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H. W. Turner, San Francisco, Cal. (communication to the Secretary*): This excellent paper apparently represents the results of extensive observation and experience among the mines of the Mother-Lode, but I strongly question its relegation of the dioritic intrusions to the period of fissuring and ore-deposition. The dioritic rocks referred to are evidently those areas represented by Ransome in the Mother-Lode folio1 as meta-diorites, and, as he says, are merely basic facies of the great granodiorite batholite of the Sierra Nevada. If followed downward I venture to predict that these meta-diorite areas would be found to connect with the great batholite, and to be in fact mere apophyses of it. I see no reason for supposing that these apophyses were intruded into the Mother-Lode slates at a period later than the intrusion of the granodiorite in general. The period of fissuring was subsequent to this intrusion; the basic granodiorite or quartz-diorite areas of the foot-hill region are themselves fissured extensively; and the fissures were filled with quartz, apparently during the same general period of the formation of the Mother-Lode veins. Prichard and Ransome2 both refer to the deposition of quartz in the same lode at different periods resulting from a reopening of the fissures. Some time since, I saw in the stopes of the

Jan 1, 1904

By O. P. Dolph

SPANIARDS were probably the first to mine the rich surface ore in the veins cutting the rhyolite capping that outcrops on the hills of La Mazata, oil the Allyones side of the Magdalena valley in Jalisco, Mexico, although the name comes from a word of Indian origin meaning "deer". The camp is about 12 km. west of Magdalena, a town on the Southern Pacific Railroad, and about 17 km. north of Etzatlán, on the Mexican National Railroad, at an elevation of 4500 ft. The climate is subtropical with no extremes of heat or cold, the rainy season beginning in June and ending in October.

Jan 1, 1938

By Tkeoclore Marvi

IT is singular that an industry quite the antithesis of flying should record tremendous strides in the utilization of aviation through- out the entire depression period, .while in the same years private interests lagged and airplatie manufacturing plants closed to such an extent that he purchase of new planes of certain types was practically impossible. Though receiving little notice from aviation publications and national associations, this use of the airplane progressed by sheer merit. It saved money, conserved energies, and made minutes in the air the equal of weeks on foot or water. The advent of aviation into mining and petroleum operations dates back many years, yet it \vas not until the depression that this new facility of the mineral industry was put on its proper economic basis. There, by its possibilities for saving effort, time, and money, it takes its place equally with other great technical advances in nietl

Jan 1, 1934

By Russell B. Cornell, William B. Plank

AT the close of the academic year 1940-'41 the largest number of students ever recorded received their first or bachelor degree in the mineral technology schools of the United States. The total of men thus prepared to enter their professional careers in the mineral industries was 1601, a number nearly 12 per cent larger than two years ago and nearly 75 per cent larger than four years ago. Notwithstanding this increase in the number of graduates and as had been predicted in the preliminary report in February, there was a slight decrease in the total student population of the schools in both the United States and Canada. During the college year 1940-'41, 9133 students were enrolled in the 54 schools of the United States and 764 in six of the seven schools of Canada.

Jan 1, 1941

By Carl Scholz

DURING November And December, 1907, Four Serious Mine-explosions Occurred In The Appalachian Coal-Field, Which Resulted In The Loss Of Nearly A Thousand Lives And Caused An Enormous . Damage To Property. These Accidents Attracted More Than The Usual Attention; Coal-Trade And Engineering Papers Contained Many Comments And Suggestions On The Cause And Prevention Of Accidents; The Daily Press In Many Instances Condemned The Coal-Operators And Charged These Accidents To Their Negligence, Or Their Anxiety To Make Money Without Adopting Precautionary Measures. Immediately After Each Accident The Respective State ..Authorities Ordered Close Investigations To Be Made, With The View Of Establishing The Cause And Suggesting Remedies To Prevent Recurrence. Representatives Of The Technologic Branch Of The U. S. Geological Survey, To Whom The Investigation Of Mine-Accidents Had Recently Been Delegated By The Secretary Of The Interior,. Visited The Mines And Co-Operated With The Local Authorities In Their Determinations. It May Be Safe To Say Here That An Investigation Of A Mine After An Explosion Has Occurred Discloses But Little, Because. The Causes Have Been Removed And Conditions Have Been Entirely Changed. On Jan. 8, 1905, The Coal-Operators Of West Virginia Organized An Association At Washington For The Purpose Of Making Extensive Investigations, And Sufficient Funds Were Pledged To Carry Out This Work. At This Organization Meeting, The Representatives Of The Geological Survey Present Had No Suggestions To Offer As To The Cause Of These Accidents. An Examination Of The Various Reports Concerning These Accidents Indicates That The Explosions Were Caused By The Ignition Of Gas Or Dust; They Show The Point Of Origin And The Direction In Which The Force Was Expended, And Give A Detailed Description Of The Damage Done. Very Little Has Been Said As To What

Jan 7, 1908

By Frank Rieber

EVERYONE is familiar with the story of the poor Indian and his leaking tepee. He couldn't repair the leak while it was raining, naturally. And when it wasn't raining, where was the incentive? Even if this traditional Indian was apochryphal, his counterparts are certainly alive today, and operating on a world-wide scale. - A recent issue of the Wall Street Journal, for example, carried an impassioned letter from an old cocoa planter, who wants the world to know why the price of cocoa has gone skyrocketing. For years, he says, British and American interests have bought cocoa at the cheapest possible price and, incidentally, from growers willing to sell at that price. Between them, they didn't put enough money back into the business, either to fight disease in the cocoa groves or to plant new cocoa trees. Until new trees are planted and come into bearing, we will be paying exorbitant prices for our cocoa, and getting less of it.

Jan 1, 1948

By George S. Rice

GROUND movement from mining, whether it be for coal, metal, industrial minerals, or .oil, will always present many difficult problems. These are especially serious when valuable surface improvements may be badly damaged. The mine itself, if mining methods are not suitable to the formation, is subject to heavy falls of the main roof in the working places; and with certain structural conditions the movements may cause in coal mines disastrous bumps and outbursts of gas, and in deep metal mines rock bursts. In open-cut work rock and earth slides may result. Absolute prevention of ground movement from mining is impossible unless large pillars are left unmined,

Jan 1, 1937

By C. H. White

Discussion of a Paper by Mr. C. H. White, read at the Atlantic City Meeting, February, 1904. (Annual Meeting, February, 1005.) ARTHUR JARMAN, Sydney, New South Wales, Australia (communication to the Secretary*) : All designs for modern metal¬lurgical and chemical laboratories should provide each student's desk with a hood or cupboard for the removal of fumes, but I doubt the advisability of placing air-baths and similar apparatus close to the hot plate. It seems to me that unless the draft be exceptionally strong the fumes from ordinary wet assay work will corrode the iron-work of the fittings, in which case the baths would have to be removed to a general desk in order to lighten the work of the laboratory attendant. Since the laboratory described by Mr. White has been in use for two years, I should like to ask if any inconvenience has resulted from this corrosion. If not, it is certainly an important improvement to have the air-baths and similar apparatus placed -on the student's desk. The hoods described by Mr. White are supplied with a good draft by means of a fan, which gives them a great advantage over those at the metallurgical laboratory at the University, Sydney, in that no doors to the hood are needed. Each hood in the laboratory at Sydney is connected by a glazed earthenware drain-pipe with a vertical flue, 20 ft. high, having a lighted gas jet at the bottom to assist the draft. Although the draft is good, fumes of sulphuric acid cannot be drawn o$ unless the doors of the hood are lowered more than half-way. In my opinion, a fan should be used for the purpose of creating the draft, and glazed drain-tile should invariably be used for the flues because no other material possesses the same advantages. I know of a recent instance in which a laboratory containing

Mar 1, 1905

Arthur Jarman, Sydney, New South Wales, Australia (communication to the Secretary*):—All designs for modern metallurgical and chemical laboratories should provide each student's desk with a hood or cupboard for the removal of fumes, but I doubt the advisability of placing air-baths and similar apparatus close to the hot plate. It seems to me that unless the draft be exceptionally strong the fumes from ordinary wet assay work will corrode the iron-work of the fittings, in which case the baths would have to be removed to a general desk in order to lighten the work of the laboratory attendant. Since the laboratory described by Mr. White has been in use for two years, I should like to ask if any inconvenience has resulted from this corrosion. If not, it is certainly an important improvement to have the air-baths and similar apparatus placed on the student's desk. The hoods described by Mr. White are supplied with a good draft by means of a fan, which gives them a great advantage

Jan 1, 1905

By H. Merton Ruth

THE northern anthracite fields, although facing the same economic problems as the southern fields, are confronted with the additional problem of fast dwindling reserves of anthracite which can be conventionally and economically won. The mining of coal which remains in thin beds and the recovery of pillars from areas heretofore considered unrecoverable, either by reason of cost or surface restriction, pose problems of in- creasing importance to the economic life of the northern field operations. Successful approaches have Been made to this problem and other work is being performed that holds promise. There exists in the northern anthracite field millions of tons of solid coal, the recovery of which has not been too successful due to the following inherent operating faults: inability to concentrate producing areas; the great quantities of rock to be cut and handled, lack of consideration of proper sequence and speed of second mining, and the continued use of the mine car as the basis of payment. A mining system that has successfully solved these major problems has been in operation in the Scranton area since 1944. Over 1% million tons have been produced from veins varying from 3 to 4% ft thick by this method, which is known as the multiple panel-triangular system-conveyor mining.

Jan 1, 1950

By S. F. Shaw

In 1913, the Tiro General mine, at Charcas, S.L.P., Mexico, which had been making from 125 to 150 gal. of water per min., was allowed to become flooded, after all the pumps had been removed, and in 1918 the problem of unwatering it came up for solution. There are two vertical shafts, the Tiro General, 1390 ft., and the San Fernando, 1225 ft. in depth, with five connecting levels between them. The San Fernando shaft had been partly retimbered, while the Tiro General had been newly timbered from the collar to 1090 ft. in depth. It had been possible to place guides in only one compartment of the Tiro General, from the collar to the seventh or 850-ft. level, to which it was necessary to lower the water before station pumps could be installed. Soundings indicated that compartments in the Tiro General were open to 1082 and 428 ft., and in the San Fernando shaft to 471, 488, and 586 ft. The water had risen to a point 140 ft. below the collar of the Tiro General shaft.. Pumping Equipment The steam plant at the Tiro General shaft includes one 300-hp., one 150-hp. and one 100-hp. Erie City water-tube boiler, and two 160-hp. Heine water-tube boilers. All but one of these boilers were supposed to be in good shape, but it was soon discovered that six years of idleness in a climate that is foggy for several months of the year had left them in poor condition. The compressed-air plant comprises one Nordberg cross-compound compressor with piston displacement of approximately 2500 cu. ft.of free air compressed to 96 Ib. per sq. in.; and another Nordberg cross-compound with piston displacement of 1235 cu. ft. of free air, to the same pressure. The main pump station is on the seventh level where had been installed a Prescott pot-valve plunger pump with capacity of 200 gal. per min.; also a Gould triplex plunger pump with capacity of 135 gal. per min., driven by a 6 1/2 by 10 by 12 in. steam engine. From the lower levels, the water had been raised to the seventh level by small station pumps and sinking pumps.

Jan 1, 1920

By P. H. Dudley

A quarter of a century of service of steel rails on our oldest railroads, many of which have changed their standard sections three or four times, has furnished, and is furnishing, excellent opportunities to study their wear and behavior in the track. Such experience is valuable for the design of new sections, now required to meet the constantly increasing severity of railroad service. Before presenting the new sections for consideration, I will briefly call attention to some features of past experience. For convenience of study, rails may be separated according to their weight and height into four groups, viz.: 1. Hails weighing per yard from 52 to 60 pounds, and 34 to 4 inches high. 2. " " " " " 60 " 72 " " 46 to 44 " " 3. " " " " " 72 " 90 ' 41/8 to 5 4. " " " " " 85 or more " " over 5 " I Experience in this country is confined mainly to sections in groups Nos. 1, 2 and 3. • During the past few years I have had the opportunity to run my car over many thousands of miles of railway laid with the principal sections in use, and to obtain diagrams showing their deflections, permanent set, and, in a great measure, their manner of wear. The First Group.—The first steel rails imported, and those manufactured here, were light sections—included in the first group—and many of them, being rolled in rolls used for rolling iron sections, have pear-shaped heads, 2 3/8 to 2 1/2 inches wide, the base being heavy and from 1/4 to 1/2 inch narrower than the height. These rails were laid upon ties of solid timber, at least 8 inches face, spaced 2 feet from center to center. The moments of inertia of these rails were low, only ranging from 8 for the lightest sections to 12 for the heaviest. The deflections were, of course, great; but the quality of the metal was excellent. It was physically hard and

Jan 1, 1890

By AIME

Lewis E. Young, who will formally assume his duties as President of the AIME at the Annual Meeting in San Francisco in February 1949, was born in Topeka, Kansas, Oct. 1, 1878. Dr. Young received his engineering education at the Pennsylvania State College, where he received the degree of B.S. in Mining Engineering in 1900. In 1904 he received his E.M. degree from Iowa State College, and in 1915 a Ph.D. from the University of Illinois. In 1947, the University of Missouri conferred on Dr. Young honoris causa the degree of Doctor of Engineering. His active career began in the educational field as instructor at Iowa State College, and following that, as professor of mining at the Colorado School of Mines, 1903-1907. While he was at Golden he launched hi: career as consulting mining engineer for various Western companies. Leaving the Colorado School of Mines, Dr. Young returned to Missouri, serving the University of Missouri as director of the School of Mines and Metallurgy at Rolla, 1907-1914. Leaving Missouri he went to the University of Illinois as assistant professor of business organization, 1915-1918, during which period he wrote exhaustive treatises on mine subsidence and mine taxation, which won for him the degree of Ph.D. before mentioned.

Jan 1, 1949

By Chas. B. Dudley

A Discussion of the papers of Mr. James Gayley, on "The Application of the Dry-Air Blast to the Manufacture of Iron," and of Mr. J. E. Johnson, Jr., on "The Physical Action of the Blast-Furnace," by Messrs. Charles B. Dudley, R. W. Raymond, J. E. Johnson, Jr., William F. Mattes, James Gayley, David Baker, John Birkinbine and F. E. Bachman. (Washington Meeting, May, 1905.) CHAS. B. DUDLEY, Altoona, Pa.:-Pam not a blast-furnace man, and this always puts me it a disadvantage because I cannot go into the details of the making of iron and steel. I have not the experience, and have to take the statements of other people, so what I say regarding the subject of this paper is not in the sense of an expert. When I first heard of Mr. Gayley's experiments, I said to myself, " I fear they will result in failure, since, apparently, Mr. Gayley has forgotten one chemical fact, namely, that carbon does not combine with oxygen in the absence of water-vapor." This fact which was so astonishing when it was first brought out some years ago, and which those who are interested may find in the Journal of the Chemical Society of London, for 18S5, page 349, and 1894, page 611, led me to think that the drying of the air would be a mistake. The general subject of the influence of water-vapor on chemical action is a large one; but the special point in which we are for the moment interested, namely, the influence of water-vapor on the combustion of carbon, was especially treated by Mr. H. B. Baker, in the papers referred to. Apparently, however, as the result of Mr. Gayley's experiments, we are to learn that the amount of moisture still left in the desiccated air is sufficient to secure perfectly satis¬factory combustion. In thinking over Mr. Gayley's paper, it occurred to me that there were two alternatives, either of which might be chosen, namely, we might dry the air as Mr. Gayley does, or possibly we might, in a very much simpler way, simply saturate the air at a constant temperature, and thus get uniform working and

Sep 1, 1905

By J. C. Bradley

THE relation of annealing temperature to conductivity of copper wire has been determined. Conductivity hard was 98.26 per cent. After a 10-min. heating at 200°C. it was 98.69. By annealing 10 min. at 300° C. a large increase, to 100.93, occurred. Maximum conductivity, 101.15, was attained after a 500° C. anneal; thereafter it decreased to 100.53 after a 950° C. anneal. If copper is gassed the decrease is much more than this. Materials and Methods The work was done on high grade electrolytic copper, 99.942 per cent. copper plus silver, silver 0.0008 per cent. It was hot-rolled to >/4 in., then cold drawn to 0.080 in. The wire was cut into 25 5-ft. lengths and numbered 1 to 25 as cut. Four samples were tested hard. The others were wound into 5-in. diameter coils. For the 100° C. heating a coil was put into water, the water brought to boiling, and the wire kept at this temperature for 10 min. For the higher temperatures the coils were placed in envelopes of sheet copper, a little water added, and the envelopes sealed by folding over the edges twice, and hammering them together. This kept the air out very well. The envelope and wire 'were brought to the desired temperature; this was maintained for 10 min., then the whole was water-quenched.

Jan 1, 1927

By William P. Blake

The salt-beds at Salton, on the line of the Southern Pacific railway, in San Diego county, California, have been successfully worked for many years by the corporation known as the East Liverpool Salt Co., and the salt has been largely used upon the Pacific coast generally and in the interior. But the industry has lately been destroyed by the overflow from the Colorado river. The salt is dissolved, and the waves of the Salton sea now roll 50 ft. above the site of this once thriving and growing business. The salt-bed was evidently the residual accumulation from the waters of an ancient lake, which I have named Cahuilla, from the name by which a large part of the valley—the home of the Cahuilla tribe of Indians—is known. The deposit covered a comparatively small area in the lowest part of the valley, 280 R. or more below the sea-level. This depressed area is now generally known as the Colorado desert, but has a soil of wonderful fertility wherever water can be had on its surface. The deserted beaches, and the water-lines, only a few feet above tide-level, upon the rocks of the bordering mountains, as well as a great abundance of shells in the soil, all bear decisive testimony to the former occupation of the valley by water. The depression is topographically the northern end of the Gulf of California, from which it is now separated by the delta of the Colorado river, extending practically from the mouth of the Gila river across the valley to the coast mountains on the

Jan 1, 1908

By Jay J. Burns

TWO zinc concentrating mills are operated by the St. Joseph Lead Co. in St. Lawrence County, N. Y. The Edwards mill is operating at present only sixteen hours a day treating 400 tons daily. The metallurgy at Edwards presents no unusual problems therefore this discussion is mainly limited to the metallurgy of the Balmat ore. The Balmat mill has a capacity of 1,250 tons per day and the operating crew consists of three shift bosses each with five millmen per shift. Two crusher operators work on each of two shifts and one cleanup man on day shift. The repair crew is made up of a foreman and three repairmen, one of the repairmen being capable of taking over any operating job in the mill from shift boss down. Each millman is capable of handling the next job in line and several men in the yard crew are broken into handling the start-off job in the mill so that temporary shortages of men do not cause extensive overtime. Sphalerite, pyrite, and galena, the principal ore minerals, occur in a gangue of calcite, dolomite, and silicates, especially diopside, plus tremo-

Jan 1, 1947

A. Bement, Chicago,Ill. (communication to the Secretary*):— Formerly it was the general practice of engineers to designate coal that is free from moisture and ash as " combustible," notwithstandirig that it contains oxygen and nitrogen. The origin of this practice was more particularly due to the requirements in connection with boiler-testing, which demanded a consideration of that portion of the fuel which took part in the combuition-process because results based on a unit of either moist or dry coal were not comparable, since both moisture and ash were recognized as variable quantities. Thus, a pound of " combustible " became a standard of value, and was treated as a constant before employing measurements of heating-power and calculating therefrom the percentage of efficiency. The recognition of this term " combustible " was an advance to be credited to the engineer rather than to the chemist, because the latter, not having to do with the interpretation of analyses in practice outside the laboratory, usually saw no reason for reporting results in terms other than those of the moist-coal composition. Some years ago I needed a table of fuel-composition in terms of moist, dry, moisture-free and ash-free coal, and of the combustible components. This table required the use of the word combustible in its proper sense, for the purpose of designating carbon, hydrogen, and sulphur, instead of including these three elements with oxygen and nitrogen, to which aggregate the term combustible was formerly applied. To make such a tabulation involved either the use of the inconvenient and cumbersome term, "ash- and moisture-free coal," or of some other representative term, and for this purpose I adopted the expression pure coal, which is short, simple, convenient, and technically correct. It is also harmonious, because it agrees

Jan 1, 1909

By H. G. Doll

'This paper discusses a method and apparatus for determining the dip of formations traversed by a drill hole, by means of electrical measurements in the hole. The process consists in recording the Spontaneous Potentials present along three oriented generatrices in the hole. By comparison of the three curves thus obtained, after application of a correction factor to compensate for any deviations of the hole, the dip angle and the dip direction are determined. Excellent accuracy is obtained for dip angles over 10°. Because the method is simp1e and the apparatus rugged, the measurements are rapid and reliable; consequently, they can be made at all the levels that are of interest at any time after the well has been drilled. Mechanical cores are not needed to evaluate the dips. A convenient, time-saving procedure is to perform the dipmeter survey at the time the electrical log is taken, using for both operations the same cable and truck. Actual examples of results obtained in wells of the Gulf Coast area are given. Introduction The problem of determining the angle and direction of the dip of the strata traversed by a drill hole has practical interest, and sometimes vital importance, which need not be emphasized to the oil industry. The need for that type of information has existed ever since wells have been drilled. Certainly it has not subsided, in spite of the numerous inventions and improvements made in other fields of the art of drill-hole exploration. The few examples given in this paper are but illustrative of this fact. In the past, methods have been devised, and used, to solve this problem, but generally they have met with limited success, possibly because they failed more or less to answer the requirements of a modern age for fast yet accurate measurements. If accurate, the results were obtained at the cost of very tedious and lengthy operations. The new S. P.* dipmeter service offered to the oil industry is the result of exhaustive and in this particular field. In 1032 a dipmeter and electromagnetic teleclinom-eter service was made available. The apparatus employed then was of a rather delicate and costly construction, and the measurements had to be made with precautions sometimes difficult to secure on the rig. Although the information given by the electromagnetic dipmeter was limited to the direction of the dip, very interesting results were obtained in California, Trinidad, Venezuela, Rumania and, most notably, in the Netherlands East Indies.+ Apparatus The S. P. dipmeter surveys present none of the drawbacks mentioned above. The apparatus is rugged and free from constructional complications, therefore well adapted to field use. This, combined with the new, basically simple approach to the problem, explains the rapidity of execution of the measurements. The results are remarkably accurate and they are complete, giving the

Jan 1, 1946

By H. G. Doll

'This paper discusses a method and apparatus for determining the dip of formations traversed by a drill hole, by means of electrical measurements in the hole. The process consists in recording the Spontaneous Potentials present along three oriented generatrices in the hole. By comparison of the three curves thus obtained, after application of a correction factor to compensate for any deviations of the hole, the dip angle and the dip direction are determined. Excellent accuracy is obtained for dip angles over 10°. Because the method is simp1e and the apparatus rugged, the measurements are rapid and reliable; consequently, they can be made at all the levels that are of interest at any time after the well has been drilled. Mechanical cores are not needed to evaluate the dips. A convenient, time-saving procedure is to perform the dipmeter survey at the time the electrical log is taken, using for both operations the same cable and truck. Actual examples of results obtained in wells of the Gulf Coast area are given. Introduction The problem of determining the angle and direction of the dip of the strata traversed by a drill hole has practical interest, and sometimes vital importance, which need not be emphasized to the oil industry. The need for that type of information has existed ever since wells have been drilled. Certainly it has not subsided, in spite of the numerous inventions and improvements made in other fields of the art of drill-hole exploration. The few examples given in this paper are but illustrative of this fact. In the past, methods have been devised, and used, to solve this problem, but generally they have met with limited success, possibly because they failed more or less to answer the requirements of a modern age for fast yet accurate measurements. If accurate, the results were obtained at the cost of very tedious and lengthy operations. The new S. P.* dipmeter service offered to the oil industry is the result of exhaustive and in this particular field. In 1032 a dipmeter and electromagnetic teleclinom-eter service was made available. The apparatus employed then was of a rather delicate and costly construction, and the measurements had to be made with precautions sometimes difficult to secure on the rig. Although the information given by the electromagnetic dipmeter was limited to the direction of the dip, very interesting results were obtained in California, Trinidad, Venezuela, Rumania and, most notably, in the Netherlands East Indies.+ Apparatus The S. P. dipmeter surveys present none of the drawbacks mentioned above. The apparatus is rugged and free from constructional complications, therefore well adapted to field use. This, combined with the new, basically simple approach to the problem, explains the rapidity of execution of the measurements. The results are remarkably accurate and they are complete, giving the

Jan 1, 1946