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William Kelly, Vulcan, Mich.:—In the northern part of Bedford county, Pa., the county immediately south of Huntingdon, the Clinton measures appear along the eastern slope of Tussey mountain near its base. The only iron-ore bed that has been worked is in the upper part of the formation. Along the mountain this seam has a dip of more than 60°. At the outcrop the ore is soft and rich, but with depth it passes often abruptly into an almost pure limestone similar to that described by Dr. Rutledge. The soft ore extends deeper in the cross-gullies than it does under the higher gound between the depressions. The slates adjoining the rich ore have been weathered, but where in juxtaposition to lean ore and limestone they are hard. The alteration of the ore-bed is evidently the result of the conditions of drainage in quite recent geo-

Jan 1, 1910

Henry D. Hibbard, New York City (communication to the Secretary): The title of Mr. Sargent's paper is somewhat misleading, since the paper itself relates chiefly to various kinds of annealing and their effects, and in very small part only to heat-treatment proper. This term has a well-defined meaning in steel metallurgf, and always includes a rate of cooling faster than the material treated would have in the open air. In bringing about this accelerated rate of cooling, some medium other than air at rest is brought into contact with the heated steel. Usually a liquid (almost always either oil or water) is employed ; but for certain steels a blast of air, and for others an easily fusible or soft metal, such as led (either solid or melted), may be used. Heat-treatment usually includes also subsequent moderate heating, followed, it may be, with another accelerated cooling.

Jan 1, 1902

Howard N. Eavenson, Gary, W. Va. (communication to the Secretary*):—For some time before the publication of Mr. Scholz's paper, I had been collecting data bearing upon its subject, and I now take pleasure in presenting to the Institute my results in the form of a discussion. It has long been a matter of common opinion among mining-men that mine-explosions are more frequent during the colder, or winter months, than during the warmer ones, and it is a matter of common knowledge among them that the air-ways and road-ways in most mines are much drier and are more inclined to be dusty during the winter than during the summer. In many mines, places which are wet and sloppy in the summer are dry and sometimes dusty during the winter. These changes, of course, can only be due to atmospheric conditions, and are caused by differences in temperature and humidity. Until recently, however, very little attention has been paid to the part that atmospheric conditions may play in mine-explosions, or, rather, to the effect they may have in rendering mine-conditions peculiarly dangerous, and in spreading and rendering more disastrous the effects of what otherwise probably would have been small explosions. To show the difference in mine-conditions during summer and winter months, I have tabulated in Table I. the results of 24 observations of hygrometric conditions in several different mines at different times of the year. Mines Nos. 1, 2, and 6 are located in the Pocahontas coal-region, in McDowell county,w.Va., the first one being a shaft-mine and the others drift. Mines 1A and 2A are drift-mines located in Logan county, W. Va. All of these are mines of fair size, but none of them has been in operation more than six years,

Jan 1, 1910

Jan 1, 1902

Jan 1, 1903

K. W. Turner, Sail Francisco, Cal. (communication to the Secretary*): The recent papers in the Transactions by Vogt,' Lindgren2 and Weed: on ore-deposits that have formed as a direct result of igneous intrusions, show that deposits of this class are widely distributed over the world, and are occasionally of commercial value. This is especially true if we consider under this head all deposits in the zone of contactrnletamorphism, the origin of which may be ascribed to the gases and vapors generated by the heat of the intrusive rock. Mr. Smith's description of the Chillagoe garnet-formations containing copper, leads one to regard these depoaits as of contactrmetamorphic origin, although he gives certain reaeons for supposing them to be of igneous origin.

Jan 1, 1904

R. V. Norris, Wilkes-Barre, Pa. (communication to the Secretary*):—Mr. Stow's paper presents a series of arguments, numbered from 1 to 18, concerning the relative merits of four systems of colliery-ventilation, designated by the author as " plain pressure-ventilation," " plain exhaust-ventilation," " obstructed pressure-ventilation," and " obstructed exhaust-ventilation." These arguments are subsequently compared by means of tables, in which an arbitrary numerical value is assigned to each, and which consequently serve no other purpose than that of showing his opinions and predilections, as indicated by his assignment of the said numerical values. In addition to this general summary, Mr. Stow intimates his preference for a fifth method of colliery-ventilation—namely, what he calls " alternating pressure-ventilation," which consists in the running of the fan at "pressure " during working-hours, and as an " exhaust" between shifts—a system which he proposes as, perhaps, new, yet which he thinks deserves recognition " as a standard form." This proposed " standard form " is not to be found in practice ; and I think it would be impracticable in gaseous mines of large extent, for the following reasons: 1. It takes considerable time to reverse the air-current in a large mine; and the reversal would involve a period of complete stoppage of ventilation, long enough to permit serious accumulations of gas. 2. In shaft- and slope-mines, at least, it is hardly practicable to have " every man out of the mine" during the night, and certainly impracticable to avoid keeping mules and horses inside. 3. The doors necessary to divide and direct the air-current are properly hung to open against the air-pressure; and, unless

Jan 1, 1910

Mr. Tays (communication to the Secretary): Mr. Wynne's criticism of my paper* brings forward a few points which are really important, and might properly have been considered in the original paper. By calling attention to them he has rendered me a service. It is quite true, as Mr. Wynne says, that, in the tests reported by me, the Bryan mill was always working at a relative disadvantage, and my comparison of the work of this mill with that of the stamp-battery should be interpreted, therefore, so much the more favorably to the mill. Of course, wire screens can be used to advantage on the Bryan mill, if they are not of smaller size than 30-mesh; but

Jan 1, 1902

Allan Gibb, Mount Perry, Queensland, Australia (communication to the Secretary):—In drawing conclusions from his observations, Mr. Van Liew has apparently overlooked the reduction in weight that takes place in the content of the converter. The percentage-compositions of the matte, etc., are not directly comparable for determining the rate of elimination of the impurities; and, in the absence of exact weights (which in such an operation could not be obtained), it is necessary to determine the relation between the impurities and the copper with which they are combined at various stages, in order to get data that are comparable. Owing to a portion of the copper being removed in the slag, etc., the weight of copper in the converter is not a fixed quantity, but.it is sufficiently approximate to permit very reasonable comparison. The analytical data given by Mr. Van Liew, reduced to this basis (a ratio between the impurities and the copper with which they are combined), are shown in the table on page 958. From this table it will be evident that Mr. Van Liea's conclusions as to the source of heat at digerent stages are not quite correct. During the first 10 minutes, no iron is scorified, the heat being derived from the oxidation of the sulphur, of which 7 per cent. of the total is removed in this time. Prom

Jan 1, 1904

Jan 1, 1906

Charles Catlett, Staunton, Virginia (communication to the Secretary*): I have had occasion to examine a few of the irondeposits in the immediate section of which Mr. Watson speaks, but have not had an opportunity to visit any of the well-known manganese-deposits. I find the former can be very safely read in light of the information which it is possible to get from the same measnres farther. north, where they are less completely decomposed. In the same way all of his conclusions in regard to the geology of the manganese-deposits bear out their occurrence in Virginia, when we allow for the far more complete decomposition in the section he has so carefully studied. Judging from the same measures farther north, I think he will be safe in agreeing even further with Penrose as to the origin of these ores. Some years ago I carried on prospecting work in these measures in Virginia, in which the iron-ore and manganese-ore were followed down to undecomposed material, and in which their occurrence along a definite line of stratification, and apparently a part of the original bedding, was plainly shown. This is unusual, however, even in the section of which I speak. At Crimora, Virginia, the decomposition is quite complete; at the same time the results of some hydraulic work, which has been done there, disclosed, at the time of my last visit, the manganese interbedded in the residual clay along a definite and distinct plane parallel to the bedding of the underlying quartzite, and which, as is shown at other points, corresponds with the plane of the original material. In view of the phosphorus reported by Mr. Watson as existing in the Cartersville ores, and the not uncommonly prohibitive amount in southern ores, I am interested to know whether

Jan 1, 1904

Gus C. Henning, New York City: In taking up the discussion of these specifications it is necessary that I give definitions of what I understand under the term " Specifications." There may be three kinds, viz.: (1) Specifications in general; (2) Standard Specifications; (3) Standard International Specifications. 1. A Specification is a document used in commerce which should clearly define the qualities of material to be supplied by the producer, the tests which shall be applied for their determination, and the methods which shall be applied for the purpose of determining that the entire product shall possess such qualities, properties and finish as are desired. The terms used in such document must be applied in accordance with their strict technical definitions as used by those most conversant with them, and the language should be of such accuracy that there can be but a single interpretation of each and every clause. A specification is a part of a contract, and should be legally perfect and accurate. Inaccuracy of definition and dic-

Jan 1, 1903

R. Trimble, Pittsburg, Pa (communication to the Secretary) : There are in the proposed specifications only two points on which I wish to comment at this time.

Jan 1, 1902

In Mr. Weed's interesting paper, frequent reference is made to the Cananea copper-deposits, which are said to have been so vigorously exploited that they produced 14,000,000 Ib. of copper in 1901. The ore-bodies which yielded this large quantity of metal are described as a product of contact-metamorphism, and in Mr. Weed's genetic classification of such deposits, they receive a place under the sub-heading, "Deposits impregnating and replacing beds of contact-zone."* They are considered by Mr. Weed to represent a special type under this head, and are further classified as: " l. Chalcopyrite deposits: (a) Pyrrhotite ores; (6) Magnetite ores, Cananea type." In condensing much information into a comparatively small space, the presentation of a subject may be so abbreviated as to detract from its clearness. The situation at La Cananea, considering its importance from an economic as well as scientific standpoint, may he worthy of more detailed description. As Mr. Weed rightly remarks, " structural differences are so important, and have SO marked a bearing, not alone on the theory of their genesis, hut also on the working of the deposits and a determination of their value as mines, that they merit a full discussion."† It is my present purpose: (1) to show that it is doubtful whether the copper of La Cananea is mined, except to a limited

Jan 1, 1903

In traversing lately the Sierra Madre, west of Sail Pedro and Guanacevi, I estimated the topographic summit at several points, by aneroid barometer, at about 8,500 ft. Mr. Weed's measurements, 40 miles further north, are from 9,000 to 9,500 ft., and indicate the correctness of the impression I obtained at the time, namely, that the greatest movement in the elevation of the Sierra was between Guanacevi and Guadaloupe y Calvo. This is suggested also by the course of the headwaters of the Rio Conchas and of the Nazas, and by the relative corrasion of the branches of the two streams. Mr. Weed's statements as to the unevenness and great relief of the andesite floor underlying the later dacites and rhyolites are very interesting, and lead me to add that the floor of the andesite breccias and flows is uncovered for several square miles east of Guanacevi. This floor is of reddish, bluish and gray shales, lying horizontal or dipping slightly east. Their age is unknown; but from the interbedded occurrence of copper sulphides, I took it to be Triassic,

Jan 1, 1903

J. E. Stead, Middlesborough, England (communication to the author): Prof. Howe's valuable paper on cast-iron brings forward most prominently the correct explanation of the part played by combined carbon in pearlite and cementite, in determining the strength and hardness of cast-iron. On a previous occasion I haveoshown that castings made by melting a white Cleveland iron and glazed iron, one containing 1.5 and the other from 4 to 5 per cent. of silicon, and each about 3 per cent. of carbon, were stronger than those made of ordinary foundry-iron; the difference in the final castings being a differ-

Jan 1, 1902

Charles H. White, Harvard University, Cambridge, Mass, (communication to the Secretary*):—In answer to Mr. Jar-man's questions I am able to say that constant use (during term-time) since 1901 has shown the new appliances in our laboratory to be very satisfactory. The draft in the hoods is sufficient to lift the fumes promptly from the baths and hotplates ; and the occasional application of stove-polish,—usually about three times a year, at the recess-periods,—so well protects all iron-work in the hoods that, up to the present time, there is very little evidence of the corroding action of acid fumes. Iron should never be used in the construction of hoods above

Jan 1, 1906

MR. Woo's succinct description of the mining and smelting of silver-lead in Mongolia, with the roasting-and-reduction process and cupellation, has much interest as a picture of methods that not only may have been in use, as he suggests, a thousand years ago, long before the existence of mining schools or chemical laboratories, but probably vary little, if at all, from the practice of prehistoric times, when King Priam's handsome silver vases, cups and bowls were formed. For it is highly improbable that such large objects were made from comparatively rare native silver, and the metal must have been smelted from ore, and most likely in great part from galena,, with cupellation of the lead. Dr. W. A. P. Martin, in his excellent book on the Lore of Cathay, points out that Chinese alchemy is over 2000 years old, antedating the European by at least six centuries; and he infers that the Chinese skill in metallurgy and many branches of practical chemistry owes its origin to " those early devotees of the experimental philosophy who passed their lives among the fumes of the alembic." Those alchemists, however, may have more likely derived some of their leading ideas from the mys terious, and at that time wholly unexplainable results observed in already very ancient metallurgical processes; in which, for example, certain stones were transmuted, as it were, into metals widely divergent in character from their ores, and even silver and gold were obtained from the most unlikely-looking mate rials. It is therefore, in any case, not improbable that the Chinese may have preceded western nations in the discovery of metallurgical methods. At all events, it is now evident that the Japanese acquired these arts from China, the former source of all their higher civilization. My own observation of old-fashioned silver-smelt ing at Hosokura, on the main island of Japan, and about 220

Jan 1, 1903

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Jan 1, 1913