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By William B. Phillips

This paper was prepared at the request of Capt. A. F. Lucas, Chair man of the Institute's Committee on Petroleum and Gas; as a pre1iminary.discussion of the fuel oils which are used in the Southwest, giving their composition, uses, prices, etc. Should it afterward be found desirable, these observations may be extended over a larger area. In this connection, I suggest that samples of all kinds of fuel oils, including various tars, from all over the country, be collected and sent to some testing laboratory for examination. We would be glad to extend the facilities of the laboratory of the Bureau of Economic Geology and Technology, at the University of Texas, for this purpose, and to do the work free of all expenses. After such examinations are made and the results classified and studied, it would be possible to suggest specifications under which fuel oils should be purchased, and to arrive at some conclusions respecting the uniformity of such specifications, with due allowance for climatic and other more or less local conditions. While such specifications do not now depart from a common standard anything like as much as specifications for illuminating oils do, yet there are discrepancies which should not exist. Some of these discrepancies are of lessening importance, due to the pronounced tendency to distill every crude oil that can be distilled with profit, and to send residues into the market for fuel oil. Residues from the refineries are of a more uniform chemical composition and physical nature than many of the crude oils that go direct into the fuel market. The lower flash-point oils are disappearing from the fuel trade and in place of them we are getting oils that do not flash below 220" F., nor burn under 320" F. In the Southwest, it has not been long since we had fuel oils that flashed as low as 110" F., and the average flash point over a considerable period was 151" F. Now we are using oil that flashes at about 30" lower than the former burning point, which was 258" F. In other words, the flash point has risen, on the average, 100"; and the burning point about 75".

Jan 1, 1915

By Clarence Zener

[ ] THE present investigation started in an attempt to understand certain details of the decomposition of austenite, and of the effect of alloying elements thereon. As the investigation proceeded it became apparent that not only these details, but all the general features of austenite decomposition, could be understood in terms of fundamental physical principles. Since the direct applicability of these physical principles has not been previously recognized, it was decided to incorporate the original results of the investigation into a review of the general subject of the kinetics of austenite decomposition. This review constitutes the present article. An extended summary of the results is given on pages 27 to 30. This article, which deals with the kinetics of phase transformations, may appropriately be considered as a sequel to two recent articles1,2 from this laboratory on the equilibrium relations in medium alloy steels.

Jan 1, 1946

By George Rupp

THE Sunrise iron mine of The Colorado Fuel and Iron Corporation is in Platte County, Wyoming, about 110 miles north of Cheyenne. It is served by the company-owned Colorado and Wyoming Railway, which connects with the Chicago, Burlington and Quincy and the Colorado and Southern railways at Guernsey, Wyoming, a distance of 6 miles from the mine. The original Sunrise claims were staked mainly by United States Army officers and soldiers stationed at old Fort Laramie, because of small showings of copper in the Carboniferous limestones that form a horizontal capping overlying the Huronian iron ore. A small copper smelter was operated for about three years at Fairbanks, now an aban-doned town on the North Platte River. As many of the copper shafts and test pits near the present Sunrise mine were deepened, they pene-trated the capping and encountered iron. ore or gray sericitic schist, and were abandoned. Evidence of an early interest in iron ore was found when the Chicago claim was stripped for mining. A narrow, winding crevice was dis-covered, which led downward 20 ft. through the capping to the underlying soft red hematite, in which a room 10 by 14 by 7 ft. had been excavated. Stone hammers and wedges and a few rusted pieces of iron were found on the floor, and the evidence is conclusive that the excavation was used up to rather recent times by Sioux Indian medicine men, to provide war paint.

Jan 1, 1939

By William E. Souder, Eugene R. Palowitch

INTRODUCTION The longwall method of mining coal underground is now a highly developed and accepted mining technology. However, it was only through a long history of successes and failures that this technology now has the potential for reversing the declining trend in underground mining productivity in the United States. From its early beginnings in the United States during the 1800's, several species of longwalls have evolved. The evolutionary record consists of a series of overlapping birth-death eras, with each era giving way to another unique longwall technology. Typically, an era begins when some new longwall technology appears in response to a new technical opportunity or economic need. This new technology is adopted initially by only a few innovators. Later, other imitators get on the bandwagon and the technology diffuses throughout the user population. But evolving technical demands and socio-economic circumstances eventually cause many of the adopters to discontinue its use. This paper chronicles seven eras in the history of the evolution and utilization of longwall technologies in the United States. Some of the important factors that have influenced this history are discussed. Some distinctions are drawn between the operators who were first to adopt longwalls (innovators), and the imitators who followed. Statistics are presented which show that longwall mining is being adopted at an exponentially increasing rate, substantiating the forecast for a significant number of new longwall installations in' the future. Potential barriers to this increased utilization of long- walls are noted.

Jan 1, 1981

By Richard H. Zinszer

APPLICATION of electric logs has been used in correlation of subsurface structure to determine the size and shape of the oil reservoir. [ ] Such a knowledge is hardly complete until saturation and productivity are determined for the various horizons. It is difficult to use electric logs successfully for this purpose because of the many factors that influence the curves. In this work an effort was made to establish an empirical correlation between formation resistivity for a series of electric-log curves and water saturation and oil productivity of sand. Electric logs were obtained by recording with 10 different electrode spacings through the same interval of a well. In the analysis of these curves all factors except two, a dependent and independent variable, were held constant. The interval studied had been cored and a large number of samples were analyzed in the core laboratory in order to compare the values of permeability and saturation with the measured values of formation resistivity. Results of this analysis indicate: (I) the depth to which mud filtrate enters a sand body, (2) a correlation between permeability and sand resistivity for shallow penetration depths, and (3) that the water saturation for an oil sand can be determined from the measured sand resistivity after making suitable correc- [ ] tions for sand thickness. The proceduer in the last method depends on a correction for thickness factor and a theoretical curve. The accuracy of the theoretical curve is now being tested in the laboratory.

Jan 1, 1944

By S. H. Chauvenet

THE binding of the boshes and in walls of blast furnaces has always been an expensive piece of work. When the old stone stack was replaced by the iron shell, the brickwork was kept at a thickness of five feet or more. These five-foot walls were still too thick, and the practice now is to have as thin walls as possible and to have a free circulation of air about the brickwork of the furnace. The "basket," or lattice-work binding, accomplishes this object, but it is expensive, as to first cost, and, if any change in the diameter of a furnace has to be made, it necessitates an alteration of the binding or of the thickness of the walls.

Jan 1, 1882

By E. V. Kleber, V. F. Novy, R. C. Vickery

The constitutional diagram has been determined in part for the sgstem Gd-Fe. Seven intermetallic compounds have been found at compositions corresponding to the following Gd-Fe ratios; 2:3, 1.2, 1:3, 2:7, 1:4, 1:5, and 2:17. The GdFe, com-pound has a congruent melting point above 18000C, whereas all of the remaining compounds melt incongruently, A eutectic exists at 13 wt pct Fe at a temperature of 860°C. ALTHOUGH an increasing amount of information is becoming available on the metallurgy of pure rare earth metals, relatively few studies have been made on alloy systems of the rare earths with the transition metals; iron, nickel, and cobalt. Even less data are extant on gadolinium alloys although it could be expected that such alloys might possess interesting structural and magnetic properties. In this paper, we report investigation of the gadolinium-iron alloy system. Studies on systems containing nickel and cobalt will be presented in subsequent papers. Previous data on gadolinium-iron compounds have been reported by Endter and Klemm1 and Jep-son and Duwez.2 Both reports agree on the existence of the GdFe2 phase, which crystallizes with the C-15type structure (face-centered cubic). This is in accord with results of the present work. EXPERIMENTAL The gadolinium metal used was prepared by met-allothermic reduction of high purity gadolinium fluoride. A typical analysis of the metal thus produced indicated the principal impurities to be oxygen, 0.24 pct, and tantalum, 0.2 pct. The iron metal used for alloying was a reagent grade material. Alloys were prepared by arc melting mixtures of the respective metals. Appropriate quantities of the two component metals were carefully weighed, blended and compacted. The compacts were then melted in an arc furnace consisting of a water-cooled copper hearth plate and a water-cooled tungsten-tipped counter electrode contained in a brass vacuum chamber. The furnace was evacuated to an absolute pressure of less than 1 with the leak rate established as being less than 20 per min. The furnace was then back-filled to a pressure of 25 mm of Hg, with a 75 pct He-25 pct Ar mixture. Arc melting at 25 v and 300 amp was maintained for about 30 to 60 sec until the entire visible area of the sample became molten, by which time surface tension had drawn the molten metal pool into a large bead. After allowing the furnace to cool, the alloy button was inverted and the melting process repeated. A series of melts was made covering entire composition ranges from 100 pct Gd to 100 pct Fe. All samples were examined metallographically in the as-melted condition. As the phase diagram became rationalized, and differential thermal analysis had given indications of temperature arrests, annealing was carried out in vacuo or in argon. Generally, compositions containing more than about 60 pct Gd were heat treated at 750°C and alloys containing less than this quantity of gadolinium were annealed at 1000°C. Prolonged annealing times were of the order of 100 to 200 hr. Metallographic examination was repeated on the annealed materials. Although little material loss was noted during alloy preparation, chemical analyses were made on all specimens prepared. The following standard, analytical techniques were used. Samples were dissolved in hydrochloric acid; insoluble material was filtered off, ignited and fused with potassium pyro-sulfate. The cold melt was leached with dilute acid and the solution thus obtained added to the main sample solution. Gadolinium was always determined gravimetri-callv as oxide from oxalate ignition. Iron was removed from an aliquot sample by electrolysis on a mercury cathode at approximately six volts. Gadolinium in the iron-free electrolyte was then precipitated as oxalate which was subsequently ignited to oxide. Iron was determined volumetrically in an aliquot solution by reduction with stannous chloride fol-

Jan 1, 1962

By R. G. Baughman

With the constantly increasing sales competition, coal to be sold today must meet the test of quality in every respect. The producers must be able to make all marketable sizes that will meet such general requirements as follows: 1. Ash content must be consistently low, depending upon the use to be made of the coal. 2. Sulfur content must be controlled accurately according to requirements. 3. All sizes must be positively free from visible impurities. 4. Free moisture of washed sizes must be reduced to a minimum. 5. The freezing of wet coal in cars must be prevented. 6. The percentage of fines in small mixed sizes must be controlled to give the uniform and proper combustion when used on various types of automatic stokers. 7. The undersize particles or degradation caused by handling must be kept to an absolute minimum in all sizes loaded. Many difficulties may be met in bringing any particular coal to meet these quality requirements, because the extent to which the quality of a coal may be controlled is determined largely by its physical characteristics. Preparation of an Impure Coal Bed The application of modern and scientific methods in the controlled preparation of bituminous coal from a bed in the mid-western field will illustrate the results that can be accomplished by adequate preparation: The bed referred to contains coal inherently excellent as to low ash and other desirable characteristics; in fact, the coal itself is one of the best in the field. It is, however, divided into four layers by dirt bands of soft shale 1 to 2 in. thick. It also contains much sulfur in the form of sulfur lenses and laminated sheets. Horsebacks or rolls varying from 6 in. to 12 ft. in width are encountered in the mining of the bed and heretofore have rendered it practically unworkable. The mines operating in this

Jan 1, 1931

For the past several years the policy of a large section of our mining industry in relation to our present bureaucratic form of government has become increasingly amusing, if not a little disgusting. In the past, mining men have always featured themselves the self-announced champions of free enterprise, and, generally, this conviction, was substantiated by their deeds. In recent years, however, a large group of the industry, while still expounding, from the front porch, the principles of free enterprise and a sound economy based upon the law of supply and demand, have gone around to the back door with palm extended, to join labor, farmers, bureaucrats, and other pressure groups to get their share of the take. The procurement of subsidies, bonuses, increased metal prices, and government assistance in a multitude of forms seems to have obscured from their thinking the welfare of the country as a whole and the sounder economic principles of a balanced budget and lower taxes. At the recent Colorado Mining Association convention in Denver, I. was alarmed to see just how far this specialinterest type of thinking has progressed within the mining industry. Government assistance to mining. was generally considered inadequate, and a flat bonus for any new mineral discovery was proposed. It was disquieting, too, to learn how far the federal alphabet agencies have entered into the mining industry and of the thousands of highly paid technical. men on the federal payroll required to man these numerous overlapping agencies and bureaus. Now all this is very fine, and some aspects of the federal give-away program can be very appealing to the unsuspecting in the mining industry as they have been to those in other groups. Some of these expensive programs may bring about a few dividends or even several new mines. But to this whole line of pump-priming reasoning there is one big disastrous fallacy.

Jan 1, 1952

By H. Ries

IN THE marketing of mineral products, it is always highly desirable for both the producer and the consumer to be able to discuss things in a common language, and this can only be done if there are standard methods for expressing the properties of the raw materials. Having developed such a form of expression, the next step would be the making of specifications, which may serve as a basis for selecting raw materials. Considering the large number of non-metallic minerals that are used, there are not a few for which there are no standard laboratory tests to be used in determining their properties, or even standard specifications on which grades or market price may be based. Indeed in many cases the consumer simply requests the producer to submit samples, and rejects or accepts them without any explanation. Could the producer know in advance just what the consumer needed, time and money might often be saved. It appears to the writer that it is of the highest importance to devise standard laboratory tests wherever possible, as this enables the consumer to state definitely what he needs, and is of great assistance to the producer. It should also work to reduce misunderstandings and disputes. 'In the case of sands, we find that they show a wide variation in their character, ranging from those that are so coarse as to be of gravelly nature to those that are so fine that they might be classed as silt; and from very clayey ones to those that are practically free from clay. For this wide range of sands, we have a corresponding variety of uses, which are based mainly on the physical properties of the sand, although these are not always very definitely stated. The chemical composition need rarely be considered, if the sand is of siliceous nature. To determine and express these properties there should be standard tests, which are to be followed in all cases where the material is tested in the laboratory.

Jan 1, 1926

By John Jermain Porter

The chief purpose of this paper is to indicate the laws governing the fuel-economy of the cupola, to examine the feasibility of some of the proposals for increasing its fuel-economy, and to show that the conditions limiting fuel-economy here are altogether different from those prevailing in the blast-furnace. The two methods available for studying the thermal efficiency of the cupola and determining the factors limiting fuel-economy are: 1, by the determination of the total heat-balance; and 2, by the application of the theory of critical temperatures. The case selected as an example represents a cupola operating under fairly efficient conditions. The data are as follows : Cupola, GO in. in diameter, 15 ft. high to the charging-door, with a 9-in. lining. Bed-charge, 2,000 lb. of coke and 4,000 lb. of iron. Subsequent charges, 400 lb. of coke and 4,000 Ib. of iron. Total number of charges, 20. There was 800 lb. of coke recovered from the drop, hence the total coke burned is 8,800 lb., or 0.11 lb. of coke per Ib. of iron. Coke contains 90 per cent. of fixed carbon and 2 per cent. of moisture. 300 1b. of kindling-wood is used in lighting. 80 lb. of limestone (95 per cent. of CaCO,) is used per charge, or 0.02 lb. per Ib. of iron. Melting-loss, 4 per cent.; distributed thus : Fe, 3.5; Si, 0.25; Mn, 0.25 per cent. Average analysis of top-gases : CO2, 15.1; CO, 10.0 per cent. Average temperature of top-gases, 1,600" F. Temperature of air and stock charged, 60" F. Dew-point of air, 50 F. The items entering into the total heat-balance and their calculation are as follows: 1. Heat of combustion of fuel.—Total heat evolved = 14,580 x lb. of carbon burned + 7,200 X Ib. of wood burned. Hence B.t.u. per lb. of iron charged =

Jan 1, 1913

By R. V. Sara

Determination of the Hf-C phase diagram was conducted primarily by metallographic and X-ray diffraction studies on appropriate alloys. The only intermediate phase observed in this binary system was HfC. This phase was found to be homogeneous between 34.0 and 48.0 at. pct C at 2200°c and between 36.0 and 49.3 at. pct C at 3150°C. The lattice-parameter variation was also determined for HfCI-, compositions prepared at 2200° and 3150°C. The most most refractory composition, with a melting point of 3830°c, was established at 47.5 at. pct C from melting-point data. Solidus temperatures of 2240' and 3150°C occur on the high-kafnium and high-carbon sides of the monocarbide, respectively. The invariant point between HfC and carbon is located at 66.0 at. pct C, whereas the 2240°C solidus corresponds to the peritectic temperature at which hafnium is formed from HfC and hafnium-rick liquid. Hafnium has a melting temperature of 2208°C and is capable of taking carbon into solution to the extent of 10.5 at. pct at this temperature. ALTHOUGH the Hf-C phase diagram has not been previously evaluated experimentally in its entirety, the belief has been that the general configuration would resemble the chemically similar Group rV carbide systems, Ti-C and Zr-c.' These binaries are characterized by a single carbide phase with a simple NaC1-type structure which is maintained over wide compositional ranges. This family of carbides has high thermal stability that increases substantially as the atomic number of the metal component increases. This trend characterizes HfC as one of the highest melting materials. According to Agte and Alterthum,2 the melting point for this monocarbide is 3890°C, a value that has been quoted quite extensively for the past several decades. Recently, in repeating the work of Agte and Alter-thum, Adams and Beall3 determined the melting point of HfC to be 3895°C. A significant departure from the commonly accepted version of the Hf-C system was reported by Avarbe and his coworkers,4 who proposed that there is an extreme stabilization of a hafnium in a narrow field to 2820°C, above which it melts peritectically to form HfC and liquid. Their study was also concerned with the melting temperature of various HfCI-, compositions, but the peak melting point was taken from the work of Agte and Alterthum. Avarbe and his associates were not concerned with the high-carbon region of the system. However, three widely varying temperatures have been reported for the HfC-C solidus by other investigators. Cotter and Kohn5 observed approximately 2800°C; Portnoy et al.' reported 3260°C; and, more recently, Krikorian7 indicated 2915°C. Equally as uncertain is the solidus between hafnium and HfC. As noted above, Avarbe et al. report a peritectic temperature of 2820°C, Krikorian7 measured 2150°C, and Benesovsky and Rudy' estimated 2000°C on their diagram. I) EXPERIMENTAL PROCEDURE The starting materials for this study consisted of reactor-grade hafnium hydride obtained from Fair-mount Chemical Co., Newark, N.J., hafnium carbide supplied by Wah Chang Corp., Albany, Ore., and Union Carbide spectroscopic-grade graphite, SP-1. The graphite analysis indicated impurities at levels of only 0.5 ppm or less. According to the suppliers, the hydride and carbide contained the typical impurities listed in Table I. The samples required for these studies were prepared by dry blending either graphite and hafnium hydride or hafnium hydride and hafnium carbide powders for approximately 5 min in a "Spex Mixer Mill". The latter combination was used only for preparing several samples in the HfC1-, melting-point studies. Small pellets, varying between 3/16

Jan 1, 1965

By C. F. Nagel

THIS paper is written primarily for those who are familiar with the processes mentioned but who desire a further insight into some of the fundamental principles. It does not give a complete description of the various practices employed in the working of aluminum and its alloys, but presents a few illustrations of the essential respects in which aluminum differs from other common metals, and emphasizes the controlling factors of the processes under consideration. HEAT TREATING Certain aluminum alloys are capable of having their mechanical properties greatly altered by a heat-treatment process. The degree of this improvement may be illustrated by some typical properties of duralumin (Table 1). It is essential that the material be in the wrought condition in order to obtain maximum heat-treatment effects. [ ] In the case of duralumin, the process consists of heating the metal to a prescribed temperature and then quenching it. Immediately after quenching, the material is relatively soft though not as soft as in the annealed state. If allowed to stand at room temperature, the material changes, increasing in hardness and strength without loss of elongation, but at the expense of the plasticity. This action is very rapid at first, gradually diminishing in intensity and to all practical purposes being completed in about four days. This process of hardening is termed

Jan 1, 1928

By A. J. Bartlett

ISLAND Creek conditions are generally referred to as ideal; yet, as at all other properties, there are all known hazards of coal mining. The hardest of these hazards to combat is the human element. The basic thought in the minds of the management of these properties is to produce coal with the utmost safety, and it has impressed upon its supervisory force that it does not want a ton of coal unless it can be produced safely. This company has instituted a mine inspection department, which reports direct to the general manager, and all matters pertaining to safety come under the direction of this department. Through the medium of the inspection department, the management is kept in touch with the actual conditions existing in general at all mines. Inspections are made regularly and continuously; that is, at all times while the mines are in operation some sections of some mines are being examined. These inspections cover all active and inactive workings. Miners are con-tacted in their working places and other employees at their respective work. A thorough check is made to see that the state mining laws are complied with and that company safety rules are being observed. Night shifts receive the same attention as day shifts. All violations and dangerous practices are brought to the attention of the plant supervisory force with suggestions and recommendations; major hazards of emer-gency nature are taken up immediately with the management. Peri-odical inspections are also made of all tipples, preparation plants, dumping and hoisting equipment, to see that all machinery is properly guarded, and walkways and platforms properly fenced; conditions of equipment and mechanical defects are also reported. Reports of inspection are written in letter form and in such a manner as to give the management a picture-of the existing conditions at the time of inspection. Copies of inspection reports are forwarded; to the superintendents with the general manager's comments.

Jan 1, 1937

By W. D. MOTTER

THE following brief description of the status of operations of the Chile Exploration Co. at Chuquicamata, Chile; and of the plant as it exists today, points out the-great progress that has been made since the initiation of prospect drilling in 1912. During the 11 years which have elapsed since then, a group of small mines, eking out a 'precarious existence, has been consolidated into one large operating property,, taking high rank among the world's producers of copper. After a drilling campaign followed by a construction period, the plant first started operations in 1915. Since then production has been gradually increased, as world conditions permitted, until the present status has been reached.

Jan 1, 1924

By R. J. Wysor

SINCE the outbreak of the European war, few problems of raw-material supply have commanded more nation-wide attention than potash. It is well known that before the war the domestic production of potash was an insignificant percentage of the imports. The average annual importation of raw potash salts for several years prior to 1914 was slightly over 300,000 net tons, and f other potash manure salts about 700,0000 tons. The sudden and almost total cessation f these imports created a unique and stringent situation. Methods of recovering potash from feldspar and other native mineral sources, and reclamation from hitherto waste products, have received a marked impetus. Soaring prices have been a keen-incentive to research and industrial development. Although several brief articles concerning the possibilities of potash recovery have appeared in recent trade journals, it still may be a matter of some surprise to the average technical mind that potash might be reclaimed as a profitable byproduct in the manufacture of pig iron. At the present time it may be of special interest to present some data, largely of a technical nature, on this subject. A fairly thorough search of the literature reveals a number of articles concerning salts of the alkali metals in the blast furnace. Many of them deal with the-theoretical role f alkali cyanides in the furnace. Several discuss the, probable effect of the alkalies on the furnace brickwork. Two or three ambitious patents have been granted for reclaiming potash or other products from blast-furnace gas. However, we have heard nothing further as to the practical application of these patents. Little literature of importance has appeared during the last 10 years concerning alkalies in blast-furnace practice, and I have discovered no record whatsoever as to the actual sale or commercial disposal f flue dust for its , potash content until this was inaugurated in our plant at Bethlehem. A bibliography of the most important articles discovered is appended.

Jan 1, 1917

By V. L., McCutchan

FORM of ore bodies, strength of wall rock, and quantity of water that must be handled differ so greatly in the various districts in which the Corporation operates that a variety of mining methods have to be employed. All are underground, however, with the exception of glory holes at Cerro de Pasco from which siliceous silver pacos ore is obtained. In general, the ors is in many relatively small bodies unsuitable for hulk mining, such as caving or top slicing. The strength of the rock and ore rarely permit open stopes, though shrinkage is successfully used on various veins with strong walls, particularly in, Casapalca. Horizontal cut and-fill and square-set stoping with careful filling are the principal methods employed, with the necessarily higher cost for supplies and labor offset as much as possible by care in the avoidance of dilution. The mines at both Morococha and Casapalca are notoriously wet, and even at Cerro de Pasco the quantity of water was enough to retard deep development until the perfection of electric pumps. In Morococha particularly, the extension of successive levels, first from adits of moderate length, then from shafts and heavy pumping installations on the 750 and 1000 levels, and finally by the 30,564-ft. Kingsmill tunnel, was one of the most difficult and long continued fights against water and resulting heavy ground that is recorded in mining history.

Jan 1, 1945

By W. H. Adams

Among the engineering plants with new features and deserving details which are constantly being brought to the working stage in the Southern States by the generous expenditure of capital, none can exceed in interest, whether to the public or the profession, the incline-railway built from base to summit of Lookout Mountain, near Chattanooga, Tennessee. Much geological and historical interest centers in this section of the middle mountain-country. Of its geology, the Transactions of the Institute contain many particulars. Of its history, the most

Jan 1, 1888

By A. J. R. Curtis

THE Portland Cement Association was organized more than a third of a century ago by a group of cement manufacturers, to do cooperatively the educational and research work needed to ensure proper use of their product. Specifically, the Association has a threefold purpose: (1) to search out facts to ensure the best possible service from concrete; (2) to give the widest possible circulation to facts affecting the use of concrete; (3) to urge practical application of those facts on actual building projects. An organization of technically trained men conducts many research projects in the Association laboratories, interprets their findings and applies them practically in the field. The net effect of this work has been to improve the design and prolong the life of roads, bridges, industrial, commercial and public buildings, homes, farm structures and concrete products. The results of this technical research and experimentation are made available to the entire construction industry through bulletins and reports. Information is also released to the general public through newspapers, magazines and Association publications. In addition to a1 technical staff in the general office in Chicago, the Association has district offices in 22 cities. Field engineers cover 37 states, the District of Colum-bia and British Columbia, to give service to users of Portland cement.

Jan 1, 1937

By E. T. Clymer

It has been the custom, from the earliest time, to grade pig-iron by the appearance of the fracture; and although, since the pneumatic and open-hearth methods of steel-making have come into existence, chemistry has been called to the assistance of the steelmaker in selecting material for his use, the consumers of forge- and more especially of foundry-iron, still rely almost entirely, as they did a hundred years ago, on the appearance of the fracture of the pig to guide them in the choice of iron. To this rule, however, each year sees more exceptions; and there are now many foundry-men

Jan 1, 1893