORR, chairman. Library-E. GYBBON SPILSBURY, chairman. Papers and Publications--BRADLEY STOUGHTON, chairman. Nominations-POPE YEATMAN, chairman.

Jan 9, 1919

By L. S. Richardson, N. J. Grant

REACTIONS of oxygen and nitrogen at low pressures with titanium have recently been studied by a number of investigators.1-3 Gulbransen and Andrew' noted that the reaction with nitrogen followed the parabolic rate law whereas the reaction with oxygen deviated slightly from this law in the temperature range 300° to 800°C. In the work reported here, commercial titanium (75 A) was used as the test material. Cylinders 2.5 in. long and 0.25 in. in diameter were machined from heavier bar stock. The test pieces were given a metallographic finish, immersed for 30 min in cold concentrated HC1, washed in water, then acetone, and dried with lint-free cloth. Reaction rates were determined in a modified Sieverts type apparatus by measuring the decrease in gas pressure of the reacting gas contained in a constant volume. The amount of gas added could be measured in a calibrated gas burette to an accuracy of 0.01 mm. During the course of a run the temperature never varied by more than 10°C and then only for brief moments. After placing the specimen in the furnace, the system was first evacuated for 12 hr at room temperature, and then flushed with purified argon five times, adsorbed gases being discharged during this period from the glass system with a high frequency spark coil. The flushing and discharging were repeated at 400°C. This rather involved procedure was found necessary after a number of trial runs indicated extraneous effects traceable to the system. Reaction periods up to 2 hr were used, at initial gas pressures of 0.2 to 0.5 atm. Experimental Results Fig. 1 shows the decrease in oxygen pressure for tests at 0.5 atm at various temperatures as a function of the square root of the time. Deviations from linearity are minor and the parabolic rate law is obeyed. Fig. 2 shows the same plot for the nitrogen reaction. A definite deviation from linearity is noted; however, it is probable that the higher initial rates are caused by the presence of small amounts of oxygen contamination, the initial faster rate changing to the slower rate after about 5 to 10 min. Calculations of the rate constants were made on the basis of the latter portion of the curves. The parabolic rate law constants calculated from these curves are shown for oxygen and nitrogen in Fig. 3. In spite of some scatter the average curves are quite definite. Changes in gas pressure of the order of 20 pct did not result in a measurable change in the rate law constants. The activation energy for the oxygen reaction was calculated to be 47,400 cal per mol (above 700°C), which is not in agreement with the value quoted by Gulbransen and Andrew' for lower temperatures, their value being 26,000 cal below 600°C. The activation energy for the nitrogen reaction was calculated to be 45,400 cal per mol above about

Jan 1, 1955

The Pueblo Viejo Mine, a 7, 250 mtpd (8,000 stpd) gold-silver cyanidation plant built by Rosario Dominicana S. A., was described in Volume I of this monograph. At the time of writing that volume, Pueblo Viejo had not yet gone on-stream and operating data or costs could not be presented. Since that time this information has been obtained and several interesting modifications and an expansion have been made to the plant. Because Pueblo Viejo is the largest open-pit gold mine in the world and one of the world's leading gold-silver operations with production of approximately 31 kg (1,000 oz) gold and 125 to 155 kg (4,000 to 5, 000 oz) silver per day, the authors have updated the previous data and flow sheet. The Dominican Government, which held a 4670 interest in Rosario Dominicana S. A., completed purchase of the mine to gain full control in 1979. Rosario Resources will continue to manage the mine, at least until the end of 1980. Gold was produced at Pueblo Viejo almost 500 years ago with initial production in the year 1505. Rosario Resources became interested in the property in 1969 and found surface oxidation had rendered the upper portion of the ore body amenable to direct cyanide treatment. The treatment of the underlying gold-bearing sulfide zone is still undergoing metallurgical studies. The ore is considered to be a laterite; and because there appeared to be few boulders in the ore zone, only a 400 m (16 in. ) square grizzly was initially installed ahead of the mills when the plant went on-stream in late 1974 at a design capacity of 7,250 mtpd (8,000 stpd). Operation also proved the ore to be harder than was originally anticipated. During 1967 a 1. 25 m by 1. 5 m (48 in. by 60 in. ) jaw crusher was installed to -feed the 1, 000 mt (1, 100 st) mill bin. Minus 200 mm (8 in.) crushed ore is fed directly to two 5.5 m by 1. 8 m (18 ft by 6 ft) semi-autogenous mills re-powered with 750 km (1,000 hp) motors and 50 mm (2 in.) grates. Each mill product is screened at 13 mm (1 /2 in.) by a vibrating screen. Screen oversize from each mill is combined on a single return belt equipped with a magnetic head pulley for grinding ball removal. The non-magnetic oversize is then split into two fractions for return to the primary mills. Originally, a minus 6 mm (1/4 in ) product was made on each screen and fed to a 300 kw (400 hp) 2.6 m by 3. 7 m (8-1/2 ft by 12 ft) regrind mill. During a plant expansion in 1978, an intermediate mill of 746 kw (1,000 hp) was installed to operate in open circuit on the combined primary mill

Jan 1, 1981

By Thomas A. Simpson, Tunstall R. Gray

The Birmingham district first produced steel from Alabama hematite ores in 1899. Since then, the district generally produced more than 6.0 million gross tons of ore a year to the late 1950's. Production has declined since then to an annual rate of about 1.5 million gross tons. Reserves calculated for the district are sufficient to last many years. Mining in the district is now confined to Woodward Iron Company's Vance and Pyne mines. The rocks exposed consist of about 15,000 feet of consolidated Paleozoic sediments with a thin veneer of unconsolidated Cretaceous sediments in the Vance area. The district is characterized by a distinctively parallel and subparallel, slightly arcuate series of faults and joint systems. In view of available information, it seems reasonable to conclude that the Birmingham red ores are of sedimentary origin, modified to a small extent by diagenetic replacement after original deposition.

Jan 1, 1968

By Leon Borgman, Michael P. Lipkewich

Orebodies at or near the surface are generally amenable to open pit mining. The development of a mining program involves designing an ultimate pit and a production schedule. This pit maximizes total profit while the production schedule maximize6 the present value of the property. Optimum pit limits can be approximated by two-and three-dimensional numerical techniques. These techniques presuppose that the mineralized area has been sufficiently sampled to allow a reasonably accurate prediction of grade at any spatial location.

Jan 1, 1969

By WILLIAM BOWIE

IN most human endeavors a knowledge of the terrain is essential to the effective carrying out of projects, but no line of work is more dependent on maps than theoretical and applied geology. Maps of a kind do exist for all of the area of the United States, but most of them are crude affairs and of little use in engineering, planning, and scientific research. Topographic mapping in the United States was initiated on a national scale by the U. S. Geological Survey and the organizations that were merged in its creation to make base maps for geologists. Their work could not be effectively done then and cannot be effectively done now without maps that accurately delineate the earth's surface. The distribution of the rock masses that contain valuable mineral bodies, or that by their intrusion brought them into existence, is the first step in a study of the mineral resources of the nation. This work requires three-dimensional maps, that is, topographic maps on which the land forms are shown by contours.

Jan 1, 1938

THE opening session was held on Tuesday evening, February 17th, in the house of the American Society of Civil Engineers. The President of the Institute, Mr. E. B. Coxe, after a few introductory remarks, congratulating the members on the general prosperity in all the branches of the professions and manufactures represented by the Institute, called on Mr. E. F. Loiseau, of Philadelphia, for the first paper, On the Successful Manufacture of Compressed Fuel at Port Richmond, Philadelphia. Professor Prime called attention to the fact that the work of the United States Testing Board had been left unfinished at a point when valuable results had just been reached, and offered the following resolutions: WHEREAS, The American Institute of Mining Engineers has seen with regret that the work of the United States Testing Board has been suspended through the lack of an appropriation by Congress, which appropriation dues not seem likely to be renewed, and WHEREAS, It seems most important to the vital interests of our iron and steel manufactures that the experiments commenced by the United States Testing Board should be carried to successful completion ; Resolved, That a committee of three be appointed, to act with a like, committee to he appointed by the American Society of Civil Engineers, to carry out to completion the work commenced by the United States Testing Board. Resolved, That the American Society of Civil Engineers be requested to cooperate with this society by the appointment of a like committee. Resolved, That the committee have authority to request, in the name of the American Institute of Mining Engineers, contributions to a fund to be devoted to the completion of the experiments aforesaid. Resolved, That the Council of this Institute be authorized, whenever requested by the committee so appointed, to petition Congress for the free use of the testing machine at the United States Arsenal at Watertown. Resolved, That a committee be appointed by the President, to select the afore-said committee of experts. Resolved, That the President of the Institute have authority to fill any vacancies which may occur in the committee. The resolutions were unanimously adopted, and President Coxe appointed the following committee in accordance with the resolutions : Messrs. A. L. Holley, James Park, Jr., and J. F. Holloway. The President also appointed Messrs. Heinrich, Mickley, and Spils-

Jan 1, 1880