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By Max Roseler

THE CHAIRMAN (WILLIAM KELLY, Vulcan, Mich.).-Some 8 or 9 years ago I was at Daiquiri, only a. few miles east of Firmeza, where there are deposits of iron ore of the same general character. There is a great conical hill, perhaps 800 or 1,000 ft. in height and the ore deposit appears to be somewhat in a canoe shape on one side of the hill. The mining has been done by quarrying the ore in benches. These are called levels and to go to the 10th level it was necessary to take mules and ride to the top of the hill, which was to me an upside down arrangement of numbering levels and a novel method of entering and viewing a mine. A little copper ore can be seen in places, and not being a geologist I thought the deposit might possibly be a gossan, but none of the geologists who have written on the subject approve of this hypothesis and the great question seems to be what part, if any, the limestones have played in the origin of ore; whether these deposits are replacements of limestone and whether they are contact ,deposits between the limestone and the other rocks. Examinations have been made by many eminent geologists and the problem has been discussed vigorously on both sides. The deposits are exceedingly interesting from a commercial standpoint and although they have been studied for a number off years the origin of the ore is still a difficult and somewhat controversial question. J. T. SINGEWALD, JR., Baltimore, Md.-I have had the privilege of visiting these deposits and have been very much interested in this paper, of Dr. Roesler's; having been on the ground, I can easily appreciate the difficulties under which he labored in attempting to work out the geology of that region, and he certainly deserves considerable credit for the way in which he has deciphered the geological relations of the Firmeza district. There are several points in his paper 1 ,would like to discuss; first, in regard to the geological interpretations. His differs from previous interpretations in the relative age of the diorite and the granite, but you will note that Prof. Lindgren suggests the probability. that those two rocks are very closely of the same age, and Prof. Kemp actually suggests, although he does not-accept the idea, that the granite is probably later than the diorite, so that there seems to be no particular reason

Jan 4, 1917

By D. B. Reger

DAVID B. REGER.-T Want to 'add that since this paper was prepared a well is now being; drilled it the location recommended do the last page. It was not, however, done at my instance; it was done at the instance of Dr. White, the State- Geologist of West Virginia, who has been trying for several years to induce the large oil and gas companies to make a test of some of these, deep sands in West Virginia and a well is now just being started in Wood County, right at this immediate

Jan 4, 1917

By E. C. Harder

J. T. SINGEWALD, JR., Baltimore, Md.-I might say a word further in regard to the Miguel-Burnier district. I am sorry Mr. Harder is not here. I had hoped to be able to ask him a few questions in regard to some of the features of those deposits. This Miguel-Burnier district is the other district that I referred to that lies in the State of Minas Geraes. The interpretation that Mr. Harder gives to, these deposits is the same as that given by Harder' and Chamberlin in a previous paper, and that is that they consist of lenticular deposits of sedimentary origin in a series of rocks that also include lenses of limestone, but they seem to think that the manganese ores occur at a definite horizon and at a horizon different from the limestone. We found that the manganese ores occur at several horizons, as also do the limestone lenses, and the limestone masses are of the same shape as the manganese orebodies, so that our own feeling was that these manganese ores simply represent concentrations within the zone of oxidation formed as. a result of decomposition and replacement of this limestone. To the east of Miguel-Burnier there is a big bend in the railroad which cuts through, at right angles to the strike, this series of rocks. Here is shown very well both the local character of the limestone lenses and the local character of the manganese lenses in that, though the distance across the bend is only a couple of hundred yards, the limestone and. ,manganese lenses do not match up at all, and it also shows plainly that both occur at more than one horizon.. Consequently there is no reason why the manganese ore could not represent alterations of this limestone. The mine workings do not as yet give very definite information on this point in that they are all comparatively shallow and within what would be the zone of oxidation so that what they will grade into below that depth, we do not know. On the other hand, the character of the ore suggests that it may, represent such -a product in the zone of oxidation in that it tends to be quite earthy; whereas, if the manganese had been there originally as such it would have undergone the same metamorphism that the other rocks have undergone and one would have expected that it would have been converted into a hard manganese ore that would today stand out pretty much as do the iron ores of that same region and not have the soft, earthy texture which is a prevailing characteristic.

Jan 4, 1917

By F. R. Van Horn

WALLACE MCKEEHAN, Douglas, Ariz. (communication to the Secretary*).-In going over this report, which I have done very carefully, I find that the summary as composed deals with the various problems almost entirely from the employer's standpoint and that practically no consideration is given to the employee's point of view. An experience of 3 ½ years as safety inspector, and almost 30 years as workman-and official, has convinced me that any plan for the betterment of working conditions which will achieve any degree of success must give the workmen their share of responsibility and allow them full participation. The company may finance and direct the movement, but its ultimate success depends upon the support given by the workmen. The cooperation of the men doing the actual work is so essential that all writers insist that this must be secured, but they do not agree as to how this can best be done.

Jan 4, 1917

By W. C. Phalen

E. G. SPILSBURY; New York, N. Y.-I would like to emphasize what Mr. Phalen says in his paper regarding the possible utilization of the waste acids in the West for the acid concentration of phosphate rock, and to call attention to the fact that this is already being done by Mr. Laist at Anaconda, who is producing concentrated phosphoric acid from these low-grade rocks. During the last year, he has not been able to carry this along to the extent he, had expected, owing to the tremendous demand which they have had for all the acid they can produce, so instead of having a. surplus of acid, as was expected, they are really short of this material for their electrolytic copper and zinc work.

Jan 4, 1917

By G. Aertsen

THE CHAIRMAN (HENRY D. HIBBARD, Plainfield, N. J).-This excellent paper fills a gap in our Transactions and is most acceptable. In the early days another way of casting tire ingots, sometimes called cheeses, because of their shape, was to use a 22-gage sheet-iron cylindrical can for each ingot of the proper size to give the weight desired. These cans were bottom cast in groups, usually of four, each can being surrounded by a heavy iron ring somewhat taller than itself the top of the can being covered by a circular cast-iron plate having a small conical riser in the center, about 2 ½ in. in diameter at the bottom and 10 in. high. The top plate was clamped down to resist the upward pressure of the fluid metal and the space between the can and the outer ring, usually about 2 in. wide, was filled with dry sand. The riser permitted the escape of some of the air displaced by the steel and also increased the pressure in the steel when the mold was filled, and so diminished somewhat the tendency for gas holes to form. But little was known of segregation and pipe in those days, though the center of an ingot was understood to be the worst part, and it was separated in part in the disk which was punched out in perforating the ingot. This disk was about 8 in. in diameter and from ¾ to 2 in. thick, the variation in thickness being to rectify the weight. When an ingot was too -heavy, a thicker disk-was made by not driving the punch in quite as far as when the ingot-weight was right. Then the bloom was turned over and the punch driven in on the other side, which finished the punching and detached the disk. The tire bloom was then" becked" and later reheated and rolled as described in the paper. The forging was done with a 10-ton double-acting steam hammer. The steel generally speaking had lower carbon, from 0.45 to 0.55 per cent., than tires today have, and the tires were smaller, the most common size of ingot weighing 1,060 lb. each. BRADLEY STOUGHTON, New York, N. Y.-This paper was specially requested by the Iron and Steel Committee, because that Committee thought so important an industry should have its history written by one who was familiar with it, and before he had forgotten, or all the rest of the world had forgotten, its early stages. Mr. Aertsen has said that it is not an exhaustive research. I think it would not be any different if it were an exhaustive research, because our library made a careful attempt to find some written light on the history of these tires, but very little was found.

Jan 4, 1917

ST. LOUIS SECTION H. A. BUEHLER, Chairman, CHARLES T. ORR, Vice-Chairman., THOMAS T. BREWSTER, Vice-Chairman, L. L. HUTCHISON, Vice-Chairman, W. E. McCOURT, Secretary-Treasurer, Washington University, St. Louis. CHARLES J. ADAMI, EUGENE MCAULIFFE, A. C. TERRILL, JAMES A. CASELTON, JAMES D. ROBERTSON. The annual meeting of the St. Louis Section was held at the St. Louis Club, Saturday evening, Mar. 10, 1917. Philip N. Moore, President, and Bradley Stoughton, Secretary of the Institute, were the guests of the Section. The meeting was preceded by a dinner, at which 70 were present, and was presided over by F. W. DeWolf. Addresses were made by Mr. Moore and Mr. Stoughton. The routine reports of the officers were- presented and the Executive Committee named above was elected for the current year. The special business of the meeting was a report of progress concerning the arrangements for the Institute meeting to be held in the St. Louis Section district, Oct. 8 to 13, 1917. The general program for the meeting met with the cordial approval and cooperation of the members of the Section. It was evident that the members are united in an endeavor to arrange a successful meeting. W. E. McCOURT, Secretary.

Jan 4, 1917

For the year ending February, 1918 PRESIDENT PHILIP N. MOORE ST. Louis, Mo. PAST PRESIDENTS WILLIAM L. SAUNDERS NEW YORK, N. Y. L. D. RICKETTS, NEW YORK, N. Y. FIRST VICE-PRESIDENT SIDNEY J. JENNINGS NEW YORK, N. Y. TREASURER GEORGE C. STONE, NEW YORK, N. Y. SECRETARY EMERITUS ROSSITER W. RAYMOND, NEW YORK, N. Y. SECRETARY BRADLEY STOUGHTON, NEW YORK, N. Y.

Jan 4, 1917

(Under this heading will be published notes sent to the Secretary of the Institute by members or other persons introduced by members) Member, aged 32. Fifteen years' experience in the mining, quarrying, and manufacture of gypsum and gypsum products, as purchasing agent, designer, operating manager and managing executive. Thoroughly familiar with the business in all branches, especially the organization of efficient producing forces and machinery and the value of cost and their application to manufacturing. Desires responsible position with a financially reliable concern in the same or similar business in which an interest may be obtained at a later date. Now doing consulting work, but free for appointments after April 1. New York or Philadelphia. No. 345. Member, technical graduate. Unmarried. Aged 32. Seven and one half years' experience in mining, timbering, and mine sampling. At present, and for past two and a half years, mine sampler for well known and highly successful mining company. Desire change. Go anywhere. Prefer assisting Mining Engineer. No. 346. Member, 40 years old. 18 years' experience in examinations and operation in the United States, Mexico and South America. Especially successful with poor class of labor. Open for engagement in any part of the world, in technical, administrative or consulting work. No. 347. Member, technical graduate. Sixteen years' experience as engineer, superintendent, and manager in metal mines. Exploratory . work, developing and equipping new properties. Operation of large mines, and various systems of mining. Low costs. Specialized in iron and copper mining, but have had some experience in zinc, lead and pyrite mining. No; 348.

Jan 4, 1917

By C. R. Hayward

CARLE R. HAYWARD.-I do not want it understood that I think that the conclusion that the time of tempering temperature is immaterial has been definitely proven, but since these are the first definite figures put out, I thought before continuing on more work ourselves, it would be well to present them as progress and for information. J. A. MATHEWS, Syracuse, N. Y.-I think that if Prof. Hayward would consult the paper of Profs. Barus and Strouhal,1 1885, he would find about 250 pages, mostly figures, on this subject, in which they investigated the tempering effect by electrical and magnetic methods. There are so many figures in the paper that it is very difficult reading. One point particularly brought out was that even at a low temperature, such as the boiling point of alcohol, about 60° C., there is a tempering effect, increasing up to 4 hr. One reason they obtained those results, with which the present authors are at variance, was that they started with a high-carbon steel which hardens thoroughly, whereas the steel Prof. Hayward and his collaborator used was a comparatively mild steel which does not take a great deal of hardening. About 3 years ago Mr. Stagg and I published 2 a few figures bearing on the same subject, but we used .a low-carbon alloy steel of high tempering qualities and found a great deal of improvement, particularly in ductility, by continuing the drawing up to 4 hr. We used a chrome-vanadium steel showing after heat treatment 250,000 tensile strength. On short drawing, we got almost no ductility, but by continuing to 4 hr., we raised it to 12 per cent. I believe Prof. Hayward's results are due to using comparatively mild steel, whereas Prof. Barus used drill rod and carried out a, wonderfully exhaustive

Jan 4, 1917

By Dorsey Hager

DORSEY HAGER, Tulsa, Okla.-I have been asked why the Dexter region is dry. I would like to know myself. I drilled two dry wells on that same anticline which has production to, the east and west and south and north. That same anticline has seven domes that have been drilled and only three have proven productive out of the seven. In other words, you have one well-defined anticline with seven domes along its length, all mappable, all checked carefully, and only three of those seven have produced. Now why the others did not produce, I do not know. L. L. HUTCHISON, Tulsa, Okla.-There is no appreciable difference in the character or structure of the sands? DORSEY HAGER.-NO, I have never .been able to see any appreciable difference in the sands where we got production and Where we did not get it. I will say that the deepest wells we drilled, in the vicinity of Dexter, had no sands at the point where they got the production farther north. I. N. -KNAPP, Ardmore, Pa.-I first went to the Kansas-Oklahoma field in 1895 and occasionally thereafter until 1899, when I began drilling; for oil. I started close to wells that were producing gas and which, when drilling, lead made good oil showings in a sand above the gas. I thought these showings were good enough evidence of an oil pool for me without looking for any anticline and I made a paying development in what' I was afterward told by geologists was probably a synclinal trough. If I remember correctly Dr. Orton's report on the lola gas pool (about 1898) he distinctly said that he found no evidence of anticlinal structure and concluded from the records of a large number of wells that there, was a terraced structure of the productive gas sands, of which there were no surface indications.

Jan 4, 1917

In accordance with the usual custom, manuscripts to be presented at the next meeting of the Institute must be in the hands of the, Secretary before July 1, 1917. Manuscripts to be properly distributed in advance of the meeting must be in the hands of the Secretary before June 1, 1917. At the last meeting of the Institute 45 papers were presented, and 42 of them were actively discussed. This experience makes us believe that advance distribution is the best possible means of getting a good discussion of papers and of securing for them the interest of the members of the profession. It will be impossible, however, to give the papers proper distribution if they bare not received before June 1, 1917.

Jan 4, 1917

NEW- MEMBERS The following list comprises the names of those persons who became members during the period Feb. 10, 1917 to Mar. 10, 1917. ANDERSON, .LAWRENCE W., Min. Engr., Boston Mine, Utah Copper Co. Bingham, Utah. AUSTIN, JOHN W., Assayer, Magma Copper Co., P. 0. Box 101, Superior, Ariz. BARNARD, C. W., Treas. and Resident Mgr., Arizona Asbestos Assn., Globe, Ariz. BIERMAN, A. C : Geol., Producers Oil Co., Box 75, Houston, Tex. BOCHERT, W. C., Prof. of Mining, South Dakota State School of Mines, Rapid City, So. Dak. BROOKS, FLOYD R., Shift Boss, Mond Nickel Co., Ltd., Worthington, Ont., Can. BROWN, CECIL J., Draftsman &,Surveyor, Wallaroo SC Moonta Min. & Smelt. Co., Wallaroo, South Australia. BURRAGE, ALBERT C., Vice-Pres., Chile Copper Co., 85 Amos Bldg.; Boston, Mass. BURGESS, JOHN ALBERT Genl. Supt., United Eastern Min. Co., Oatman, Ariz. CARLOCK, JOHN BRUCE, Supt., O'Neall Oil Process Co., - 608 Haas Bldg., Los Angeles, Cal. CARPENTER, BYRON H., Min. Engr., . . Willoughby, Ohio.

Jan 4, 1917

By F. H. Willcox

THE CHAIRMAN (HENRY D. HIBBARD, Plainfield, N. J.).-This paper is timely because of the changed conditions due to the great war, but apparently its scope is limited to oxidation process steels. Referring to the four numbered observations on page 199: No. 1 seems to ignore Johnson's discoveries about oxygen in cast iron. No. 2 ignores crucible steel. No. 3 ignores red short steel containing enough gas solvents to make it solid, while No. 4 assumes that a deoxidizer is necessarily a gas decomposer or solvent and vice versa, which it not always is. From these observations it is deduced. that the only hole-forming gas in steel is an oxide of carbon (CO presumably is meant), which is not true.

Jan 4, 1917

By J. M. Callow

H. A. MEGRAW, New York, N.,Y.-One interesting thing that might be brought out in this connection is the cost of making sulphide gas. I had a communication the other day which suggested that, in view of the high cost of oil, sulphur and sodium sulphide, we might make use of a well-known chemical reaction to form this sulphide gas by the use of aluminum sulphide. It is difficult to see any advantage in this, however, since aluminum has been affected just as much as any other commodity by the rise in prices, due, to war conditions. RUDOLF GAHL, Miami, Ariz. (communication td the Secretary*) Mr. Callow refers to my paper, History of Flotation at Inspiration, which was presented at the Arizona meeting of the Institute. These notes of Mr. Callow's contain much valuable information on flotation practice, as is to be expected from an article written by an author of Mr. Callow's experience in this branch of metallurgy. Nevertheless, I cannot help contradicting a number of the statements made in the references to my paper. In passing, I will also say a word about the reference in Mr. Callow's paper to the article by Messrs. Laist and Wiggin entitled "Flotation Concentration at Anaconda, Mont." Mr. Callow calls attention to the fact that evidently Callow flotation machines are not very sensitive, inasmuch as one man per shift handles four 800-ton sections of Callow machines or 3,200 tons per day at the Inspiration plant. While-it has been the experience of the Inspiration company that the four sections of Callow machines in the Inspiration concentrator are easily handled by one American operator per shift, it is only fair to state that each man operating four sections is assisted by two Mexican helpers who constantly clean the bottoms of the machines. The tonnage per section, by the way, whether equipped with Callow,, Inspiration or Minerals Separation machines, is considerably in excess 4 800 tons.. Mr. Callow further says that local opinion at Inspiration is that, two 800-ton sections consisting of two 10-compartment and four 6-compartment Minerals Separation machines (these machines are of the Hebbard type) is the limit that one man can properly attend. I do not hesitate to say that I consider it perfectly feasible to have four such sections operated by one man, perhaps assisted by "one helper. The Minerals Separation machines of this type have undoubtedly an advantage as far as easiness of operation is concerned,

Jan 4, 1917

By A. L. Field

WOOLSEY McA. JOHNSON, Hartford, Conn. (written discussion).¬When ;we regard the number of British thermal units running into the billions that-must be applied to metallurgical slags in the United States, we cannot but conclude that the physical chemistry of-slags is a very important subject when measured in dollars and cents. A further contemplation of the subject shows us that it has been hitherto treated in too purely a practical manner. It is needless to comment at length on the cost of these heat units and on the cost of fluxes to produce these metallurgical slags, for, it amounts to tens of millions of dollars annually. Accordingly, this research is of value to the country. But we must,all balance our results against our efforts. Therefore, while the speaker is unwilling to criticise unduly this meritorious research, lie does criticise it in the interest of the profession for the reason that it seems to him too highly theoretical. The article is much too, scientific to produce results at a minimum cost. Let us explain our meaning. It has been said that there are always two sides to a question. It may be further said that there are always three sides to a question, the two extremes and the middle ground. In any industrial research there are the highly theoretical side, the purely practical side, and the theoretico-practical side. To study a slag and be practical in the studying, there is something needed that represents in the laboratory (or in microcosm) what actually happens macrocosmically in the blast furnace. There is such a thing as the art of metallurgical research occupying the middle ground between theory and practice.

Jan 4, 1917

By Henry Howe

W. E. RUDER, Schenectady, N. Y.-In 1913 I presented a paper before this society on Grain Growth, and at that time it seemed to me that the only explanation for grain growth was that of critical strain. I do not think I published the photographs at the time, but I made some experiments on the effect of stretching sheets of metal. This allowed for fairly accurate determinations of the amount of cold deformation, At the time I worked-with silicon steel because one could see the change in grain growth with the naked eye. I stretched about 10-samples from 0.5 per cent. to 10 per cent., and, after heating to 1,050° C., I found that the maximum grain growth occurred at about 2 ½ per cent. cold deformation. This I designated "the critical strain" for maximum grain growth. About a year ago I talked with Prof. Jeffries, who explained to me his ideas of grain growth. It occurred to me that it would be a very easy thing to check the strain hypothesis against the strain and temperature hypothesis, if we took a certain number of these strips, strained exactly alike and heated to different temperatures; in that case the maximum grain growth ought to appear at a different percentage of deformation for each temperature. These experiments showed that there was, as Mr. Jeffries shows in his present paper, a decrease in germinative temperature with increased cold deformation. The samples were stretched from ½ to 8 per cent. and heated for 10 hr. in hydrogen. Samples were introduced into a furnace previously heated to temperature. A maximum grain growth was obtained at 5 per cent. deformation, when heated to 750° C.; at 2 ½ per cent. when heated to 800' C.; at 1 1/4 per cent., if heated at 950°C.; and at 5/8 per cent.. when heated at 1,100° C. This shows very clearly that the germinative temperature decreases with the increase in cold deformation. The growth was very much more marked, however, at the high temperature, i.e., the grain grew more rapidly and attained a much larger size than at lower temperature. In considering the photographs (Fig. A) those along the lateral edges should be ignored because.

Jan 4, 1917

By W. G. Matteson

BENJAMIN L. MILLER, So. Bethlehem, Pa.-In discussing the question personally with Mr. Matteson I have found that he simply proposed this as a suggestion and he recognizes, as well as a great many other oil geologists and oil operators, that to put into practice such a suggestion would mean the overcoming of many difficulties. Yet perhaps it may be possible to overcome the various objections that may be offered. Undoubtedly one of the most serious objections is that of incomplete and inaccurate well records. Faulty records are worse than no records at all. Perhaps, however, definite instructions and insistence on their observation may remedy this defect after a time. THE CHAIRMAN (M. L. REQUA, San Francisco, Cal.).-This subject is a. very important one, but just how far the National Government can go in .taking action is a question: It involves, of course, the question of State rights. California, I .think, has done very well up to date and probably will do better in the future. The law that was passed at the session of the Legislature 2 years ago is working as satisfactorily as anything of that kind can work with so little experience to guide the framers of the statute. We recognize in California the vital necessity of conserving the oil of the State. We have come to the conclusion that there is not as much oil ,in California as we thought there was. In the month of December the State drew on its oil stocks to- the extent of 1,800,000 bbl. and I think that the January statistics will show probably as much more. There is more or less of a.: panic at the present time among the large marketing concerns regarding the question as to where they are going to get their oil for future requirements

Jan 4, 1917

ROESLER MAX-Geology of the Iron-Ore Deposits of the Firmeza District, Oriente Province, Cuba. Discussed by William Kelly, J. T. Singewald, Jr., B. L. Miller, J. D. Irving, L. C. Graton, C. P. Berkey 439 SINGEWALD, J. T., JR., AND MILLER, B. L.-The Manganese Ores of the Lafayette District, Minas Geraes, Brazil. Discussed by L. C. Graton, J. T. Singewald, Jr., F. Lynwood Garrison HARDER, E. C.-Manganese Ores of Russia, India, Brazil, and Chile. Discussed by J. T. Singewald, Jr., E. C. Harder 454 SCHRADER, FRANK C.-Geology and Ore Deposits of Mohave County, Arizona. Discussed by J. C. Anderson McDOWELL, J. SPOTTS-A Study of the Silica Refractories. Discussed by J. W. Richards, H. D. Hibbard, W. F. Rochow, J. B. Umpleby-: 460 PHALEN, W. C.-The Conservation of Phosphate Rock in the United States. Discussed by E. G. Spilsbury 462 NORTON, S., AND LEFEVRE, S.-The Magnetic Concentration of Low-Grade Iron Ores. Discussed by G. C. Foote, J. L. W. Birkinbine, F. L. Nason 462

Jan 4, 1917

By J. B. Warriner

S. A. TAYLOR, Pittsburgh, Pa.-What was the distance of haul? J. B. WARRINER.-There is practically no limit to the haul. The length is determined entirely by the feasible location for a dump. -I have known of hauls up to 2 miles in length. R. V. NORRIS, Wilkes-Barre, Pa.-This paper was originally presented to the Anthracite Section as the result of the appointment of Mr. Warriner as the Chairman of the committee to study this matter and present this paper. As he has stated, he obtained data very freely from all the stripping operations in the region, and it is a type of paper of which we should have more in the Transactions. Two or three things in it strike me as particularly valuable. The two tables, 1 and 2, showing the coal remaining, have been the result of a great amount of study, as it is not an easy matter to obtain data as to the amount of coal left in mining. As an example, one of the, anthracite mines was mined and robbed out in 1850, so the maps show. That mine is today producing 250,000 tons of coal, over 50 per cent. from the bed which on the maps is marked as exhausted. What actually happened is that the seam was on a light pitch inconvenient to mine. There was ample thickness of coal and the chambers were driven at a convenient pitch through this 30,-ft. bed, leaving top and bottom, taking out about 10 ft. The pillars were removed and the working caved and marked as gone. That is the type of area that is now being stripped, which explains the reason for the enormous amount of coal left in, and the fact that Mr. Warriner has worked out the actual results from a large number of strippings is of great interest to the operators in any region handling thick coal which has been mined over in the past, generation. The modern mining, of course, is different. We do not have all the coal we want in big veins, and we do not mine it that way. Another interesting feature of the paper to me was the study of losses. It is not uncommon to assume that after you have stripped off the overburden all the coal goes to market. Mr. Warriner has shown that there is a loss ranging up to 10 or 15 per cent. that does not go, so 'that estimates made on stripping, figuring on all the coal, are subject to this very material correction.

Jan 4, 1917