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By J. Gardner Brooks, Sidney Sigel, Irvin R. Kramer

In 1942 Grossmannl proposed that the hardenability of a steel may be calculated from its chemical composition by considering the base hardenability associated with its carbon content and grain size and multiplying this base by factors for each element present. Since Grossmann's original publication, several investigaton2-6 have reexamined the multiplying factors for the individual elements and in general have found that the multiplying principle is valid. However, some of the individual factor curves developed have been in poor agreement. Inasmuch as the carbon-factor curve obtained by Grossmann was dependent Lipon the factors for all the other alloying elements present in the steel, it logically followed that his results were in need of correction in the light of the new data available for manganese, silicon, and the other alloying elements. Furthermore, in order to avoid the possibility that errors in the manganese, silicon, or other curves might influence the carbon-factor curve, investigation of iron-carbon alloys containing little or no manganese and silicon was necessary. That the effect of carbon on hardenability was greater than indicated by Grossmann is shown by a comparison of the diameters of completely hardened rounds of iron-carbon alloys with the ideal critical diameter calculated from Grossmann's factors. These alloys have a greater hardenability in a finite quench than predicted by Grossmann's factors for an infinite quench (Table I). Among the other important variables that were in need of further investigation were the effect of deoxidation practice on the grain-size correction curves and the effect of stable carbide-forming elements on the depth of hardening. Most Of the work by Kramer, Hafner, and Toleman4 was done on silicon-killed steels. It was not known whether Gross-mann's grain-size correction curves, determined on aluminum-killed steels, was valid when applied to steels with different deoxidation practice. More data on the

Jan 1, 1947

By J. C. Reed, J. M. Hansell

Cinnabar was discovered in southwestern Arkansas on Little Missouri River in sec. 1, T.7S., R.26W., in April, 1930, and near Antoine Creek in sec. 28, T.6S., R.23W., some 15 miles farther east in May of the same year. It was not, however, until June, 1931, that cinnabar was identified as such in a specimen from the original discovery area sent to W. M. Weigell by Walter F. Hintze of Murfreesboro. Almost simultaneously2, in July, 1931, Moritz Norden of Hot Springs identified specimens from the Antoine Creek area as cinnabar. Immediate interest in the district followed the identification of cinnabar and by January, 1932, the district was known to extend as a mineralized belt about one mile wide trending east-northeast from sec. 13, T.7S., R.27W., in Howard County across central Pike County and into Clark County to sec. 19, T.6S., R.23W., thence extending southeast into sections 33 and 34 of the same township. Since then, cinnabar has been found in sec. 6, T.7S., R.22W., thus giving a total east-west length to the district of approximately 30 miles. Interest focused mainly on the two discovery areas, with the result that mining development has progressed most rapidly in those localities. In the Antoine Creek area the Arkansas Quicksilver Co. has done considerable exploration work and has retorted the high-grade ore so obtained. In the Little Missouri area the Southwestern Quicksilver Co. has had a 12-ton rotary furnace in more or less continuous operation since April, 1932, and has been the largest producer in the district. In March, 1934, the United States Geological Survey began a study of the Arkansas quicksilver district, which was made possible by an allotment of funds from the Public Works Administration. Until

Jan 1, 1935

By J. C. Reed, J. M. Hansell

Cinnabar was discovered in southwestern Arkansas on Little Missouri River in sec. 1, T.7S., R.26W., in April, 1930, and near Antoine Creek in sec. 28, T.6S., R.23W., some 15 miles farther east in May of the same year. It was not, however, until June, 1931, that cinnabar was identified as such in a specimen from the original discovery area sent to W. M. Weigell by Walter F. Hintze of Murfreesboro. Almost simultaneously2, in July, 1931, Moritz Norden of Hot Springs identified specimens from the Antoine Creek area as cinnabar. Immediate interest in the district followed the identification of cinnabar and by January, 1932, the district was known to extend as a mineralized belt about one mile wide trending east-northeast from sec. 13, T.7S., R.27W., in Howard County across central Pike County and into Clark County to sec. 19, T.6S., R.23W., thence extending southeast into sections 33 and 34 of the same township. Since then, cinnabar has been found in sec. 6, T.7S., R.22W., thus giving a total east-west length to the district of approximately 30 miles. Interest focused mainly on the two discovery areas, with the result that mining development has progressed most rapidly in those localities. In the Antoine Creek area the Arkansas Quicksilver Co. has done considerable exploration work and has retorted the high-grade ore so obtained. In the Little Missouri area the Southwestern Quicksilver Co. has had a 12-ton rotary furnace in more or less continuous operation since April, 1932, and has been the largest producer in the district. In March, 1934, the United States Geological Survey began a study of the Arkansas quicksilver district, which was made possible by an allotment of funds from the Public Works Administration. Until

Jan 1, 1935

Cinnabar was discovered in southwestern Arkansas on Little Missouri River in sec. 1, T.7S., R.26W., in April, 1930, and near Antoine Creek in sec. 28, T.6S., R.23W., some 15 miles farther east in May of the same year. It was not, however, until June, 1931, that cinnabar was identified as such in a specimen from the original discovery area sent to W. M. Weigell by Walter F. Hintze of Murfreesboro. Almost simultaneously2, in July, 1931, Moritz Norden of Hot Springs identified specimens from the Antoine Creek area as cinnabar. Immediate interest in the district followed the identification of cinnabar and by January, 1932, the district was known to extend as a mineralized belt about one mile wide trending east-northeast from sec. 13, T.7S., R.27W., in Howard County across central Pike County and into Clark County to sec. 19, T.6S., R.23W., thence extending southeast into sections 33 and 34 of the same township. Since then, cinnabar has been found in sec. 6, T.7S., R.22W., thus giving a total east-west length to the district of approximately 30 miles. Interest focused mainly on the two discovery areas, with the result that mining development has progressed most rapidly in those localities. In the Antoine Creek area the Arkansas Quicksilver Co. has done considerable exploration work and has retorted the high-grade ore so obtained. In the Little Missouri area the Southwestern Quicksilver Co. has had a 12-ton rotary furnace in more or less continuous operation since April, 1932, and has been the largest producer in the district. In March, 1934, the United States Geological Survey began a study of the Arkansas quicksilver district, which was made possible by an allotment of funds from the Public Works Administration. Until

Jan 1, 1935

By J. C. Reed, J. M. Hansell

Cinnabar was discovered in southwestern Arkansas on Little Missouri River in sec. 1, T.7S., R.26W., in April, 1930, and near Antoine Creek in sec. 28, T.6S., R.23W., some 15 miles farther east in May of the same year. It was not, however, until June, 1931, that cinnabar was identified as such in a specimen from the original discovery area sent to W. M. Weigell by Walter F. Hintze of Murfreesboro. Almost simultaneously2, in July, 1931, Moritz Norden of Hot Springs identified specimens from the Antoine Creek area as cinnabar. Immediate interest in the district followed the identification of cinnabar and by January, 1932, the district was known to extend as a mineralized belt about one mile wide trending east-northeast from sec. 13, T.7S., R.27W., in Howard County across central Pike County and into Clark County to sec. 19, T.6S., R.23W., thence extending southeast into sections 33 and 34 of the same township. Since then, cinnabar has been found in sec. 6, T.7S., R.22W., thus giving a total east-west length to the district of approximately 30 miles. Interest focused mainly on the two discovery areas, with the result that mining development has progressed most rapidly in those localities. In the Antoine Creek area the Arkansas Quicksilver Co. has done considerable exploration work and has retorted the high-grade ore so obtained. In the Little Missouri area the Southwestern Quicksilver Co. has had a 12-ton rotary furnace in more or less continuous operation since April, 1932, and has been the largest producer in the district. In March, 1934, the United States Geological Survey began a study of the Arkansas quicksilver district, which was made possible by an allotment of funds from the Public Works Administration. Until

Jan 1, 1935

CHARLES P. BROOKS Charles P. Brooks, who had been identified with the mining industry in the West since 1874, having served at various times as mining and consulting engineer for most of the largest mining properties in Utah, died Dec. 11, at his home in Salt Lake City, of heart failure, after an illness of about one month. He was a very close business friend of the late Thomas Kearns and David Keith. In recent years he had been closely identified with the Silver King Coalition Mining Co., the Chief Consolidated Mining Co., the Grand Central Mining Co., the Prince Consolidated Mining & Smelting Co., and many other large properties. Mr. Brooks was born in Washingtonville, Orange County, New York, Aug. .21, 1851; he was the son of Charles Edward Brooks and Adeline Cannon Brooks. When 14 years of age he attended school at Chester, N. J., for one term, and accompanied the assistant principal of Chester Academy to New Paltz, N. Y., and finished the school year there. In 1866 he entered Dr. Stiles's school at Deckertown, N. J., and later the Sheffield School at Yale in 1867, where he received the degree of civil engineer with the class of 1870.

Jan 2, 1919

By Jack L. Taylor

WITH the exception of the work of Vogel,&apos; and Rolla and Iandelli, very little information has appeared in the literature on titanium binary systems with the rare earth elements. Rare-earth additions to titanium alloys may possibly parallel the beneficial effects on the physical properties of certain steels. Having this in mind, some knowledge of solubility limits and intermediate phases, if any, would be useful. An investigation of the titanium-rich Ti-Ce system was started. Alloy Preparation The iodide titanium from the New Jersey Zinc Co. and the cerium metal from the Institute for Atomic Research Ames Laboratory used in this work were supplied with the typical analysis shown —iodide titanium: 0.0065 pct Mn, 0.0022 pct Fe, 0.0015 pct Cu, and 0.0042 pct Pb; cerium metal: <0.01 pct Fe, <0.03 pct Si, <0.05 pct Ta, <0.02 pct Pr, <0.03 pct Ca, <0.02 pct Mg, with no trace of Nd, La, or Th. The cerium metal, stored in oil, was washed and scraped just before weighing into capped cups machined from iodide titanium. The cold hearth helium-arc furnace described by Schramm et al3 was used for melting. The alloy buttons from the arc-melted cup were cut in two, mounted, and examined. Homogeneous alloys were demounted and rolled to approximately 1/4-in.sq bars. Sections l/8 in. thick were cut from the bar to provide samples. The Ti-Ce alloy buttons analyzed for cerium were of the following composition: 0.19, 0.36, 0.48, 0.61, 1.15, 2.52, 3.06, 3.70, 4.30, 9.20, 14.26, and 18.50 wt pct. Nominal

Jan 1, 1958

THE Institute assembled in the metallurgical lecture-room of Pardee Hall, Lafayette College, at 7 o&apos;clock P.M. on Tuesday evening, October 21st. The session was opened by the President, R. W. Raymond, with an address on Mining Industry as illustrated at the Vienna Exposition. The second session was held on Wednesday morning. The Council reported the following names for election as members and associates. They were unanimously elected. †Ayres, W. S., - Easton, Pa. *Baker, Prof. A. L., - Easton, Pa. †Browne, Thomas Nicholl, - Hamilton, Nev. *Carter, Frank, - Pottsville, Pa. *Davis, E. F. C., - Pottsville, Pa. *Fox, Prof. J. G., - Easton, Pa. *Haight, Ogden, - Etna, Pa. †Hall, Norman, - Sharon, Pa. *Knap, Joseph, - Fountain Mill, Pa. †Miller William McKeen, - Easton, Pa. †Pardee, I. P., - Easton, Pa. *Plater, John E., - Eureka, Nev. *Platt, Joseph L., Jr., - Franklin Furnace, N. J. *Plumb, W. H., - Mauch Chunk, Pa. *Reis, George L., - New Castle, Pa. *Samuel, Edward, - Philadelphia, Pa. *Smith, William Allen, - Trenton, N. J. *Smock, Prof. John C., - New Brunswick, N. J. *Weberling, Charles, - Salt Lake City, Utah. Also the following as foreign members Beaulieu, Ad. le Hardy de, - Brussels, Belgium.. Beaumont, Major Fred., - London, England. Beck, Alexander, - Mons, Belgium. Bodmer, J. J., - London, England. Brassert, Berghauptmann, Dr., - Bonn, Prussia. Brogden, James, - London, England * Members. † Associates.

Jan 1, 1874

The Institute assembled in the metallurgical lecture-room of Pardee Hall, Lafayette College, at 7 o&apos;clock P.M. on Tuesday evening, October 21st. The session was opened by the President, R. W. Raymond, with an address on Mining Industry as illustrated at the Vienna Exposition. The second session was held on Wednesday morning. The Council reported the following names for election as members and associates. They were unanimously elected. Ayres, W. S.,.......Easton, Pa. *Baker, Prof. A. L.,.. Easton, PR. Browne, Thomas Nicholl,.... Hamilton, Nev. *Carter, Frank,......Pottsville, Pa. *Davis, E. F. C.,... Pottsville, Pa. *Fox, Prof. J. G.,...,..Easton, Pa. *Haight, Ogden,...Etna, Pa. Hall, Norman,...Sharon, Pa. *Knap, Joseph,......Fountain Mill, Pa. Miller William McKeen,.... Easton, Pa. Pardee, I. P.,....Easton, Pa. *Plater, John E.,......Eureka, Nev. *Platt, Joseph L., Jr.,.....Franklin Furnace, N. J. *Plumb, W. H.,......Mauch Chunk, Pa. *Reis, George L.,......New Castle, Pa. *Samuel, Edward,. ..Philadelphia, Pa. *Smith, William Allen,.....Trenton, N. J. *Smock, Prof. John C.,..... New Brunswick, N. J. *Weberling, Charles,.....Salt Lake City, Utah. Also the following as foreign members: Beaulieu, Ad. le Hardy de,. . Brussels, Belgium. Beaumont, Major Fred.,..London, England. Beck, Alexander,.Mons, Belgium. Bodmer, J. J.,..London, England. Brassert, Berghauptmann, Dr.,. .. Bonn, Prussia. Brogden, James,.London, England.

By J. W. Fuller

During the last 20 years, experimenters have sought to utilize pulverized coal in boiler plants, but refractory and slag troubles have usually overbalanced any gains in efficiency that were obtained. These troubles were caused largely by lack of knowledge of the proper methods of coal preparation and lack of a furnace design that would be adaptable to pulverized-coal firing. When this information was obtained the results were so much more satisfactory that within the last 5 years approximately 80,000 boiler hp. have been installed in plants ranging from 1000 to 20,000 boiler hp. rated capacity, which are operating at an average of 174 per cent. of rating. The first commercial installation for burning pulverized coal under boilers was made at the Parsons shops of the M. K. & T. railroad in 1916. Of eight 250-hp. water-tube boilers thus fitted, six were operated continuously for 3 yr., when oil was obtained at such a low price as to warrant its use. Since then, this plant has been operating alternately on pulverized coal and oil, depending on prevailing prices. Recently gas has been discovered within 20 mi. of this plant, so that this fuel may also be used. No change in furnace design was made when changing from pulverized coal to oil or gas firing. One of the principal advantages of this method of firing is its ability to utilize, with maximum efficiency, all kinds of coal, irrespective of quality or physical characteristics. In fact, quite a number of the present pulverized-coal installations were made for the purpose of utilizing coal that could not be marketed or used in any other way. The Pacific Coast Coal Co., at Black Diamond, Wash., formerly hand fired the boilers, using approximately 125 tons of prepared steam-size coal daily. The Black Diamond steam coal is the best quality of coal for steaming purposes mined in that section of the country, and there is a market for all that can be produced. By installing a pulverizing plant, it was possible to substitute coal of a size and quality that had no commercial value, so that 125 tons daily of the best steam coal formerly used at the mines is now marketed. This company made a similar installation, at its New Castle, Wash., mine with approximately similar results. Each of these two plants has a

Jan 1, 1922

Ahrenholz, Herman William, Jr., Student, Lehigh Univ Bethlehem, Pa. &apos;35 Allen, Carl A., Student, Colorado School of Mines Golden, Colo. &apos;35 Allen, Paul W., Student, Mass. Inst. of Tech Cambridge, Mass. &apos;35 Allen, R. M., Jr., Student, Virginia Polytechnic Inst., "G" Co Blacasburg, Va. &apos;35 Amberger, K. H., Student, Michigan College of Min. & Tech Houghton, Mich. &apos;35 Andersen, Burton Lee, Student, School of Mines, Univ. of Washington Seattle, Wash. &apos;35 Anderson, Joseph S., Student, Univ. of Texas El Paso, Tex. &apos;35 Anderson, R. C., Student, Univ. of Washington Seattle, Wash. &apos;35 Ansel, Gerhard 627 Clyde St., Pittsburgh, Pa. &apos;34 Anutta, Frederick P., Student, Michigan College of Min. & Tech Houghton, Mich. &apos;35 Apsouri, Constantin N., Graduate Student, Univ. of Arizona Tucson, Ariz. &apos;35 Arakelian, Haig Mark, Student, Mass. Inst. of Tech Cambridge, Mass. &apos;34 Archer, George K 1420 Court Pl., Denver, Colo. &apos;34 Argall, George O., Jr., K. E. House Golden, Colo. &apos;35 Argiielles, Alfredo, Student, Univ. of Texas El Paso, Tex. &apos;35 Atwater, Ralph, Student, South Dakota School of Mines Rapid City, S. D. &apos;35 Austin, Robert B., Miner, Page Mine, Federal Min. & Smelt. CoSpokane, Wash. &apos;34

Jan 1, 1934

By C. H. P. Lupis, R. Hocine, G. Bernard

The necessary and sufficient conditions for the stability of a multicomponent phase with respect to infinitesinzal fluctuations are derived and transformed to be written in terms of activity coeffcients and mole fractions rather than in terms of the customary second deritlatives of the free energy. NECESSARY conditions for the stability of a multi-component system were derived by Gibbs as early as 1876.&apos; However, as the usefulness of these conditions is greatly enhanced by the simplicity of their translation in terms of functions of common usage, the present contribution establishes these conditions in terms of activities or activity coefficients-and mole fractions. It was shown in another article2 that not only may these conditions be used for the prediction of the appearance of new phases, but they may also provide a check on the orders of magnitude of the interaction coefficients involved. "Spinodal" decomposition is said to occur when, at constant temperature and pressure, the system is unstable with respect to infinitesimal fluctuations in composition. As a result, the "phases" which appear may be attained through continuous changes in the system rather than discontinuous ones, and, consequently, the free energy of these phases may be described by a unique continuous free-energy function. For a binary system, the familiar curve of Fig. 1 illustrates the case we wish to extend to a multicom-ponent system. The conditions to be written pertain to the decomposition of a system of n moles into moles of phase moles of phase v, ...hen moles of phase 9, where the phases a, ...v, ...9 are—at least initially-arbitrarily close in composition to that of the original phase. Each A, is positive and since the total number of moles n in the system remains constant: Each phase v contains hv(nl +dnY) moles of component (I), ...xV(ni +dny) of component + dnk) moles of component (m). The total number of moles ni in the system remaining also constant, it is clear that:

Jan 1, 1968

By Charles W. Goodale

The principles and theory on which the U. S. mining law of 1872 was based are well understood, and have been discussed at great length by many writers. The papers by Dr. R. W. Raymond1 in the Transactions of the American Institute of Mining Engineers have covered the subject very fully, with explanations of practical results in many adjudicated cases. It is believed that the following instance of the application of the law in recent years will have some weight in a discussion of proposed changes in our mining laws. The litigation between the St. Louis Mining & Milling Co., and the Montana Mining Co., Ltd., a British corporation, over portions of the Drumlummon lode covered more than 20 years, and resulted in a judgment for damages in favor of the St. Louis Co. of such an amount that the Montana Co. declined to pay the judgment, and therefore lost the entire property. The Drumlummon lode claim in the Marysville district, Mont., was located in 1876 by Thomas Cruse. When he staked out his claim, he assumed that the discovery on the Drumlummon vein, and another showing of mineral about, 200 ft. distant, were on the same vein, and the center line of the claim was given a course of N. 579" E. Development of the Drumlummon vein soon showed that its strike was about N. 15" E., and that the other outcrop was on the North Star lode; so it was inevitable that the Drumlummon vein would cross one or both side lines of the location, and the Montana Co. found it advisable to acquire adjoining claims on both sides of the Drumlummon, in order to avoid possible litigation over apex rights. They bought the Marble Heart, but would not purchase the Hopeful (see Pigs. 1 and 2), at the terms proposed for the reason that exploration in the Cruse level had shown the vein to be barren in that region. The owners of the Hopeful were sinking an incline from that claim in 1889, and the Montana Co. enjoined them, contending

Jan 1, 1915

New York Meets first Wednesday after first Tuesday of each month. DAVID H. BROWNE, Chairman. PERCY E. BARBOUR, Vice-Chairman A. D. BEERS, Secretary, 55 Wall St., New York, N. Y. C. A. BOHN, Treasurer. JOHN V. N. DORR, LEWIS W. FRANCIS. Boston Meets first Monday of each winter month. W. E. C. EUSTIS, Chairman. R. L. AGASSIZ, Vice-Chairman. E. E. BUGBEE, Secretary-Treasurer, Mass. Inst. of Technology, Boston, Mass. ALBERT SAUVEUR, H. L. SMYTH. Columbia Holds four sessions during year. Annual meeting in September or October. W. H. LINNEY, Chairman. OSCAR LACHMUND, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. STANLY A. EASTON, S. SHEDD.

Jan 3, 1917

By J. B. Dilworth

In estimating the investment-value of a mining-property or plant, the value of which decreases with operation, it is often necessary to know the sum which must be set aside periodically from earnings either to renew the plant at the end of its life, or to return the capital involved when the earningpower of the investment has ceased. In such cases it is manifestly incorrect simply to divide the total amount to be retired by the &apos;number of periods (usually years) during which the investment shall be active, as the sums periodically withdrawn have a certain interest-earning power varying with the length of time they are held and with the opportunities afforded for their investment. But though the interest may be considered to accumulate regularly year by year, yet the rules and tables for compouiid interest do not apply, owing to the addition of a fixed amount of new money to the total at the beginning of each period. Briefly stated, the problem of sinking-funds is, to find the amount of money which must be periodically set aside at a certain rate of interest, regularly compounded, to yield a certain sum in a given length of time. In most practical cases the interest is compounded and the fresh amount added at the same time—usually once a year—and on this basis the problem may be solved as follows : Let S = total amount to be retired, Let T = interest rate : R = 1 + r, Let n = life of tlie sinking-fund or the amortization-period, Let L = the sum set aside at the end of each year. Then the amouilt of the sinking-fund at the end of first year is 2, which at the end of n years will have illcreased by compound interest to IRn-l. Similarly, another amount, x, will be set aside at the end of second year, which will in turn increase

Jan 1, 1911

By Minoru Sasabe, Mayurni Sorneno, Kazuhiro Goto

I) The Object of the Present Experiment. When the oxygen chemical potential in the gas phase is changed, the oxygen chemical potential in the liquid metal or in the liquid oxide phase will be subsequently changed. The object of the present experiment is to develop a method of measuring the change in the chemical potential of oxygen in liquid metals and in liquid oxides with respect to time, when the oxygen potential in the gas phase changes. II) The Experimental Method. The following types of the oxygen concentration cells with the solid electrolyte of Zr0z-CaO are used: KAZUHIRO GOTO, MemberAIME.MINORU SASABE,and MAYUMl SOMENO are Associate Professor, Research Associate, and Professor, respectively, Department of Metallurgical Engineering, Tokyo Institute of Technology, Meguro-ku, Tokyo, Japan. Manuscript submitted March 12, 1968, EMD. Igas phase liquid Ag or Pb ZrO2-CaO electrolyte!, The measured reversible electromotive force can be expressed by the next equation, provided that the transference number of the oxygen anion in the electrolyte is unity: E = RT/nF log (at electrode I)/P~ (at electrode 11) where is the electromotive force, R is the gas constant, T is absolute temperature, n is valence of oxygen anion, and Pq is the oxygen pressure at the electrodes. As shown in the previous work1 of the authors, the electromotive force is determined by the difference in the chemical potential of oxygen at the vicinity of the interfaces between the solid electrolyte and the electronic conductors used for the two electrodes. Fig. 1 shows the two kinds of the cell assembly used to measure the change of the chemical potential of oxygen in liquid metals and liquid oxides with respect to time. In both cases, the change of the oxygen pressure in the gas phase is measured by the independent oxygen concentration cell located above the

Jan 1, 1969

By F. C. Farnham

In this paper it is shown that the vertical component of the earth&apos;s magnetic field for the area of the United States can be very closely approximated by assuming it to be the sum of the vertical components of two magnetic fields. The first of these is the field of the centered dipole described by J. Bartels,l the axis of this dipole intersecting the earth&apos;s surface at two antipodal points, the one in the Northern Hemisphere being at latitude 78.5°N. and longitude 69°W., and the dipole having such strength that the vertical component of its field at its axis pole is 0.63 oersted. The second field is that due to a second dipole situated halfway between the center of the earth and a point on the earth&apos;s surface at latitude 38.5°N., longitude 91.5°W., the axis of this dipole being along this radius, the south pole being toward the surface, and the dipole being of such strength that its field at the point on the surface mentioned above is 0.069 oersted. Using the field computed on this basis, tables of latitude and longitude correction factors were computed and are included in the paper. It is also shown that the secular variation in the earth&apos;s magnetic field may be roughly accounted for by assuming it to be due to motion of the second dipole described above. Although there is an error in the equation used for computing the strength of the field due to the second dipole, the distribution of the field computed is very nearly that of the assumed arrangement of dipoles. Subsequent work by the author reveals that minor changes can be made in the location of the second dipole, which will make the computed field fit the observed field even more closely. It has also been found2 that the vertical component of the field may be represented equally well by a purely empiric relationship.

Jan 1, 1940

By F. C. Farnham

In this paper it is shown that the vertical component of the earth&apos;s magnetic field for the area of the United States can be very closely approximated by assuming it to be the sum of the vertical components of two magnetic fields. The first of these is the field of the centered dipole described by J. Bartels,l the axis of this dipole intersecting the earth&apos;s surface at two antipodal points, the one in the Northern Hemisphere being at latitude 78.5°N. and longitude 69°W., and the dipole having such strength that the vertical component of its field at its axis pole is 0.63 oersted. The second field is that due to a second dipole situated halfway between the center of the earth and a point on the earth&apos;s surface at latitude 38.5°N., longitude 91.5°W., the axis of this dipole being along this radius, the south pole being toward the surface, and the dipole being of such strength that its field at the point on the surface mentioned above is 0.069 oersted. Using the field computed on this basis, tables of latitude and longitude correction factors were computed and are included in the paper. It is also shown that the secular variation in the earth&apos;s magnetic field may be roughly accounted for by assuming it to be due to motion of the second dipole described above. Although there is an error in the equation used for computing the strength of the field due to the second dipole, the distribution of the field computed is very nearly that of the assumed arrangement of dipoles. Subsequent work by the author reveals that minor changes can be made in the location of the second dipole, which will make the computed field fit the observed field even more closely. It has also been found2 that the vertical component of the field may be represented equally well by a purely empiric relationship.

Jan 1, 1940

Discussion of the paper of N. V. Hansell, presented at the Cleveland meeting, October, 1912, and published in Bulletin. No. 72, December, 1912, pp. 1497 to 1,517. F. L. GRAMMER, Leesburg, Va. (communication to the Secretary*).:-Mr. Hansell conies from a country where charcoal is the fuel, and fuel is therefore costly. The Swedes appreciate more than most Americans the value of ore-concentration, not only in fuel-economy, but also in its influence on the quality of metal produced. Neither in these particulars nor in our knowledge of the dressing of iron-ore do I think. we can claim to be their equals. A 60 per cent. ore is not merely- twice, but more than four times, as valuable as an ore carrying 30 per cent,. Failure to appreciate this fact explains many idle American stacks, erected in defiance of it. Next to the rule that the equipment-cost of a blast-furnace increases approximately as the square of the hearth-diameter, I know of no mathematical relations involved in smelting iron which are less appreciated than the disadvantages of lean ores. Mr. Orn told me, when I was in Stockholm, that 2,500 patents on magnetic concentration had been taken out. He may have been joking as to the exact figure, but his remark indicated the great activity of inventors in this field. The magnetic separators seem to represent two main ideas, namely, wet and dry separation. The wet separators, such as the Gröndal, are applicable to ores requiring the greatest comminution by reason of the small particles of associated minerals or because of the occurrence of magnetite with a soft mineral likely to cake, as in those of Cornwall, Pa. Of the dry magnetic separators some are well suited for large-grained ores, such as those of Mineville, N. Y. We have also magnetic separators, like the Wetherill, for ores not usually classed as magnetic.

Jan 5, 1913

By Frank Firmstone

The piece of spiegeleisen, the analysis of which is given below, was collected by my father, together with various other specimens, while he was manager of the Glendon Iron Works. It bears a label stating that it was taken from a building in the town of Newton, New Jersey, erected in 1765 and torn down in 1863. The building belonged, in 1863, to T. N. McCarter, Esq. The label is in the hand-writing of Mr. McCarter, now deceased, well known as a member of the bar of northern New Jersey. The specimen was, no doubt, given by him to illy father, with whom he had business in 1863 and 1864. It is now in the metallurgical collection of Lehigh University. I know nothing further as to the history of the specimen, but there is no reasonable doubt that it was made from ore from the Andover mine, at the old charcoal-furnace which once stood at the village of Andover, about 5 miles south of Newton, on the Sussex railroad. It was probably broken from one end of a bearer over an open fire-place, is about 6 in. wide by 2.5 in. thick, has been cast in open sand and shows the charcteristic fracture of spiegeleisen rather low in manganese, as shown in Table I. One edge has been white-washed. Table I.—Analyses of Spiegeleisen Made from Andover Ore. 1. 11. Per Cent. Per Cent Graphite,.0.101 0.005 Combined carbon,... 4.529 4.212 Silicon,..0.037 0.294 Manganese,..... 5.760 3.750 Sulphur,.0.003 0.031 Phosphorus,.0.060 0.072 Iron,........ 89.440 91.570 99.920 99.934 I. Spiegeleisen made at Andorer (charcoal) furnace not later than 1765. IT. Spiegeleisen made from Andover ore at Phillipsburg, N. J., anthracire-furnwe, 185-. Both analyses were made by Dr. P. W. Shimer.

Jan 1, 1907