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By D. J. Blickwede

PRESENT knowledge of the effects of time and temperature upon stabilization of the austenite-martensite reaction in steel is fairly complete,1-3 but at the time the work described herein was initiated there was no information about the effects of alloy elements on the phenomenon. However, it has been assumed on theoretical grounds that alloy elements, particularly carbide formers, may have a significant effect on stabilization.' The present work was undertaken to provide information about the effect of two common elements, nickel and molybdenum, on stabilization in hypereutectoid and hypoeutectoid steels. Seven induction-furnace melted, 1.2 pct C steels ' with a variation of nickel from 0 to 6 pct and of molybdenum from 0 to 1.0 pct were used for most of the experiments. Along with these a series of 0.4 pct C steels containing 0 to 6 pct Ni were also studied. The chemical compositions of the steels are listed in Table I. Stabilization in these forged, hot-rolled, annealed, and centerless ground steels was measured by aging brine-quenched specimens (aus-tenite temperature, 1800°F) at 95" and 150°F and then determining the change in specific volume produced by subsequent cooling from room temperature to —320°F.³ In presenting the results the decrease in the change in specific volume, ?V, after various stabilization times is used. This is given by ?V -= ?VO - ?V1 where AVO is the change in specific volume on quenching directly to —320°F and aV, is the change in specific volume on quenching to —320°F after stabilizing for time t. In other words, ?V is a direct measure of the amount of martensite that is lost to the subzero quench as a result of stabilization and hence is greater, the longer the aging time or the higher the aging temperature. The results are shown in Fig. 1. The scatter of the data, which are not shown for clarity and brevity, was sufficient to make the relative location of the curves on the ?V axis inaccurate within ±2x10-5 cc per g. However, some generalities appear which are of interest. Effect of Nickel In the 0.4 pct C steels, up to 3 pct Ni has little, if any, effect on the rate or amount of austenite stabilized at 95°F, Fig. la. Increasing nickel from 3 to 6 pct almost doubles the amount of austenite stabilized in a given time. In the 1.2 pct C steels aged at 95°F, increasing the nickel from 1 to 3 pct appears to decrease the amount of stabilization, and a further increase to 6 pct Ni completely eliminates stabilization as shown in Fig. lb (M, of 6 pct Ni steel was below room temperature). The same behavior was exhibited by these steels stabilized at 1500°F, especially after aging for periods longer than 5 hr, Fig. lc. Thus it appears that up to 1 pct Ni has little effect on stabilization at low or high carbon levels. More than 1 pct Ni increases stabilization at low carbon contents and decreases it at high carbon contents. Ward, Jepson, and Rait5 have found that at inter-

Jan 1, 1954

By K. H. Coats, M. H. Terhune

Analysis and example applications have been performed to compare the accuracy and computing speed of alternating-direction explicit and implicit procedures (ADEP and ADIP) in numerical solution of reservoir fluid flow problems. ADIP yields significantly greater accuracy and requires about 60 per cent more computing time than ADEP, not 300 or 500 per cent more as reported elsewhere. l,2 INTRODUCTION Several recent papers 1-3 discuss an alternating-direction explicit difference approximation (ADEP) to the diffusion equation. Example applications of ADEP and ADIP4 were reported to support conclusions that ADEP is comparable in accuracy to ADIP and requires one-fifth to one-third the computing time of ADIP. Applications of ADEP in calculation of two-phase flow in reservoirs was also proposed. 3 This study was performed to compare further the relative merits of ADEP and ADIP in simulation of two-dimensional flow of one and two fluid phases in reservoirs. Since two-phase flow equations are often essentially elliptic rather than parabolic, the efficiency of ADEP in solving the elliptic equation was also examined.

Jan 1, 1967

By W. J. Garmoe

Distinct areas of mineralized and non-mineralized brecciated rock are found in the Ontario Unit of the United Park City Mines. These breccias contain an appreciable fraction of the present ore reserves and probably will become even more important as deeper levels are developed. Three ages of breccia have been recognized in the Ontario Mine to date: ( 1) Pre-mineral breccia that may or may not be mineralized, (2) early post-mineral breccia with mineralized fragments, and ( 3) late post-mineral breccia that is younger than and cuts through ( 1) and (2) above. These age ,relations are known from detailed underground mapping. Locally, both pre-mineral and post-mineral breccias have sufficient lead-zinc-silver content, either as matrix or fragmental material, to constitute ore. Ore-grade breccias occur throughout a vertical range of over 1000 feet and are found in both the Humbug and Deseret formations from above the Ontario 1300 level to below the Ontario 2200 level. The mineralized breccias, which are difficult to distinguish on mine maps, are not well delineated by underground workings, and their horizontal outline and vertical extent are not known beyond the immediate mining areas. The greatest amount of truly mineralized breccia is exposed on the 2200 level.

Jan 1, 1968

By John V. Beall, William F. Haddon

A long the mighty Andean Cordillera, there is splendor beyond imagination-in the natural beauty of the mountains and in daring engineering and lavish investment in the mines. This is the story of the great copper mines of Chile and Peru. Each mine has a special quality which has tested the physical and spiritual resources of the founder. In the early days of the older mines, the mining engineer of song and story was more the rule than the exception. He was physically tough, ingenious and a leader of men. In the current political and social environment of Chile and Peru, the foreign contract mining engineer is still needed; but he must be a different type of man. To John J. Selters at Cerro's Rio Blanco, the principal ingredient is still "toughness," but it is "toughness of mind" that is needed. "He probably should be a teacher." The copper mines are not new. They were, almost without exception, worked by Indians (La Exotica might prove the rule), and later by the intrepid Spaniards. Modern mining began after the turn of the century. In Chile, the first of the big ones was the Braden Copper Co. founded on the El Teniente deposit. This development was followed by Chile Exploration Co. at Chuquicamata and Andes Copper at Potrerillos. These properties have been developed over the years by vast expenditures of money and a monumental amount of labor. None was free of technical problems-metallurgy at Chuqui, marginal grade of the old mine at Andes, avalanches and the great fire at El Teniente. The evolution which has brought the established mines of Chile, and the new ones coming on stream, to their present state of development is in reality the work of wonders of input-money, engineering and responsible management in an atmosphere of political stability. Without any one of these, the result would have been failure.

Jan 11, 1969

By A. L. Holley

THOSE who are familiar with working gas furnaces will perhaps admit that the ordinary producer is the least satisfactory feature of the- whole system, chiefly by reason of its great waste of fuel, both above and below the fire. The waste of fuel in cleaning the fire has not, as far as I am aware, been carefully measured ; it has been roughly estimated at various works as averaging twenty per cent. to twenty-five per cent. The coke that falls into the ash-pit is largely mixed, if not stuck together with clinker; when this coke is not recovered and utilized (and where coal is cheap it does not pay to recover it), the waste is certainly as high as above estimated. Cleaning a fire on a grate (especially a fire of dirty coal, like much of our Western coal), by inserting a few temporary grate-bars, then withdrawing the regular grate-bars and letting the whole lower part of the fire tumble into the ash-pit, must necessarily be wasteful of fuel, but it has been found to be the most practical system. The fire under a boiler should be thin, to insure perfect combustion; hence it may be moved from one side to the other, so that .the clinker and ashes may be uncovered and removed. But a producer fire should be so thick that carbonic oxide only shall rise from it ; a thick fire cannot be thus manipulated. In several of the French works the ordinary producer without grates is employed ; the whole body of the fire rests on the floor of the ash-pit. It did not seem to me that less fuel was wasted here than with grates in cleaning fires. The bottom layer of the fire had to be drawn out with hooks, and there was nothing to prevent much coke from coming away with the clinker and ash. A producer shaped like a cupola furnace has many advantages, but if grates are employed the waste of coke in cleaning is not lessened. But the waste at the bottom of the fire is only a part of the waste in the ordinary producer. Mr. Emmerton, chemist to the Joliet Iron and Steel Company, has lately made a number of gas analyses from the producers of that company, worked with impure Illinois

Jan 1, 1880

By Bennett Bates

NOWHERE in the world has cone classification in closed-circuit grinding with tube mills reached as high a state of development as on the Witwatersrand. In the development of the Far East section the necessity of fine grinding to obtain. satisfactory residues gave rise to a situation with which the cone could cope only at a great sacrifice in efficiency of tube-mill grinding. H., A. White1 recognized the limitation of the cone in his study of the theory of tube milling as early as 1915, but it was not until Ewing, Davis and. Willey2 carried out their tests at Springs Mines during 1920 that the advantages of mechanical classifiers' were demonstrated. During the fall of 1924 the writer supervised a series of tests with Dorr classifiers undertaken by Mr. White, Consulting Metallurgist, at the mill of the Geduld Proprietary Mines, Ltd., Dersley, Transvaal (Far East Rand). The importance of classification to obtain efficient tube-mill grinding was thoroughly demonstrated. The installation of classifiers of the above type that followed the test, confirmed the results of the experimental work.

Jan 2, 1926

In 1776 two Franciscan friars, Dominguez and Escalante, started to find a direct route from Santa Fé to Monterey, and in their misguided wanderings northward they reached Timpanogos, now known as Utah lake, where they heard of a much larger body of water to the northwest, of which they were told that it was extremely salt.* They never saw this great lake, because they passed south of it on their way to the Pacific coast. The Dead Sea of North America was discovered in 1835 by James Bridger, a trapper. He and other trappers had ascended the Missouri and had reached the Bear river. A discussion arose as to the course of this river, and a bet was made, to settle which Bridger followed the Bear river to its source, in the Uintah mountains, and from the crest of the watershed he caught sight of the lake, to which he then descended.† He tasted the briny water of the inland sea and wondered if it were an arm of the Pacific Ocean. The lake was first seen by the Mormons on July 24, 1847. A band of them, numbering 145 and led by Brigham Young, had migrated from Missouri in search of a new home in the western wilderness. It is recorded that when Brigham Young stood on the summit of the pass over the Wasatch range and saw the valley of the Jordan outspread before him, he exclaimed: "It is enough. This is the right place". He had seen it in a vision, so he claimed, and foresaw the future glory of the new Zion that was to be planted in that happy

Jan 1, 1932

By Harrison Schmitt

THE definitions of the terms commonly used in connection with metamorphism at elevated temperature near igneous contacts are re-examined. As the study of tactite zones associated with igneous contacts progresses, more and more emphasis is put on the localization of the ore by structural forms. The generally early age of the silicates and late age of the sulphides is well established. Postsilicate structural deformation is likely to localize ore bodies. The silicates are often replaced by the ore minerals. We may not be far from proving that the elements involved in the formation of silicate aureoles are merely normal "volcanic" emanations, that silica, lime, magnesia, and alumina and probably soda and potash are likely to undergo local transfers only. The work of Newhouse suggests the agents of the formation of sulphides in deposits of various classifications are the volcanic emanations.

Jan 1, 1947

By K. L. Meissner

IT is well known that the so-called pure aluminum contains noticeable amounts of impurities, chiefly iron and silicon, and many investigators have studied the forms in which these impurities exist. Hanson and Archbutt1 state that iron exists in aluminum as FeAl3 and silicon as elementary Si. The solubility of FeAl3 in solid aluminum is practically zero, or at, least so small that the smallest trace of this compound is always visible as a separate constituent. Under the microscope an untrained eye can hardly distinguish, without etching, the two constituents FeAl3 and Si, but they can be differentiated by suitable etching reagents. Anderson2 also found the same results. At the same time, Merica, Waltenberg, and Freeman3 found a constituent of unknown composition. They found a small thermal effect, at 610° C., on the cooling curves of aluminum with small amounts of iron and silicon. The intensity of this effect increased with increasing silicon content, until an effect occured at 576° C. due to the eutectic between aluminum and silicon. The authors ascribed the effect at 610° C. to a compound, which they call "X constituent." It was thought to be a ternary compound containing iron and silicon and could be observed under the microscope as dark particles. Dix4 has published unetched photomicrographs of an aluminum with 0.51 per cent. iron, 0.99 per cent. silicon, and 0.32 per cent. copper that shows three constituents: the dark Si (black in the figure), the lighter FeAl3, which appears in half tone and crystallizes in needles, and a constituent of the same color as FeAl3 but of different crystal form, often resembling Chinese script. This last constituent, Dix thought, is a compound of Fe and Si; not the compound FeSi but a compound containing a relatively small amount of silicon. Therefore an alloy of aluminum, iron, and silicon (the copper should not be regarded in the following considerations) must contain the following four constituents: Al, FeAl3,

Jan 1, 1926

By John Lovejoy

As the Seminole area, Seminole and Pottawatomie Counties, Okla., appears to be the chief danger zone of overproduction in the United States, it may be of interest to review the production records of the various pools which make up this area; also to dis-cuss the future prospects of these pools, together with the structurally "high" points which may develop into new pools. It is also of interest to appraise the effect of the curtailment program in this general area, which was agreed to in principle by the various Seminole op-erators at a meeting held on May 23 at the offices of W. C. Teagle in New York. There are four large pools in the greater Seminole area. They are, in the order of their importance Seminole City, Bowlegs, Earlsboro, and Searight pools. A glance at the accompanying general map of the area will show their relative situation. The detail maps show the extent and area of these prolific spots. Seminole production comes from the Wilcox sand of Ordovician age, found at a depth of 3900 to 4300 feet. Semninole City Pool:-This pool was discovered in Wilcox sand in July, 1926. By Jan., 1927, there were 123 wells completed, making 146,000 bbl. per day. The field reached its peak of 253,000 bbl. per day the last week of Feb., 1927, with 211 completions and a per well average of 1200 bbl. On July 4 there were 304 wells completed, producing 102,000 bbl., with a per well aver-age of 336 bbl. per day. This pool will cover an area of approximately 3500 acres. It has produced approxi-mately 38,000,000 bbl. to. July 1. Estimates of total ultimate production are around 55,000,000 bbl. or somewhat better than 15,000 bbl. per acre. Some of the individual leases have already yielded 30,000 and 40,000 bbl. to the acre. Bowlegs Pool:-This pool shows 175 drilling wells and 131 completions making 180,000 bbl. per day, with an average per well production of 1380 bbl. It appears that this pool will develop into nearly as large an area as Seminole City. The wells, however, do not give up

Jan 8, 1927

By H. C. George

THE Wisconsin. Zinc District, or the Upper Mississippi Lead and Zinc District as it is often called, lies in the southwestern corner of Wisconsin, in, Grant, Iowa and Lafayette Counties, and it includes adjoining parts of Illinois and Iowa. The district is about 70 miles long, north and south, and about 40 miles wide, east and west. It lies wholly within what is geologically known as the non-glaciated area of the Upper Mississippi Valley. HISTORY OF THE DISTRICT The district was first opened up as a lead producer in 1822. From this time until 1860, about 205,000 tons of cog lead (galena) and washed lead (galena) was produced from shallow crevices and openings. From 1860 to 1900, about 74,500 tons was produced, and since that time, from 5000 to 7000 tons has been produced annually. Since-1900, most of the lead concentrate produced has been as a byproduct of the zinc mines. The first zinc ores were mined about 1862. These were the carbonate ores, locally known as " drybone." Very little zinc blende was mined in the district, previous to 1875. The zinc blende ores mined from 1875 to 1900 were mostly of the high-grade, hand-cobbed, sheet-ore class, which usually contained from 45 to 60 per cent. metallic zinc. Such nines as the "Sallie Waters," ? Quinlin," "Lead Mine," "Benton Blende" and "Ida Blende," located near Benton, Wis., were mines which produced ores of this type, during this period. The mines located at Highland, the "Coker Mine" located at Livingston, Wis., and the "Opencut Mine" located at Shullsburg, Wis., were mines that were heavy zinc carbonate producers, previous to 1900.

Jan 12, 1917

By L. B. McConville

The general term "tar sand" refers to sand that contains varying amounts of dense, viscous petroleum. Tar sand deposits have been found throughout the world, often in the same geographical area as conventional petroleum. The largest one by far is known as the Athabasca Tar Sands, in the province of Alberta, Canada. Actually a group of three deposits, these particular sands underlie an aggregate area of more than 12,000 sq miles. Current estimates place the contained raw petroleum at about 700 billion bbl; and via currently available technology, the amount of recoverable synthetic oil may be as much as 300 billion bbl-which is roughly equivalent to five times the combined US and Canadian total crude oil reserves. With the ever-widening gap between energy supply and demand, mining and petroleum companies are now evaluating all possible energy resources-both developed and underdeveloped-and, certainly, the Athabasca Tar Sand deposit is one of the more important ones to merit such attention. The first section in ME deals with the geology and historical developments; the other four sections, with mining methods, extraction technology, economics, and outlook.

Jan 1, 1975

By F. V. Tideswell

COAL being essentially a complex conglomerate of plant remains that have undergone decay and interaction in varying degree, it is understandable that attack on the problem of its chemical constitution by normal chemical methods should have been attended by but slight success. The obvious method of fractionation by means of selective solvents has yielded a few results of some value. Thus it is known that from many, if not all, bituminous coals organic solvents extract small percentages of oxygenated compounds, which are generally assumed to have been derived from the original plant resins, though a more probable source would appear to be the glycerides and waxes of the plants. Organic solvents also extract small proportions of hydrocarbons, the origin of which is doubtful. Of more importance is the action of such pseudo solvents as pyridine, which, in addition to their specific solvent action, have the power of resolving and simplifying a portion of the coal substance in a manner analogous to that by which water can disperse a hydrogel. Early, work with pyridine indicated that coals are composed of two main classes of compounds: the one soluble in organic solvents, the other capable of being partly dispersed in pyridine. Recent work has shown that the dispersion is colloidal in character and that it may be accomplished by the use of solvents less active than pyridine, such as benzene or chloroform, provided that the temperature of extraction is raised or the coal has been suitably preheated. The action of reagents on coal has proved of little value in the past, but some insight into the constitution of coal has been given by regulated .destructive distillation. Thus, it has been shown that coals behave on distillation as though composed of two main classes of compounds: the one readily decomposable at moderate temperatures (yielding mainly the paraffins), the other undergoing a preliminary early decomposition (with evolution of oxides of carbon and water) and yielding a residue that at higher temperatures breaks down, yielding much hydrogen.

Jan 3, 1925

By H. P. Allen

THE Achotla mill of the Cia. Minera de Peñoles is of special interest in that it is one of the few still employing the chloridization process. The ore milled comes from the Suriana mine and consists of both oxide and sulphide, from neither of which can the gold or silver be extracted by a simple cyanide treatment. The mill was built in 1927, after several years of study in the development of the process1, and operated from December of that year until October 1930. Operations were resumed in February 1935, and have been continuous since, treating approximately 5000 tons per month, while the mine is getting up to full tonnage of 6500 tons per month.

Jan 1, 1937

By William Sharp

DISCOVERY of new ore in the Eureka district, Nevada, as a result of bold and persistent exploration based on a geologic interpretation of structure has recently aroused wide comment in mining circles. It may therefore be of interest to the profession to have a summary of the historical background and an account of the recent program of development. The mines of Eureka, discovered in the late 1860's, were the first important silverlead mines in the United States. They have a production record of more than fifty-one million dollars.1 After the ore bodies were apparently bottomed in the 1880's, repeated attempts to find new ore were unsuccessful until 1940, when a diamond-drill hole cut a 40-ft width of sulphide ore 1409 ft below the 841-ft level of the Locan shaft. The next hole cut 30 ft, of ore and three additional holes drilled in 1943 and 1944 showed the ore body to be continuous, Shaft sinking to reach and open up the ore body has been in progress since 1945. GEOLOGY Stratigraphy The ore in the Eureka district occurs in a series of Cambrian sediments which is exposed through a thickness of over 6000 ft. The stratigraphic column is as follows:2 [THICKNESS, FI ORDOVICIAN Pogonip limestone (upper part). Thin bedded limestone with some chert. UPPER CAMBRIAN: Pogonip limestone (lower part). Thin-bedded limestone (with shaly limestone and chert).... 425+ Dunderberg shale. Shale (clay and calcareous shale) and thin bedded limestone340+ Hamburg dolomite. Dolomite and limestonegoo+ MIDDLE CAMBRIAN: Secret Canyon shale. Shale and thin-bedded limestone1,035 Geddes limestone. Carbonaceous, flaggy limestone with some shale partings 335 MIDDLE (?) AND LOWER CAMBRIAN: Eldorado dolomite. Dolomite and limestone2,000 LOWER CAMBRIAN: Prospect Mountain quartzite. Quartzite with occasional inter calated conglomerate and shale 1,660+ The Prospect Mountain quartzite has been subdivided into two formations: Upper part, Pioche shale. Shale, quartzite with some intercalated limestone (Lower Cambrian fossils)-200 ft. Lower part, Prospect Mountain quart zite proper-I,460+ft. Total thickness6,695+] Much the most productive of these formations has been the Eldorado dolomite, which yielded more than $42,000,000 at Ruby Hill and an additional amount

Jan 1, 1947

By V. Lessels, W. A. Hamilton

White Pine Copper Co. is a wholly owned subsidiary of the Copper Range Co. The property of White Pine is about 5 miles south of Lake Superior in Carp Lake Township, Ontonagon County, Mich. The new town of White Pine, adjacent to the company plant, is 18 miles south and west of the town of Ontonagon, and about 55 miles north and east of Ironwood, Mich. A diamond drilling program begun in 1937 to develop the orebody was carried on until 1950. During this period a test shaft, known as the Schacht shaft, was sunk on the orebody and approximately 8000 ft of development drift were driven. In an effort to solve the ore beneficiation problems, considerable metallurgical test work was done on ore extracted through the mine development. This work was conducted in a small pilot plant located in the mill of the Copper Range Co. at Freda, Mich.

May 1, 1956

By Zay Jeffries

TUNGSTEN has the highest melting point of all the known metals, namely 3350° C.; it is one of the hardest of the metals; it has the highest equiaxing or recrystallization temperature after strain hardening, of any pure metal known. It is particularly distinguished because, when composed of small equiaxed grains, it is extremely. brittle and fragile at room temperature, and when possessing a fibrous structure it maybe ductile and pliable at room temperature. The common ductile metals act in exactly the opposite manner in this respect. The present paper will include a brief note regarding the manufacture of wrought and. ductile tungsten. The metallography of wrought and ductile tungsten in the various stages of manufacture will be considered more or less in detail. The general relationships between the properties of tungsten and other metals will also be considered. A discussion will be given explaining why fibrous tungsten is ductile at room temperature, even though past experience with other metals would indicate that it should be brittle. Finally, a brief note regarding some new fundamental metallographic propositions relating to all metals will be given.

Jan 6, 1918

A PROSPECTOR stood atop a Venezuelan mountain called El Florero just 25 years ago, and shouted to the world that he had found a large, rich new source of iron ore. But his words were lost in the big green South American jungles and besides, the world had more iron ore than it could handle. There were no crises in 1926, no major wars on the horizon, no worries about mineral supplies. In the U. S., the populace was "keeping cool with Coolidge," and the solid foundation of the economy-the steel industry-rested on a still firmer basis, the Lake Superior iron ores.

Jan 5, 1951

By Edgar Bain

IN STUDYING the structural characteristics of martensite it is desirable that a clear conception of the material from which martensite is produced should first be obtained. Any theory of its formation and structure incompatible with the facts of its parent substance, austenite, can be eliminated with little consideration. Austenite is the name applied to solid solutions of carbon and other elements in gamma iron. At temperatures above about 900° C. (1650°, F.), pure iron exists in a system of crystallinity1 entirely different from the crystal structure below that temperature. This high-temperature allotrope of iron is of an atomic structure associated with great ductility, having very manifold symmetry and an abundance of easy slip planes. The exceptionally ductile and malleable metals (gold, silver, platinum, copper, aluminum, and nickel) have this same atomic arrangement-the face-centered cubic. The low-temperature allotrope of iron, alpha iron, the solid solutions of which are known as ferrite, has a body-centered cubic arrangement of atoms. Like it, in crystal structure, are the less ductile and malleable metals, molybdenum, tungsten, titanium and chromium. Fig. 1. shows the two atomic arrangements known in iron; the diagrams are drawn to scale. Either of these modifications of iron may dissolve other elements in the solid state; by so doing, the temperature of the transformation is changed. In general2-7, it appears that a solid solvent metal dissolves a metal solute by substituting foreign atoms in its own space lattice. Thus, iron may dissolve nickel in either of its crystalline forms by permitting an atom of nickel here and there to occupy the normal position

Jan 2, 1924

Discussion of the paper of F. E. Lucas, presented at the Cleveland meeting, October, 1912, and printed in Bulletin No. 71, November, 1912, pp. 1315 to 1326. F. Louis GRAMMER, Leesburg, Va. (communication to the Secretary *):--Mr. Lucas's paper reminds us of our extravagance in coking, and our tardiness in the adoption of by-product ovens, as compared to Germany. We are, however, so rich in coal-having mined, so far, less than 1 per cent. of our known national resources-that the argument of conservation is not very pressing. It is true that our so-called coking-coal beds are not inexhaustible; but by-product ovens coke coal that bee-hive ovens cannot handle, and so really enlarge our reserves of coking coal. " Conservation of Resources " is a phrase in great vogue. It is overworked and abused at times; being used by those who desire to be the exclusive custodians of resources or the sole purveyors of commodities. It does not carry great weight as regards coal. There are, however, aside from the attractive considerations of profit set forth by Mr. Lucas, several other important reasons why by-product ovens should be introduced more widely. One is that coal-tar pitch is the keynote to the extension of the coal-briquette industry. The more coal-tar pitch is available, the more briquetting will be carried on; and this will utilize much coal which is either waste or a drug in the market. Heretofore, in several instances coking and steel-making plants have been built, primarily, to market bituminous slack.

Jan 5, 1913