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Discussion of the paper of Frederick W. Apgar, presented at the Butte meeting, August, 1913, and printed in Bulletin No. 7S, June, 1913, pp. 1011 to 1022. L. C. GRATON, Cambridge, Mass.:-I presume I am one of the few who are exceedingly interested in microscopic work, and I am sure we have all enjoyed this paper very much. I will not attempt to express my own feelings in regard to it beyond saying that it seems to me that this sort of investigation and study has been overlooked and slighted, and its possibilities are very great. There are one or two, details which impressed me, because they were novel to me, and one was the development of secondary galena with dull luster. I have never seen any galena which seemed to be secondary, and have never seen any that was secondary or primary that did not have a bright luster. KIRBY THOMAS, New York, N. Y. (communication to the Secretary *) :-The present-day mining engineer is expected to " see into the ground farther than the point of the pick " and he is justified in making free claim to his ability to do so. Mr. Apgar has recorded the development of the application to the work of the engineer of a very useful but tardily recognized instrument-the petrographic microscope, an instrument which is helping to shatter the proverbial "point of' the pick" limitation-and he has shown its use and its possibilities very clearly. Some further field examples of the use of the microscope in engineering problems may add to the appreciation of Mr. Apgar's scholarly paper. In exploration by diamond drills in the Sudbury, Ontario, nickel district it is often of great importance to determine when the drill has passed out of the norite and into the foot-wall formation. Structural calculations may give a clue to the expected point of contact, but the variations are considerable, and, since to stop the drill before reaching the contact is futile, and too continue beyond it is needless, it becomes of theoretic and economic importance to determine positively the lithological nature of the corer at critical stages in the work. In some places the foot-wall is an earlier norite, only distinguishable from the nickel norite (Sudbury-: ite), by means of an examination of the rock slides with a petrographic; microscope. Again, certain diabase dikes which cut the norite and. the foot-wall formations cannot be easily or with certainty distin-

Jan 11, 1913

Discussion of the paper of Robert Franke, presented at the Butte meeting, August, 1913, and printed in Bulletin No. 79, July, 1913, pp. 1201 to 1205. ARTHUR 0. GATES, Lafayette, Ind. (communication to the Secretary*) :-In connection with the comparison of mechanical crushing efficiencies in Tables I and II of Mr. Franke's paper, I wish to suggest a somewhat simpler way of making this' comparison, based upon what the writer has called the "crushing-surface diagram," as published by him in the Engineering and Mining Journal for May 24, 1913. Such a diagram, based on the data given in Table II, is submitted herewith, Fig. 1, cumulative percentages being plotted as abscissas and reciprocals of diameters (theoretical mesh per inch). plotted as ordinates.. Such a diagram averages the diameters without calculation, and areas upon it are proportional to surface produced, and, in accordance with Rittinger's law, to energy spent on crushing alone.

Jan 11, 1913

Discussion of the paper of Reno H. Sales, presented at the Butte meeting, August, 1913, and printed in Bulletin No. 80, August, 1913, pp. 1524 to 1626. L. C. GRATON, Cambridge, Mass.:-It has been my privilege to read with some care Mr. Sales's paper, and I feel it a sense of duty and a pleasure to discuss it briefly. After two months spent underground in the Butte mines by my associates-Messrs. Augustus Locke, A. M. Bateman, and E. H. Perry-and myself, it seems only fair to record our appreciation of the almost baffling structural complexity of the Butte veins, of the remarkable accuracy with which their mechanical details have been worked out, and of the unusually effective and intelligent use of geologic conceptions in interpreting their subtler characters and significance. During this period, under the courteous and helpful guidance of either Mr. Sales, the members of his staff, or the geologists of other companies, we have been afforded opportunity to test many of the conclusions embodied in the present paper, and it is but just to state that as our observations have accumulated sufficiently the great majority of these conclusions have received unquestioned confirmation in our minds. The pleasure consists in realization that the science of mining geology, to which so many of us have devoted ourselves, actually embraces the possibilities that this paper exhibits. The science of geology has been favored by many brilliant contributions of general nature, and by a smaller number of studies remarkable because of their detail and precision. I know, however, of no other piece of work like this, which, including Mr. Winchell's administration, virtually represents the combined results of over 15 years of work by a staff of trained geologists in a district which measures not much more from end to end than it now does from top to bottom. That this concentration of effort and observation has been required, and that it has been repaid by the results attained, are plentifully evident in Mr. Sales's paper. If one were inclined to doubt this after perusal of the text, surely he would be convinced by the maps and sections, several of which, I venture to say, are unapproached in detail and accuracy by anything attempted before.

Jan 11, 1913

Discussion of the paper of Dorsey A. Lyon and Robert M. Keeney, presented at the Butte meeting, August, 1913, and printed in Bulletin No. 80, August, 1913, pp. 2117 to 2149. C. D. WOODWARD, Butte, Mont.:-We constructed a small blast furnace, and used first carbon electrodes and an alternating current of about 50 to 75 volts. We were able to smelt the material which was fed to the furnace, but we did not carry on experiments far enough to see just exactly what the power consumption was and compare it with the amount of material treated. We found that the blast seemed to help materially in reducing our charge and cutting down our power consumption. There were several other experiments tried at the time, and I do not call to mind now just what they were. We were trying to do away with the carbon electrode and replace it with an iron one, and it also seems to me we tried to use the ore for an electrode; but I believe that the electric furnace in the reducing end is simply a question of British thermal units per kilowatt-hour compared with British thermal units in a pound of coke. Now, if a pound of coke costs us 0.5 c. and a kilowatt-hour costs us in the neighborhood of 1.5 c., I think there is a big advantage in using coke instead of the electrical current for copper reducing. We tried steam, and a number of other methods, to throw copper down, but it has been some time ago and I am not very familiar with them now. The outlook of the experiments did not seem to be very promising, and we took it more as a thermal problem than an electrical one. PROF. JOSEPH W. RICHARDS, South Bethlehem, Pa.:-Mr. Woodward has spoken of the question as a thermal problem. I would call attention to the fact that electric furnaces usually utilize the heat of the electric current at from four to ten times the efficiency with which the heat generated by fuel is utilized; so it will not do simply to compare by thermal units generated. Your total thermal units may cost much less from coke than from electricity, yet you will find the electrically generated thermal units utilized in a properly designed furnace from three to ten times more efficiently than in the combustion furnace. You must make that allowance is comparing the cost of thermal units generated electrically and thermal units from coke.

Jan 11, 1913

By Frank Linforth

THE object of this paper is to present a brief outline of the methods of geologic mapping employed in the Geological Department of the Anaconda Copper Mining Co., at Butte, and to show by means of a few typical examples the practical nature of the results obtained. The extremely complicated geological conditions early encountered in Butte mining led mine operators to realize the necessity of accurate detailed geologic mapping as an aid to successful development of the ore bodies. The organization of the Anaconda Geological Department was undertaken in 1900 by H. V. Winchell, who, in conjunction with D. W. Brunton, worked out the essential methods of procedure which are, in the main, followed at the present time. Since the year 1906 the geologic work has been under the direction of Reno H. Sales, and in some respects the scope of the work has been slightly enlarged. Au excellent article describing the general equipment of the geological department was presented by D. W. Brunton at the British Columbia meeting of the Institute in 1905.1 His idea, that data collected underground and recorded should be put to practical use and not remain a mere " inventory of the company's underground possessions," is the keynote to the success of applied geology in Butte. The geologic notes are taken as soon as possible after the ground is broken so that any mistake in the mining may be corrected at once, or any particularly advantageous procedure may be suggested before any useless work is done. Taking the notes underground is a comparatively simple matter, but a few necessary precautions may be pointed out. The essential to success is that the notes shall show exactly what geological facts are disclosed. The observer must discriminate carefully between important and unimportant exposures in making the record, especially as regards the relation between veins and stringers, between faults and minor slips, or between the characteristics of veins of different ages. A simple color scheme has been adopted for making this record: Red pencils are used to indicate.

Jan 11, 1913

(Members are urged to send in for this column any notes of interest concerning, themselves or their fellow-members.) Members and visitors who registered at institute headquarters during October A. Adiassewich, St. Petersburg, Russia. Charles W. Merrill, San Francisco, Cal. A. F. Lucas, Washington, D. C. Carl J. Trauerman, Butte, Mont. Allan J. Clark, Lead, S. D. Herbert B. Cox, Boston, Mass. Prof. Loewinson-Lessing, St. Peters- James W. Malcolmson, Kansas City, Mo. burg, Russia. A. E. Sunderhauf, Paramaribo, Dutch F. Maury Gillespie, Abangarez, Costa Rica. Guiana, S. A. M. Gardner Talcott, Irvington-on-Hudson, N. Y. D. W. Brunton, Denver, Colo. A. P. Watt, Newark, N. J. Dwight E. Woodbridge, Duluth, Minn. S. A. Taylor, Pittsburg, Pa. Alexander Fyfe, Boston, Mass. Ralph Wilcox, Miami, Ariz. Robert A. Seip, Wilkes-Barre, Pa. William J. Cox, Denver, Colo. A. J. Eveland, Boston, Mass. E. P. Ross, Duquesne, Pa. M. F. Sayre, Brewster, N. 1. H. Mortimer-Lamb, Montreal, Canada. Albert Sauveur, Cambridge, Mass. F. L. Grammer, Leesburg, Va. Robert H. Leach, Brockton, Mass. R. R. Moore, Mexico City, Mex. Steinar Foslie, Kristiania, Norway. Charles E. van Barneveld, San William A. Wong, Honolulu, Hawaii. Fran¬cisco, Cal.

Jan 11, 1913

Maps and Mining Data for the Library. I suggest that the Institute Library can increase its usefulness by systematically soliciting from the engineers and mining companies all published reports and maps, and parts of reports and records, not of a private or confidential nature. If this is done an engineer assigned to report on a well-known property or district may depend on finding at the library a large amount of preliminary data and general information from these official and engineering reports relating to his prospective investigation. In many mining reports a large part of the report is of a general technical and scientific character, and there could be no good objection on the part of either the engineer, or his client to making such information thus of record. I believe there would be a great deal of information furnished by the engineers if they were properly solicited under this plan. I have found on different occasions that much work could be saved by such records now in the Library. The plan would also have the advantage of keeping the Library in closer touch with the active engineers, a feature to be desired. I also have in mind that the Library should undertake to collect all the prospectuses and financial literature which is issued in connection with mining. Of course a great deal of this is unreliable, but even this is valuable for record in the matter of legal and other investigations. I shall be glad to co-operate with you, and do anything I can to develop more in detail the general ideas above noted. Yours very truly, KIRBY THOMAS NOTE.-The Library of the Institute makes a specialty of collecting and filing material of this character, and the letter printed above is brought to the attention of members in the hope that they will co-operate by sending in copies of maps, reports of properties, etc.

Jan 11, 1913

Discussion of the paper of Frederick Laist, presented at the Butte meeting, August, 1913, and printed in Bulletin No. 79, July, 1913, pp. 1147 to 1162. J. C. DICK, Salt Lake City, Utah :-I would like to ask Mr. Laist why a 10 per cent. salt solution was used. MR. LAIST :-The reason for using salt in the solution is to get .the sulphur. The solution of dilute sulphuric acid has no solvent action on the sulphur even after roasting, and the addition of the salt is made primarily to dissolve the sulphur chlorides. MR. DICK:-I would like to ask also if you made any experiments as to grinding fine your calcines, rather than leaving the coarse material. MR. LAIST :-We have not made any experiments along those lines except in the laboratory, but the objections which we have to grinding are that the difficulties of roasting are very much greater when roasting finely ground material than when roasting coarse material, and the difficulties of leaching are somewhat increased; the percolating system is simpler and easier to manipulate, particularly when acid solutions are used, so that we prefer from our experience not to grind. STUART CROASDALE,* Denver, Colo. (communication to -the Secretary +) :-In order to meet the conditions involved in his ore-treatment problem, Mr. Laist has developed a very interesting and apparently successful metallurgical hybrid which he calls the oxychloridizing roast. The lower floors of the MacDougall furnaces are made to accomplish what used to be done on the " cooling floor" in the old days of salt roasting and " hypo " or brine leaching of silver ores.

Jan 11, 1913

Discussion of the paper of Ralph Hayden, presented at the Butte meeting,. August, 1913, and printed in Bulletin No. 80, August, 1913, pp. 1443 to 1467. JOHN V. N. Done, Denver, Colo.:-Mr. Hayden has placed the metallurgical profession greatly in his debt .for this valuable paper. The importance of such a complete description of the research work on which is based the building of a plant to add at least 10,000,000 lb. of copper per year to the production of the Anaconda Copper Mining Co., at small expense, will be appreciated by all our members, and especially those who are facing similar problems. The information given in regard to the treatment methods discarded will be a great help to many workers, as it is often of as much importance to know what ? not to do" as what method to adopt. I Some further comment on the tests of the Dorr thickener may be of interest, as they have led to developments which I believe will prove of great importance. Before the Dorr thickener was installed, I had shown Mr. Laist reports from the Steptoe Valley concentrator, in which it was stated that one thickener 17 ft. in diameter was the equivalent in settling capacity of twelve 8-ft. cones, although the latter-contained double the surface area.. Mr. Laist, had made careful tests on the settling capacity of in 8-ft. cone on Anaconda slime, and we naturally expected the thickener would show a much higher capacity for equivalent area. When, is Mr. Hayden stated, the tests showed no increase, I realized that we were comparing it with a cone under test conditions, while the Steptoe results were based on operative conditions, find the explanation given by Mr. Waddell for the great difference had been, that " there is only one unit to watch instead of twelve, without the constant result of feed to twelve cones becoming unbalanced. Also the one 1 1/8-in. spigot used on the Dow requires no attention compared with the dozen 3/8-in. spigots of the cones.' I realized also as a. result of the tests that the total settling area required to handle the immense tonnage of the Anaconda company would be enormous, and very expensive in view of the housing required by Montana climatic conditions. After studying the matter over, I told Mr. Laist that I believed a thickener operating in a much shallower tank would have nearly the same capacity. I asked him to test it out in the same tank filled 3 ft. deep, and stated that if my idea

Jan 11, 1913

By E. P: Mathewson

Discussion of the paper of E. P: Mathewson, presented at the Butte Meeting, August, 1913, and printed in Bulletin No. 78, June, 1913, pp. 1033 to 1037. PROF. JOSEPH W. RICHARDS, South Bethlehem, Pa. :-Speaking to the question of the development of the basic lining, and speaking from a somewhat considerable study of the history of the process, ,I think Mr. Mathewson's conclusion (in the last paragraph. of his paper) is perfectly justified and is very fairly stated. Messrs. Smith and Pierce worked at developing their process for many years ; copper men had been trying their level best to get away from the silica lining of the converters and had uniformly failed. On one page of Mr. Mathewson's paper we read that at the old works of the Anaconda Company, at Anaconda, the experiments " were abandoned on the score of cost and lack of advantages." On the next page, after describing the work of Messrs. Smith and Pierce, we have the statement that the Anaconda Company lined a shell with mangnesite brick and the ?results were excellent." I think Mr. Mathewson's statement that to Smith and Pierce belongs the credit of developing a long-discredited idea, is correct. C. D,. DEMOND, Anaconda, Mont. :-It seems to me that the matter of the lining is important; my impression is that they used tar in their basic lining and that did not seem to be at all successful at Anaconda, but silicate of soda was very successful. MR. RICHARDS :-I did not know that they- had abandoned the use of tar. MR. DEMOND :-I said I thought that was the practice. At Anaconda that was not at all satisfactory in the basic linings. Silicate of soda was very satisfactory and is so.

Jan 11, 1913

ALBERT SAUVEUR, Chairman. A. A. STEVENSON, Vice-Chairman. HERBERT M. BOYLSTON, Secretary, Abbot Bldg., Cambridge, Mass. John Birkinbine, William Kelly, J. S. Unger, William H. Blauvelt, Charles Kirchhoff, Felix A. Vogel, James Gayley, Richard Moldenke, Leonard Waldo, Henry D. Hibbard, Joseph W. Richards, William R. Walker, Henry M. Howe, C. F. W. Rys, William R. Webster, Robert W. Hunt, E. Gybbon Spilsbury, Frederick W. Wood. J. E. Johnson, Jr., The innovation of a special meeting under the auspices of the Iron and Steel Committee was well justified, if we accept as a criterion the number of papers presented at the meeting held on Oct. 16 and 17 in New York and the attendance at that meeting. Twenty-four papers were read, and most of these were widely discussed orally, while doubtless the written discussions will be even larger in extent. Discussions will be received up to Dec. 1, 1913. The attendance at the meeting of 106 members and 75 guests is an evidence of the wide anti growing interest in the Institute of men interested chiefly in iron and steel. It is especially interesting to note this large attendance at a meeting where very little of a social nature was introduced into the program. An informal dinner for the men at the Engineers' Club closed the meeting. At this dinner were present about 70 members and guests. One of the Vice-Chairmen and the Secretary of the new Committee on Petroleum and Gas told of the important plans in prospect of that Committee. Brief impromptu speeches by a considerable number of the members and guests were enjoyed. Professor Marburg reiterated his previous assertion that he believed that the Institute and the American Society for Testing Materials, as well as some of the other technical societies, were all fighting for one good cause; that there was room in the field for all of these societies with their various points of view; and that they should march shoulder to shoulder. The success of this dinner was due largely to the efforts of Mr. Johnson who had the affair in charge.

Jan 11, 1913

Meeting, Oct. -04, 1913.-The sum of $1,250 was directed to be sent to the International Engineering Congress, 1915, in accordance with the terns of the Institute's guarantee. It was voted to request the several Technical Committees to recommend names of their members as sub-chairmen and members of sub-committees to co-operate with the Bureau of Mines. The Finance Committee was empowered to send all members in arrears a notice that the provisions of the Constitution, by which they cease to hold the privileges of membership if their dues are not paid by Jan. 1, 1914, become operative on that date, unless the Directors vote to extend the time in each individual case. The report of the Nominating Committee, printed on page i, was accepted. It was voted that a notice to be prepared by the Committee on Increase of Membership and an application blank for membership be printed in the front of each Bulletin. The report of the Committee on Patent Law Legislation was adopted and the Committee discharged. The Budget of the Chairman and the Secretary-Treasurer of the Colorado Local Section for the balance of the present calendar year was accepted and an appropriation of $47.75 made to them. Upon the nomination of two members of the Committee on Honorary Members, backed by 13 members of the Institute who are not members of the Board of Directors, Dr. Frank Dawson Adams, of Canada, was unanimously elected an Honorary Member of the Institute. Upon the nomination of two members of the Committee on Honorary Members, backed by 11 members of the Institute who are not members of the Board of Directors, Mr. Ezequiel Ordoñez, of Mexico, was unanimously elected an Honorary Member of the Institute.

Jan 11, 1913

(Members are urged to send in for this column any notes of interest concerning themselves or their fellow-members.) Members who registered at Institute headquarters during September: William B. Phillips, Austin, Texas. Will L. Clark, Jerome, Ariz. Olof Wenstrom, Boston, Mass. Robert H. Richards, Boston, Mass. Anthony F. Lucas, Washington, D. C. Hennen Jennings, Washington, D. C. P. H. Griffin, New York, N. Y. Waldemar Lindgren, Boston, Mass. H. N. Lawrie, Portland, Ore. C. Snelling Robinson, Youngstown, 0. Clarence P. Linville, Everett, Pa. E. P. Ross, Johnson, Tenn. Members of the XII International Geological Congress who made the Institute Office their headquarters while in New York A. Bigot, Caen, France. E. Gentil, Paris, France. J. Caillebotte, Paris, France. H. Saint-Clivier, Paris, France. John Ashworth, Manchester, England. Tadasu Hiki, Kioto, Japan. T. Dahlblom, Falun, Sweden. L. Milch, Greifswald, Germany.

Jan 10, 1913

By P. H. Griffin

WHEN a subject, such as the manufacture and service of chilled car wheels, as has been fruitlessly discussed for ten or fifteen years, it is difficult to revive interest and action by the mere repetition of statements and arguments that have been made before. And when a situation involves serious responsibilities for conditions that have grown up under circumstances beyond the control of any particular individuals or authority, it is even more difficult to deal with. But there is one phase of every subject that need not involve these particular points if presented in a, proper manner; and that is, " the future state." I will try to present the subject of this communication from the latter standpoint and with the hope that all of those interested will feel disposed to give the matter attention from the basis that it is a, vitally important one to all that travel on railroads, whether as employees or officials, or as dependent on those in charge of the operation, or in the matter of materials and equipment used. The conditions of chilled wheel service have been changed so radically in the past ten or fifteen years by the use of freight cars of 40 and 50 tons capacity, that it is fair to say in the interest of all concerned in the use and in the manufacture of such wheels, that the increased strains and loads have been quite sufficient to account for much of the service results that have transpired. That proper provision was not made for increased possibilities of strength and wear, in fact that previous factors of the kind were allowed to deteriorate, is no proof that such wheels cannot be made equal to heavy service conditions as shown in the data given herein.

Jan 10, 1913

NEW MEMBERS. The following list comprises the names of those persons who became members during the month of September, 1913: Members. ANDERSON, ANDREW P., Min. Engr 908 Story Bldg., Los Angeles, Cal. ANDROS, STEPHEN 0., Min. Engr University of Illinois, Urbana, Ill. BECKETT, PERCY G., Min. Engr Globe, Ariz. BLAIR, THOMAS S., JR., Prest. Blair Engrg. Co 343 S. Dearborn St., Chicago, Ill. BOYLE, HARRY, Min. Engr S07 Lowman Bldg., Seattle, Wash. BRADEN, EUGENE B., Vice-Prest., Selby Smelting & Lead Co., Merchants Exchange Bldg., San Francisco, Cal. CHALMERS, JOHN W., Min. and Elec. Engr., Morro Velho, Villa Nova de Lima, Honorio Becalho Minas Geraes, Brazil, So. America.

Jan 10, 1913

By Clarence Linville

IN an article published in the Iron. Trade Review 1 I gave a convenient arrangement for the installation of wet and dry bulb thermometers for use in making moisture determinations in the air being blown into a blast furnace, and also gave a chart for use in obtaining moisture values from the thermometer readings. The data from which this chart was prepared were obtained from the tables in use by the U. S. Weather Bureau.2 The work of Carrier 3 has shown that these tables are somewhat in error. He has recalculated the values for moisture as referred to, wet and dry bulb thermometer readings, and he has prepared a psychrometric chart from the values thus obtained. This work has priced the subject of psychrometry upon a correct scientific basis. I think it is proper that we should recognize the importance of his work and give him credit for one of the most interesting and valuable researches that have been published in recent years. Blast-furnace men are not ready to use, as he suggests 4 a value expressed in grains of water accompanying a pound of dry air. However convenient this may be for heating and ventilating work and other engineering problems, there are several reasons for preferring the use of a value expressed in grains of water in a. cubic foot of mixed air and water vapor, in connection with combustion phenomena and the effects of moisture on blast-furnace operation. Previous papers presented to the Institute have used such values and we have

Jan 10, 1913

71 BROADWAY, NEW YORK, Sept. 22, 1913. CHARLES W. GOODALE, Chairman, . DARSIE C. BARD, ESQ., Secretary. Committee on Precious and Base Metals, Butte, Montana. Gentlemen The wonderful success of the meeting of the Institute held in Montana makes it necessary that some public acknowledgment should be made to those to whom this success is due. We are conscious that the securing of the great number of technical papers of lasting value and the carrying to success of most complete detailed arrangements for holding the meeting have called for several months of skilled effort on your part. The benefit of the meeting is very great and extends not only to those who were fortunate enough to be present, but to our four thousand absent members and their friends as well. To you and your associates on the Committee whose efforts have made this never-to-be-forgotten meeting possible we owe far more than can be expressed in votes of thanks. Very respectfully, CHARLES F. RAND, President.

Jan 10, 1913

By Robert Abbott

THE influence of various elements in retarding or accelerating the absorption of carbon during the process of carburization is fairly well known. In general those elements which forth carbides accelerate the absorption, while those which do not retard it. It has sometimes been wrongly stated that those elements which raise the temperature of the critical range increase the absorption, while those which lower this temperature decrease it. Silicon is a notable exception to this rule, for its influence is to raise the critical range but to lower the absorption of carbon. Some elements which do not form carbides have no apparent influence upon the absorption rate. Carbon itself retards the absorption rate. With a view to obtaining more exact data upon the subject the following experiments were undertaken : 208 steels of different chemical composition were selected to represent most of the types of modern constructional steels. Specimens 3 in. in diameter and in. in length were weighed to milligrams. They were then packed in the special carburizing box shown in Fig. 1, and kept in .the furnace for 10 hours at a temperature of 900° C. A duplicate experiment was conducted at 1,000° C. At equal' intervals of time the box was rotated in the furnace so that. two complete revolutions were made in the 10 hours. This precaution was taken to neutralize as much as possible any effect of unequal heating. At the end of the 10 hours the box was allowed to cool in the furnace with the doors open. The specimens were then weighed again and the increased weight (carbon) determined. In. the following table are given the analyses of the various steels, together with the. increased weight of .carbon expressed in milligrams.

Jan 10, 1913

By Richard Lee

SINCE the economics in the blast furnace resulting from enriching iron ores are so great, much attention, has been paid during the past few years to the various methods of concentrating lean ores, and, as the concentrated ore is usually of extreme fineness, various methods . of agglomeration and sintering, of more or less value, have been put 'into operation. The resulting agglomerated concentrates are generally obtained in the form of briquettes or nodules. The briquettes naturally divide themselves into two classes: (1) those made by the mixture of some binding agent, and then formed into briquettes under great pressure; and (2) those made by sintering the concentrates, the latter either being formed into bricks before exposure to heat or the sintered mass broken into fragments afterward. Of the first class I will not speak, as they are not used on an extensive scale in this country. The second class of briquettes, or those made by sintering, are simply masses of melted or fused silicate and oxide of iron mingled with more or less silicates of aluminum, lime, and magnesia. The fact that the material in a briquette is sintered is proof positive that there are no pores in the material. There are, however, quite a number of holes of greater or less diameter through the substance of the briquette. They are not pores in the common acceptance of that term as applied to ores by furnacemen, as the sides of the holes and channels are fused. In reality the material is simply mill cinder. It is practically untouched by the gases in the upper part of the furnace, and the iron has to be reduced by solid carbon in the boshes and hearth. Briquettes sometimes show a little saving in fuel in the furnace over an ore mixture of large lumps, but that saving is made simply because, owing to the numerous holes and channels through the mass, the briquette is practically composed of numerous small or fine lumps, and, as is well known, the finer the

Jan 10, 1913

New York Meeting, October 16 and 17, 1913.-The One Hundred and Sixth meeting of the Institute for the reading and discussion of professional papers will be held in New York City, on Thursday and Friday, October 16 and 17, 1913. Headquarters will be at the Institute office in the Engineering Societies Building, 29 West 39th Street. The sessions will be held in one of the assembly rooms of the building. Because of the many valuable papers on iron and steel obtained with the assistance of the Iron and Steel Committee, which papers could not appropriately be presented and discussed at the Montana meeting, this October meeting of the Institute is held for the purpose of reading and discussing these papers, most of which will be printed and distributed in advance. The members of the following societies have been invited to attend the meeting, and several have accepted and declared their intention of taking part in the proceedings: American Society for Testing Materials, American Iron and Steel Institute, American Society of Mechanical Engineers, American Society of Civil Engineers, American Institute of Electrical Engineers, American Foundrymen's Association. The meeting will be conducted under the auspices of the Iron and Steel Committee, and the latest revised program of the proceedings will be found on page xi, under the notes of this Committee.

Jan 10, 1913