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By W. H. Bassett

THE ease and value of the application of spectrum analysis to industrial chemistry appears to be appreciated in few of the large works laboratories of this country. For 8 years, this analysis has been of great value to the authors in both analytical and metallurgical work. To the analyst the complete qualitative analysis of an unknown alloy, revealed by a spectrogram, is a sure basis for the planning of the most direct and rapid method of attack. As the determination of each element proceeds, the purity of precipitates may be checked as often as desired. The spectrograph proves invaluable in the recognition of impurities, the separation of which would entail a lengthy and difficult procedure, or when the weight of an unknown is less than is necessary to complete the desired determinations. A few hundredths of a gram will usually suffice for spectrographic analysis. In the separation of the rarer elements, the spectrograph will show, with precision, the point where each step has been successful. In zinc of certain classes, indium, gallium, and germanium have been isolated in this way; the presence of antimony in lake coppers has been proved; and bismuth has been detected in zinc and in alloys where the presence of a few thousandths of a per cent. would be harmful. An antimony precipitate in a delicate determination may contain a considerable proportion of tin or arsenic, both of which will be revealed. The spectrograph is consequently important to the metallurgist as well as to the analyst.

Jan 2, 1922

By C. L. Berrien

BEFORE the present company was formed, in 1916, each group of mines comprising the old organizations made its detailed daily and monthly mine cost records along the lines used before the consolidation; that is, there was no attempt made to standardize and compare the stope costs of all mines. The general cost sheets for all mines, however, were standardized, and cumulative labor cost sheets were compiled in the general superintendent's office. At most of the mines, a daily record or distribution sheet for each working place was kept, showing the number of men, hours of drilling, hours of timbering, hours of tramming, cars of ore, cars of waste, sticks of powder and feet of fuse. This information was kept by each shift boss and entered on the distribution sheet by him or, at some mines, by a tram boss. The superintendent solved his own problems under the direction of the general superintendent, but without coming in touch with other superintendents, either through records or general conferences. Probably 95 per cent. of the stopes were square-set worked by day's pay; there were some back-filling and shrinkage stopes. Many of the development places, such as shaft sinking, station cutting, drifting and raises had always been run by contract. These contracts were given, for no definite period, at so much per linear foot and were measured monthly, or when completed; the men being paid monthly. In some cases, fairness to the employee, was not maintained. On the whole, there was no standardization. There were no stope contracts, because of the objections of the Western Federation of Miners to general contracting in the mines.

Jan 2, 1922

By C. D. Woodward

THE Anaconda Copper Mining Co. purchases 25,000 kw. of electric power for its mining operations at Butte Mont. This power is delivered, over duplicate feeders, in the form of 60-cycle, 2400-volt, three-phase current, to five compressor plants, where most of the energy is used for driving air compressors. At the compressor plants are located the switching apparatus for controlling the 2400-volt power and distributing it to the various mines. At these points, also, there are a number of motor-generator sets for converting the alternating current to 275-volt. direct current for the haulage systems. Pole lines convey the power from the compressor plants to outdoor transformer substations at most of the mines. When it is not economical to distribute the power at the lower voltages in the mines, transformers and motor-generator sets are placed at strategic points .underground. All power is purchased on a maximum-demand basis, therefore there is installed at one of the compressor plants an eight-element totalizing graphic wattmeter. This instrument records simultaneously the value of all power taken at the numerous points of delivery, which not only eliminates the diversity factor but permits load dispatching between compressor and pumping plants, and thus materially reduces the maximum demand from the power system. As most of the mine hoisting is done, by 90-lb. compressed-air winding engines, the air-compressor equipment for the winding engines and mining operations is quite extensive. The standard air compressor has a rating of 7500 cu. ft. per min. of free air, and most of the compressors are directly connected to synchronous motors. The synchronous motors are designed for 80 per cent. leading power factor, thus facilitating power-factor correction of total mine load. Consequently by cooperation with the power company, the voltage of the power received at the compressor plants is constant.

Jan 2, 1922

By Harold Roast

THE object of this investigation was to compare the arsenical antimony-lead alloy with some of the regular bearing-metal alloys. With this end in view, the following tests were made: 1. Chemical analyses to show the composition. 2. Thermal analyses. 3. Macroscopic examination of fractures. 4. Microscopic examination. 5. Tensile tests. 6. Crushing tests. 7. Scleroscope tests. 8. Brinell tests, at temperatures from 80° to 400° F. Tests 3 to 8 were conducted on both sand-cast and chill-cast specimens. For the purposes of this paper the alloys have been numbered from 1 to 6; their composition is as follows: LEAD, ANTIMONY, TIN, COPPER, ARSENIC, NUMBER PER CENT. PER CENT. PER CENT. PER CENT. PER CENT. 1 82.64 12.95 4.40 0.01 none 2 27.54 9.94 59.87 2.65 none 3 77.65 20.75 none 0.13 1.47 4 82.95 16.85 none 0.20 none 5 83.78 15.35 none 0.05 0.82 6 0.15 7.87 84.13 7.85 none The analysis, in the case of the antimony, was made by solution in sulfuric acid and titrated with permanganate. For tin, the ferric-chloride method was used; for copper, the alkaline separations, and the thiocyanate methods; for arsenic, volatilization of arsenic and titration with iodine. The lead, with the exception of alloy 6, was taken by difference.

Jan 2, 1922

By David Kellogg

THE electrodeposition of iron has been practiced for many years. The earlier work along this line was directed toward the preparation of pure metal, but later applications were the production of thin adherent coatings as used in the electrotyping of Russian banknotes in 1860. A historical discussion of this subject, however, would require too much space and would be inconclusive. Much has been written on the subject but no two experimenters use the same methods or materials. During the war, the British army repair, shops developed a method for building up worn parts of automotive machinery, aero engines, etc., using the cold surfate . bath and low-current density method.1 The method has been used successfully in commercial work for the production of about 6000 repaired parts, therefore experiments along the same lines have since been made at the Westinghouse research laboratory. The apparatus used was essentially that described in the article mentioned except that the current -used for cleaning was obtained from a 3/4-kw. 60-volt, house-lighting generator, direct connected to a 2-h.p., 870-r.p.m., 440-volt, three-phase, type CS induction motor; while the plating current was taken from the storage batteries at any desired voltage. The anodes were made from 0.036 in. (0.9 mm.) Armco iron made into cylinders 5 in. (127 mm.) long by 8 in. (203 mm.) in diameter with a disk of 1/8 -in. (3.17 mm.) micarta, having a 2 in. hole in the center fitted at each end of the cylinder for stirring. The anodes were hung on a wooden rocker frame driven by a wooden connecting I rod directly connected to a small reducing gear, such as is sold by most of the apparatus supply firms; 3 gal. stoneware crocks were used as containers. The solution used by Thomas, 75 gm. of the crystallized ferrous ammonium sulfate per liter, was tried, using the current density recommended by him; namely, 0.33 amp. per sq. dm. Under these conditions the deposit on a ½ -in.

Jan 2, 1922

By R. T. Murrill

BLOCK-SIGNAL and dispatching systems have been in use on surface railways for years, but only recently have they been applied to underground mining conditions. Formerly, all ore was moved underground by hand tramming; the surface openings were numerous and fairly close to the ore being mined. As the tramming distances increased, animals were brought into service. Then came the locomotive, and since its introduction, haulage lines have gradually been reduced to fewer levels and to fewer surface openings until more than 20,000 tons are being handled daily on one level in some of the larger mines. Under the, se conditions many trains must use the same-tracks, and signal systems have become necessary. In some cases it has been found more advantageous to use train dispatchers than to install signal devices. The dispatcher may be simply a flagman at a busy point or he may have mechanical signals to operate at more distant points. At the inspiration mine, Inspira-tion, Ariz., the station is equipped with a switch-con-trol board, whereby the dispatcher throws electrically all track switches in a certain block, which gives him complete control over all trains passing through that block. In a few cases, dispatcher stations are established in connection with a signal system.

Jan 2, 1922

By D. Harrington

EFFICIENT ventilation of metal mines consists in having such complete control of air currents that. there is always supplied at places where men work sufficient moving air to allow working at maximum capacity without injury to health; and in case of underground fire or of surface fire in the vicinity of mine openings, underground air currents may be quickly reversed if desired, or air may be sent into or excluded from any region and fire fumes confined to only part of the mine workings, instead of penetrating practically the entire mine. Health and safety of workers in mines as well as proper safeguarding and operating efficiency of mining properties are so intimately associated with proper ventilation of mines (both coal and metal) that they are inseparable, yet mine ventilation is only too frequently neglected, especially in metal mines. The metalliferous operator, generally not confronted with inflammable gas or explosive dust which so frequently force ventilation of coal mines, usually disregards air supply altogether except such as may be obtained from compressed air; and generally, even when attention is given to metal-mine ventilation, the air currents rarely are found where they are needed, namely, the working places, especially the working faces. After several years' study of miners' consumption, the writer is. convinced that long continued breathing of air impregnated with large quantities of any kind of finely divided dust, such as is found in a large number of the working places of our mines, will ultimately produce some respiratory disease, whether it be asthma, bronchitis, or phthisis; and the progress of these diseases is hastened. if there are also present high temperatures, high humidities, or harmful gases or if there is present (and allowed to remain to be breathed) large quantities of the finely divided dust when air temperatures are low, hence favorable to maximum performance of work with accompanied maximum breathing into the respiratory passages of the harmful material. It is generally accepted

Jan 2, 1922

By H. M. Ziesemer

PRIOR to 1909 that mountain of porphyry, known as. Sacramento Hill, had remained hardly touched but had always aroused suspicions as to the presence of ore within.. During that year, exploratory work was started by underground methods; drifting and raising continued until 1913. It was proved that a mineralized zone existed, the limits of which had not been determined; so, because of the lower costs of exploratory work and the greater desirability of vertical sections, it was decided to prove the extent of the ore zone by churn drills. Drilling continued until the year 1917, when it seemed almost certain that the horizontal limits of the orebodies had been determined. Ore continued in depth in one direction beyond a point where it was economical to explore by churn drilling; this extension is still being developed by underground methods. The irregularities of the boundaries of the ore zones, together with the variable grades of ore encountered, made it necessary to drill on the corners of 100-ft. squares. Two ore zones were proved, known as the East and West Orebodies. The Sacramento Hill porphyry stock intruded into the Dividend fault. The fault ran roughly east and west with a dip to the south, having pre-Cambrian schists on the north against Paleozoic limestone on, the south. This intrusion was accompanied by a silica breccia on the south periphery, along the limestone contact side. The ore lay in the silica breccia and in the porphyry, some distance from the breccia. No ore was found in the heart of the porphyry mass on the north side, along the schist contact. The West Orebody is elliptic in shape, having a major axis of 1200 ft. (366 m.) and a minor axis of 800 ft. (244 m.); these diminish with depth until, at 300. ft., the axes are 500 ft. and 300 ft., respectively. The ore consists of chalcocite, some bornite, chalcopyrite, and considerable pyrite in a silicious gangue. About 30 per cent. of the copper is caused by

Jan 2, 1922

By A. S. Richardson

THE conditions that make necessary the mechanical ventilation of the Butte mines of the Anaconda Copper Mining Co. are due to a number of causes, all of which are incidental to the depth at which mining operations are now carried on. The main object to be accomplished, of course, is the reduction of the temperature and humidity of the air in the working places. Ventilation fans, both surface and underground, have been used for many years, but increasing depth has made the problem much more difficult. Further improvement in both ventilation equipment and methods, therefore, became necessary; and it is the purpose of this paper to describe the work planned and done under the improvement program. The mines of the district have been frequently described in various technical publications, so a description is unnecessary here. From a mine-ventilation viewpoint, compared with coal-mine ventilation systems, the problem is complicated by the fact that the workings to be ventilated are situated on a large number of steeply dipping veins which frequently intersect and are faulted, and also by the fact that the extent, or existence, of orebodies is not definitely known in advance of actual development work. For these reasons ventilation work cannot be planned in advance of actual operations, nor can such regular systems of ventilation as are used in working the more uniform and continuous bodies of coal be developed. When operations are conducted at a normal rate, about 10,000 miners are employed on two shifts, so that about 5000 men will be underground at one time. But as ventilation is necessary to reduce high temperature and humidity due, mainly, to natural causes, the quantity of air per man per minute is not a governing consideration in determining ventilation requirements. Most important among the numerous sources of heat and humidity in the mines are : heat generated during decay of mine timber; heat and humidity given off by mine rock and water; heat generated by oxidation of sulfide minerals; heat given off by electrical equipment; heat generated by mine fires (in certain localities).

Jan 2, 1922

By Sir John Cadman

IN THE changed circumstances which now confront the world, an international open-door policy is the only way to keep pace with the world's demand for oil. You may rest assured that as far as the British Empire is concerned, American capital for the develop-ment of oil resources is welcome, and little obstruction will be found in the way to permit the use of foreign capital in the group of countries which constitute the British Empire. In the war days we worked in close cooperation and harmony, but in disbandment of the Petroleum War Service Committee, when the war ended, I feel that it left its task unfinished. In the wake of war there appeared a ghost of war-time conditions in the form of belief that Great Britain was straining to corner the petroleum resources of the world. I am certain that if the war-service committee had continued its work in the period of reconstruction the real story would be known and this sinister ghost would have long since vanished before the truth.

Jan 2, 1922

By C. W. Goodale

THE motives behind the organization of the Bureau of Safety were twofold. First, there was the policy of the company toward its employees, which was one of fairness and consideration for their welfare and which entails the prevention of injuries; second, in order to prevent injuries, a study of their causes was essential, and this study could be made only by a thorough systematic classification of accidents, which required a special department to form and carry out the plans. The Bureau of Safety was organized to begin operation Jan. 1, 1914, but practically all of the first year was spent in collecting data, making plans, etc. This department is semi-independent of others and reports directly to the president and general manager. It consists of the president of the company and the managers of the following departments: Mines, Washoe Reduction Works, Great Falls Reduction Works, Coal Department, Lumber Department, B. A. & P. railway, and the chairman of the Bureau of Safety. Working under this group is the General Safety Committee consisting of the manager of mines, as chairman, the general superintendent, two assistant general superintendents, and the heads of the following departments: mechanical, geological, purchasing, sampling works, and framing plant, as well as the safety engineer. Operating under the General Safety Committee are the group safety committees, consisting of the Anaconda group of mines, Boston & Montana group of mines, zinc group of mines,.Washoe reduction works at Anaconda, B. & M. reduction works at Great Falls, coal department, lumber department and the B. A. & P. railway. Each of these group safety committees was in charge of the superintendent or manager of the group represented and the committee consisted of the foremen of the mines or works that the committee served, as well as the safety engineer.

Jan 2, 1922

By Oliver Bowles

SUPERFLUOUS varieties and standards which are meriting the critical scrutiny of the manufactur-ing industry have a special significance in the non-metallic mining industries, where, many of the final or intermediate products are manufactured at the mine or quarry. Such processes of manufacture must be considered an integral part of mining in its broader sense. Improvements may be either elimination or standardization. - The chief requirement of elimi-nation is an agreement between consumers and pro-ducers based on facts deduced from: statistical data. Standardization is much, more complex. Standards .may be established only when a very; thorough knowledge has been gained of the physical and chemical properties of the products, and the requirements of consumers. The activities of the Bureau of Standards are. largely directed toward such determinations. Paving-brick manufacturers, together with highway engineers, representatives of certain engineering socie-ties, and Government bureaus, have agreed that of the 66 styles of paving brick on the market 11 only are, essential and 55 are superfluous. Steps have been taken to reduce the output of -all but the 11 standard types. It is customary for manufacturers of structural slate to prepare it in sizes specified by builders and architects. Thus the material cannot be manufactured in advance and the result is irregular activity of mills, delays in filling orders, etc. To improve this condition, the Structural Slate Co. has issued a series of pamphlets giving complete specifications of structural slate for various purposes. Architects find it so much easier .to, order slate from these sheets that standard sizes are specified in preparing plans for new structures. Slate switchboards are usually manufactured after. the order has been received. One manufacturer claims that 80 per cent. of all switchboards are of standard sizes, and he keeps such sizes in stock. The facility with which orders may be filled from stock, and the improved quality of seasoned switchboards, will undoubtedly influence electrical, companies toward a more uniform standardization in size. Simplicity, could be further attained by the elimination of minor irregularities in .style; for example, in the beveled. edges.

Jan 2, 1922

THE gold medal of the Mining and Metallurgical Society of America was presented, on Jan. 10, 1922, to Charles Warren Goodale, "for signal services in furthering the welfare and safety of workers in the mining and metallurigical industries of America." The presentation was made by Dr. J. E. Spurr, presi-dent of the Society for the year 1921, at the annual meeting held in New York City. Dr. Van H. Manning, formerly director of the U. S. Bureau of Mines, made the first address. Toward the close of his brief speech, he said, "It has happily been suggested, ?Let us balance our praise of war heroes by pausing to honor a hero of peace.' We have with us tonight a man who has been a leader and inspirer of thousands of his contemporaries. . . . His zeal in the great work of increasing the safety of men engaged in mining and metallurgical operations has become an obsession with him. . . . That lie has been success-ful is evidenced by the great work, of which I have personal and intimate knowledge, done by him in con-nection with the Anaconda Copper Mining Co. and its subsidiaries." Dr. J. F. Kemp gave a brief sketch of Mr. Goodale's career, in the course of which he said, in speaking of .the consolidation of the Boston and Montana, the Anaconda, and smaller companies, "at the same time electric current was introduced for haulage in the mines and on the surface for the running of air compressors and the hoisting of the cage. . . . We can see that there was great danger to the miner and that safety first became a very important feature of the work. . . .

Jan 2, 1922

By Cornelius Kelley

I HAVE been asked to discuss "What Can be Done to Revive the Mining Industry," particularly from the standpoint of the copper industry. It is impossible to consider this problem, if in fact there can be one, from an isolated position. The mining industry is but a part, although a very important one, of that exceedingly complicated machine characterized as commerce, which comprises within its operation and functions the-multitudinous activities that, combined, make up the sum total of the production, manufacture, distribution, sale and utilization of goods and products resulting from the agrarian, industrial and commercial effort of mankind. We survey a world today with its disturbed mass of humanity permeated with discontent, passions loosened by brutal combat not yet brought under control, class hatreds aroused, national prejudices in a state of stimu-lated excitement, governments for the most part enfeebled, some destroyed to their foundations, with fragile structures raised in place of those that seemed enduring, and which have disappeared. A burden of indebtedness incurred in defiance of all economic law exists, to meet the exactions of which, levies of taxation that constitute a grievous burden upon effort and industry are exacted by the needs of those nations that are most favored, while printing presses are busy manufacturing currency that either has, or approaches, a negative value among those less favored. This picture, while not pleasant, is one that should be looked at squarely and carefully appraised in estimating the immediate future. For four years the world marshalled, and exerted without stint, its combined endurance, vitality and resource in an effort of destruction, which violated no less the orderly working of physical and economic laws than it did the conventions of social and civic relations. To have imagined that without travail the orderly processes that governed the relations of mankind could at once be reestablished and begin functioning, was, as has been demonstrated, fallacious; perhaps no more so than the error that is committed today by those opportunists who fail to take cogni-zance of basic conditions which must be remedied be-fore the world can resume its progress to a universally prosperous and satisfactory condition. Please do not gather from this somewhat unpleasant recital that I regard the future with gloomy foreboding or entertain pessimistic doubts, for, emphatically, I do not.

Jan 2, 1922

By H. M. Wolflin

SOMEWHAT more than a year ago the writer collected some extensive notes on metal-mine fires and a paper on metal-mine fire prevention and fighting, a summary of these notes, was hastily pre-pared, with the assistance of G. Chester Brown, chief mining engineer, Industrial Accident Commission for the National Safety Council meeting. This summary, which is admittedly incomplete, is submitted in the hope that it will evoke some discussion that may result in a reduction in metal-mine fire hazard along the line. To accomplish such a reduction does not require the application of complicated scien-tific data. The use of just a little care, a small amount of thoughtfulness and a bit of common sense will work wonders. UNDERGROUND FIRE FIGHTING There may be some interest in a short list of con-clusions of a rather general nature that were reached in connection with some recent mine-fire fighting opera-tions. No effort has been made to cover the field; the items have been jotted down loosely, and very hastily, in the order in which they occurred to the writer. Originality is claimed for, only a few of them. 1. Temperature readings and analyses of mine-air samples, systematically taken, are invaluable aids to effective metal-mine fire fighting and recovery opera-tions. The analysis of the return-air samples fre-quently gives a surprisingly accurate indication of conditions existing underground. 2. Employees must be thoroughly trained in the use, of mine rescue apparatus, because a relatively slight difference in the amount of training makes a vast difference in the amount of work they can per-form under oxygen. In general, slender, wiry men make better apparatus men than those of heavy, more muscular physique, although there are frequent excep-tions to any such general statement. 3: Surprisingly high temperatures, up to 165° F. or 170° F. pan be endured for short periods by wearers of mine rescue apparatus if the air is dry, but lower temperatures, 135° to 140° F. are almost unbearable if the air is very moist.

Jan 2, 1922

By W. M. Weigel

THE rapid advance, during recent years, in the manufacture of articles that have been in common use for generations and the development of new materials entering into appliances and devices unheard of fifty years ago, have created a demand for some of the more common non-metallic minerals. To supply this demand there has quietly developed a branch of the mining industry of which little is known by most mining engineers the mineral-filler industry. In this paper, and generally in the trade, the term mineral filler is applied to a mineral used, in its natural state after mechanical preparation only (such as. grinding, milling and washing), without undergoing any chemical change and without exerting any chemical action on the substance with which it is incorporated. The consumption of mineral fillers is confined chiefly to large manufacturing centers in the eastern and northern states. Where available, materials originating near the place of consumption are used, as most fillers bring a comparatively low price and, frequently, the freight may equal the cost of the finished filler at the mine. The southern states have abundant deposits of non-metallic minerals suitable for fillers, which supply the manufacturing industries in adjacent states. Many of these deposits are equal to, or superior, in quality to those mined in the north, but they can not compete with them because of the freight rates. The mineral-filler industry has felt the present depression, but it has suffered less than most mining industries for as a rule the mills are simple, the overhead expenses are low, and the labor is entirely local and can revert to farm work when the plant closes down. Many other deposits in the southern district will undoubtedly be developed when business. revives and freight rates are adjusted.

Jan 2, 1922

By Colin Rae

THE absence of paraffin and other oil hydrocarbons in the soil, although they are concentrated in extensive deposits in some localities, the common distribution of plant remains through many formations that .are not productive for oil, and many other factors, seem to indicate the existence of an intermediate organic compound between the complex plant compounds and the petroleum hydrocarbons; and much evidence points to the humus acids or associated organic compounds, which are probably collected by surface waters and concentrated in certain areas by means of precipitation by electrolytes, which would be contained in sea water or possibly in various inland seas or lakes. PRESENT-DAY EVIDENCE There are many present-day evidences of the association of petroleum with humus acids. Binney, in 1912, made observations without explanations on the peat mosses of Down Holland, England, where he found petroleum being formed by decomposition, in the presence of an infiltration of sea water. The analysis of a typical peat will show its relationship to the humus acids under consideration. SAMPLE 'No. 1, SAMPLE NO. 2, PER CENT. PER CENT. Water : 20.0 29.5 Ash 3.0 3.05 Fiber 47.0 54.95 Humus acids 30:0 12.50 J. D. Haseman and others have noted the association of asphalt and hydrocarbons with the swampy, boggy areas, particularly adjacent to the sea.

Jan 2, 1922

By Donald Gilbert

PRIOR to July, 1919, the sampler at each mine of the Anaconda Copper Mining Co. in Butte did his work in his own way and was responsible to the mine foreman only. At that time, the sampling at all the company's Butte mines was placed in charge of a member of the geological department and stand-ardized methods of doing the work, were adopted. These standards were incorporated in a set of instruc-tions accompanied by blueprints representing typical conditions. The main features of the instructions were as follows: All samples to be cut at breast height and horizontally, regardless of dip of vein, and the horizontal width reported. A single sample to include not more than a 5-ft. width of the breast and to weigh not less than 4 lb. for this width. Where the vein is made up of two or more streaks of different hardness or mineral content, each streak is to be sampled sepa-rately and the average value of the combined width figured. If two streaks of ore are separated by a streak of waste, which is not sampled, in obtaining the average value of the breast the waste must be figured in with a zero assay. Drifts to be sampled in the breast after each round. Raises to be sampled for each floor raised. Each end to be sampled separately and the average width and value of the two ends to be used as the average of the floor. All veins cross-cut to be sampled along the side of the cross-cut, at breast height and horizontally. Where the vein strikes at an acute angle to the line of the cross-cut, the width of sample must be corrected to show the horizontal width at right angles to the line of strike of the vein. Rill stopes must be sampled across the full mining width. In square-set stopes, each set must be sampled separately along the line of the caps. Waste portions of the vein which are mined for filling must not be included in the sample.

Jan 2, 1922

By Masayuki Otagawa

THE mining methods adopted in Japanese mines are less known to the mining world than those of other countries, owing to the geographical remoteness, but they present many features of interest to mining engineers. The Ashio copper mine is at the village of Ashio, in Tochigiken, about 109 mi. (175 km.) from Tokyo by the Imperial Government railroad. The area of the concession owned by the Furukawa Mining Co. is 5000 acres (5023 ha.). The mine was formerly divided into three, viz.. Honzan, Kotaki, and Tsudo, which are distant 3 mi. (4.8 km.) from each other as shown in Fig. 1. However, in 1914, when the writer was general manager, the three mining plants were amalgamated into one with the result of simplifying the working projects and increasing the operat-ing efficiency. The mine was visited-by the Institute party in November, 1911, when Mr. K. Inouye was the general manager. Shortly afterward, the writer was appointed manager, and, in 1915, he was succeeded by Dr. K. Asano. At the end of 1917, Mr. K. Kibe became general manager and, after two years, was succeeded by the present manager, Mr. I. Sugimoto-. For some time Dr. J. Kojima was acting general manager. It is needless to say that the gentlemen mentioned are all members of the Institute, as is also Baron T. Furukawa, president of the company. Since the discovery of the enormous masses, called "kajika" or "bullhead" deposits; which the writer has described elsewhere,' the mining methods have been varied to meet the different conditions presented by these deposits.

Jan 2, 1922

By R. M. Raymond

THE Mining Section of The National Safety Council recently sent out a questionnaire to operators, regarding the class of rope used, specifications required or obtained, factors of safety observed, methods of fastening ropes, lubrication, inspection, and points observed when rope is to be discarded. The answers received from this questionnaire, largely from metal mines, give interesting information, from which recommendations for safety practice on hoisting ropes are drawn. DEPTH OF MINE The depth in the majority of cases noted is from 1000 ft. to 1500 ft. (304 to 457 m.) and records come from a number hoisting from depths of 2000 to 3000 ft. Hoisting is generally done in balance, with a few companies using counterweights. Seldom, more than two shifts are occupied in hoisting. A number of large operators limit the shift for engineers to 6 hr. A few of the larger operators have separate hoists for men and supplies, with a higher class rope for men. The range of loads varies from 7 to 17 tons and greater in a few cases, with a balanced weight of 4 to 7 tons.

Jan 2, 1922