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TO metallurgists generally, Arthur S. Dwight is no stranger even to those who do not know him personally. He is one of those contributors to technical progress whose names will go down to posterity because of their being attached to a successful machine or process, such as Dorr, Hardinge, or Marcy, or Wedge, MacDougall, or Herreshoff. The roasting and sintering method and equipment developed by Colonel Dwight and his associate, the late Richard L. Lloyd, may be found in lead smelters throughout the world, and also in many metallurgical works dealing with other ores, including those of iron. It is ordinarily used to desulphurize and agglomerate fine ores for subsequent smelting. Colonel Dwight's citation as James Douglas Medalist reads: "For his contributions to the art of smelting nonferrous ores; and particularly for his pioneer work in developing equipment and technique for sintering such ores and metallurgical products." The medal was awarded at the last Annual Meeting of the A.I.M.E. but unfortunately the medalist was unable to leave Florida at the time to receive it in person.

Jan 1, 1942

By AIME AIME

AT bottom of this page is a photograph recently taken by a student-John E. Stewart-of the most northerly situated college in the world, the Alaska Agricultural College and School of Mines. It is situated at College, near Fairbanks, Alaska, approximately on the 65th parallel of latitude, and therefore just south of the Arctic Circle. It is farther north than Hudson Bay, and in about the same latitude as southern Greenland.

Jan 1, 1932

By Frank Firmstone

Discussion of the paper of John B. Dilworth, presented at the Pittsburg meeting, March, 1910, and printed in Bulletin No. 35, November, 1909, pp. 1041 to 1043. FRANK FIRMSTONE, Easton, Pa. (communication to the Secretary*) :-Mr. Dilworth's formulas and tables are of course correct, and the extinction will occur as calculated, provided the money periodically set aside for sinking-fund be really invested. and the interest compounded as assumed in the calculation. Actually, in almost all cases, such funds are used "in the business," in which case, in addition to the periodical charges for principal of the fund, additional charges must be made at the end of each period to cover the interest and compound interest on previous charges. The periodical charge for sinking-fund thus becomes a varying and continually increasing one until the date of extinction. On many accounts it seems more natural and convenient to make the extinction by a fixed periodical charge under the legal rule for partial payments, namely, that each payment should apply first to the interest due at the date of payment;: and any remainder, after this is satisfied, be deducted from the principal before the interest for the next period is calculated. The formula below is convenient for such calculations S, Principal to be extinguished. Q, Periodical payment or charge for sinking-fund. B, Balance unpaid at date of nth payment, but before that payment is made. r, Rate of interest per period per cent. n, Number of payments or periods. Then, B=S(1+r)n-Q(1+ r)n-(1+r) Received July 27, 1910.

Apr 1, 1911

By Alexander Anderson

TABLES showing the drift and inclination of wells surveyed in the years 1924 to 28' and in the year 1929' have already been published. Each of these tables included a little over 1,000,000 ft. of rotary hole. In the year 1930 the table -shown-in . Fig. 1, comprising, the results of surveys .of 1,030,344 ft. of hole and representing 11,642 individual survey readings, was compiled. For that purpose we selected 'I only wells that had been drilled in California during that year. The footage of Fig. 1 differs from the two earlier tables in that the wells were all drilled in the year 1930. In the earlier tables, the footage shown was surveyed in the years designated, but some of the wells were drilled in earlier years.

Jan 1, 1931

By AIME

BILL BREWSTER was a natural for the steel business. His family lived at Iron Mountain, Mich., when Bill was born on June 14, 1889, so that he had iron in his blood. Always he has looked toward the finished product, rather than the raw material, so that it was a fore-gone conclusion that he should work toward the steel end of the business. After preparing for college at Hotch-kiss Academy he entered the Sheffield Scientific School of Yale University from which he graduated in 1910 with the degree of Bachelor of Philosophy. No reunion of his class would be complete without Bill Brewster. Unlike many of us who try several jobs before settling down, Bill shot straight for the mark. After a summer's work at Iron Mountain, making sure of his background in the production of the raw iron ore, he entered the employ of Wisconsin Steel Works of the International Harvester Co. in September 1910 and has been there ever since. It wasn't much of a job to start with, just a laborer in the billet dock department, but soon there was an opening in the blast-furnace department, where he started as superintendent's clerk in December 1910.

Jan 1, 1946

By E. P. Mathewson

A Discussion of the Paper of E. P. Mathewson, presented at the New York Meeting, April, 1907, and printed in Bi-Monthly Bulletin, No. 13, January, 1907, pp. 7 to 14. PROF. HENRY M. HOWE, New York, N. Y. (communication to the Secretary *) :-The results presented in Mr. Mathewson's paper are of very great interest. Perhaps the most interesting is that shown in Table I. and Fig. 1, in which the arsenic decreases in 10 min, from 0.22 to 0.07 per cent. This is such a large decrease that it is to be hoped that Mr. Mathewson will verify it by repeating his tests with a matte of similar composition. This is particularly to be desired, because the simultaneous removal of sulphur appears to be very small. All three blows further agree in showing that the removal of arsenic is in the very early part of the blow. The fact that the removal of arsenic then ceases abruptly cannot be explained completely by the fact that the arsenic has fallen so low as by its lowness to resist further removal, because in the first blow the arsenic becomes stationary at 0.06 per cent., whereas in the third blow it does not become stationary until it has fallen to 0.034 per cent. The abrupt ending of the re¬moval of arsenic is more likely to find its explanation in the composition of the slag, and it is to be hoped that. Mr. Mathewson will supplement these extremely valuable data with others in which the composition of the slag at the same time shall be given. The sudden rise of arsenic toward the end of the third blow I suppose must be referred to an error in sampling or analysis. Mr. Mathewson speaks on page 14 of the "percentages of iron . . . volatilized during the first period." Is it his meaning that all this iron is really volatilized, or does he mean that the iron is scorified and the sulphur volatilized ?

Jul 1, 1907

Mr. John J. Porter, Chicago Ill. (communication to the Secretary†):—Mr. Baker's account of his experiences with stock-distribution has been particularly interesting to me, as it

Jan 1, 1905

By W. J. Garmoe

Distinct areas of mineralized and non-mineralized brecciated rock are found in the Ontario Unit of the United Park City Mines. These breccias contain an appreciable fraction of the present ore reserves and probably will become even more important as deeper levels are developed. Three ages of breccia have been recognized in the Ontario Mine to date: ( 1) Pre-mineral breccia that may or may not be mineralized, (2) early post-mineral breccia with mineralized fragments, and ( 3) late post-mineral breccia that is younger than and cuts through ( 1) and (2) above. These age ,relations are known from detailed underground mapping. Locally, both pre-mineral and post-mineral breccias have sufficient lead-zinc-silver content, either as matrix or fragmental material, to constitute ore. Ore-grade breccias occur throughout a vertical range of over 1000 feet and are found in both the Humbug and Deseret formations from above the Ontario 1300 level to below the Ontario 2200 level. The mineralized breccias, which are difficult to distinguish on mine maps, are not well delineated by underground workings, and their horizontal outline and vertical extent are not known beyond the immediate mining areas. The greatest amount of truly mineralized breccia is exposed on the 2200 level.

Jan 1, 1968

By AIME

AS with Phil Kraft, referred to on this page last month, travel has always held a great fascination for Raymond Frank Baker and for that reason he determined to become a geologist. He had heard that geologists travel and that was what he wanted to do. Now as chief geologist for The Texas Co. his early wish has been fulfilled-he spends almost one third of his time journeying' from one oil field to another. Mr. Baker was born in New Haven, Conn., on Jan. 11, 1892, and went through the public schools in New Britain. A stalwart New Englander, he attended Yale and in 1912 received a degree in civil engineering. For a year following this he worked as a civil engineer for the New York Central Railroad, but his early urge to travel widely could not be satisfied here. So in 1913 he re-entered Yale and until 1916 studied mining and economic geology. He had a little taste of field work, which later became so enjoyable to him, in the summer of 1915 when he worked with the U. S. Geological Survey as a geologic aid. In 1916 he made his first contact with The Texas Co. when he entered their Tulsa office as a geologist. This early career was interrupted by service in the

Jan 1, 1947

Edward Halse, Puerto Berrio, Colombia, S. A. (communication to the Secretary): I have read with much pleasure the interesting and valuable paper by Mr. Kunz, and hope that the following brief notes, gathered a few years ago, while a resident in Mexico City, may help to elucidate the subjcct: Turquoise.—This was known to the Aztecs as Xihuitl. Santiago Ramirez states that they found it in the Cerro Xicohtzonc, close to Atzcapatzalco, a suburb of the City of Mexico (compare page 59). Opal.—This was known to the ancient Mexicans, for they named it mezcuitlatt (compare page 63). Jade.—Under this was iucluded a third mineral, prehnite, not mentioned by Mr. Kunz. According to James D. Dana, part of the "jade " of China is prehnite; and Humboldt informs us, in his work on New Spain, that the same species of jade is known in some parts of Mexico as mahagua (majagua ?). The same writer says, in his Views of the Cordilleras, that the Aztec name Tecpatl included flint, hornstone, and green jade; and finally, in his Travels in South America," he discusses the nature of the ancient amazon-stones, and declares them to have been made out of a jade resembling " compact feldspar," one of the constituents of the gabbro verde di Corsica. IIence those stones were probably composed of nephrite. According to Humboldt, the form given to them most frequently is that of the Babylomian cylinder, longitudinally perforated, and loaded with inscriptions and figures. They were also cut by the natives into very thin plates, perforated at the center, suspended by a thread, and worn as amulets. According to the historian Clavijero, the specific name given by the Aztecs to the nephritic stone (jadeite) was Quitzalitztli,

Jan 1, 1902

By Arthur L. Walker

DURING my trip around the world last year, covering a total of 45,000 miles, I saw many things of especial interest from an engineering viewpoint. Sailing from New York, I went through the Panama Canal, down along the west coast of South America, then over the Peruvian and Bolivian Uplands; thence to the celebrated copper mines of Chile; across the Andes, to Buenos Aires, then to Rio Janeiro; across the Atlantic to Lisbon, Portugal; through Spain to the Rio Tinto mines; across southern Europe to Italy; thence to Alexandria and Cairo; up the Nile to Assouan, to Palestine through the Suez Canal, Red Sea and across to Bombay; up to the country of the Moghul Emperors; then to Calcutta, from which point I shipped to Singapore, as having crossed the Equator twice, I wished to shake hands with it again; thence to Shanghai and Pekin; up to the Great Wall of China, back to Nanking and up the Yangtse to Hankow; then back and eastward across the Pacific Ocean. The climatic changes were sudden and severe; there was winter where, for me, it should have been summer and vice versa. The weather man was very kind, however, and until I was near the Aleutian Islands there were only three rainy days in a total of 220.

Jan 1, 1924

By Walter O. Roberts

A TOTAL eclipse of the sun is a brief, exciting spectacle witnessed by most men but once or twice during a lifetime. But to an astronomer an eclipse of the sun is an event of utmost scientific importance. For then, certain phenomena of the sun normally obscured by the brilliant glare of sunlight become spectacularly visible. For over seventy years prior to 1930 astronomers vainly attempted to discover a means of observing all of these eclipse features of the sun without a natural eclipse. But in 1930, through the genius of the French scientist, Bernard Lyot, astronomers met final success. Dr. Lyot invented a new kind of telescope known as a coronagraph, which made possible photography of all of the eclipse features of the sun. In 1940 Harvard University completed final testing of its Lyot-type coronagraph. the only one in the Western Hemisphere, and shipped it to Climax, where Donald H. Menzel, of Harvard College Observatory, supervised its establishment on the southeastern edge of the mining community of the Climax Molybdenum Co., with whose help and advice the modern residence and telescope dome of the observatory were constructed. Ever since that summer the station has been operated by me, first as a graduate student, and now as a staff member of Harvard College Observatory.

Jan 1, 1946

By Charles H. Moore

When lime and magnesia are used as fluxes in the smelting of titaniferous ores fluid, digestible slags low in iron oxide and high in titanium dioxide are produced. The mineral phases present in such slags are (Fe,Mg)O.2TiO2, CaTiO3, and minor amounts of silicate glass (or its devitrification products). The flux additions are added to the ore in relative amounts to crystallize a ratio of (Fe,Mg)O.2TiO2 to CaTiO2, of near the eutectic proportions of 60 pct (Fe,Mg)0.2TiO2 and 40 pct CaTiO3. FeO-Ti02 (ilmenite) remains present in the slag until the FeO content is reduced to approximately 8 pct. Op- timum slag composition is obtained by reducing the FeO content to between 2 and 6 pct. Continued reduction shifts he (Fe,Mg) 0.2Ti02 to oxygen deficient structures classified as MgTi30e and MgTi204. Further reduction yields titanium oxycarbides and freezes the melts.

Jan 1, 1949

By H. Evans, L. A. Hunt

In the pellet-producing industry it is sometimes claimed that "The pellets are made in the concentrator," or that "The key to good pellets is in the balling operation." However, one claim is generally agreed on: If you can put in, on, and through the indurating furnace a good green ball of Proper size and adequate strength to withstand the handling, load, dehydration, and thermal shock until it is properly heat-hardened, you will have the pellet product you desire-that is, a "competent" green ball. The strength requirements that enable a competent green ball to withstand the environment of the indurating furnace are usually less restrictive than those for transporting the green ball from its source of production to the furnace. Experience has shown that different types of material may have different balling characteristics which may impose limitations on the quality of the green ball that can easily be produced under normal conditions. Therefore, if a specific material will produce a green ball that meets the physical requirements for competency in the furnace, but not for handling or transportation, various practices must be instituted to overcome this deficiency. In other words, if a normal handling system is too rigorous for the green balls that can be produced under standard conditions, then "handling with care" should be tried.

Jan 5, 1967

By L. H. JEFFRIES

In the mining operations of The Canyon Corp., Deadwood. S. D., the use of mucking machines has been of definite advantage. The type used is that which depends upon the traction of the motor-driven wheels to crowd the dipper into the muck pile, while the car in which the muck is received is coupled to the mucker and moves forward or back with it. This general arrangement is entirely satisfactory on a substantially level track. The ores which occur in this district are a replacement of dolomite and the beds are now tilted to an inclination of about 7-1/20. In our operations it is necessary to drive inclines down-hill on this slope, which makes a difficult hand-mucking job even if water were not present. With these facts in mind, an attempt was made to use the mucking machine for driving down the in- cline, but as expected, the traction was insufficient to handle the machine and the necessary car. The means used to correct this condition will perhaps impress most readers as too complicated and cumbersome to effect any economy, but the idea may be of service to some who have a similar condition. After considering several s

Jan 1, 1940

With a mine output as high as 5000 tpd and mill capacity of 7000 tpd, the uranium mining and milling complex owned and operated by Kerr-McGee Nuclear Corp. in the Ambrosia Lake area is the largest in the U.S. and is likely to remain so for some time. Next year, Kerr- McGee expects to have in production another mine in Section 19 of the Ambrosia area-and will begin ore production in 1976 at its new $15-million mine at Church Rock, located northeast of Gallup, N. M., where the company has already completed the shaft work and is in the early stages of project development. Ore from Church Rock will be transported to the company's facilities at Ambrosia Lake for processing. Kerr-McGee's existing eight mines in Ambrosia Lake go to depths of about 800 to 1500 ft to tap the various horizons of uranium-bearing sands in the Westwater Canyon of the Morrison formation.

Jan 8, 1974

By J. Leslie Goodier

The International Law of the Continental Shelf, so far ratified by 35 nations, extends the national boundary of any coastal nation to the edge of the continental shelf, this normally being at a continuous water depth of 200 m. The Law further extends this boundary to include the floor of the deep ocean to any depth that can be mined by advanced mining technology. In effect, proof of mining can constitute proof of ownership of the subaqueous land and the minerals on or below the sea floor. Irrespective of the fact that present technology is too limited to permit mineral exploitation in the high seas-and the law regarding the right to mine appears hazy-the U. S. Treasury Department's Bureau of Customs, has a ruling that would further deter mining operations on the high seas. This law contends that minerals mined on the continental shelf of the United States are actually mined within the continental United States and are free of tariff, but mined products or other articles obtained from the ocean or the sea floor beyond the continental shelf, if brought into this nation, must be considered as imported and are subject to such customs duties as are applicable under the tariff schedules of the United States.

Jan 7, 1968

By W. S. Ayres

By Ralph H. Phelps

WHAT information do you have on precision investment casting? Please send me all available information on the removal of paraffin from oil wells and pipe lines. How can I find out how to remove magnesium oxide from lime? I want a good book on the pickling of steel. Can liquid oxygen be used as an explosive in a mine? Where can I get a bibliography on the plasticity of metals? These questions, selected from the scores of questions asked the Engineering Societies Library staff every day, indicate some of the diversity of the requests received. The samples chosen relate to interests of AIME members but the questions that come to the Library by mail, telephone, telegraph, and in person cover all fields of engineering, science, and technology. Some questions can be answered quickly; others require extensive searching. Those that can be answered in a few minutes or ten, twenty, or even thirty minutes are usually done without charge. For the more difficult questions a charge is made. In this way those requiring considerable service pay for it and the Library finds it possible to serve more persons.

Jan 1, 1948

By Ernest J. Stocking

ENGINEERS are the key men in our war program today. Upon the technical knowledge and skill of the engineer and upon his administrative and executive abilities rests the entire success for the production of vital materials of the war. Naturally the work load of the engineering examining unit of the U. S. Civil Service Commission has increased greatly since our active participation in the war. At present, over 550 separate requests for certification of eligibles are received by the engineering unit per week. These represent more than a fourth of the total requests received for personnel by the Commission's central office at Washington and represent a recruitment work load of three to four times that carried by the whole Commission previous to January 1940. These requests represent a minimum of a thousand vacancies to be filled each week, while an average week will produce, at present, approximately 1400 vacancies and a weekly maximum may approach well over 2000 vacancies.

Jan 1, 1942