Search Documents

SOME days ago a visiting member from Pittsburgh who is an ardent supporter of the Institute remarked: "There are a lot of men who would be members of the Institute if it weren't so expensive. It is not so much the $15 dues as the $20 initiation fee. This makes quite a hurdle, especially for the younger fellows." A little further conversation developed the fact that the member had never learned of the changes in the By-laws regarding initiation fees and dues made by unanimous vote of the Board of Directors last November. As a great many others doubtless are unaware of these changes, the substance of two of the amendments is here repeated. They provide: (1) That the initiation fee for Junior Members (heretofore ten dollars) he abolished. (2) That the age limit for entrance as a Junior Member be increased from 27 years to 33; provided further, that the period during which the dues of a Junior Member are ten dollars shall be a maximum of six years but in no event shall extend beyond his thirty-third birthday. The Junior Member gets the identical privileges enjoyed by his seniors and he likewise assumes the same obligations with the sole exception of the financial payments. This one exception is justified by the fact that the engineers of more mature years, who are established in the profession, - are able and willing to assume a slightly greater financial burden. In effect, it is a small subsidy for the younger men; but these in turn will later enter the group of those that give instead of receive assistance. The practical result is that an engineer under 27 can obtain every privilege and benefit of membership for six years on the payment of only $10 per year without any initiation fee. A man of thirty can do the same for a period of three years. Incidentally, a candidate applying for membership (either as senior or junior) in the next few months need pay dues for the second half of 1935 only. A Junior Member -can be enrolled with an immediate outlay of only $5. The Institute does not seek-members indiscriminately merely to swell the number. These facts are not presented as a "bargain" offer in any sense. The standards for admission are high and are watched zealously. But it frankly-wants to give qualified men who can benefit from membership every encouragement to apply. Naturally, the Institute does not want lack of accurate information regarding initiation fees and -dues to be a stumbling block to any that are eligible and desirous of enrolling. Members are urged to take it upon themselves to clear up misapprehensions on this point, particularly among younger engineers.-Editorial reprinted from MINING AND METALLURGY, May, 1935.

Jan 1, 1935

By Eugene F. Poncelet

This paper attempts to analyze the phenomena involved in the fracture of brittle solids by simple compression. Glass squares standing on edge, and compressed between two parallel steel jaws, developed jagged fractures, roughly parallel to the compression. Polarized light disclosed the presence of high local stress concentrations indicating poor contact all along the contact surfaces with the steel jaws. Teszar has shown that partial contact between the jaws and such a compressed solid causes tensile stresses in the free surfaces of the solid normal to the compression. Furthermore, Scoble has shown that in brittle solids fractures are caused by, and develop normally to, a sufficient tensile stress. It follows that such "partial-contact" cracks must be expected. With optically flat jaws and specimens, no "partial-contact" cracks developed. Instead, very smooth cracks vertical to the compression appeared 'upon release of the pressure. Investigation showed that the friction with the rigid steel opposed the return of the glass to its original width, after creeping on the steel as compression built up, thus setting up tensile stresses in the glass surfaces. It was not found possible to eliminate these "release" cracks. Compressed to destruction, such specimens flew to dust. A Microflash photograph taken during the explosive disintegration revealed: (I) oblique parallel fragmentation cracks, 30" off the direction of the compression; (2) transverse forking fragmentation cracks, normal to the former; (3) release cracks parallel to the compression; (4) a disintegration cloud. Given a distribution of submicroscopic cracks of random orientation throughout the glass, Griffith has shown the highest tensile stresses to be located at the tip of the cracks 30" off the direction of the compression. Although the preexistence of such cracks or flaws in unstressed glass is doubtful, they can be generated by the distorting forces set up by the compression itself. Atoms, in a structure held together by Morse-type forces or bonds, have under tension both a stable and an unstable state-of equilibrium. The difference in energy level between these two states is a function of the tension, and this difference must be borrowed from the thermal energy level of the bonds to reach the unstable state and result in a broken bond. As the fraction of the bonds having at any instant a sufficient thermal energy level is a known function of that level, it is possible to determine, in function of the prevailing tension, the fraction of the bonds that are broken. Upon breaking of the bond uniting two atoms at the tip of an advancing crack, the two atoms accelerate away from each other, causing in the solid propagation of a

Jan 1, 1944

Theoretically mobile primary crushers at the mine working face can be considered the ideal comminution system. A crusher which follows the ore can reduce materials handling costs because it eliminates about one ton of truck deadweight per ton of ore hauled to the crusher. It also eliminates the backhaul of this same deadweight ton. Development of mobile primary crushers has centered in Germany where many soft iron ore and limestone deposits are flat-lying and thus readily adaptable to the use of shiftable conveyors which easily followed the working face. These ores were easily crushed in impact- type mills which had extremely large receiving openings and therefore large reduction ratios. The feeding of such a unit was done with a front-end loader which dumped its load to an inclined apron feeder, which in turn fed the impactor. Under the crusher was an inclined conveyor which transferred the crushed ore to a belt wagon for delivery to the shiftable overland conveyor. Low headroom overhead eccentric single-toggle jaw crushers and short-shaft gyratories were also used on these units, which generally travelled on tracks. While these early mobile primary crushers were versatile and served their purpose, they generally suffered from low capacities. Manufacturers have quickly responded with larger crusher, feeders, and moveable supports, however; and today mobile crusher s have capacities of up to 1500 metric tons per hour, a figure comparable to the capacity of some 54 in. by 74 in. gyratories. An example of a quarry portable crushing plant is at the Bath cement plant of Canada Cement Lafarge, Limited. Two 12 cu yd front-end loaders are digging the stone and hauling it to the portable crushing plant which feeds a field conveyor system. The crushing plant is moved and the field conveyors extended whenever the length of the haul exceeds 300 ft. At the crushing plant, the loaders discharge the stone onto a pan feeder which feeds into the hopper of a Weserhutte-Hazemag compound crusher which combines primary and secondary rotors in the same housing. These are driven at 1200 rpm by 800 hp and 1,000 hp motors (600 and 750 kw). The maximum 3 ft feed (914 mm) is reduced to 3/4 in. (19 mm) at 800 tph. The Weserhutte steered walking mechanism, operated by hydraulic cylinders, takes five -foot strides. Another example is at Alcoa of Australia's operation at Huntley in Western Australia. At the mine face, front-end loaders load 50 mt rear-dump trucks that transport the bauxite ore to the mobile crusher which follows the mine operation. The crusher can turn 360° within its own length, walk at a speed of 34. 5 ft per minute (10.5 m per

Jan 1, 1978

those who are to lie in the torn fields of France. Today we read of Lieut. William Hague, whom we said good-by to hardly more than a month ago-—so clean, ao young, so strong—who, abandoning the professional career in which he had won such commendation and which held for him such promise, leaving his wife and his little boy to whom he was so dear, answered at once the call for men of his training, and is now dead "in the service of his country." There are many friends of that courtly and dignified gentleman James D. Hague who recall, both here and in Stockbridge, the parental pride in the promising lad of such a little time ago—the eager schoolboy at Milton, the rather grave youth at Harvard, his entry into new experiences in the Western mining world, and who, seeing him during his stay at Camp Upton, realized that the old Puritan stock was still sound and true—and now with him the struggle is over and the sacrifice made. Captain William Teasdale Hall Captain Hall, who was admitted to Junior Membership in the Institute in 1915, while still a student of mining at the University of Toronto, was killed in action in France on May 19, 1917. Captain Hall was born in Toronto in 1893, and received his academic training at Harbord College, from 1908 to 1911, when he entered the University of Toronto, School of Practical Science. During the three summer vacations of his university course, he was employed by the O'Brien mine at Gowganda, next by the McIntyre Mining Co., at Porcupine, and finally by the Mines Branch of the Geological Survey, which was conducting magnetic surveys to the north of Port Arthur. When war was first declared, Mr. Hall endeavored to join the artillery as an officer, and for the purpose secured a provisional lieutenancy with a Hamilton battery, but he did not receive an overseas appointment, and on being graduated as a mining engineer in 1915, he was offered a position in Chile, which he accepted. He left Toronto on May 27, 1915, and was engaged in Chile as a mining engineer for nearly a year. In the latter part of April, 1916, he decided to offer himself again for service at the front. He crossed the Andes and sailed for LiverpooI, where he landed on May 13, 1916. On May 27, 1916, Captain Hall was given a commission as a lieutenant in the Royal Flying Corps, 21st Squadron. He went to the front on Sept. 1, 1916, and remained there continuously. His

Jan 1, 1920

By F. M. Waring

produced when zinc is substituted for a certain amount of tin are decidedly unsatisfactory. The substitution of aluminum for tin is entirely impractical, and such castings are worthless. This does not, however, exhaust all the possibilities of substituting other metals for tin in the copper-tin-lead alloys, but it is my opinion that the substitution of any other metals, in those alloys, can be made only by sacrificing the quality of the alloy. The possibility of substituting alloys of an entirely different type presents an attractive field for research. The copper-tin-lead alloy has attained its position as the most desirable bronze bearing alloy, but this does not mean that some other alloy may not be found which may give equally good or better results. In the search for such a substitute alloy it should be borne in mind that a bearing metal should possess the following properties: (1) It should be sufficiently rigid to support the load or resist the impact, but yet not so brittle that it will easily crack. (2) It should have as great a yielding or plastic nature as is consistent with its ability to support the load or resist the impact without deformation of the bearing as a whole. (3) The ideal structure combines a hard matrix to support the load and a softer metal or alloy contained within such matrix, to permit the bearing surface to adjust itself to irregularities of service. (4) It should be easy to handle in the foundry and machine shop. (5) It should be capable of being remelted without deterioration. (6) For use in babbitt-lined bearings, it should be capable of being tinned, so that the babbitt can be applied thereto. (7) It should have good heat conductivity in order to dissipate the heat generated by friction. Pennsylvania Railroad Anti-friction and Bell Metals F. M. Waring," Altoona, Pa.—Thc necessity for conserving tin has recently been very forcibly brought to the attention of all consumers, and efforts are now being made to reduce the tin content in certain alloys or to substitute other alloys not containing tin. The approximate composition of the non-ferrous alloys in general use on the Pennsylvania Railroad are given in the accompanying table. Phosphor bronze is used principally for rod bushings, main-rod brasses, and crosshead shoes. Ex. B bronze is used to a small extent for backs of car and coach bearings, but the majority of these are now made of the car-journal bronze, which contains, on the average, about 5 per cent. tin.

Jan 1, 1919

By L. G. Huntley

Discussion of the paper of L. G. HUNTLEY,. presented at the San Francisco meeting, September, 1915, and printed in Bulletin No. 102, June, 1915, pp. 1333 to 1349. E. W. SHAW, Washington, D. C. (communication to the Secretary*). -The comparatively great extent and uniform character of the Dakota sandstone make it of great interest to the student of rock pores and the movements of their fluid contents. However, compared with other sands in areas of carbonaceous rocks facts concerning it do not seem to be of such great direct importance to the producer for it has thus far yielded few important pools of oil or gas. Information concerning the sandstone is extensive but scattered, hence a general treatise regarding it-particularly its pores, the fluids they contain, and the movements of the fluids-has been much needed. I therefore feel that the. chief thing to be ,desired concerning Mr. Huntley's paper is that it were more extended, particularly as to the discussion of the data presented. The general structure map of the Dakota is of especial interest. Slight changes in wording seem to be desirable here and there in the paper. For example, at the beginning of the third paragraph one-wonders if flora instead of fauna were not intended. In Figs. 2, 3, 4, and 5 the vertical scale seems incorrect. Concerning the analyses of oil quoted it is noted that they "are given, as indicating what may be expected in different localities." This seems to need modification for the average analysis of oil from Powder River, which indicates for example that this oil begins to boil at 213°C. The fact is that the samples to which this figure refers were taken from seeps long exposed. to the air :find hence the underground Dakota oil of this district no doubt differs profoundly from that which the analysis indicates. The product of a well here would probably differ more in boiling point and other. respects from the samples analyzed than it would from almost any other petroleum in the world. The use of the word synclinorium does not conform to the original definition, but this may be pardonable because misuse of the term, though a different misuse, has become general. Synclinorium is an orographic term and cannot be correctly applied outside of mountain regions, for it is derived in part from the Greek word for mountain. It has, however, been widely used in a purely structural sense for compound syncline. The broad shallow syncline of the Dakota sandstone falls in neither category. Objection might also be made to the use of

Jan 12, 1915

By R. P. Rothwell

AT this our first meeting I beg to call the attention of the members of our Institute to what is certainly a question of the greatest possible importance to the industries we represent; and more particularly to the welfare of the coal and iron trades: I refer to the enormous waste of coal in mining and in its preparation for market, as now practised in our anthracite coal-fields. I t is a fact which many of you can certify to, that we are wasting fully me-half of all the coal in the veins we are now working, and there are cases, which might be mentioned where this proportion, immense as it is, has been greatly exceeded. The popular belief that our deposits of anthracite coal are "practically inexhaustible," is very far from being founded on facts. On the contrary, supposing the present rate of increase in the production to be maintained, it is probable that a maximum yield for our coal-fields would be attained in about fifteen years ; there are in fact some of our smaller basins where the principal veins are nearly exhausted and the production has already attained its maximum. There are others, again, where the depth attained-and it must be borne in mind that we commenced working at the surface outcrop moderate though it is (scarcely ever reaching eight hundred feet), has so increased the cost of mining as to imperil the capital invested, and though it requires but little foresight to predict the time when the difficulties of mining will be very considerably increased by reason of the greater depth, greater quantity of water, fire-damp, and other fruitful sources of cost, yet, ignoring these recognized facts, we continue to waste more than one-half of the coal where it is obtained with the least danger, expense, and trouble, that is, near the surface-either above water-level or at a moderate depth . below it. The inspection of almost any accurate mine map will satisfy you that, on an average, we leave fully one-third. of the coal in the ground as pillars to support the roof; in some places more than one-third thus remains, while it is very rare that less than one quarter is left. In almost every case this coal is absolutely lost, for it will very rarely pay to reopen gangways and lay roads to it after that portion of the mine has been abandoned. Is it necessary in all cases to support the roof, and where it is, may not some artificial

THE annual winter meeting of the A.I.M.E., which is to open in New York on Feb. 14, will be charac-terized by a number of novel features. The most important is that the technical sessions will be dis-tributed over four days instead of three as heretofore. This makes it possible to reduce the number of conflicts between sessions and also will enable each member to attend a larger number. At the same time the ses-sions are so arranged by groups that those interested only in one or more that are related can, if necessary, cover all in that group in three days as heretofore. The general excursion to which the fourth day has, for some years, been devoted has been regretfully given up, mainly because of the uncertainties of the weather in New York in February. In its place a series of group excursions are being offered at various times during the meeting, arranged, so far as possible, so as not to con-flict with any technical session likely to be of interest to those taking part in a particular excursion. Among the places to be shown the visitors are: the construction work on the Eighth Avenue subway, a real mining job; the Vehicular Tunnel, the world's greatest ventilating project; the manufacture of 42-in. conveying belts; one of the largest and most modern steam plants; a coal terminal; manufacture of mining equipment; a cable-making plant; an oil terminal and refinery. Other en-tertainment features include a smoker Monday evening with a real chance to get together and talk; an informal dance and entertainment given by the Woman's Auxiliary on Tuesday evening; the dinner-dance at the Waldorf Wednesday evening, with no long speeches; a general session Thursday evening when the Petroleum Division will present a series of important reviews of the year. An extensive program has been arranged for enter-taining the ladies, and members are urged to bring their wives. There will be dinners, teas, theater parties, shopping and sight-seeing excursions as well as the dances. The usual general luncheons for members, guests and ladies will be served each day at headquar-ters, and various committees and groups will hold lunch-eons, dinners, and round table conferences as indicated in the schedule on the page opposite. The Mining and Metallurgical Society of America and the American Society of Steel Treaters are participat-ing in this meeting and their members will be welcome as guests at any session or function. A joint conference of the Mining and Metallurgical Society and the A.I.M.E. has been arranged for Tuesday afternoon, under the chairmanship of Clinton H. Crane, at which the whole matter of the mineral reserves of this country is to be up for discussion.

Jan 2, 1927

By G. H. Enzian

W. C. Ellis—The intergranular fracture observed by these authors in brass seems to be characteristic of metals when tested under similar conditions. It has been observed by us in room temperature tests on lead alloys subjected to constant stress when the stress has been low enough to afford a small strain rate. If, however, the test be carried out at a high stress and therefore at a large strain rate, a characteristic, tapered, transcrystalline fracture is obtained. The same change of fracture has been observed by others with decrease of strain rate and increase of temperature for other metals—for example aluminum—and may be presumed, as the authors point out, to be general for metals. These findings suggest a plastic flow mechanism under conditions of small strain rate and high corresponding temperature differing from classical block slip. The required conditions point to a process fundamentally diffusive in nature—a less organized process than block slip. Nabarro18 has shown that plastic flow can occur by stress induced diffusion of vacant sites— a process of self-diffusion. Movements of a pseudo-viscous nature at grain boundaries are suggested in the work of Ke.15 Deformation near to a grain boundary by other than a slip mechanism appears necessary to Boas and Hargreaves.19 Wood and Rachinger20 report a cellular structure in slowly deformed alumi- num—the cell size is larger, the higher the temperature and the slower the strain rate. Presumably in the latter case diffusive movements occurred in the cell boundaries. In any case the nonslip mechanism seems somewhat obscure and further work is indicated. Such studies will undoubtedly clarify the nature and behavior of lattice imperfections—the very core of the strength and plastic properties of metals. F. H. Wilson and E. W. Palmer (authors' reply)—It is certain that the metallic behavior which has been termed "creep" includes many interdependent phenomena of which a nonslip type of plastic flow may well be one. The reports to which Mr. Ellis refers are illustrative of the many different observations that must be correlated for a complete understanding of creep. The list could be extended considerably. For example, we ourselves have been impressed by the sensitivity of creep phenomena to the presence of minor impurities and feel that this aspect of the problem warrants more thorough study than it has yet received. References 18 F. R. N. Nabarro: Report of Bristol Conference on Strength of Solids. P. 75, (1948) London. 19 Boas and Hargreaves: Proceedings Royal Society. (1948) 193. 89. 20 wood and Rachinger: Journal Institute of Metals. (1949) 17, 237.

Jan 1, 1951

By A. S. Joy

Vacuum flotation tests carried out according to the method of Schuhmann and Prakash1 have shown that the acid limiting edge of the flotation area for a Brazilian hematite, in the presence of dodecylamine, is a straight line of slope approximately unity. The flotation tests and the structure, surface ionization, and electrokinetic properties of this hematite have been fully discussed elsewhere. 2 The numbers of adsorbed H+, and OH- ions and collector molecules have been determined in the range of critical conditions defining the acid limit of the flotation area. The total amine adsorption is shown in Fig. 1 as a set of contours superimposed on the straight part of the flotation area. These were determined by spectro-photometric estimation of the complex formed between residual amine and the anionic dye Orange II.3 The ionic strength of the solutions was kept constant and at a value in sufficient excess of the amine concentration to ensure that the diffuse part of the double layer was populated predominantly by indifferent ions. Adsorption of H+ and OH- in the absence of amine was found by potentiometric acid-base titration in the presence of hematite.4 The form of the adsorption-titration curves suggested that the hematite surface behaves in an amphoteric manner, and that positively charged sites arise through loss of a hydroxyl ion, and negatively charged sites by loss of a hydrogen ion. On this basis, curves 8 and 9, shown in Fig. 2, were calculated from the titration curves. These show the variation of the numbers of positive (s +) and negative (s—) sites with pH. To distinguish between ionic and other modes of adsorption, zeta-potential determinations have also been made using the streaming potential technique. The influence of amine on the zeta-potential of the mineral over a wide pH range is shown in Fig. 3. The change in charge ?s, due to adsorption of amine ions in the Stern layer, was calculated by applying the Gouy-Chapman theory, as modified by Stem, to the results shown in Fig. 3. The validity of this treatment has been shown by Ottewill and Jaycock.5 The three full lines, Nos. (1) through (3), included in Fig. 2 show the relationship between ?s and pH at three amine concentrations. The general conclusion from the zeta-potential curves is that adsorption of amine causes a reduction in the negative charge on the surface. Comparison of the values shown in curves (1) through (3) of Fig. 2 with the - curve shows that the magnitude of the reduction is comparable with that of s - at any given

Jan 1, 1964

By Frederick W. DeVries

Since we first agreed to present this talk we have learned that some of you may have been covering ground we intend to discuss: Bob Schechter, Daryl Tweeton, Don Seidel, Herb Burgman; however, the ideas were original when we began, "novel" as in the title of the talk, and whether our results are news or merely corroborative, we feel they point a direction that could be valuable to all. We worked with many of you in the past on using hydrogen peroxide in in-situ uranium leaching. Our talk today is not directly related to peroxide; it is, I hope, illustrative of Du Pont&apos;s interest in providing service to this industry in any way we can. The scouting work we are presenting was stimulated by field inputs: First, ammonium carbonate leaches cause restoration problems, primarily because ammonium ions exchange on clays with calcium. Second, sodium carbonate solutions, especially in South Texas deposits, can cause intolerable swelling of clays. From discussions with Dr. van Olphen, who wrote the book on clay chemistry, we inferred by comparison of the radii of the hydrated ions of the elements in these clay systems, that since potassium had about the same radius as ammonium, and sodium was much larger, potassium occupied a unique position to solve both problems. We have shown: FIGURE 1 Potassium bicarbonate systems leach uranium without loss of permeability found with sodium Potassium salts are very effective in restoring ammonia-leached sites Before reviewing the details of our work, which was performed by Hazen Research, Inc., I should like to stress its scouting nature. We are trying to assist the in-situ industry by pointing out new, potentially important directions. But, as with our previous work on sodium silicate to restore permeability, we feel the development phases can generally best be carried out in cooperative programs with companies directly involved with operations. DISCUSSION Test Parameters Now for the details: Our leaching tests were designed to note pressure-drop changes across the ore sample as the uranium was leached. Figure 2 shows the apparatus. The [ ] packed length was 20.5 inches (52 cm) with fifteen hundred grams of ore in the two-inch (5 cm)-diameter bed. Pressure drop was measured by manometer and feed rates were maintained constant with a tubing pump. The samples, from a South Texas leach site, were sealed in "Zip Loc" bags, frozen with "dry ice", crushed (still frozen) through six mesh, and blended before placement into the columns. The ores analyzed as shown here: FIGURE 3 Ore Analyses [Sample A Sample B U308 015% 0122% Mo 0004% 0086% Se0012% <0001% Fe3,078%076% Fee- 098% 044%]

Jan 1, 1979

It is particularly interesting at this time to notice the recommendations of F. L. Bishop, clean of the University of Pittsburgh School of Engineering as to the types of engineers required and the training that should be given each type. Dr. Bishop&apos;s recommendations, which follow, are substantially the same as the first two recommendations made by resolution at the National Conference recently held to discuss commercial engineering problems. This provided business training for the engineer arid engineering training for commercial enterprises. Dr. Bishop says: "The first type is that of the man who may be called a technician, who is highly trained in science and mathematics, who possess the instinct of the research man and who can devote his entire time to highly technical research problems, either in the research laboratories which are now rapidly being developed in the large industries, or by applying the results of his research to engineering science. For the training of this type of man, there is needed the best of scientific equipment, the members of the faculty must be those who are intimately interested in research problems, and the student himself must have what is sometimes called a mathematical mind. It is doubtful if this type of nan can be developed in a four-year course under existing conditions. In fact, it is probable that such a man can be developed only M. a school which has a thorough graduate department. "The second type which seems to be demanded by the industries is the man who has a broad general knowledge of engineering subjects and can apply that knowledge in an effective way in present engineering problems. He must have ability to command men, a knowledge of the applications of economic principles to industries, and a broad training in the so-called humanities, since he is the man in contact with men of other types in other fields of human activities. He should not be a research man, his training in mathematics need not be of necessity so extensive as that of the research technician, but his understanding of engineering problems should be extensive. Such a man cannot be trained in the ordinary schools because of the artificial conditions which of necessity exist in academic institutions. He must become familiar with the industries while yet, a student in order that he may understand thoroughly the application of his theoretical courses in school and their application to industries, and also that he may become familiar in the formative period of life with the problems of labor and the human factor in engineering. It is in the development of this type of man, who is to become. the manager and operating head of our large manufacturing industries, that the advantages to be derived from the cooperative system of engineering education are needed."

Jan 9, 1919

By Willard Ide Pierce

THE native methods of mining and milling gold-ores in Korea may not present any specially new features, but are chiefly interesting as primitive practices, still followed at the present day. In mining where the rock is hard, wood is piled up near the face of the tunnel or drift and then set on fire. The fire bums for twenty-four hours, after which, three or four days are given for the rocks to cool, before the miners go in and extract the loosened material. The only tools in use are a hammer, a steel gad about five inches long, and a flat spoon-shaped basket. The pay-streak or chute is closely followed, and in places the workings are very small and intricate. Rock not yielding more than $6 per ton is not extracted. The manner of opening a mine is to begin on the outcrop, where the rock pays, sink a shaft or run a tunnel on the vein, and follow the pay-streak and more easily worked ore. When this is exhausted, or the influx of water interferes, the opening is abandoned and operations are begun again at a new spot on the outcrop. The place usually selected is as high up on the mountain as possible, and in no instance is advantage taken of the topography by running a cross-tunnel to tap the vein. The ore is brought in baskets to the surface, and there placed in sacks, holding about 150 1bs. each, and taken to be crushed. The rock is first crushed between two stones, as shown in Fig. 1. The upper stone is oval and rounded on the bottom, so that it can be readily rocked on the under stone. Two pieces of wood, used for handles, are placed, one on each side, in grooves in the upper stone, and held in position by means of straw rope. The lower stone is not smooth on top, but exhibits three elevations running lengthwise, with shallow depressions between them. The middle elevation acts as a fulcrum on which the upper stone may be rocked. From two to ten men, according to the weight and size of the stone used, are employed in rocking. With four men, from 300 to 350 lbs. of rock can be crushed per day, the stone making 50 complete oscillations per minute. The men squat on each side of the stone and move it to and fro by means of the wooden handles. The ore is fed, in pieces up to the size of an egg or even larger, by one of the men. During the crushing one man on each side, as the stone rocks from

Jan 1, 1890

By Henry N. Toler

Development in the Jackson gas field, Hinds and Rankin counties, for 1935 continued at a slow pace, there being only nine wells drilled on the structure, of which five resulted in gas producers and four in dry holes. There were no wells drilled deep enough during 1935 to test any of the horizons below the producing Selma chalk. There are 113 producing gas wells in the Jackson gas field, with three wells on the southeast edge of the field making some oil with a large quantity of salt water; this oil comes from the same horizon as the gas. The combined open flow of the 113 gas wells is about 4,100,000,000 cu. ft. The proven area of the field is approximately 8000 acres. The production of 10,291,000,000 cu. ft. for 1935 represents the largest yearly pull from the field by almost a billion cubic feet. The total production from the field to date is 45,104,000,-000 cu. ft. It is interesting to note that the rock pressure has dropped from 1010 lb. per sq. in. initial to 943 Ib. at the end of 1935, a decline of only 67 lb. in 6 years. There is a difference of opinion as to the age of the deepest formation tested on the Jackson structure; some people holding that it is Tuscaloosa, others, Trinity, and still others that it is Paleozoic, probably Pottsville. The production of the Amory gas field, Monroe County, continued to decline and the capacity was far under the demand. Originally there were four producing wells in the field with a combined open-flow capacity of approximately 15,000,000 cu. ft. and a rock pressure of 680 lb. per sq. in. At the end of 1935 only two wells were producing with a combined open-flow of less than 1 million cu. ft. and the rock pressure down to 100 lb. or less. No attempt has been made to drill new wells in the immediate field but three wells are being drilled in the county in an effort to secure new supplies of gas. The wildcat operations for 1935, with only 11 wells drilled, were the lowest since 1932, just about one-half the number drilled during 1934. None of the wildcat wells drilled in 1935 resulted in producers and, so far as the writer is aware, did not uncover any large structures. The 11 wells drilled were abandoned or junked at comparatively shallow depths, except the well drilled in George County to 6928 ft. by the United Gas

Jan 1, 1936

* A complete magnetic picture of the Mesabi range is now available for the first time with the release of 21 additional maps based on the aeromagnetic survey of 30,000 square miles made jointly by the USGS and the Minnesota Geological Survey. A potential iron formation with a magnetic pattern remarkably like that of the Mesabi iron range lies buried beneath the glacial drift in a wide belt extending some 30 miles across the northwest corner of Itasca County in north central Minnesota. Identification of three new uranium minerals by the USGS was recently announced. The new minerals, andersonite, swartzite, and bayleyite are, respectively, hydrous uranyl carbonates of magnesium, of sodium and calcium, and of calcium and magnesium. They were first observed by Charles A. Anderson, Survey geologist, in a coating on gypsum on the 300-ft level of the Hillside mine, Yavapai County, Arizona. International Minerals and Chemical Corp. has announced a $4,000,000 expansion and development program in the Polk County phosphate fields in Florida, Plants for the manufacture of multiple superphosphate and phosphate chemicals including dicalcium p osphate for animal feed and chemical purposes, and a sulphuric acid are planned. Office building, machine shop, warehouse, and laboratory are also scheduled for erection. A new type of tramp iron detector is being used on the conveyor belt feeder at the South Agnew stripping operation. It is made of an alloy of aluminum, nickel and cobalt and does not have any electric coils. The alloy, known as Alnico, is remarkable for the permanence and intensity of the magnetism which it retains. The detector was made by Dings Magnetic Separator Co. and it is probable that Alnico will be used in magnetic separators. The American Society of Engineering Education estimates that unless the percentage of high school graduates entering engineering colleges is increased, there is a strong possibility that instead of a large surplus of engineering graduates, which has been propehsied rather widely, there will soon be fewer engineering graduates available than are needed annually by our national economy. This conclusion is reached from a survey that shows that engineering enrollments are only slightly higher than prewar whereas industrial expansion is increasing the need for engineers. * The natural resources of Korea are being investigated under ECA sponsorship. E.J. Longyear has just embarked 8 crews for that country; two drills are scheduled for base metal search while six are slated for development of coal reserves. An innovation in the development work in the iron country has been the adoption of the Drill-Mobile, jumbo-mounted drills on rubber-tired carriage, by Cleveland-Cliffs at the Mather A and B mines. The machine is being used to cut stations in the new Mathed B shaft and for driving development headings at the Mather A.

Jan 5, 1950

By Theron Wasson

The state of Michigan showed considerable activity during 1935. The center of greatest interest was the Crystal field, which was unknown until March, 1935, and is an illustration of the effect of the unknown and unexpected on Michigan oil development. The fields of the state (Fig. 1) produced a total of 15,770,000 bbl. of oil in 1935, or about 5 million more than in 1934. In order to keep up this production 307 new oil wells were drilled, of which 88 were in the Crystal area, which produced 3,600,000 bbl. This field had a rapid development and reached its peak in October. Since that time increasing water encroachment has caused a rapid decline. The pay horizon at the top of the Monroe dolomite is only a few feet thick. Big producers were offset by dry holes or small wells. The discovery well, which was in section 11, Crystal township, Montcalm County, was drilled March 28, 1935. Its initial production was 5000 bbl. per day, and up to Dec. 31, 1935, had produced 350,000 bbl. of oil—dose to one-tenth of the total production of the field to that date. The Beaverton field, which was discovered at the close of 1934, did not develop rapidly. Four small producers were finished in the Dundee lime during the year. West Branch was active and at the end of the year had 97 producers, 72 of which were drilled during 1935. Most of the wells produce from the Dundee lime; a few are finished in the Traverse. The Birch Run field deserves special mention, for it is the one area where consistent production continues to be found in the Berea sand at about 1500 ft. Wells are small, 20 now producing a total of about 300 bbl. per day of oil of fine quality. The old Central Michigan producing area, extending from Nit,. Pleasant through Yost to Porter, continued to be the principal producing area of the state and accounted for 10,370,000 bbl. from 660 producing wells. Ninety-three new wells were drilled in this territory. The Porter field, at the southeast end of this producing trend, was outstanding from the standpoint of production. The old Leaton field of Isabella County added several new producers. Its production was greater than in 1934.

Jan 1, 1936

By M. G. Cheney

THE production record of the Sinclair-Moren pool, in southeast Young County, Texas, demonstrates that under efficient operating methods a single well may obtain normal oil recovery from an area of 100 acres or more. This record is the more surprising in view of relatively adverse reservoir conditions such as lack of water drive, moderate initial reservoir pressures and a consolidated sandstone reservoir with original permeability greatly reduced by processes of lithification. This case history is considered worthy of special study in view of the ever present problem of proper spacing of wells. Cupidity, abetted by the unrestrained law of capture, has in too many instances guided development and production methods without regard for sound economic and engineering principles. Largely as a result of ill advised spacing of wells, many oil fields have brought financial losses instead of deserved profit to those using capital, time and energy in this important business of adequately meeting the petroleum requirements of what is known as our modern civilization. In March 1923, the Sinclair Oil and Gas Co. obtained initial daily production of about 12,000,000 cu. ft. of gas and 1100 bbl. of oil in its first well near the center of a 372-acre lease on the L. P. Moren land, James Rose survey, Abstract 245. This exploratory test was drilled as a geological prospect of average promise, on a plunging anticline with possibly 10 ft. of closure as mapped on the outcropping limestone of upper Canyon (Pennsylvanian) age. In subsurface, the top of the producing res-ervoir is 16 ft. lower in this well than in the highest wells but probably 25 ft. above lowest closing contour. Wells No. 2 and 3 were drilled about 1/4 mile west and southwest near a normal fault with some 30 ft. of downthrow to the southwest. The producing sand was reached at a depth of 2512 ft. and drilled to 2529 ft. in the first well. This sandstone reservoir is of Millsap Lake (middle Strawn, upper Cherokee) age. It was absent in the second and third wells, which were abandoned at the depths of 3725 or more. In April 1925, a fourth well was drilled 600 ft. east and 24 ft. lower for top of sand than No. I. Production of about 100 bbl. daily was reported from 2521 to 2562 after an 80-quart shot. This well was drilled to 4560 ft., plugged back to 2575 and shot again; but was abandoned soon thereafter because of small production.

Jan 1, 1940

By D. A. Bailey, F. L. Kadey

During recent years, expanded perlite has found extensive use in a wide variety of commercial applications. Specifications for a range of uses call for aggregates having different physical properties and requiring various types of processing. The mitre scopic examination of expanded aggregates in specially prepared thin sections has yielded important information regarding internal structure and can be a useful aid in evaluation of the product. Perlite is an acid volcanic glass containing from 2 to 5 pct combined water. When crushed and rapidly raised to a temperature of 1500° to 2100°F, the volatilization of the combined water, coincident with softening of the siliceous glass, causes the particles to expand or pop. Expansion of perlite to densities as low as 1-1/2 lb per cu ft has been achieved, although the normal range is from about 2.5 to 10 lb per cu ft. Low-density materials of this nature have found application in cryogenic insula- tions, insulating tile and board, plaster and lightweight concrete, soil conditioners, filter aids after comminution, and a host of other uses. The expansion of perlite may be controlled by a number of variables. Some of these are ore milling, furnace design, expanding temperature, use of preheating techniques, screen size distribution, and feed rate of the crude. For the specific intended uses, the art of perlite expanding has developed to the point that much is known about the effect of these variables on the end product. The requirements, however, for an aggregate to be used in plaster are different from those for an expanded perlite to be used in lightweight concrete or for cryogenics. In the study of perlite, many practical questions remain unanswered. One of the most important is, "why do some perlites make hard aggregates while others cannot resist crushing or compaction?" The usual tests and methods for evaluation of nonmetallic substances have been tried and have contributed their share to our knowledge. But chemical analyses, compaction resistance tests, screen analysis, etc., will reveal only a limited amount of information. The answers to these complex questions may well be found in an examination of the intemal structure of the expanded particle. Such questions and the ex-

Jan 1, 1962

RICHARD A. CONKLING (communication to the Secretary*).-Mr. Hager says that his results on the correlation of well logs in the north Cushing field are the opposite to those of the author. Can he, then, explain why the structural dip of the formations increases with depth, as Dr. Ohern, in his criticism, sets forth that it does, and as all who have worked in these fields will admit, if the shales thicken on the crest of the anticline, as he says they do? We are willing to agree with Dr. Ohern that there is some evidence of a slight unconformity below the Bartlesville sand and think that we can prove, from a specimen in our office, that .this unconformity comes at the base of the Bartlesville sand in the south Cushing pool. On the Ingalls dome, in the southeast corner of Township 19 North, Range 4 East, however, we get results the same as those given by the author on Cushing. The Ballard well in the center of the Northeast Quarter of Section 33 is just 10 ft. higher, structurally, according to tile, surface contour, than the Ringold well -in the center of the Southwest Quarter of Section 34. The dip in the Bartlesville sand, between these wells, is 40 ft. and the dip on the top of the Mississippi lime is 75 ft. This also might be accounted for, partly by the unconformity, but the author used the interval between the top of the Oswego lime, which is about 420 ft. above the Bartlesville sand, and the oil horizon found in the lime in the Ballard well-just mentioned above-to find the depth at which the same oil should be found in a well in Section 5, Township 22 North, Range 3 East, 25 miles North. Using this interval below the Oswego in the former well, we predicted within 2 ft. where they would find the oil in the latter well. Of course, we know that it was accidental that we missed it only by 2 ft., but if there were much of an unconformity in this interval it would be more of an accident if we came within 100 ft. of the depth. Since it can be proven from most of the structures in this section that the clip continues to increase downward, below the Bartlesville at least, to the Mississippi lime, it does not seem necessary to the author to try to prove otherwise that the depth at which the shales will tend to thicken on top of a fold, has not been reached above the

Jan 6, 1917

By W. G. Woolnough

It is perhaps a little difficult for Americans fully to appreciate the slow progress in the search for oil in Australia. Conditions are so different from those in the United States that methods must also differ considerably. Australia possesses an area almost exactly equal to that of the United States, but has a population of less than 7,000,000, and this population is concentrated almost entirely around the eastern and southern coasts of the continent. There are, therefore, vast "empty spaces" entirely unpopulated or exceedingly sparsely populated. The emptiness is due not to any lack of energy or initiative on the part of Australians but to the arid and waterless character of much of the country&apos;s interior. Throughout the greater part of the area that is comparable with the Mississippi drainage area of the United States, there is not a single flowing stream, and over most of it the rainfall is less than 7 in. a year. This hinders exploration and geological survey, and also isolates from potential markets many of the regions that otherwise might be considered worth prospecting. Also, Australia consists of six independent and sovereign states. With the establishment in 1901 of the Commonwealth of Australia, the states retained complete control of lands and mineral rights. Each state has its own petroleum legislation, and the absence of a central controlling authority has tended to confusion and to the introduction of many complications in oil prospecting. There are three major "territories," administered by the Federal Government; namely, the Northern Territory, enclosed between the northern parts of Queensland and Western Australia, within Australia itself, and the Territories of Papua and New Guinea in the island of New Guinea. Land and mineral legislation in these territories is not uniform. Furthermore, during the late twenties there occurred an orgy of company flotation and indiscriminate drilling, wQch resulted in the discovery of some definite indications of oil in three of the states and two of the territories, but which failed to develop any producing oil field in the common acceptation of the term. Much money was squandered,

Jan 1, 1938