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R. W. NEWCOMB, New York, N. Y. (written discussion *).-This paper is particularly interesting to me, because it gives data on a much mooted question, viz., the serviceability of Le Chatelier (platinum-platinum-rhodium) thermocouples under severe industrial conditions. It has always been supposed that platinum-platinum-rhodium thermo-couples, used at high temperatures under strong reducing conditions, would not give long service and were subject to rapid volatilization. The fact, however, that the carefully kept records indicate that a little more than 3 gm. out of more than 830 gm. was lost over this considerable period, shows what kind of service can -be obtained from platinum-platinum-rhodium thermocouples,, when properly installed, and well cared for. While the writer has no actual figures on the loss of weight, etc. of platinum-platinum-rhodium thermocouples under service, he was told, by the man in charge of pyrometers at a large industrial plant in which over 400 platinum-platinum-rhodium thermocouples were installed in furnaces doing various kinds of heat-treating work, that the average maintenance cost, for materials alone, including platinum-platinum-rhodium wires and protecting tubes, was 27 c. per furnace, per month:

Jan 12, 1919

By A. C. D. Chaklader, Ashok K. Kakar

The basic density equation originally dericed ' to predict the increase in density of a compact of spherical particles with the progressive deformation at the points of contact has been further modified to include the yield strength of the material. This has been done by assuming that the contact areas grow to stable sizes under a fixed stress which is equal to three times the yield strength. The final equation has the form: where Do and D me the initial and final bulk densities of the compact, u is the applied pressure, and Y is the yield strength of the material. This equation was tested with the data obtained on spheres of lead, K-Monel, and sapphire. The calculated yield strength t~alues for lead and sapphire are within the range of values reported in the literature. A few of the earliest hot pressing models proposed to explain the mechanism by Murray, Livey, and williams2 and then by McClelland3 are based on a plastic flow mechanism. However, more recent investigations suggest that the overall densification process is a combination of several mechanisms, such as particle rearrangement, fragmentation, plastic flow, and stress-enhanced diffusional creep. While fragmentation and particle rearrangement are considered to be responsible for the densification in the early stages,"475 it has been concluded that the final stages of hot pressing are controlled by stress-enhanced diffusional creep.516 The manner in which the densification takes place, i.e., by fragmentation, particle rearrangement, plastic flow, or stress-enhanced diffusional creep, would depend upon the type of material, the temperature, and the stress level used during the hot-pressing experiments. Metal compacts can be expected to have a much greater contribution from plastic flow than ceramic oxides. Also, plastic flow would be a significant contributing factor to densification at high temperatures and high stresses. Most of these works, directed towards elucidation of densification mechanism, have dealt with kinetics of the process. The results of most of the authors vary from one another and they have proposed either new empirical or semiempirical equations to fit their data. The densification rate was found to vary with the type of the powder, shape and size of the powder, initial packing density of the compact, and a few other factors such as rate of heating, pressure, and so forth. Beyond the initial stages, the densification process has been considered to be as time-dependent flow, controlled by a diffusional process, e.g., Nabarro-Herring creep. Palm our, Bradley, and johnson' have attempted to use modified creep rate equations to interpret the data of densification under hot-pressing conditions. Beyond the initial stages, however, the densification would be controlled by a process depending upon the temperature, pressure, and size of the powders. It is the authors' belief that such densification cannot be exclusively controlled by a single process and so attempts should be made to study some observable phenomenon like microstructure, yield strength, and so forth. The emphasis of this work has been toward studying the densification problem from a more fundamental point of view. Some of the principal variables, like initial packing density, mode of packing, and size of the powders, have been controlled to a great extent. The total strain produced on pressure application (instantaneous) in such a case can be considered to be due to plastic and elastic deformation. The elastic component of the strain can be determined by decreasing the load to the initial value. The strain remaining then can be correlated with the contact areas produced by deformation and the corresponding applied load. In a previous paper,' the possible deformation behavior of spheres in a compact has been theoretically analyzed and experimentally tested. The change in contact area radius a relative to the particle radius R was related to the bulk density and the bulk strain for simple and systematic modes of packing. Tt was found that a density equation relating the above parameters can be represented by: where D and Do are the bulk densities of the compact at any value of a/R and a/R = 0, respectively. This basic equation should hold for any material as it was derived from geometrical considerations alone. An attempt has been made in this work to include the yield strength in the above density equation, so that a knowledge of the properties of any material can be used in predicting the densification behavior during the hot-pressing process. THEORETICAL CONSIDERATTONS The deformation of two spheres in contact under a static load can be compared to the deformation occurring between a hard spherical indentor and the flat face of a softer metal. Tt has been shown theoretically by both ~encky~ and lshlinskyg and experimentally by ~abor" that, for a material incapable of appreciable work hardening, the mean pressure required to produce plastic yielding (for deformation occurring between flat face and a hemispherical indentor) is approximately equal to three times the elastic limit, Y, of the material (in tension or compression experiments). Tabor has further observed that the same relationship is valid in the case of work-hardening materials, if the elastic limit at the edge of the indenta-

Jan 1, 1969

By Fred P. Peters

T. D. Yensen.*—As my information is of a negative nature, I think it belongs under this paper. We are particularly interested in magnetic materials and we would like very much on occasions to make use of powder metallurgy. We have tried repeatedly to use powder metallurgy in preparing our nickel alloys but always. with negative results; that is, we cannot get as good magnetic properties by powder metallurgy as we can by starting with a molten material. We have tried by all possible means to make materials' like 50 per cent iron-nickel alloys by powder metallurgy. The compacts can be regularly lorged and rolled but no matter what we do in the way of annealing, the magnetic properties come out very much poorer than if we start with molten material. F. V. Lenel. †—I want to mention one characteristic of articles made from metal powders which distinguishes them from die castings; that is, their wear resistance. Die castings usually are made from zinc or aluminum alloys and a few copper-zinc alloys; all of them are comparatively soft and not very wear resistant. I know of a number of cases where powder metallurgy rather than the die-casting method was used for producing a certain part because higher wear resistance was needed than could be attained in die castings. A, J. LanghammeR.*—The subject of powder metallurgy is somewhat difficult to discuss, and portray, in the time that his been allotted. Most of you would rightly be bored if we went into details. However, I will cite one incident that possibly will help illustrate some of the potentials. Last summer I was in Washington and met Navy officials for the purpose of studying the possibility of making a certain part by powder metallurgy. The part is highly intricate and I happened to remark that the material cost would be high; that is, the cost on one raw material. Promptly a high-ranking Navy officer said: "Mr. Langhammer, if you must pay x dollars a pound for the raw material, but achieve the desired results, the cost of the finished part would still be low."

Jan 1, 1945

By Edgar S. Cook

At the close of the Bethlehem Meeting, the writer was experimenting with large fuel-charges, 4000 Ibs. basis, as compared with 2000 Ibs., hot had not made sufficient progress to draw any safe conclusions. Previously me had always used 2000 Ibs. fuel, the ore-burden being proportioned to this as a basis. I could never persuade myself that there was any advantage to be derived from following the more popular method of larger fuel-charges. Our men were accustomed to the old way of filling ; and we did not care to run the risk of the errors likely to follow any alteration in routine work, particulary as I could not, by my course of reasoning, discover ally compensating gain. Nevertheless, after reading Mr. Gordon's discussion of Mr. Birkinbine's paper, '' Operations of Warwick Furnace from August 27th, 1880, to September 1st, 1885" (Transactions, xiv., 833), I determined to test by actual experiment the value of large fuel-charges : the change was made in the week commencing March 28th, 1886, and continued until July 25th, about four months. The fuel and ores remained during the trial the same as had been used before, and have been used since. For the first two weeks, the furnace worked with great regularity, giving excellent results, exceeding those of the two weeks immediately preceding. But for my remembrance that the furnace had on former occasions worked with equal uniformity for longer periods without any apparent reason, I should doubtless have concluded that this improvement was due to the different method of filling and congratulated myself that a means had at last been found to prevent inconvenient "dirt" accumulations. Before abjuring my previous skepticism, however, I resolved to pursue the trial further. The fourth meek developed the peculiar conditions that had prevailed previous to the change; and these continued with more or less frequency during May, June and July. At last, finding no improvement over the smaller charges—no change in fact for better or for worse—I commenced filling the 2000 lbs. fuel-charge in the latter part of July, and have continued it up to present writing, September 4th.

Jan 1, 1887

Albert Sauveur, Cambridge, Mass. (written discussion).— In his introductory paragraph, the author states that he has come to bury Beilby, not to praise him. The paper, however, gives the impression that while he may have dug the grave, Beilby is still at large. I am not one of those whom the author calls enthusiastic supporters of Beilby's amorphous theory and in support of this claim quote from a book I am writing: "Attractive as the amorphous theory is, and notwithstanding the ability with which it has been presented and the renown of its sponsors and supporters, it should not be accepted without reservations as a demonstrated fact.... So long as it explains more satisfactorily than other theories a greater number of phenomena in which it may play a part, we should use it in preference to others as the best available. Let us avoid the danger, however, into which too many fall, of accepting as indisputable truths, statements and theories emanating from those whom we hold in great esteem. It is not what those men themselves would wish us to do. I am entitled, I think, to occupy a position in the middle ground. Neither should Howe be classified with the enthusiastic supporters for he has written that the theory should be classed rather among the precious working theories than among those firmly established," a very wise and prudent statement. Jeffries, on the other hand, I would not hesitate to describe as an enthusiastic supporter. The author reproaches the advocates of the amorphous theory with having taken whatever properties they needed and with having assigned them arbitrarily to the hypothetical amorphous phase. He then applics their method to small crystals. If the existence of an amorphous phase is assumed, its greater tenacity and greater hardness is satisfactorily explained in the words of Howc: '(This greater strength is natural, because the amorphous state lacks the cleavages and slip planes which weaken crystalline substances." Can the greater strength and hardness claimed for small crystals be as satisfactorily explained? Nor do I think that the cold deformation of metals through successive slips within the crystalline grains can he accounted for as acceptably by the "small crystals theory."

Jan 1, 1923

Albert Sauveur, Cambridge, Mass. (written discussion).— In his introductory paragraph, the author states that he has come to bury Beilby, not to praise him. The paper, however, gives the impression that while he may have dug the grave, Beilby is still at large. I am not one of those whom the author calls enthusiastic supporters of Beilby's amorphous theory and in support of this claim quote from a book I am writing: "Attractive as the amorphous theory is, and notwithstanding the ability with which it has been presented and the renown of its sponsors and supporters, it should not be accepted without reservations as a demonstrated fact.... So long as it explains more satisfactorily than other theories a greater number of phenomena in which it may play a part, we should use it in preference to others as the best available. Let us avoid the danger, however, into which too many fall, of accepting as indisputable truths, statements and theories emanating from those whom we hold in great esteem. It is not what those men themselves would wish us to do. I am entitled, I think, to occupy a position in the middle ground. Neither should Howe be classified with the enthusiastic supporters for he has written that the theory should be classed rather among the precious working theories than among those firmly established," a very wise and prudent statement. Jeffries, on the other hand, I would not hesitate to describe as an enthusiastic supporter. The author reproaches the advocates of the amorphous theory with having taken whatever properties they needed and with having assigned them arbitrarily to the hypothetical amorphous phase. He then applics their method to small crystals. If the existence of an amorphous phase is assumed, its greater tenacity and greater hardness is satisfactorily explained in the words of Howc: '(This greater strength is natural, because the amorphous state lacks the cleavages and slip planes which weaken crystalline substances." Can the greater strength and hardness claimed for small crystals be as satisfactorily explained? Nor do I think that the cold deformation of metals through successive slips within the crystalline grains can he accounted for as acceptably by the "small crystals theory."

Jan 1, 1923

Air-sand Process of Cleaning Coal Discussion of paper by THOMAS FRASER and H. F. YANCEY, presented at the New York Meeting, 1926, and issued, as Pamphlet No. 1561-F, with MINING AND METALLURGY, February, 1926. T. DEVENNY, Edgarton, W. Va.-How near the size of the sand can the coal to be treated be brought? Do you use an 8-mesh coal on that cleaner? J. J. RUTLEDGE, Baltimore, Md.-From the little I have seen of the apparatus in operation, I should say 8-mesh. In my experience in metalmine concentration work, trying to separate different minerals on one jig, sometimes I have succeeded and sometimes not. This apparatus has appealed to me; something of this kind should be useful with the silicates and carbonates of zinc. I think this apparatus has possibilities in metal mining. Recently in our coal field a screen has been introduced for cleaning coal; it is giving excellent service. When I asked the inventor why he did not take it to the metal mines, he said there was a good and sufficient reason, in a patent way. There may be reasons why it would not be applicable for metal mining; but the simplicity of it appeals to me and I cannot see why it could not be so used. T. FRASER (written discussion).-We feel that 8-mesh would be about -the minimum size of coal practicable to treat by the air-sand process. This would depend partly upon the friability of the coal. The more nearly the lower size limits of the coal- approaches the size of the sand, the more .time will be required in screening the sand out of the cleaned coal, which would mean a little more chance of breakage. In regard to the treatment of ores; this would necessitate the use of some heavier mediums than ordinary silica sand, or some other means of making the separation at a higher specific gravity than is required for coal. We are now working on a method of obtaining this effect for the preparation of anthracite coal without resorting to the use of heavier and more expensive material than common sand.

Jan 1, 1927

By Arthur Redfield

IN ESTIMATING the unmined petroleum reserves of Central America, it is not feasible to employ the methods that have been worked out in the oil fields of the United States. No producing wells have been brought in and no drilling sections have been made public. It is accordingly necessary to fall back on a crude "barrels per square mile" estimate. The method chosen is a comparison of the structure of the foreign field of unknown reserves with that of some supposedly analogous North American field of which the reserves have been estimated. This method makes no pretense at scientific accuracy; bit furnishes a working basis for an estimate. The areal geology of Central America is illustrated in the map prepared by Sapper and more recently in the geologic map of North America accompanying U. S. Geological Survey Professional Paper No. 71, "Index to the stratigraphy of North America." Disregarding for the present the Arrow Quaternary coastal plains and alluvial deposits of the river valleys, three chief zones may be distinguished. These are: A zone of late eruptive and effusive rocks; a zone of highly folded pre-Cambrian(?) or early Paleozoic crystalline schists and slates, considerably intruded by pre-Tertiary plutonic rocks; and a zone of more or less folded sediments, chiefly of Cretaceous or Tertiary age. The zone of late eruptive and effusive rocks of Central America begins in southeastern Chiapas, Mexico,. and extends, with increasing breadth, across southern Guatemala, across practically the whole of El Salvador, and across southern Honduras to the valley of Rio Goascorán, where the igneous zone attains a width of about 100 mi. (160 km:) East of the Goascorán Valley late eruptives and effusives play a subordinate part, being confined largely to the Departments of Valle and Choluteca. Dikes and sills of igneous rocks intrude the sedimentary formations of central and northern Honduras.

Jan 7, 1922

By M. R. Daly

In a recent paper on Geologic Structure in the Cushing Oil and Gas Field, Oklahoma,l Carl H. Beal has pointed out some interesting peculiarities in the distribution of the hydrocarbons and the disposition of the "planes of separation" between the oil and the water (water surfaces). Mr. Beal's principal statements on this matter may be, summarized as follows: I. In every important dome in the Cushing field, which has not been complicated by folding along its sides, the oil area in each of the three oil and gas sands studied (Layton, Wheeler and Bartlesville) apparently extends farther down on the long axis of the dome than it does on the steeper sides. The result is that water is encountered at a lesser depth below datum plane (sea level) on the steep sides of the dome than along the ends where the beds are more gently tilted. II. In the Layton and Wheeler sands (to which the detailed study of water surfaces has been almost entirely confined), the water surface is not level, but dips at a gentle angle (maximum dip 100 ft. to the mile) away from the center of the structure. This inclination existed prior to development, and it has been rendered greater by the rapid extraction of oil and gas. To these statements, the following observations are added: The dominant structural feature in the Cushing field is a broad north and south anticlinal fold, along whose axis the domes are distributed (Fig. 1, p. 897), and the more important oil areas in each sand lie on the west side of the field. In many cases, gas has been forced to the east side of the structure, sometimes as far as the water line. From the distribution of the oil and gas bodies, Mr. Beal concludes that the hydrocarbons in this region probably migrated from the west or the northwest. It seems as if these different features would be susceptible of some

Jan 1, 1918

[A Editor's Note: Annual Reviews of various subjects and areas are found in February issues of Mining and Metallurgy and Mining Engineering. These Annual Reviews are not listed per se in the Index. Abating Stream Pollution in Anthracite Coal Fields. ME Mar 50 Abbadia San Salvatore mine, Italy. T178, 297 Abbott, C.E.: Limestone Mine in the Birmingham District. With Discussion. T129, 62 ABC Typifies Trend to Mechanized Mining and Coal Preparation. ME Dec 50 Abel, J.F.: Statistical Analysis of Tunnel Supporting Loads. T235, 288 Sulzbach, J. F., and Walker, D.K.: Ice Tunneling in Greenland. ME Jun 59 Aberfoyle tin mines, sphalerite, chalcopyrite, stannite, as intergrowths. T214, 1147 Abnormal Behavior of Some Ore Constituents and Their Effect on Blast Furnace Operation, The. T241, 1 Abrams, C.J.: Industry's Responsibility in Postwar Economy. M&M Mar 45 and Haley, D.F.: History of Crushing and Milling at Climax. M&M Jun 46]

Jan 1, 1972

By F. J. Williams

BARITE, naturally occurring barium sulphate, is the chief barium mineral that is produced commercially. Barite is also called "barytes," "heavy spar," sometimes "baryta" and, locally in Missouri, "tiff." Pure barite is white, opaque to transparent. It crystallizes in the orthorhombic system, frequently with twinning. Impurities cause a wide variation in color, commonly buff, gray and white with irregular reddish iron stains. Less frequently found are shades of yellow, green, blue, brown, and black. The rock is brittle and breaks with an uneven fracture, although specimens from some of the residual deposits, particularly in Missouri, appear to have a cleavage due to the separation of the different layers of deposition. The hardness varies from 2.5 to 3.5 on Mohs' scale and different localities are said to produce either "hard" or "soft" barite. This generally refers to the ease of grinding of the product. The specific gravity of pure barite is 4.5 and this will vary downward, depending on the impurities present. The mineral has a white streak and a pearly to vitreous or sometimes stony luster. Pure barite contains 65.7 pct BaO and 34.3 pct SO3. Witherite, native barium carbonate, is not mined in the United States at the present time although a number of occurrences have been reported. A small quantity of witherite has been removed from a mine at El Portal, California, but the area high in witherite was small and soon depleted. The bulk of the deposit is predominantly barite. Great Britain is the world source of witherite and small quantities are imported into the United States. DISTRIBUTION OF DEPOSITS Occurrence of barite is widespread; it has been reported on all the continents and in all the major countries of the world. Deposits vary from those containing millions of tons down to scattered rock fragments

Jan 1, 1949

By AIME AIME

LIFE will not be difficult for those who attend the fall meeting of the Petroleum Division at the Conoco Club, Ponca City, Okla., Sept. 30-Oct. 1. An attractive program to appeal to oil company executives and lawyers, as well as technologists, has been arranged and the Continental Oil Co. has contributed for the occasion the buildings, grounds and facilities of the club. E. 0. Bennett, Continental Oil Co., Ponca City, is chairman of the arrangements committee, and reservations for rooms and trips, requests for information, etc., should be sent to him.

Jan 1, 1932

A. E. Hunt, Pittsburgh, Pa : I have heard these papers read with a great deal of pleasure. I am particularly interested, in a financial way, in the bauxites as ores of aluminum, and it is safe to prophesy that there will be many more mining engineers in the future who will be interested in these ores of aluminum, in the same way as many are

Jan 1, 1895

Beall: Mr. Donovan, would you tell me something about your early life, leading up to your going into I he mining industry? Donovan: I was born in St. Charles, Minn., on November 18, 1879. At that time my father was a school teacher, but he later entered the Congregational ministry. He was pastor in several small Minnesota towns, so we moved about quite a bit.

Jan 8, 1966

By Arthur S. Dwight

The profeseional career of Thomas Septimus Austin, who died at El Paso, Tex., Aug. 23, 1906, was contemporaneous with the growth of the silver-lead smelting-industry of the Far West, to which his talents and zeal contributed in no small degree. Born at Stratford, Conn., Dec. 7, 1853, he was the seventh son in a family of thirteen. His parents were well-to-do; and he received a thorough preliminary training at the Hopkins Grammar School, New Haven, Colin., passing thence to the Columbia School of Mines, in New York, where he was graduated in 1876. His first professional work was that of analytical chemist with a Cuban sugar company. In this position he spent a year, and, whatever else of benefit he may have acquired during that year in Cuba, he gained a facility of speech in the Spanish language which was of inestimable value in his subsequent work in Mexico and the southwestern United States. In 1877, he went to the Rocky Mountains, and, under the firm name of Murphy & Austin, opened an assay-ofice in Lead-ville, Colo., which was just then coming into public notice as a rich silver-lead camp. The next year, however, he entered the service of the Germania Smelting & Refining Co. at Salt Lake City, Utah, where he remained until 1882, first as assayer and chemist, and later as Assistant Superintendent. The Germa-nia bears the honorable distinction of being one of the first of the large " custom" lead-smelters erected in the West. Its founders may be called the pioneers of the modern lead-smeltr ing practice, and the Germania served, to a large extent, as a model for the many plants that sprang into existence during the next few years in Utah, southern Idaho, Colorado and other lead-producing districts. The formulation, for the first

Jan 1, 1908

By E. J. Rapperport, C. S. Hartley

I TTRIUM is a close-packed-hexagonal metal with a c/a ratio of 1.5712.1 This low c/a value prompted a cursory examination of the deformation modes to obtain more data on the deformation characteristics of hcp metals with subideal c/a ratios. The chemical analysis of the arc-melted stock from which the specimen was cut is given below in Table I.

Jan 1, 1960

By W. S. Morris

PETROLEUM'S importance in World War II can perhaps be better realized by the recitation of a few facts and figures: Gasoline needs in this war are already eighty times greater than in the last war. It takes nearly three pounds of gasoline to deliver one pound of bombs, filled with petroleum explosives, on an enemy objective. Every American soldier overseas requires an average of more than fifty gallons of petroleum products per week, with the oil used by Navy and supply ships and America's Allies boosting the consumption of oil per soldier to an even higher figure. Every oil well in the United States now must produce each day an average of four barrels of oil for war and combat jobs. More than fifty million gallons of gasoline, fuel oils, lubricants, and other petroleum products are now going directly to the fighting forces every day.

Jan 1, 1945

By L. Webster Wickes

The bad effects of arsenic in commercial copper are well-known to metallurgists. The refining of copper by electrolysis eliminates practically all of the arsenic, provided certain requirements are fulfilled. The first, and most important, of these requirements is, that the voltage of the depositing current shall not be too high. It has been known for some time that the percentage of arsenic in the deposited copper increases with the voltage. To investigate the relation between the electro-motive force (e.m.f.) and the freedom of the precipitated copper from arsenic, the experiments were made, of which a brief summary is here given: I made three copper-arsenic alloys, containing respectively 3.56, 2.24 and 0.96 per cent. of arsenic. From these alloys I cast several anodes. For cathodes I used sheets of thin copper,

Jan 1, 1905

By R. W. Jigins

OPERATIONS of the Braden Copper Co. are in the Chilean Andes, southeast of Santiago. Most remote of the company communities is Sewell, a town of 12,000 people, 7000 ft above sea level at the junction of the Coya and Teniente rivers. Four miles down the Coya River is the smelter town of Caletones, elevation 4500 ft, with a population of about 3000. At the junction of the Coya and Cacha-poal rivers 24 miles below Sewell is Coya, elevation 2500 ft, location of the company's two hydroelectric plants. The principal accounting offices; steel, iron, and brass foundries; railroad shops; and major mechanical repair and fabricating shops are at Rancagua in the central Chilean valley, 44 miles from Sewell. The company owned narrow-gage railroad connects with the Chilean national railroad at Rancagua and above Coya is the only modern means of travel. El Teniente mine at Sewell is the largest underground copper mine in the world. The mill, at the portal of the main tunnel, has a capacity of 34,000 tons of crude ore daily, although production is lower during the winter beacause of electric power restrictions. When operating at capacity the mill produces 2000 tpd of copper concentrates and 32,000 tpd of tailings. Tonnage of tailings is equivalent to about 100,000 tons of pulp at normal water to solid ratio. Because the streams flowing from the Andes in the area of Braden's operations are used for irrigation, it is impossible to dump tailings directly to the river. The tailings pulp must be separated into solids and decanted clear water, and the clear water returned to the same water shed from which the original water was removed. Remaining sands and slime must be deposited in a reservoir where they will not cause trouble to farmers.

Jan 1, 1958

Gentlemen of the American Institute of Mining Engineers.—As you well know an application is about to be made to Congress, by the American Society of Civil Engineers, for the appointment of a cornmission composed of persons skilled in the production and use of iron, steel, and other structural materials, whose duty it shall be to test the strength, elasticity, and other quatities of such materials ; not simply the substances used as such, but the members of large structures composed of such materials, of the forms and sizes in which they are actually used. As I understand, the papers that will be read here to-night will have for their object to show the necessity for such tests, and therefore the necessity for the commission asked for. As the representative of the Society of Civil Engineers, I have to thank you, gentlemen of the Mining Engineers, for the great zeal with which yon have taken up this subject, and seconded the efforts of the Civil Engineers; or, perhaps I ought rather to say, initiated the efforts to get a suitable commission appointed to obtain most vitally important information which it is admitted on all hands we do not now possess. In drawing up the memorial to Congress, in connection with some of the ablest and best informed of our Society, and in all the discossions on the subject, I have been struck with the emphasis with which the confession is made, that so little is known of the strength of the larger-sized members constantly used in building structures of the magnitude which the present requirements of the country now demand. I presume the remarks made to-night will bring this out very prominently. This is no disgrace, for with the means here-

Jan 1, 1882