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By F. R. Cattoir, R. W. Kimball, C. T. Anderson, V. V. Donaldson

THIS paper is the second of a series on the effect of various elements on hot-working characteristics of Fe-C alloys to be issued by this laboratory. The investigations being conducted at the Ferroalloy Research Branch of the U.S. Bureau of Mines, Redding, Calif., involve fundamental research on the effects of various alloying materials and impurities on the physical properties of high purity Fe-C alloys. This paper deals with the determination of the limit of forgeability of steels containing varying amounts of manganese and sulphur. A paper discussing the hot-working characteristics and the physical properties of the forgeable alloys is being prepared. One of the principal impurities in all steels is sulphur.. The phenomenon, hot-shortness, commonly attributed to sulphur, has long been a source of expense and inconvenience to both the maker and user of steels. In steelmaking practice, this effect of sulphur has been overcome by the addition of manganese which, apparently, acts as a desulphurizer. Manganese is also used as a deoxidizer and alloying material. The critical and strategic position of man- ganese gives added importance to research which may contribute to its conservation and more effective utilization. It is not the purpose or intention in the present paper to give any explanation of the mechanism of either hot-shortness or its prevention but rather to report the results of forging high purity Fe-C alloys of the range of compositions near the limit of hot-forgeability. Temperatures for each phase of reduction were duplicated within 20" to 30°F for all tests. The starting material was sponge iron, which, after melting and purification, gave a high purity iron containing about 0.001 pct each of silicon and phosphorus. Scrap iron was not considered suitable because of its high percentage of contaminants and wide variation in analyses. The sponge iron was melted and refined for melting stock in a three-phase, direct-arc, size ST, Moore Rapid Lectromelt furnace with a 500 kva rating as described in the preceding paper. Additives were carefully selected to avoid addition of contaminants. The sulphur was added as resublimed flowers of sulphur or purified roll sulphur of analytical grade. The manganese used was dehydrogenated high purity electrolytic material produced by the Bureau of Mines plant at Boulder City, Nev. High purity aluminum in the form of wire was used for deoxidation. The limestone was obtained locally and had the following analysis: CaO, 53.7 pct; MgO, 0.8; ignition loss, 42.4; R2O3, 0.2; SiO2,3.0; and P2O5, 0.014.

Jan 1, 1955

By Felix A. Vogel

I (New York Meeting, February, 1912.) FLUE-DUST, to most blast-furnace operators, means a troublesome by-product, the formation of which should be curtailed, if not prevented entirely. However, with the increasing use of fine ores, larger furnaces, and high-pressure blast, the production of flue-dust is constantly increasing, and amounts annually in the United States to from 3,000,000 to 3,500,000 tons, An exceedingly high tonnage, of which a large part has been discarded as valueless. As a result of greater economy in the iron industry, the attention of our furnace-men has been directed towards the utilization of this enormous amount of waste material, a problem which had also been given due consideration by metallurgists abroad. Flue-dust is generally a fine material containing considerable coke and iron-ore, with a small admixture of lime and silica, depending upon the burden. The iron-ore is partly reduced, which shows that the dust originates largely in the reducing-zone of the blast-furnace. In the United States this dust usually contains 20 per cent. of coke and more than 40 per cent. of iron. Estimating coke to be worth $3.25 per ton, and iron-ore 7 cents per unit, a ton of flue-dust, unless made available, represents a loss to the furnace-man of $3.50. This accounts for the first efforts to recharge the flue-dust into the furnace, either by moistening it clown with an excess of water, or mixing it with clay to form balls of pulp, or treating it with lime-water. These methods, however, have been practically discarded, as they failed to produce the desired economies. To recover, in the blast-furnace, all the values represented by the material contained in the flue-dust, the following con¬ditions should be complied with

May 1, 1912

By AIME AIME

THE outstanding event of the past month has been the conference in Washington of the representatives of about seventy-five of the leading national, regional and local engineering and allied technical organizations." Editorial-July Journal-The American Society of Mechanical Engineers. ?Prominent engineers from all parts of the country, representing more than 75 engineering societies, with an aggregate membership of more than 125,000, participated in the organization.? Editorial-July Journal-American Institute of Mining and Metallurgical Engineers. ?Civil, mechanical, electrical, mining, heating, sanitary, chemical, agricultural, marine, refrigerating, radio, fire protection, automotive, industrial and military engineers, as well as some architects and geologists assembled at Washington, D. C. to consider the advisability of organizing a national federation capable of bringing the united efforts of the entire membership to a focus on any problem of mutual interest." American Architect, June 23, 1920. ?"the object sought places it above any engineering gathering ever held." Editorial-American Machinist, June 17, 1920. "The youngest. profession has voluntarily accepted its responsibility in human affairs and is now reaching forward to a career of essential service." "This is .unmistakably the meaning of the Organizing Conference " Editorial-Industrial Management, July; 1920.

Jan 1, 1920

By Ferid Kromer

This paper is the first in a series which will describe geology, mining methods, and production costs of some, of Turkey's more important minerals. In this paper the economically significant minerals-chromite, meerschaum, and magnesite-of the Tagtepe district are described. The cost data presented are believed by the author to be the first made public on Turkish chromite mining.

Jan 1, 1950

The question, Who won the war?, has been the text for innumerable newspaper, and magazine articles, the answers running from "bread and butter" to "poison gas," in a material sense, and from the "Y. M. C. A." to the "boys in the front lines," humanly speaking. Personally, I think the margin by which success was secured was so narrow that none of the complex, interdependent factors could have been .spared, and that, as Admiral Sampson said after the battle of Santiago: "There is glory, enough for all." But if any one human factor can be said to have been absolutely indispensable, I think all will agree that it was the engineer. The engineer, as a rule, is a modest fellow, so modest in fact and so averse to publicity of any kind that, referring to him as a class, he was hardly occupying the place he should in public estimation before the war. By way of illustration, in the early history of a mine in Bisbee, the chief owner was also the proprietor of a saloon and spent most of his time there. When asked why he did not pay more attention to the mine, lie replied: "Oh! I can hire a boy to look after that; it takes a man to run this bar." Comparisons of the position and pay of engineers with other occupations are sometimes made to show that the engineer is not getting all that he should, considering the time of preparation and the qualifications required. Perhaps at least a part of the cause may be his aloofness from many of the practical affairs of everyday life. Whether he won the war or not, the part played by the engineer has certainly placed him on a sort of pedestal in the public estimation at present and it is very desirable to keep him there and maintain the position he has made for himself.

Jan 9, 1919

By AIME AIME

YOU can place an exclamation point after the "and How" if you want to, but the way it stands it sum¬marizes the Mining Geology sessions quite nicely; "Why" in the morning, "How" in the afternoon. It is altogether fitting that Prof. McLaughlin and Reno Sales, who have themselves achieved enviable reputations in company work, should have led the program by presenting informally a chapter from the volume dedicated to the beloved dean of all economic geologists, Waldemar Lindgren. In opening the morning session, over which Sydney Ball presided, Donald McLaughlin emphasized the continuous role mining geology should play in operating technique. He pointed out the importance of structural relations in a broad sense, and the preponderant role they play in developing the manner of ore occurrences. He illustrated this by an account of the work at Homestake, using slides to show the stratigraphic sequence, the folding, and the orebodies of that camp. An interesting piece of detail was the distinction they found could be made be¬tween the chlorite near the ore masses, and that in the country rocks. Whether the cummingtonite, characteristic of the rock in which the ore is found, is of regional or of contact metamorphic origin caused some discussion. Dr. Lindgren inclined to the belief that it was contact, but L. C. Graton replied that they had found the weight of evidence was for a hydrothermal origin. D. F. Hewett raised the question as to whether, in the advancing development of the mining industry, there was still a place for the U. S. Survey geologist, and the consensus seemed to be that there should be. His role is changing from that of mapping mining districts in detail, now the task of the companies, towards a more general serving of the industry through the wider perspective his work gives him in contradistinction to the greater detail of knowledge accumulated by the resident geologist.

Jan 1, 1933

By D. V. BURR

THE ORIGINAL HUDSON RIVER TUNNEL. NOT quite forty years ago a man of uncommon character entered New York. He had several hundred thousand dollars earned by railroad building in the Nest. He was not an engineer, but he had ideas of engineering work which he was destined to prove correct.. He introduced new ways of tunneling, but his plans had only one distinguishing feature-they were simply interesting as showing how such work could be done; they added nothing to the science, have never been used since his clay, and never will be used again. Engineers of repute ridiculed his proposition ; he was an Ishmael in the profession. But if engineers looked askance at him, he certainly returned their contempt in the heartiest fashion, and had no hesitancy about expressing his views of them individually and collectively. This worked to. his disadvantage when he afterward tried to raise the means to go on with the work. He found that the opinion of engineers was respected by financiers, and that money would not flow contrary to their advice. While his conception of large constructions was distinguishingly original, much more marked was his method of demonstrating the feasibility of, his schemes. In the present clays of great undertakings it is the custom to make the other man pay for the experiments. But the man from the West had other notions of how the thing ought to be done. Having wonderful confidence in his own ability and in his perception of the task before him, he used up all his own money before seeking outside assistance. By building several hundred,, feet of tunnel he proved the correctness of his theory, and the tunnel then dug forms a part of the present tube. The result-he failed to finish the tunnel. He was blind in

Mar 1, 1908

By A. C. Dittrick

THE Simon-Carves washer, originally known as the Baum jig washer, was first built in Europe about 1892. It was probably the first washer to use intermittent pressure of air on water in one part of the wash box to obtain water pulsations in another part. This type of washer was also the first to successfully clean various sizes in the same unit. Previous practice was to size closely before washing. Today there are several large firms abroad, and a few in the United States, that are constructing the Baum type washer. The design of all is practically the same, their differences being only in details. In 1928, the Hanna Coal Co. first gave consideration to the question of coal cleaning. It was believed at that time that by efficient removal of so-called noncombustibles appearing in the Pittsburgh No. 8 seam, certain markets that had been lost due to poor preparation might be recovered. Mechanical cleaning and mechanical loading were under consideration. This type of cleaning was considered the most practical means of removing impurities in the sizes below 4 in. It was decided to adopt mechanical cleaning and develop a system of mechanical loading that would be successful on No. 8 coal.

Jan 1, 1935

By T. E. SCHTVARZ

THE publication of the report by Mr. F. L. Ransome was welcomed by many engineers who had mined in the heart of the Sail Juan country, braved its long and snowy winters, climbed its lofty peaks, run the gauntlet of its snow-slides, and studied its problems of geology, while making dividends for their English or American clients. This report helps one to understand why the bonanzas occurred, and why the inevitable borrasca presents itself where least expected. The Red Mountain district of Ouray county, a very productive section from 1884 to 1893, occupies considerable space in the report mentioned.. The character of the ore-occurrence, being distinctive and presenting many features not existing elsewhere, has been deserving of special study. It is to be regretted that Mr. Ransome was .unable to observe the conditions underground, as all the principal properties, many of which I opened and developed, were closed at the time of his investigation: It has been my privilege to have contributed a few brief papers recording my observations in developing these properties ; and it is the object of the present paper to present certain sections of the Yankee Girl mine, which throw additional light on the geology of the section and make the available data more complete. The main Yankee Girl chimney or " stock" was the most productive for the first 500 ft. in depth of any chimney in the district.

Mar 1, 1905

By Betty L. Gibbs

A company must have an organized approach to effectively sort through the profusion of available software and hardware and find the programs and equipment which fit defined needs. The selection process must build a complete compatible system which includes hardware and software. The methodology presented in this paper helps identify some of the more important considerations. The steps needed for an organized approach to software/hardware selection are: •All involved staff should contribute to an assessment of current computer capabilities and projection of future needs. •Alternatives are analyzed to determine what software and hardware is available and how selections may possibly be merged into the existing computer system. The evaluation process focuses on details of program capability and hardware compatibility. Analysis must be done to determine how closely individual programs fit the established requirements. The final decision is often a balance of needs between program capabilities and hardware availability. Any programs selected must be able to run on existing and newly purchased hardware. Any additional hardware selected must be capable of meshing with the available computer system.

Jan 1, 1983

By C. L. Sainsbury

Lode and placer tin deposits of the western Seward Peninsula, Alaska, have produced more than 2200 tons of metallic tin and constitute the only known domestic deposits of economic grade and size. The lode deposits consist of quartz-topaz greisens containing cassiterite and wolframite as well as numerous base-metal sulfide minerals, and most are in or near altered biotite-granite that forms isolated stocks or in rhyolitic dikes near granite. Within the main lode-producing area in the central York Mountains, nonpegmatite beryllium deposits, consisting principally of fluorite, chrysoberyl, diaspore, tourmaline, and white mica, with minor euclase, bertrandite, phenakite, hematite, and todorokite, are distributed zonally around the tin deposits and locally are transitional with them. All the known beryllium deposits are replacement lodes in carbonate rocks. In the area discussed, both tin and beryllium deposits are localized in a structural belt striking N70° to N85°E across the central York Mountains. The belt is characterized by numerous normal faults, which cut extensive thrust sheets, and by dikes of rhyolite, rhyolite porphyry, and lamprophyre that were injected along the faults. Ore deposits are localized where the dikes intrude brecciated rocks beneath thrusts and, although complex in detail, form tabular lodes that tend to lie along the thrusts. The granites contain abnormal amounts of tin, beryllium, lithium, and boron, and the tin and beryllium lodes are believed to be genetically associated with these enriched granites

Jan 1, 1968

Cyril w. Knight, Toronto, Ont., Canada (communication to the Secretary*).—Mr. Hore's paper presents an interesting summary of our knowledge of this important mineral field ; and is therefore acceptable as giving information which our Transactions did not already contain, although it presents little or nothing not made known by other writers before 1906, when Mr. Hore began work in the field as a student assistant. Contributions of this kind, however, should be made completely valuable by such references to previous work as will enable the reader to follow to their original sources the theories or conelusions stated by the author. It is quite natural, and even excusable, that a new observer should find novelty in his on observations—especially if he is not acquainted with the work of predecessors in the same field. Moreover, the independent repetition of an observation or conclusion has a distinct value as a confirmation, though it may have none as a discovery. But the publication of it, without reference to its predecessors, may place the author in an unfavorable light as either ignorant of the history of his subject, or willing to claim credit to which he is not entitled. Of the latter fault, I do not accuse Mr. Hore ; but I cannot wholly acquit him of the former. Without disparaging his intelligent work, I must point out that his paper, as it stands, might easily give the impression that he claims originality for many statements which are by no means new, and that he emphasizes unduly his own publications. Thus, his remark (p. 481) "I have described the silver-fields in a general way in my paper " (not yet published), should have been accompanied with reference to some of the numerous papers, already published, which describe these fields. Again, on p. 486, he refers to four papers of his own on the Porcupine gold-area, but neither in the text nor in the appended

Jan 1, 1912

By A. D. Hughes

C. W. MERRILL*—Mr. Hughes' paper not only is very well presented but is most timely in that it covers a subject of vital interest to the United States. Tin is one of the strategic metals which has not been found here in appreciable quantities. The total United States tin output since the first recorded production over 100 years ago would not supply current consumption for a fortnight. On the consumption side, tin is extremely important in national defense because of its use in tin plate which, in the form of tin cans, makes it possible to feed properly the armies that the United States recruits from its civilian population in emergencies. Moreover, the internal combustion engines so important in powering tanks, planes, and other war machines, require large quantities of tin alloys for bearings and for soldering. These considerations, along with the fact that Malaya, historically, has been the leading source of tin to the United States, make the kind of information that Mr. Hughes has presented so ably. a matter of vital interest. Your Chairman, Mr. Romanowitz, in his introduction, referred to the fact that I had been a member of the United States delegations to the three meetings of the International Tin Study Group. Some cominents on the Group's objectives and deliberations may be of interest. When it appeared that the International Tin Committee, the prewar producer's cartel, might soon revive its operations and extend its control agreement beyond the expiration date of Dec. 31, 1946, the United States Government became interested in some kind of an international trade organization concerned with tin which would give the consumers' interest equal representation with the producers' interests. An international meeting was called in London in October 1946 to consider this problem. I did not attend that meeting hut the result of the meeting was the organization of the International 'Tin Study Group which

Jan 1, 1950

By A. E. Wells

In this paper are described various comparative tests made on cracked and straight run gasolines. The results of these tests may be briefly summarized as follows: Samples of 54 to 55° Bé. gravity cracked gasolines, with end point of about 442° F., and with a somewhat larger proportion of the less volatile fractions than conformable to government specifications, were used in a single cylinder variable compression engine under the same conditions as were samples of straight run gasoline of 58 to 59° Bé. gravity, and of which one had a greater proportion of the more volatile fractions than called for in government specifications. The cracked gasolines showed decidedly less tendency to knock, hence could be used at higher compression ratios and thereby developed from 10 to 20 per cent. more power than did the straight run gasolines. These figures may be taken as one measure of the superiority of the cracked gasolines under test with the straight run gasolines. It is not claimed that all cracked gasolines are superior to all straight run gasolines to the extent indicated by the above tests; cracked gasolines vary as do the straight run products. Cross's work and that of others have indicated that certain cracked products may have a much greater superiority over straight run than that determined above. From various sources and by different methods of testing data are being obtained to show the definite and generally quite considerable superiority, as an anti-Cetonating fuel of cracked gasolines over straight run gasolines. It is now becoming generally recognized that by increasing the production of cracked gasoline motor fuel from those heavier petroleum fractions, which otherwise would be used for burning purposes, the petroleum industry is not only working in the interest of the conservation of the world's supply of petroleum, but is at the same time making available to the gasoline-consuming public a product distinctly superior to the straight run gasolines.

Jan 1, 1927

A USEFUL and very ingenious idea was surely that of the inventor of AN a short way of extracting gold and silver from the sweepings of all those arts that handle them as well as every particle that smelters of ores might have left in the slags, and also that in some ores themselves. This is done without using great labor in smelting but by the sole means and virtue of mercury. To do this, first make a large bricked pan of stone or wood and arrange a millstone inside which rotates in the hollow of this pan like that of a flour mill. In the hollow of the pan put some of your material containing gold after it has been crushed well in a mortar and then washed and dried. Grind it in the said mill, moistening it meanwhile with vinegar or water in which sublimate, verdigris, and common salt have been dissolved. Then enough mercury to cover these materials is poured over them. They are agitated inside for an hour or two, by turning the mill either by hand or with a horse, depending on the device that you have arranged. Remember that the more the mercury and the material are rubbed together in the mill the more it can be believed that the mercury absorbs the substance that the materials contain. Finally, thus prepared, the mercury is separated from the earthiness with a sieve or by washing and thus the mercury is retrieved. Then, make it rise with a little cucurbit or pass it through a purse and there will remain at the bottom the gold, silver,. copper, or whatever metal you placed in the pan under the millstone to be ground. Wishing to know this secret, I gave to the one who taught it to me a ring with a diamond worth twenty-five ducats, and I also pledged myself to give him the eighth part of whatever profit I should gain from this

Jan 1, 1942

Discussion of the paper of Robert R. Abbott, presented at the New York Meeting, October, 1913, and printed in Bulletin No. 82, October, 1913, pp. 2389 to 2400. ALBERT SAUVEUR, Cambridge, Mass.:-Mr. Abbott has certainly made a strenuous effort to ascertain the influence of the various elements on the absorption of carbon by steel-a subject of great importance to those dealing with the case hardening of that metal. Because of the extensive and careful character of Mr. Abbott's experiments, one is all the more disappointed that his results, as he himself recognizes, are not more satisfactory; for, indeed they leave us just about where we were,-still entertaining uncertain views in regard to the carbon-absorbing power of various alloy steels. It might be asked whether Mr. Abbott's method of estimating the amount of carbon absorbed-namely, by weighing the specimens before and after the carburizing treatment-was the best one to select. Are not serious sources of error. inherent to such procedure because of the difficulty of satisfactorily removing the earburizing material attached to the specimen ? The method of least squares has certainly failed to solve the problem satisfactorily. By manipulating Mr. Abbott's results in a different manner I have obtained the following expression: P = 100 - 50 C - 7 Ni + 20 Cr, in which P represents the carbon-absorbing power; C, the percentage of carbon; Ni, that of nickel; and Cr, that of chromium. It is assumed that the carbon-absorbing power of pure iron, or what might be called its carburizability, is represented by 100. Applying the formula, for instance, to a steel containing 0.15 per cent. C, 3 per cent. nickel, and 0.50 per cent. chromium, its carbon-absorbing power would be 100-50X0.15-7X3+20X0.50=81.50; that is, 81.50 per cent. of the carbon-absorbing power of pure iron.

Jan 12, 1913

By E. M. Norris

In the summer of 1917 it was decided to fireproof the main tramway hoisting shaft of the Anaconda Copper Mining Co. at Butte, Mont. The shaft has three hoisting compartments and one pump compartment; it is timbered with 12 by 12-in. (30.5 by 30.5-cm.) fir timber, and is 2475 ft. (754 m.) deep. Subsidence and displacement of the surrounding country rock had produced exceedingly heavy ground, and had carried the shaft out of line, in several places, by as much as 2 ft. (0.6 m.) displacement. Constant repairing and realigning of the timbers had been necessary in order to maintain clearance for the cages. The most feasible method of fireproofing, therefore, seemed to be to cover the timbers with a coat of concrete applied with the cement gun. The cement gun, which is operated by compressed air at ordinary mine pressures, feeds a mixture of sand and cement through a hose to a nozzle having a water connection. The mortar in fluid form is thus sprayed upon the prepared surface in thin layers, which can be built up to any desired thickness. The cement gun can be set up at any convenient point; satisfactory results have been obtained with the nozzle a distance of 500 ft. (152 m.) from the gun. The shaft was thoroughly overhauled and the timbers put in the best possible state of repair. Between the 1000 and the 1400 levels, much loose ground lay against the shaft timbers on the north side; this was breast-boarded back and a 30-in. (76-cm.) reinforced-concrete retaining wall was erected, leaving a space of 12 in. (30.5 cm.) outside the shaft timbers to allow for future movements of the ground. For convenience in handling men and materials; it was arranged to concrete the auxiliary hoisting-cage compartment and the pump compartment first, using the cages of the main hoist to serve the cementing crews. The auxiliary cage was then available while the remainder of the shaft was being concreted.

Jan 3, 1918

By J. S. Kasper, R. M. Waterstrat

IN view of the recent findings of a pronounced ordering of atoms in s phase alloys containing elements of the first long row of the periodic table (and including molybdenum),l it is of interest to resolve the question of ordering for s phases containing second and third-row elements. Examples of the latter have been provided recently by Greenfield and Beck2 and two of them, Re-Cr and Ru-Cr, would appear to be favorable for a study of ordering by X-ray diffraction methods because of the considerable differences in the scattering factors concerned. In addition, s phase is found to occur in the Os-Cr system, where the difference in scattering factors is even larger. Accordingly, X-ray powder intensities have been measured in an attempt to learn the nature of the ordering, if any, in these three v alloys. Since there is no reported work on intermediate phases in the Os-Cr system, an exploratory investigation was made in this system, and it was found that, in addition to the s phase, the phase with the A-15 or ß-W structure also occurs. Specimen Preparation—The alloys were prepared by compressing mixed powders of —200 mesh size and sintering in an atmosphere of pure dry hydrogen. All alloys were rapidly cooled from the annealing temperature to room temperature in a stream of cold dry hydrogen in a water-cooled chamber. Table I lists the sources and purities of the starting materials, as well as the details of processing for each of the alloys investigated. Intermediate Phases in the Os-Cr System—In the absence of information on intermediate phases in the Os-Cr system, it was suspected that this system would resemble that of Ru-Cr, where a s phase, RuCr2,2 and a phase with the A-15 structure, RuCr3,3,4 have been identified. Both these phases were found in the Os-Cr system and at compositions

Jan 1, 1958

By D. W. Mitchell

J. H. Schlobohm (Joy Manufacturing Co., New York) —This paper has been read with a good deal of interest; however, there are several salient features which Mr. Mitchell has overlooked. The initial emphasis on selection should be placed on type of material to be loaded and method of mining involved. There is no possible connection in the comparison of scraper or Joy Lohite loaders with loaders of any other type. Neither can an operating comparison be made between "Rocker type" loaders and those equipped with loading head and gathering arms. Each unit has its application, but the application depends on material and the mining system involved. Mr. Mitchell's compilation of data on various loaders, while it represents a great many facts, does not represent true operational data, i.e. Table I, column heading "Max. Rated Capacity for 7 hr;" these figures are meaningless inasmuch as little or no time at all is allowed for tramming or switching or moving the loader from place to place. Table I, column heading, "Best Reported Field Shift," would be a better source of operational data, assuming of course that conditions, applicable to each class of loaders, were average to avoid enthusiastic performance figures. Table I, column heading, "Repair Parts Cost per Ton," is still another item which will not stand up under comparison unless the loaders involved are put into type classes, i.e., there are simply no means possible to show the repair costs of scraper loading versus a caterpillar mounted loader in abrasive material. The source of information here is also important. Actual field tests have proved that these costs are of a constant nature. Manufacturers are striving to hold them to a minimum and many interesting studies have been made. A fairly recent example of this in a large United States gold producer has proved that Joy HL-3 loaders can be consistently average, less than $0.025 per ton mucked. This cost represents repair labor and parts over a two year

Jan 1, 1952

By M. H. De Hora

(Butte Meeting, August, 1913.) IN giving my opinion of the importance of Colombia as a field for investment for those interested' in mining for the precious metals, I must begin by quoting Sir Clement Markham, who, in one of his presidential addresses to the Royal Geographical Society of Great Britain, called the attention of its members to the fact that " although Colombia is the least known and least developed of the South American republics, it is far and away the richest mineral country of them all." This to American investors is extremely interesting, as the country is the most accessible of all the South American republics from the United States. .Almost all of the gold shipped by the Spaniards from Madre de Dios, now Colon, came from Colombia, and statistics from the Mint at Medellin, the capital of the Department of Antioquia, go to show that the . total production of the precious metals of Colombia, dating from the Spanish conquest in the fifteenth century to the present time, aggregates the enormous total of $700,000,000. Of this amount, nearly 70 per cent. represents gold obtained from the placers of the Republic, more than one-half of which came from the Department of Antioquia, the balance, being divided between the placers of the Choco and the rest of the Republic. The remaining 30 per cent. of the $700,000,000 represents the silver and gold obtained from the quartz mines, the silver greatly predominating. A glance at the map of Colombia shows the territory somewhat in the shape of an outspread human left hand extended palm downwards on the paper, with the wrist adjoining the Republic of Ecuador, the bones of the hand, fingers, and thumb representing the divisions of the great Andean mountain chain known as the Cordilleras of Colombia. The first finger represents the Eastern Cordillera, with the thumb as the extension to the Nevada de Santa Maria, forming

Jan 7, 1913