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NAME AND OBJECT SEC. 1. This Institute is incorporated under the Membership Corporations law of the State of New York; its corporate name is American Institute of Mining and Metallurgical Engineers, Inc.; and its abbreviated title A. I. M. E. SEC. 2. The objects of this Institute, as set forth in its certificate of incorporation, are: "To promote the arts and sciences connected with the economic production of the useful minerals and metals, and the welfare of those employed in these industries by all lawful means; to hold meetings for social intercourse and the reading and discussion of professional papers, and to circulate by means of publications among its members the information thus obtained, and to establish and maintain a place for meeting of its members, and a hall for the reading of papers and delivery of addresses, and a library of books relating to subjects cognate to the sciences and arts of mining and metallurgy."

Jan 1, 1923

By A. Eilers

A number of the copper refineries in this country have lately separated some of the rarer metals from the slimes in the refinery tanks. One of these has furnished me the following table of recoveries from given amounts of blister. I publish this to show the proportions, to gold and silver and to each other, in which these rarer metals may be expected to occur in copper from certain localities. GarFIeld, Utah :—The blister copper comes principally from the Bingham porphyry copper mines. Steptoe, Nev. :—All the blister copper is produced from the Nevada Consolidated mines. (Also porphyry deposits.) Omaha, Neb. :—Blister copper comes principally from concentrated copper-lead mattes shipped from the different lead-silver plants of the Rocky Mountain region to the converters at the Omaha lead refinery. Mountain, Cal. :—Ores occur in connection with diorite (?).

Jan 1, 1914

By Walter M. Small

Austria produced approximately 800 cisterns of 10,000 kg. each (56,000 bbls.) of crude oil of a 0.9428 sp. gr. during 1935. Of this Gosting II well near Zistersdorf, owned by the Erdolproduktions-Gesellschaft m.b.H., produced 86 per cent of the total, averaging a little over 1.8 cisterns, or about 125 bbl., per day. Gosting IVa of the same company was put in production early in December and produced a total of about 70 cisterns (4900 bbl.). Gosting IV was a failure, but a directional hole drilled from the same derrick produced Gosting IVa. Gosting I, a well owned jointly by the company above mentioned and the Raky-Danubia, was deepened late in the year and made about 2800 bbl. of oil at the rate of 70 bbl. per day. Completions during the year were as follows: In the Gosting pool, Gosting IV and IVa, drilled with rotary tools, the latter producing from Sarmat at a depth of 934 meters (3065 ft.); Kronberg I, of European Gas & Electric Co. with cable tools in Flysch at a depth of 566 m. as a dry hole; in the Oberlaa gas pool, one cable-tool well of the same company at a depth of 266 m. as a dry hole and one Fauck-Haiek system well of the Vacuum Oil Co. at a depth of 483 m. as a dry hole; one rotary hole of the European Gas & Electric Co. at Enzersdorf a/d. Fischa plugged and abandoned in Sarmat after a blow out and gas eruption at a depth of 699.5 meters. The status of drilling wells at close of the year is as follows: In the Gosting pool, Erdol Bohr- und Verwertungs G.m.b.H., north of the producing area, was drilling with rotary at 990 m., Raky-Danubia is rigged up to deepen the old Windisch-Baumgarten hole, Rohoel-Gewin-nungs A.G. (Vacuum-Shell combination) rigging up rotary south of the production, and Steinberg-Naphta G.m.b.H. (Musil) was deepened with light rotary to 830 m.; at Enzersdorf a/d. Fischa, the European Gas & Electric Co. E-2 rotary-drilled hole stood at 1533 m. in Miocene waiting

Jan 1, 1936

By Walter M. Small

Austria produced approximately 800 cisterns of 10,000 kg. each (56,000 bbls.) of crude oil of a 0.9428 sp. gr. during 1935. Of this Gosting II well near Zistersdorf, owned by the Erdolproduktions-Gesellschaft m.b.H., produced 86 per cent of the total, averaging a little over 1.8 cisterns, or about 125 bbl., per day. Gosting IVa of the same company was put in production early in December and produced a total of about 70 cisterns (4900 bbl.). Gosting IV was a failure, but a directional hole drilled from the same derrick produced Gosting IVa. Gosting I, a well owned jointly by the company above mentioned and the Raky-Danubia, was deepened late in the year and made about 2800 bbl. of oil at the rate of 70 bbl. per day. Completions during the year were as follows: In the Gosting pool, Gosting IV and IVa, drilled with rotary tools, the latter producing from Sarmat at a depth of 934 meters (3065 ft.); Kronberg I, of European Gas & Electric Co. with cable tools in Flysch at a depth of 566 m. as a dry hole; in the Oberlaa gas pool, one cable-tool well of the same company at a depth of 266 m. as a dry hole and one Fauck-Haiek system well of the Vacuum Oil Co. at a depth of 483 m. as a dry hole; one rotary hole of the European Gas & Electric Co. at Enzersdorf a/d. Fischa plugged and abandoned in Sarmat after a blow out and gas eruption at a depth of 699.5 meters. The status of drilling wells at close of the year is as follows: In the Gosting pool, Erdol Bohr- und Verwertungs G.m.b.H., north of the producing area, was drilling with rotary at 990 m., Raky-Danubia is rigged up to deepen the old Windisch-Baumgarten hole, Rohoel-Gewin-nungs A.G. (Vacuum-Shell combination) rigging up rotary south of the production, and Steinberg-Naphta G.m.b.H. (Musil) was deepened with light rotary to 830 m.; at Enzersdorf a/d. Fischa, the European Gas & Electric Co. E-2 rotary-drilled hole stood at 1533 m. in Miocene waiting

Jan 1, 1936

By W. Hodge, A. F. Haskins, R. M. Evans

Refractory boron compounds are shown to resist corrosion by molten zinc. Coatings were made from ferroboron and manganese boron by several methods: welding, hard facing, and pack diffusion; and techniques of coatings are very important. Mechanical failure of the diffusion coatings can be partially eliminated by applying them to type 416 chromium steels rather than carbon steels. Welded coatings made with a tungsten arc are better than those made by other welding methods. Sintered compacts of mixtures of iron and chromium borides developed strengths of about 30,000 psi. They resisted corrosion of zinc at 600°C and oxidation at higher temperatures. MOLTEN zinc rapidly attacks common metals of construction. The rate of attack is greatly amplified at temperatures over 500°C. However, there are many applications where it is necessary, or at least advantageous, to use metal construction, such as for galvanizing pots and zinc smelter equipment. Condensers and agitator linings used in continuous zinc smelting processes are eroded and corroded by violently agitated molten zinc. Pumps, tubing, and other parts to permit transfer of molten zinc would be desirable in many zinc handling operations. The development of metallic materials which are resistant to molten zinc also might permit its use as a heat-transfer medium in modern high efficiency power plants. In reviewing previous work on zinc-resistant metals, it was evident that most of the available data refer to corrosion at temperatures just above the melting point. Tungsten and high Mo-Fe alloys containing more than 80 pct Mo resist corrosion by molten zinc.', ' Imhoff states that because chromium is not attacked by zinc, chromium plating improves galvanizing pot life." Nitrided cast iron has been used in die-casting machines' where the molten alloy is 96 pct Zn and 4 pct Al. Other metals that have been suggested as of possible value for zinc resistance are columbium, tantalum, and titanium.V he corrosion of steel by zinc has been discussed by many authors,z, "2 None of these materials resisted corrosion by molten zinc at the temperatures used in this investigation, i.e., 600" to 700°C. I. Exploratory and Resistant-Coating Tests To make a study of zinc-resistant metals, exploratory tests were conducted to sort out roughly those materials which seemed most worthy of further development. This preliminary study included both solid metals and surface coatings. Exploratory Corrosion Tests in Molten Zinc—In initiating a study of this problem, numerous samples of metals and alloys were evaluated by dynamic corrosion tests made at 440 °C. Each metal was tested in its most readily available form, which, because of shape and size, was often unsuited for standard corrosion testing. The equipment used for dynamic corrosion testing of all materials, except in a few initial experiments, is shown in Fig. 1. Samples were tied to tungsten rods with tungsten wire, immersed in the zinc, and revolved at 12 rpm about the circumference of a 4 in. diam circle. Speed of travel was about 12.5 fpm. The molten zinc was protected from oxidation by an atmosphere of carbon monoxide, or, at a later period in the program, by a 9:1 mixture of nitrogen and hydrogen. When the effect of both molten metal and atmosphere was desired, the zinc level was lowered. Special high grade zinc was used in all of the corrosion tests. Corrosion losses for materials tested are shown in Tables I and 11. Whenever the materials were available in suitable form, the losses are reported in mils per year. It was recognized that weight losses on irregularly shaped specimens did not show the corrosion rate but the important consideration—poor resistance to corrosion—could be determined readily.

Jan 1, 1956

Without having asked for it, the writer has apparently been drawn into the discussion regarding relative hoisting capacities which was started by Woodward Iron, egged on by Joe Haller of Cleveland-Cliffs [Mining Engineering, August p. 642] and Axel Kjelgaard [November p. 919], who took exception to Mr. Haller's remarks of tonnage hoisted and avers that they do better in Sweden. It does not appear to the writer that Mr. Haller was inclined to refer to the tonnage hoisted at Cleveland-Cliffs in a manner to imply that they claimed any hoisting record, but rather as a statement that they had hoisted a certain amount of ore during the year 1950. Mr. Haller has been in the mining game long enough to appreciate what Mr. Kjelgaard did not apparently take into consideration, that length of haul, shifts hoisted, nature of ore, method of loading and the many other factors which influence the hoisting cycle make a comparison of tonnages hoisted of two given mines almost an impossibility. Mr. Cheyette sent you .a copy of his letter to Bob Manegold relative to the capacities of the Orient #2 mine. There are several mines around the Country which constantly set up records about which little or nothing at all is ever heard. We cite the Snow Hill Coal Co. mine at Terre Haute, Ind., which has an automatic Nordberg hoist and which hoists 12 tons per trip or 700 tons per hr from 700 ft. This is a counter-weighted installation and a complete cycle is made every 62 seconds or 58 trips per hr. Another mine, The Potash Company of America mine at Carlsbad, N. Mex., has a Nordberg automatic hoist, hoisting eight tons per trip from 1150 ft on a one minute cycle. The materials hoisted in these two mines are ideal for automatic hoisting-they are free flowing so that no hang up is anticipated and hoisting is continuous. Multiplying out the above figures you will find that it is possible to hoist 11,000 tons in two shifts at Snow Hill or over 3 million tons in 300 days per year and over 2 million tons at Potash. Other mines have records which can be pointed to with pride. When a record for one year is established, it doesn't stand too long as here in America the ambition of all the men connected with the operation forces them on to larger tonnages. T. C. WIEDENHOEFER MANAGER MINE HOIST DEPARTMENT NORDBERG MANUFACTNRING CO. MILWAUKEE, WIS.

Jan 1, 1952

By Norman Yarborough

Much has been written about the energy fuels including their standing with respect to reserves, their delivered Btu costs, their potential in the electrical generating market and their capabilities to meet a burgeoning demand. Yet, when all factors are placed in their proper perspective, the spiraling electrical energy market alone should guarantee each fuel a better than average market for the foreseeable future. In fact, a study made by the U.S. Federal Power Commission on the spare capacity utilities have on hand indicated that 39 of the 181 major utility systems had less than 10% reserves on hand at the end of 1969. Fuel supplies are critically low in some areas, especially in the Southeast, South Central and Midwest areas of the U.S. In other systems equipment shortages resulting from faulty equipment or delays in getting new equipment deliveries causes power failures during peak loads. In addition, lack of labor curtails the erection of some new facilities and prevents many other facilities from operating at capacity.

Jan 1, 1970

Sec. 1. This Institute is incorporated under the Membership Corporations law of the State of New York; its corporate name is American Institute of Mining and Metallurgical Engineers. Incorporated; and its abbreviated title A. I. M. E. Sec. 2. The objects of this Institute, as set forth in its certificate of incorporation, are: "To promote the arts and sciences connected with the economic production of the useful minerals and metals, and the welfare of those employed in these industries by all lawful means; to hold meetings for social intercourse and the reading and discussion of professional papers, and to circulate by means of publications among its members the information thus obtained, and to establish and maintain a place for meeting of its members, and a hall for the reading of papers and delivery of addresses, and a library of books relating to subjects cognate to the sciences and arts of mining and metallurgy."

Jan 1, 1940

NAME AND OBJECT SEC. 1. This Institute is incorporated under the Membership Corporations law of the State of New York; its corporate name is American Institute of Mining and Metallurgical Engineers, Incorporated; and its abbreviated title A. I. M. E. SEC. 2. The objects of this Institute, as set forth in its certificate of incorporation, are: "To promote the arts and sciences connected with the economic production of the useful minerals and metals, and the welfare of those employed in these industries by all lawful means; to hold meetings for social intercourse and the reading and discussion of professional papers, and to circulate by means of publications among its members the information thus obtained, and to establish and maintain a place for meeting of its members, and a hall for the reading of papers and delivery of addresses, and a library of books relating to subjects cognate to the sciences and arts of mining and metallurgy."

Jan 1, 1938

JOHN H . NELSON,*Worcester, Mass.-In reply to the question "Is there any final information in regard to the relation between the temperature or the rate of cooling of a piece of heat-treated steel from the drawing temperature, and the so-called notch toughness?" I might say that we have conducted a large series of tests in the study of impacts on chrome-nickel and carbon steels and have gone into the subject of quenching from drawing temperature quite thoroughly but have found that one cannot lay down any definite rule or law with respect to the effect of quenching from the drawing heat. We conducted experiments on the effect of cooling by quenching in water, cooling in air, and burying the coupon in lime. Steels that have practically no impact value when air cooled may show very marked results when they are quenched in water, depending on the temperature at which the drawing is done.

Jan 6, 1919

IN comparing the living conditions of the worker or peasant of the past with those existing today, his-torians might point out many strange contrasts. From the Doomsday Book we learn that at the time of Wil-liam the Conqueror the 1,375,000 inhabitants of Eng-land and Wales owned less than 1000 horses and 5000 oxen. Even as recently as 1871 when England and Wales had a population of 31,845.000, the total number of horses in the country was estimated at 1,110,000. Compare the necessary drudgery of labor in those days with conditions in Canada today where a population of less than ten million people own 3,500,000 horses. Re-member that there is also a turbine installation in` this country of more than four million horse-power, besides steam boilers and locomotive and automobile engines which reduce the traction and hand labor of the farm and factory. Frequently, poetic license has glossed over the poverty and hardship of the common people in the "good old days," and the imagination has created an idyllic world, far from being justified by the condi-tions which actually prevailed. Simon Patten's de-scription of the Middle Ages as "A Thousand Years Without an Ice Box" came nearer portraying the true situation. No one is likely to forget that the discovery of America was an incident in Europe's attempt to find a short route to the Indies, but the fact is usually for-gotten that the summer diet in Europe in 1400-an ice-less age-was such that spices were more precious than gold. Though the glamor of the Indies may never sur-round the modern refrigerator, certainly the modern housewife is likely 'to feel that the applied art called "cookery? may attain to higher levels with the assist-ance-6f such an adjunct. Those who have spoken slightingly of the uniformity of the modern apartment and have eulogized some of the exceptional hand-made furniture which has been bequeathed by former generations, have failed to com-pare modern house furnishings with those in the typical peasant's hovel. Machine-made furniture, though with-out particularly good lines, contrasts quite favorably with the pile of rags in the corner, and the poorest gas or oil stove is better than an open fire on a dirt floor. The scientist's application of the theories of physics, chemistry, biology and mathematics .to practical prob-lems has brought about a series of kaleidoscopic trans-formations in agriculture, industry and commerce. Large scale production, improved means of communica-tion and the prevailing higher standard of living are terms which imply a very human meaning when in-terpreted as actual changes in individual living. Though the student and the teacher may deprecate the influence of commercialism upon science, humanity as a whole has received great benefits from the close relationship which has developed between science and industry, and industry in turn has done much for science through the building and endowment of laboratories and by supply-ing funds to maintain research workers.

Jan 11, 1927

By George M. Humphrey

It is indeed a pleasure for me to have this opportunity to discuss with you a subject which I find infinitely interesting and intriguing - namely, world-wide iron ore supply and demand. We will be examining the following: (i) current iron ore production and requirements; (ii) the major ore producing countries; (iii) the seaborne iron ore trade; (iv) ore grades or types; and (v) future requirements. For those who may not be familiar with the iron ore mining industry, it may be useful to know at the outset that our industry has been plagued with overcapacity for the past seven years. The optimism which prompted substantial expansion of productive capacity in the early to mid-1970's has unfortunately proved to have been unfounded. I shall begin by describing where we are today as well as a little about how we got there. In the latter regard, it's not so much that historical knowledge will solve any of the industry's problems or provide clairvoyance with regard to the future. Rather it's a feeling on my part that some knowledge of the past will provide a useful perspective capable of enhancing our analysis of future trends. At the time of writing, the most recent year for which we have definitive world-wide iron ore production and consumption statistics is 1980. In that year the world consumed approximately 859 million metric tons of iron ore to produce approximately 510 million metric tons of primary iron consisting of 502 million tons of pig iron and 8 million tons of sponge iron. Crude steel production for the same period attained a level of 719 million metric tons. Because it is possible in today's world to produce steel without consuming iron ore simply by melting scrap, the key statistic insofar as iron ore demand is concerned is primary iron production. In 1980 the ratio of iron ore consumption to primary iron production was 1.68:1.00. The comparable ratio over the past seven years has varied from 1.63 to 1.87 and averaged 1.72:1.00. All the same, as a practical matter crude steel production and iron ore consumption tend to parallel one another closely, and for the time being a good rule of thumb is that to produce an average ton of crude steel requires 1.20 tons of iron ore. Let's turn our attention now to the regions where the 859 million tons of iron ore necessary to support 1980 world-wide iron and steel production were produced. Not surprisingly, most of the ore was produced in the same region where it was smelted. In round numbers 65% of the world's iron ore production is currently consumed in the same general region as it is produced, while 35% enters the seaborne trade and is transported in ocean vessels to a more remote consuming area. Approximately 85% of the world's seaborne iron ore trade is directed to the Western European and Japanese markets, both of which are almost entirely dependent on off-shore sources for their mammoth iron ore requirements. The following tabulation lists, in order, the twelve leading iron ore producing countries in 1980 as well as their percentages of total and free-world production; in addition their export potentials are presented. As a group these countries accounted in that year for 89% of world-wide production which stood at 871 million tons. Leading World Iron Ore Producing Countries [ ] One will first note that world iron ore production is dominated by the top four producers - namely, the U.S.S.R., Brazil, Australia and the U.S.A. - which together accounted for nearly 60% of total 1980 production. Of these four major producers the U.S.A. and the U.S.S.R. produce almost exclusively for consumption in their own regions, whereas Australia and Brazil produce primarily for the seaborne export trade. In fact Australia and Brazil accounted for about 50% of all seaborne iron ore trade in 1980! It is also interesting to note that Australia, Brazil, the U.S.A. and Canada accounted for nearly 60% of free world iron ore production in 1980. Once again the importance of Australia and Brazil shows itself, with their share alone of free world production reaching 35%. As has already been noted, a significant 35% of the world's iron ore production in the year 1980 was

Jan 1, 1982

SEC. 1. This Institute is incorporated under the Membership Corporations law of the State of New York; its corporate name is American Institute of Mining and Metallurgical Engineers, Inc.; and its abbreviated title A. I. M. E. SEC. 2. The objects of this Institute, as set forth in its certificate of incorporation, are: "To promote the arts and sciences connected with the economic production of the useful minerals and metals, and the welfare of those employed in these industries by all lawful means; to hold meetings for social intercourse and the reading and discussion of professional papers, and to circulate by means of publications among its members the information thus obtained, and to establish and maintain a place for meeting of its members, and a hall for the reading of papers and delivery of addresses, and a library of books relating to subjects cognate to the sciences and arts of mining and metallurgy."

Jan 1, 1932

By Oberlin Smith

It may surprise the learned metallurgists who read this paper to learn that, by a recent discovery, nails of good quality can be made at one operation, directly from the ore, at the rate of, say, sixty per minute for each operator. It should be stated, however, that the raw material referred to does not answer strictly the ordinary assayer's definition of' an ore. It is found, in strata of various thickness, in Harlem, N. Y., and other localities where the débris from restaurants and from sheet-metal factories of various kinds has been dumped. In other words, it is old and new tin-scrap—one of the few substances which this generation, mainly occupied in exhausting the accumulated resources of the past, seems to have laid up, by way of atonement, for the benefit of posterity. In speaking of this material as ore, we are simply looking forward, prophetically, to the time when our descendants may dig it. up and write learned papers for the American Institute of Mining Engineers upon the best methods of assaying and smelting it. At least such has seemed to be its destiny hitherto. It may fairly be said that the many attempts which have been made to utilize it by separating, through chemical or electrolytical processes, its two valuable constituents, metallic tin and first-class wroughtiron, have failed, either technicaljy or commercially. The reasons fur such failure need not here be discussed: Either the separation has been incomplete, the iron still retaining enough tin to spoil it for the sinking-fire, or other use short of re-melting (perhaps even for that), or the manipulations of the process have been too expensive to make its results profitable—or both. Meanwhile the great tin-scrap deposits have gone on growing faster than any other strata of our Post-Tertiary, Psychical Era; given up by metallurgists, not yet attacked by geologists, and explored only by that mining engineer of the transitional period, Gulielmus Caper. Before leaving these heaps of tin-scrap, however, to become mere mineral deposits for future ages, it may be well to consider a novel plan for their immediate utilization—novel, not only in its means, but in its principle. For it undertakes to use this material just as it is, without trying to separate its constituents at all, and to use it,

Jan 1, 1889

By H. E. Doerr

The writer has been unable to find much information relative to tests made to determine the effect of forging on the specific density of steel. The opinion, however, among men engaged in the business, seems to be that forging greatly compresses or consolidates the steel. While such is doubtless the case with spongy or porous steel, the following experiments indicate that there can be little or no change in the density with steel initially free from cavities. Ten ingots of basic open-hearth steel cast as shown in Fig. 1 were used in the experiments. All the specimens were 0.53 carbon with all other elements the same, the analysis being determined from drillings taken midway between the center and outside of the upper end, as shown in Fig. 2. The specimens were selected from over one thousand ingots so that the tests could be comparative for the work done in forging only, but no two of the ingots were cast in the same heat. Each ingot remained in the mold approximately 30 min., when it was removed and sir-cooled. About 12 hr. later, when the temperature had been reduced to approximately that of the surrounding atmosphere, the head was discarded and the ingot heated in an oil furnace to approximately 2250" F. (1235" C). Approximately 1 min. was required to forge under the steam hammer to 1 1/4 in. (31.75 mm.), rough diameter, as shown by the dotted lines in Fig. 2. All ingots were allowed to air-cool after forging. Cylinders 1/2 in. (17.7 mm.) in diameter and 1/2 in. high were then turned from the forged and unforged parts of the ingots and numbered. The ten pairs of specimens were submitted to Louis E. Endsley, Professor of Railway Mechanical Engineering, University of Pittsburgh; A. N. Talbot, Professor of Applied Mechanics, University of Illinois; L. Z. Slater, chief chemist, Scullin Steel Co., St. Louis, Mo. NO information was furnished as to which specimens were forged or unforged and each laboratory used the same specimens, submitting the average of three independent determinations, a tabulation of which is shown in the accompanying table in which the laboratories are designated by the letters A, B, and C. While there is considerable difference in the individual determinations for a number of the specimens, the averages

Jan 1, 1920

By H. Foster Bain

Jan 1, 1910

By H. S. Drinker

I. The Mines THE first discovery of zinc on the property now worked by this company was made by the celebrated mineralogist, Prof. William Theodore Röpper, in 1845. Different claimants kept the property in continual litigation till 1861, when everything was satisfactorily settled by the purchase of the land by the company, who have worked it ever since. The mines are situated in a valley, four miles south of Bethlehem, Pa., in Lehigh County. The valley is from two to three miles broad, and is bounded on the north and south by syenitic hills. Syenite underlies the valley, and upon this is deposited the Potsdam sandstone, then a layer of slate, and, finally, a dolomitic limestone, belonging to the Chazy or Black River formation, in which the zinc deposits are inclosed. The rocks occur in folds, and have evidently been subjected to tremendous pressure from below, the zinc deposit being found in an anticlinal axis, in nearly vertical veins. It is supposed that the zinc was originally disseminated through the

Jan 1, 1873

By J. C. Bayles

An obstacle to the more careful and satisfactory study of metals has been the difficulty in harmonizing the results of chemical and physical tests. These give us records of observations made from different and often widely separate points of view, and while it is true that they furnish bases for more or less accurate triangulations into the realm of speculation, it is doubtful if, with only the laboratory and the testing machine, our investigations would not move in parallel lines, leaving between them an unexplored field in which must probably be sought the information which shall connect the results of chemical and physical tests, and give to both a practical value which neither has yet been found to possess. The use of the microscope in the study of metals is not a new thing, but it is only lately that it has begun to attract the attention it merits or to show results of tangible value to the metallurgist. Among recent valuable contributions to the literature of this subject, I have been especially interested in the work of Mr. A. Martens, of

Jan 1, 1883

By P. K. Lucke

ONE of the interesting features connected with the great continental uplift, which formed the table land of Mexico, is the great depth to which oxidation and secondary enrichment of orebOdies occurred. This table land lies at altitudes ranging from 4000 to. 7000 ft. (1219 to 2133 m.) above sea level. Several cases could be cited of oxidized zones in copper and lead mines which reached depths of upward of 1500 ft. (457 m.) below the surface, and it is universally admitted that the oxidized zone in a mine is limited by the permanent water level. FIG. 1. Mexico, however, like many other countries in which deserts occur, is visited at rare intervals by tremendous floods, which sometimes cause variable water levels over long periods. The following cases bear out the idea, and lead to interesting conclusions of commercial value. My paper demonstrates that carbonates of ores may occur below water level and sulphides above, and I will endeavor to explain the causes of the phenomena in certain specific instances.

Jan 6, 1918

By James C. Ray

DURING the summer of 1931, I spent four months in a study of the Willow Creek district, Alaska. This work was part of a general investigation of the territory contiguous to the route of the Government- owned Alaska Railroad. It was conducted by the U. S. Geological Survey to determine the real and potential merits of the mineral deposits, to stimulate development of them, and thus to increase the traffic on the Alaska Railroad.

Jan 1, 1932