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PRESIDENT AND DIRECTOR HOWARD N. EAVENSON PITTSBURGH, PA PAST PRESIDENTS AND DIRECTORS SCOTT TURNER WASHINGTON, D. C. FREDERICK M BECKET NEW YORK, N. Y. VICE-PRESIDENT, TREASURER AND DIRECTOR KARL EILERS NEW YORK, N. Y

Jan 1, 1935

By H. W. Immolz

The Palo Pinto limestone pools of Jones and Shackelford Counties were defined and almost fully developed during the year. A new Palo Pinto limestone pool was apparently discovered when the K. B. Nowels NO. 1 Pardue, S.F.I. and W. survey, south central Haskell County, was completed for a small well in Palo Pinto limestonc at 3395 to 3421 feet. In Haskell County, Amerada Petroleum Corporation's C. J. Kleiner, J. M. Cass survey, drilled to the Ellenburger with a total depth of 5607 ft., where it was abandoned. A Bluff Creek sand field of undetermined size was discovered by the Fain-McGaha No. 1 Dawson-Conway, P. G. Holcomb survey, which was chompleted for 37 bbl. at 1496 feet. The Cook field was extended by the Roeser-Pendleton B-113 Cook in sec. 113, E.T.R.R. Co. survey, the well being completed for 510 bbl. from Cook sand encountered at 1545 to 1568 feet. Several shallow pools of minor importancc mere also discovered in Shackelford County during the year. In Jones County the Lewis and the Steffens fields, in block 15, T. and P.R.R. Co. survey, were further developed during the year but the limits of the Steffens field were not definitely defined. The most, important discovery in Jones County was the Guitar field, where most of the wells that had been producing from the Cook sand were deepened to the Hope limestone, a new producing horizon. In Taylor County, the Bowles field, see. 28, B.A.L. survey, was defined arid proved to he of minor importance. The Goldsboro and Novice area, ill northwest Coleman County, continued to hold considerable interest because of the developments near the town of Novice, where new Ieases continued to be opened for production. Nolan County was placed in the ranks of the producing counties when the S. B. Owens No. 1 Tipton, sec. 43, block 19, T. and P.R.R. Co. survey,

Jan 1, 1940

By H. W. Immolz

The Palo Pinto limestone pools of Jones and Shackelford Counties were defined and almost fully developed during the year. A new Palo Pinto limestone pool was apparently discovered when the K. B. Nowels NO. 1 Pardue, S.F.I. and W. survey, south central Haskell County, was completed for a small well in Palo Pinto limestonc at 3395 to 3421 feet. In Haskell County, Amerada Petroleum Corporation's C. J. Kleiner, J. M. Cass survey, drilled to the Ellenburger with a total depth of 5607 ft., where it was abandoned. A Bluff Creek sand field of undetermined size was discovered by the Fain-McGaha No. 1 Dawson-Conway, P. G. Holcomb survey, which was chompleted for 37 bbl. at 1496 feet. The Cook field was extended by the Roeser-Pendleton B-113 Cook in sec. 113, E.T.R.R. Co. survey, the well being completed for 510 bbl. from Cook sand encountered at 1545 to 1568 feet. Several shallow pools of minor importancc mere also discovered in Shackelford County during the year. In Jones County the Lewis and the Steffens fields, in block 15, T. and P.R.R. Co. survey, were further developed during the year but the limits of the Steffens field were not definitely defined. The most, important discovery in Jones County was the Guitar field, where most of the wells that had been producing from the Cook sand were deepened to the Hope limestone, a new producing horizon. In Taylor County, the Bowles field, see. 28, B.A.L. survey, was defined arid proved to he of minor importance. The Goldsboro and Novice area, ill northwest Coleman County, continued to hold considerable interest because of the developments near the town of Novice, where new Ieases continued to be opened for production. Nolan County was placed in the ranks of the producing counties when the S. B. Owens No. 1 Tipton, sec. 43, block 19, T. and P.R.R. Co. survey,

Jan 1, 1940

By Walter Miller

BY the beginning of 1945 the output of petroleum products for war had reached a volume and a rate of growth which practically assured all requirements so long as war continued. The programs for making gasoline, lubricating oils of required quality, toluene for T.N.T., and chemicals for manufacture of synthetic rubber, as well as numerous other lesser petroleum products, were all well in hand, and unless catastrophic developments occurred there was no doubt of the ability of the industry to meet all demands. The end of the fighting found the refining industry working at top capacity on war commodities, but also in position to convert quickly into peacetime civilian production. 100-octane Aviation Gasoline Production of the vital 100-octane aviation gasoline, starting with approximately 44,000- bbl. daily capacity at our entry into the war, reached a top of 525,000 bbl. a day in the United States by the end of hostilities. With 75,- bbl. from other Allied sources, the grand total was 600,000 bbl., or 25,000,000 gal. each 24 hr. available to the armed forces had fighting continued. At times it was a close race between requirements and production, but never were any important military operations involving the use of high-octane aviation gasoline held up or delayed for lack of sufficient output of such material. The undivided effort of the entire refining industry in full cooperation with the Government made this record possible. Little diminution in output followed the German surrender on May 7. Plans called for a correspondingly greater activity for the Japanese war and possibly for well into 1946. But when the Japanese sued for peace on Aug. 10 most contracts were quickly canceled. Substantial stocks, reputed to be somewhere between 20,000,000 to 30,000,000 bbl., built up largely between V-E and V-J day pending organization of the larger Japanese war program envisaged after Germany gave up, were in the Government's hands in this country, in addition to working stocks in the war areas. Toluene and Lubricating Oil Requirements for toluene for T.N.T. increased rapidly as bombing speeded UP with increasing control of the air by the Allies in Europe and Asia. Production in excess of T.N.T. requirements which had been going into 1000-Octane aviation fuel blending during 1943 and 1944 was again drawn into explosive manufacture early in 1945. In anticipation of the war continuing into 1946, two new plants were ordered constructed, the decision being announced in April, plans calling for one of them to get into production about the end of 1945, the other in the first quarter of 1946. Both of these projects were later canceled as victory made it evident that the additional supplies would not be needed. Production was

Jan 1, 1946

By Walter Miller

BY the beginning of 1945 the output of petroleum products for war had reached a volume and a rate of growth which practically assured all requirements so long as war continued. The programs for making gasoline, lubricating oils of required quality, toluene for T.N.T., and chemicals for manufacture of synthetic rubber, as well as numerous other lesser petroleum products, were all well in hand, and unless catastrophic developments occurred there was no doubt of the ability of the industry to meet all demands. The end of the fighting found the refining industry working at top capacity on war commodities, but also in position to convert quickly into peacetime civilian production. 100-octane Aviation Gasoline Production of the vital 100-octane aviation gasoline, starting with approximately 44,000- bbl. daily capacity at our entry into the war, reached a top of 525,000 bbl. a day in the United States by the end of hostilities. With 75,- bbl. from other Allied sources, the grand total was 600,000 bbl., or 25,000,000 gal. each 24 hr. available to the armed forces had fighting continued. At times it was a close race between requirements and production, but never were any important military operations involving the use of high-octane aviation gasoline held up or delayed for lack of sufficient output of such material. The undivided effort of the entire refining industry in full cooperation with the Government made this record possible. Little diminution in output followed the German surrender on May 7. Plans called for a correspondingly greater activity for the Japanese war and possibly for well into 1946. But when the Japanese sued for peace on Aug. 10 most contracts were quickly canceled. Substantial stocks, reputed to be somewhere between 20,000,000 to 30,000,000 bbl., built up largely between V-E and V-J day pending organization of the larger Japanese war program envisaged after Germany gave up, were in the Government's hands in this country, in addition to working stocks in the war areas. Toluene and Lubricating Oil Requirements for toluene for T.N.T. increased rapidly as bombing speeded UP with increasing control of the air by the Allies in Europe and Asia. Production in excess of T.N.T. requirements which had been going into 1000-Octane aviation fuel blending during 1943 and 1944 was again drawn into explosive manufacture early in 1945. In anticipation of the war continuing into 1946, two new plants were ordered constructed, the decision being announced in April, plans calling for one of them to get into production about the end of 1945, the other in the first quarter of 1946. Both of these projects were later canceled as victory made it evident that the additional supplies would not be needed. Production was

Jan 1, 1946

By Kenneth E. Skiff

INTRODUCTION United Nuclear Corporation and Homestake Mining Company are partners in a major uranium mining and milling venture near Grants, New Mexico. The partnership was formerly called Homestake-Sapin Partners and was recently renamed United Nuclear-Homestake Partners (UN-HP). The mill, originally built in 1958, had a capacity of 1,650 tons per day. With subsequent improvements and the addition of the adjacent Homestake - New Mexico Partners mill, the UN-HP mill is currently rated at about 3,500 tons per day. An alkaline type leach process is utilized by the mill. Milling consists of five basic steps: A. Ore handling and preparation B. Extraction C. Solid-liquid separation D. Precipitation and purification E. Product preparation MILLING Ore Handling and Preparation The primary source of ore for the UN-HP mill is from its four

Jan 1, 1983

No review of underground mining should begin with anything but the new world safety record set at the Grace underground iron mine of Bethlehem Steel at Morgantown, Pa., on Friday, November 12. There had not been a disabling injury (an injury which keeps an employee away from his next scheduled shift) for 550 working days. In all, 2,660,080 man-hours had been worked by nearly 950 employees without a disabling injury. The record was wrested from Johns-Manville's Jeffrey mine at Asbestos, Que. At 3 p.m. Friday, December 3, miner Stanton E. Friend was completely buried under several feet of coarse rock, fortunately sustaining only cuts and multiple abrasions. But with his fall, the accident- free period came to an end at 2,778,600 man-hrs worked without a disabling injury-the new record!

Jan 2, 1966

By A. W. Worthington

It would be futile in this short discussion to attempt to cover the subject of misfires with the thoroughness which it deserves. No effort is made to set forth a list of the many causes of misfires, nor to analyze the various preventives and methods of treatment which are advocated by those who are most interested in promoting good practice. These details, as well as the fundamentals, have been rather fully covered in many published articles based on years of experience in the manufacture and use of explosives and on research covering specific problems. We shall assume the knowledge of and familiarity with those many facts which have been proved beyond reasonable argument, and will discuss the problem of misfires as it has actually been experienced in the operation of the limestone quarries and underground mines of the Pittsburgh Limestone co. and its associated companies, which produce fluxing stone for the furnaces of the United States Steel Corpn. in the Pittsburgh district. These opinions are based on data compiled from written records at each of our operations, and they are concurred in by our assistant general manager in charge of operations, our safety director, and the superintendents at each of our plants, to whom we are indebted for assistance in gathering many of the data. Each of these men is not only interested in the subject but is fully capable of analyzing results obtained under his supervision. The entire subject of the proper storage and use of explosives, of which the problem of misfires is only a part, has been given a great deal of study. In this we have been aided by having the advantage of the publications of the U. S. Bureau of Mines. A number of the states have also, more recently, given to quarrying and general mining methods the attention which they deserve. Their findings should prove of value to the operators. We feel, further, that operators particularly owe gratitude to the various manufacturers of explosives for their thorough and intelligent study of the many problems relating not only to the manufacture but to the use of explosives, and for their willingness and efforts to disseminate the results of their investigations.

Jan 1, 1930

By Joseph P. Kittredge

At the time this matter first came up in 1912, the National Malleable and Steel Castings Co. had seven basic-bottom open-hearth furnaces in its plant at Sharon, Fa., using fuel oil, then costing about 2½¢ per gallon. The fuel was satisfactory but its cost fluctuated widely, therefore the use of pulverized coal, which had been successful in the cement industry and in some metallurgical furnaces, was suggested. After a thorough investigation, and an actual trial on one of the open-hearth furnaces, to be certain that the siliceous ash in the coal would not seriously affect the basic slags, the management of this company approved its adoption and a complete installation was started. The conclusion had been reached that the success of the operation depended on pulverizing the coal to greater fineness than had thus far been accomplished, and all equipment was chosen with this in mind. A coal drier was deemed essential, and one of ample capacity and efficiency was selected, which has done all that was expected of it, working without failure and with very small maintenance cost, and is still in operation. Pulverizers The company demanded a pulverization of at least 90 per cent through a 240-mesh screen, with consistent results, and a machine was chosen that was grinding other materials than coal to the fineness desired. The control of fineness was obtained through a vacuum separator, and was governed by the size of the separator and the number and construction of the valves necessary to expand and direct the air current. These valves can be set to obtain any degree of fineness desired, and the result is consistent. Two machines were installed, each capable of producing 2½ tons per hour, 95 per cent through 240 mesh. These machines have done everything expected of them, have run continuously, and are still in operation. An examination of some of our pulverized coal by elutriation and microscopic measurement disclosed that a 1-lb. lump of bituminous coal,

Jan 1, 1940

By Joseph P. Kittredge

At the time this matter first came up in 1912, the National Malleable and Steel Castings Co. had seven basic-bottom open-hearth furnaces in its plant at Sharon, Fa., using fuel oil, then costing about 2½¢ per gallon. The fuel was satisfactory but its cost fluctuated widely, therefore the use of pulverized coal, which had been successful in the cement industry and in some metallurgical furnaces, was suggested. After a thorough investigation, and an actual trial on one of the open-hearth furnaces, to be certain that the siliceous ash in the coal would not seriously affect the basic slags, the management of this company approved its adoption and a complete installation was started. The conclusion had been reached that the success of the operation depended on pulverizing the coal to greater fineness than had thus far been accomplished, and all equipment was chosen with this in mind. A coal drier was deemed essential, and one of ample capacity and efficiency was selected, which has done all that was expected of it, working without failure and with very small maintenance cost, and is still in operation. Pulverizers The company demanded a pulverization of at least 90 per cent through a 240-mesh screen, with consistent results, and a machine was chosen that was grinding other materials than coal to the fineness desired. The control of fineness was obtained through a vacuum separator, and was governed by the size of the separator and the number and construction of the valves necessary to expand and direct the air current. These valves can be set to obtain any degree of fineness desired, and the result is consistent. Two machines were installed, each capable of producing 2½ tons per hour, 95 per cent through 240 mesh. These machines have done everything expected of them, have run continuously, and are still in operation. An examination of some of our pulverized coal by elutriation and microscopic measurement disclosed that a 1-lb. lump of bituminous coal,

Jan 1, 1940

By A. O. Bartell

Do you know that valuable clues to the geology and mineralization of a district can be found in a handful of sand from a stream bed draining the area? This handful of sand has a story to tell to those who have a little patience. The handful of sand may contain tiny specks of valuable minerals (gold, scheelite, cinnabar, chromite, tourmaline-to mention a few), that will lure you upstream with the hope of uncovering a new deposit. More practically, this handful of sand can indicate the type of rocks that are exposed by the drainage system. Any mineral that has a specific gravity of 3.5 or higher can be separated from soil by panning. Garnet and pyrite, for example, can indicate an outcrop of metamorphic rock. In one district where the writer prospected, small boat-shaped orthorhombic crystals of topaz always indicated the presence of andesite outcrops.

Jan 1, 1948

By Alan K. Burton

The individuality of off-highway trucks is largely determined by a number of truck components that include beds, frames, and suspensions. With the exception of tires, these features are generally standard equipment and the mine operator gets "what comes with the truck." With the advent of larger trucks, more complicated haul profiles, and sophisticated production control systems, a new truck support-component industry is rapidly appearing. The impact of the new options for off-highway trucks can be significant in terms of future fleet performance. Innovations include "Mesabi" radiator cores that reportedly offer greater engine temperature control; load indicators that insure proper truck loading at the shovel; and digital communication systems that signal truck status in the haulage cycle. An understanding of tires, brakes, and newly introduced support components is necessary before an optimum choice of truck can be made

Jan 11, 1975

By H. J. Maguire

Those familiar with mill-practice understand the work required of an average bucket-elevator, but I wish to call special attention to the wear on the buckets. I have been studying in what manner the life and service of the bucket might be improved, and I feel that an adjustable lip, attachable to each bucket without the aid of rivets, will be of material advantage. For illustration, consider the feed-elevator of a typical mill in the Cæur d'Alene district. The ore is carried by water in a launder from the feed-rolls and dumped in the " boot" of the elevator, directly in front of the ascending bucket. Middlings from the return-rolls are similarly handled. Under this condition the bucket not only carries the ore, but also picks it up, and this latter requirement determines the life and service of the bucket. It might be said that it would be better practice to convey the feed to the elevator and dump it directly into the bucket, but at one mill at which this plan mas tried the results were disappointing and the rubber belt was badly worn. The wear of the bucket is confined to the lip and the corners which have to pick up the material. When the lip on a corner of a '7- by 12-in. malleable cast-iron bucket is worn down about 3 in., the bucket is of no further value as a carrier and has to be replaced. The worn bucket, containing about three-quarters by weight of the metal of the original bucket, has a scrap value of about 10 per cent. of that of a new bucket. To the cost of the bucket, however, should be added the time-

Jan 1, 1913

By Walter Miller

Petroleum refining, like other industries in the United States in 1940, focused much attention on its duties and opportunities in the field of national defense. In crdiiter-distinction to the situation during the World War, the industry is well constituted as to existing equipment, processes, and capacity, together with planned additions, to handle any demands that may be made upon it by the defense program needs. Evident throughout was the growing sense of ability to manipulate oil molecules for the production of materials not hitherto considered as being available commercially from petroleum. The development and application of catalytically induced reactions on a broad front is one of the distinguishing characteristics of refining progress during the year. In the hands of the refiner, catalysis has developed into a most important means to secure higher antiknock motor fuels and 100-octane fighting grade aviation gasoline in greatly increased quantity. One illustration of the importance being assigned to catalytic refining is the construction by the Houdry group of an experimental laboratory at a cost of $7'307'30'3, to be staffed with over 100 research men7 solely for the purpose of studying catalytic reactions. In the aviation gasoline picture a modification of specifications by the Government widened the field from which acceptable fuel can be secured, and the continued expansion of the alkylation process in itself promises to go far in filling the demands expected from 50,000 fighting planes. It is conservatively estimated that eyen now the industry can turn out 1,300,000 gal. of 100-octane aviation gasoline daily. The upper limits of octane numbers for regular grades of motor gasoline reached in 1939 were not exceeded, but the average octane number approached the upper level more closely. A survey made of the 1940-model cars showed no rise in average octane requirement of the engines. The trend throughout the year was for greater reliance on the A.S.T.M. method for octane determination. The "1939 Research Method" is less widely used, although still considerably in evidence; the older L-3 method seems to have lost considerable ground and to be on the way out. Re-forming Capacities Increased Interest continued to grow apace in re-forming low-octane naphthas into high-octane gasolines. Some additions, although not great, were announced in thermal re-forming capacity. Interest in catalytic re-forming was greatly stimulated by the technical success of the operation of the converted hydrogenation unit at the Bay-way, N. J., rehery of the Standard Oil Company of New Jersey, mentioned in last year's review, and also by the knowledge that recoverable proportions of toluene are present in the hydroformed (catalytically

Jan 1, 1941

By Walter Miller

Petroleum refining, like other industries in the United States in 1940, focused much attention on its duties and opportunities in the field of national defense. In crdiiter-distinction to the situation during the World War, the industry is well constituted as to existing equipment, processes, and capacity, together with planned additions, to handle any demands that may be made upon it by the defense program needs. Evident throughout was the growing sense of ability to manipulate oil molecules for the production of materials not hitherto considered as being available commercially from petroleum. The development and application of catalytically induced reactions on a broad front is one of the distinguishing characteristics of refining progress during the year. In the hands of the refiner, catalysis has developed into a most important means to secure higher antiknock motor fuels and 100-octane fighting grade aviation gasoline in greatly increased quantity. One illustration of the importance being assigned to catalytic refining is the construction by the Houdry group of an experimental laboratory at a cost of $7'307'30'3, to be staffed with over 100 research men7 solely for the purpose of studying catalytic reactions. In the aviation gasoline picture a modification of specifications by the Government widened the field from which acceptable fuel can be secured, and the continued expansion of the alkylation process in itself promises to go far in filling the demands expected from 50,000 fighting planes. It is conservatively estimated that eyen now the industry can turn out 1,300,000 gal. of 100-octane aviation gasoline daily. The upper limits of octane numbers for regular grades of motor gasoline reached in 1939 were not exceeded, but the average octane number approached the upper level more closely. A survey made of the 1940-model cars showed no rise in average octane requirement of the engines. The trend throughout the year was for greater reliance on the A.S.T.M. method for octane determination. The "1939 Research Method" is less widely used, although still considerably in evidence; the older L-3 method seems to have lost considerable ground and to be on the way out. Re-forming Capacities Increased Interest continued to grow apace in re-forming low-octane naphthas into high-octane gasolines. Some additions, although not great, were announced in thermal re-forming capacity. Interest in catalytic re-forming was greatly stimulated by the technical success of the operation of the converted hydrogenation unit at the Bay-way, N. J., rehery of the Standard Oil Company of New Jersey, mentioned in last year's review, and also by the knowledge that recoverable proportions of toluene are present in the hydroformed (catalytically

Jan 1, 1941

By Hans W. Brodbeck

The main problem in tunneling without the use of explosives lies in the development of tools capable of continuous mechanical destruction of rock, resulting in a fragmentation which lends itself to a smooth, uninterrupted transportation of the broken rock away from the tunnel face. While all moles of U.S. design mainly achieve this by crushing the rock by means of "disk cutters" or "roller bits," a boring system based on the principle of cutting the rock came into being in Europe, whereby the rock is worked in a manner very similar to the milling of metals. For tunneling purposes, this principle was first developed by the late Austrian engineer Wohlmeyer. Between late 1962 and the spring of 1965, the first experimental machine was tested in a German coal mine, working in coal and shale over a distance of some 3000 ft, divided over two runs separated by a period of time to allow for equipment modifications. In 1964, a collaboration was started between Wohlmeyer and the Habegger engineering firm of Thun in Switzerland. The normal Habegger range of equipment consists of aerial ropeways, ski lifts, and certain tool machines, to which in later years have been added monorail passenger-transport systems. One of these was installed as the main mode of transport at the 1967 World Fair in Montreal. After taking over the Wohlmeyer patents, Habegger further developed the original cutting principle, aiming at more robust machines in order to be able to tackle harder rock. A first machine was built and tested at a site near Thun in sandstone averaging 17,000 psi compressive strength and limestone of 25,000 psi. In May 1966 this machine was delivered to Japan for the boring of a pilot tunnel for the Honshu-Hokkaido railway connection under the sea. A second machine, incorporating many improvements based on experience gained with this first mole, was built during 1966 and tested in the same limestone as mentioned previously (25,000 psi), before being installed to bore the head race tunnel of the Julia hydroelectric power scheme near St. Moritz, Switzerland, in the early summer of 1967 (Fig. 1 ) .

Jan 1, 1970

By V 7. 0 / 300 dpi

THE cams at present universally used in stamp mills lift the tappets with an involute form of curve, to which the surface of the tappet is always tangent; moreover, the line of contact between tappet and cam, if produced, would pass through the center of the stem. This is no doubt a desirable feature, but the writer has long believed that it would be much more desirable if the cam were to pick up the stamp without shock, and gradually increase the upward velocity of the stamp throughout its upward movement. The involute form of cam attempts to impart instantly a considerable upward velocity to the stamp, starting it from a state of rest, and the result is a destructive blow, a great deal of noise, and much wear and vibration. The writer has developed a form of cam which will lift the stamp with a motion similar to that of the piston of an engine between the end and middle of its stroke; in other words, harmonic motion, from the point. of zero to maximum velocity. The curve will give this ideal motion only when the stamp is set for the exact drop for which the cam was designed, but the improved cam will not be as bad as the involute cam until the drop is reduced one-half. In other words, if a cam is designed for a 6-in. drop, it will be some improvement over the usual form of cam until the drop is only 3 in. Any cam, whatever its form, must of course lift the stamp in the same number of degrees of revolution; therefore, with this new form, since the stamp starts more slowly on its upward course, it must end up by going faster, the average speed being the same as with the involute cam. The stamp, after it is no longer in contact with the cam, keeps on going up a certain distance, which is easily calculated. It is therefore possible to hang up a stamp without a cam stick, if the fingers are not more than 1/8 in. longer than necessary to hold the tappet above the cam.

Jan 12, 1914

By Walter A. English

The four papers making up this symposum have been prepared especially for those who have no knowledge of seismograph prospecting. To many people mathematics is a formidable subject, and many are discouraged from studying seismograph prospecting under the mistaken assumption that the mathematical requirements are severe. In the papers presented here there is not a single mathematical equation. We believe that considerable competence in dealing with some of the most important problems of this work can be attained without any mathematical training whatever. At the present time, there is a real need for interpretation of results by persons thoroughly competent to bring geologic experience and imagination to bear on data that are subject to multiple interpretation from a strictly physical viewpoint. Likewise, those charged with the responsibility of planning seismograph exploration campaigns would do well to become familiar with as much as possible of the technical aspests of the work. They would then be in better position to judge of its success in individual cases. It has often been said that the seismograph is a new structure-finding tool for the geologists to use. Using a tool and using its product are two different things. One does not use an automatic screw-threading machine when he buys a box of screws at the hardware store. Neither does the geologist

Jan 1, 1940

By Walter A. English

The four papers making up this symposum have been prepared especially for those who have no knowledge of seismograph prospecting. To many people mathematics is a formidable subject, and many are discouraged from studying seismograph prospecting under the mistaken assumption that the mathematical requirements are severe. In the papers presented here there is not a single mathematical equation. We believe that considerable competence in dealing with some of the most important problems of this work can be attained without any mathematical training whatever. At the present time, there is a real need for interpretation of results by persons thoroughly competent to bring geologic experience and imagination to bear on data that are subject to multiple interpretation from a strictly physical viewpoint. Likewise, those charged with the responsibility of planning seismograph exploration campaigns would do well to become familiar with as much as possible of the technical aspests of the work. They would then be in better position to judge of its success in individual cases. It has often been said that the seismograph is a new structure-finding tool for the geologists to use. Using a tool and using its product are two different things. One does not use an automatic screw-threading machine when he buys a box of screws at the hardware store. Neither does the geologist

Jan 1, 1940

By Orvar Nyquist, Klaus W. K. Lange, John Chipman

Liquid Fe-C-Si alloys containing 0 to 12 pet Si and up to 4 pet C were equilibrated with carburizing gases at 1550°C. Two to 5 alloys simultaneously were held in close proximity for 5 to 7 hr to establish uniform carbon activity in the group. Analysis of the data gives the activity coefficient of carbon as a function of the mole fractions of carbon and silicon, Fig. 7. Values of the interaction coefficients at infinite dilution are

Jan 1, 1962