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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

By N. J. Grant, B. C. Giessen, M. Morris

The slvuclures of alloys in the system In-Bi have been investigated after (levy vapid queuching from the mell (splat cooling) to -190°C. Tuo-phase fields could be suppressed over most of the tota1 concentvalion range; five melastable phases a1, a2, ?, ?1. and ß exisl, of which four have simple elementtike structures. For example, ß has the A5 struclure of white till. Crystal-tographic data and coordination numbers for these phases aye given, as well as addilional information on the equilibrium diagram, where a new phase In5Bi3 teas found. THE phase diagrams of binary combinations of B elements from the groups B2, B3, B4, and B5 are usually of a simple type and show considerably fewer intermediate phases than combinations of these elements with A metals, transition metals, or the B1 noble metals. Aside from phases such as the typical B3-B5 compounds with the ZnS-B3 structure type, few stoichiometric phases are known; among them are In2Bi and 1nBi.l Nonstoichiometric phases include ß (In-Sn), a1, (In-Pb), and the tin-rich ? phases in the In-Sn, Cd-Sn, and Hg-Sn systems.' The first two phases have a close relationship to indium, while the latter group are known to be structurally related to a Sn. Thus, there are generally no immediate experimental data for the correlation of the crystal structures of B metals and B metal combinations with certain monotonously varying parameters, such as the valence electron concentration (VEC), or the average atomic size. Such parameters have been recognized as structure determining, e.g., for the transition 4 Sn — y phase,2,3 where nonintegral valence electron concentrations are encountered. It should be possible to extend such correlations to other binary systems, if nonequilibrium single-phase alloys could be produced over broad valence electron concentration ranges, and if their crystal structures could be regarded as being imposed by their electronic states. It has been shown in the case of the tin-rich 7 phases3 that alloy phases with typical crystal structures can be produced in B metal alloys rapidly quenched from the liquid to -190°C by the splat cooling technique due to Duwez,3-8 and reviewed in Refs. 5 and 6. The In-Bi system was selected because it extends over a valence electron concentration range in which several metastable, nonstoichiometrir phases could be expected to occur. Further, the low melting points of the known intermediate phases, In2Bi and InBi, Fig. 1(a), indicated low binding energies and thus possibly low driving forces for the formation Of the equilibrium structures. EXPERIMENTAL TECHNIQUES AND RESULTS The preparation of the quenched foils followed the practice described in Ref. 3. Master alloys were produced by melting of indium (99.97+) and bismuth (99.99+) in evacuated Vycor capsules or in an inert gas arc furnace; quantities of 20 mg were splat-cooled onto copper and silver substrates held at - 190°C; and crystal structures and lattice parameters were determined on a GE XRD-5 diffractometer using Cu Ka, radiation at -190°C and at room temperature. The duplication of each run with both substrates permitted the elimination of overlap of the substrate diffraction pattern and that of the investigated substance. The XRD patterns were usually taken from sin2 " = 0.03 to 0.35; the substrate was used as a means of internal calibration. The fractional accuracy of the lattice parameters of metastable phases is approximately 10-3 In the following, all percentages are in atomic percent. The stable and metastable phases found after rapid quenching to -190°C are listed in Table I, together with estimated concentration ranges and crystallographic data. The investigated alloys and phases present in them are given in Table 11. Except for the region between indium with 33 and 50 pct Bi, where a revision of the equilibrium phase diagram became necessary to include a new stoichiometric phase In5Bi3, the diffraction patterns taken after heating to room temperature agreed with those expected from the phase diagram, Fig. l(a). This suggests that the new nonstoichiometric phases are not stable at room temperature, thus following the observations made for the y phases based on tin.3 Results concerning the equilibrium phases In2Bi and In5Bi3 and the revision of the equilibrium phase diagram which is made necessary by the inclusion of In5Bi3 will be treated first. The Crystal Structure of In2Bi. Makarov7 had identified In2Bi as belonging to the AlB2-C32 type ; however, in a later paper the structure was revised.8 In2Bio was found to be of the Ni21n-B8ß type,21 with a = 5.496A, c = 6.57.9A, and N = 6 atoms per unit cell.9 This crystal structure was confirmed in the present work; definite evidence for the doubling of the c axis, as compared to the A1B2-C32 type, and for the proposed order structure, was found in the powder pattern. The observed lattice parameters agree well with those of Ref. 8; those measured at -190°C are given- in Table I. The Crystal Structure of In5Bi3. A new, equilibrium, intermediate phase was identified in slow-cooled, as-cast alloys; it was identified as In5Bi3. The structure has been worked out by Giessen and Grant;" lattice parameters at -190°C are given in Table I. This phase is probably identical with "In3Bi2", produced by vapor deposition techniques, but not recognized as an equilibrium phase by Palatnik et a1.11 After completion of the present work, the existence of In5Bi3 has also been demonstrated by superconductivity measurements on In-Bi alloys.20

Jan 1, 1968

By Alec M. Crowell, Harry P. McClintock

Production of oil and gas condensate from the 45 oil and gas fields of South Arkansas increased for the eighth consecutive year, the production for 1943 being 27,605,647 bbl. Six new pools were discovered during 1943, bringing the state's crude oil and condensate reserve to 475 million barrels, a net increase of 70 million barrels for the year. The gross increase in proven reserve was 98 million barrels, from which, of course, is subtracted production of approximately 28 million barrels to reach the net figure of 70 million barrels. There were 35 more wildcats in 1943 than in 1942, and 29 more wells were drilled in fields of the state. Sixteen companies operated exploratory crews during the year for a total of 677 crew weeks, divided as follows: 563 weeks seismograph, 111 weeks gravity and 3 weeks core drill. There was a decided increase in gravity work and a decrease in seismic work. The year started with 15 seismic crews and ended with 5 seismograph and z gravimeter crews. Geologically, it is interesting that the number of wells bottomed in Gulf, Comanche, and Jurassic strata were near equal for the year 1943. During 1942 Jurassic was much higher than the other two. However, Jurassic still led in wildcats for the year 1943. Abandoment of wells in the stripper areas of the state reached about the same figure for the year 1943 as for the year 1942; that is, 145 wells were permanently abandoned. However, 243 wells were drilled in 1943, as against 184 for the previous year. The completions for the year were divided into 103 dry holes, 137 oil and condensate wells and 3 dry gas wells. Among new developments perhaps the most significant was the pressure-main-tenance project for the Midway field of Lafayette County, which is utilizing fresh water as the maintenance medium. This is the first fresh-water pressure-maintenance operation during primary production of an oil field in the United States. The operator of the project, Barnsdall Oil Co., estimates that the ultimate recovery of oil from this field will be increased from 32.5 to 65 million barrels. The Midway pool is of the dissolved-gas type, but a similar project is getting underway for the Magnolia field, Columbia County, a pool of the gas-cap and water-drive type. Dual completion of wells, on concurrent production from two productive zones through a single well bore, became common practice in South Arkansas during the year. As the year ended, some 50 wells had been dually completed and it was estimated that the first 37 of these wells represented a saving of more than 2 1/4 million dollars and a saving in steel of 7000 tons. The majority of the wells dually completed were those reaching depths in the neighborhood of 9000 ft. below the surface and initially productive there. Selective completion at lesser depths in the same well bore proved mechanically feasible and economically sound. The year was marked by the successful completion and placing into operation of three large natural-gas desulphurization

Jan 1, 1944

By Harry P. McClintock, Alec M. Crowell

Production of oil and gas condensate from the 45 oil and gas fields of South Arkansas increased for the eighth consecutive year, the production for 1943 being 27,605,647 bbl. Six new pools were discovered during 1943, bringing the state's crude oil and condensate reserve to 475 million barrels, a net increase of 70 million barrels for the year. The gross increase in proven reserve was 98 million barrels, from which, of course, is subtracted production of approximately 28 million barrels to reach the net figure of 70 million barrels. There were 35 more wildcats in 1943 than in 1942, and 29 more wells were drilled in fields of the state. Sixteen companies operated exploratory crews during the year for a total of 677 crew weeks, divided as follows: 563 weeks seismograph, 111 weeks gravity and 3 weeks core drill. There was a decided increase in gravity work and a decrease in seismic work. The year started with 15 seismic crews and ended with 5 seismograph and z gravimeter crews. Geologically, it is interesting that the number of wells bottomed in Gulf, Comanche, and Jurassic strata were near equal for the year 1943. During 1942 Jurassic was much higher than the other two. However, Jurassic still led in wildcats for the year 1943. Abandoment of wells in the stripper areas of the state reached about the same figure for the year 1943 as for the year 1942; that is, 145 wells were permanently abandoned. However, 243 wells were drilled in 1943, as against 184 for the previous year. The completions for the year were divided into 103 dry holes, 137 oil and condensate wells and 3 dry gas wells. Among new developments perhaps the most significant was the pressure-main-tenance project for the Midway field of Lafayette County, which is utilizing fresh water as the maintenance medium. This is the first fresh-water pressure-maintenance operation during primary production of an oil field in the United States. The operator of the project, Barnsdall Oil Co., estimates that the ultimate recovery of oil from this field will be increased from 32.5 to 65 million barrels. The Midway pool is of the dissolved-gas type, but a similar project is getting underway for the Magnolia field, Columbia County, a pool of the gas-cap and water-drive type. Dual completion of wells, on concurrent production from two productive zones through a single well bore, became common practice in South Arkansas during the year. As the year ended, some 50 wells had been dually completed and it was estimated that the first 37 of these wells represented a saving of more than 2 1/4 million dollars and a saving in steel of 7000 tons. The majority of the wells dually completed were those reaching depths in the neighborhood of 9000 ft. below the surface and initially productive there. Selective completion at lesser depths in the same well bore proved mechanically feasible and economically sound. The year was marked by the successful completion and placing into operation of three large natural-gas desulphurization

Jan 1, 1944

High-type research metallurgist with approximately following qualifications: American, 30 to 45 years old. Mind-Analytical. Education-college graduate. Practical shop experience-not less than 5 years. Metallurgical experience in steel making-at least 5 years. Chemical experience-should have some chemical training. Research ability -should be the type of man who is interested in new developments or research work. No. 337. Engineer with some underground, experience who is physically able to spend a large portion of his time underground, to act as general efficiency engineer. He will have cost keeping on special work, charge of contracts, labor distribution, etc. No. 338. The services of a man experienced in flotation and familiar with the Callow apparatus are required for a short engagement in South America. No. 339. A position as surveyor and draftsman for mines in Mexico is open. Opportunity for advancement. Climate pleasant and healthful. Knowledge of Spanish required. No. 340. The Bureau of Construction and Repair, Navy Department, Washington; D. C., is in need of a few draftsmen of experience for work in connection with the development of industrial yards and shops of the Navy, under the cognizance of the Shore Establishment Division of the Bureau of Construction and Repair. Training in one of the following courses would be considered a requisite qualification:

Jan 9, 1918

By C. H. G. Bushell, M. Malnarich

Reagent control in flotation is more an art than a science. Operators vary the amount of re- agents used according to the metallurgy obtained. The amount of collector may be increased, for example, if tailings losses are high and decreased if concentrate grades are low. Often control decisions are based on only one assay, such as the tailings analysis by microscopic or quick assaying techniques. This method of control has given reasonably satisfactory results but is clearly far from perfect. No adjustment in reagent addition can be made until information is received that metallurgy has deteriorated, that is, until the optimum time for adjustment has already passed. The first adjustment probably will be an overcorrection or an undercorrection, and time will be required to establish the best new addition rates. The seriousness of the problem depends on variability of the ore. In ore of continually shifting composition and complexity, mill results will shift back and forth from excessively high concentrate grades and high tailings losses to excessively low concentrate grades and low tailings losses. Economic incentive for improved control also increases with increasing size of mill. Even a small improvement in percentage recovery in a large mill pays for expensive control equipment.

Jul 1, 1956

By William P. McConnell

At the dawning of the first century of AIME, mechanical handling of bulk materials was largely confined to movement of grain and light mill products by belt and screw conveyors, but grain handling experience inevitably led to the use of the belt conveyor for coal, ore and other heavier materials. In 1891, the first major U.S. conveyor installation for heavy minerals was completed at the Edison, N.J., plant of the New Jersey & Pennsylvania Concentrating Co. Functionally, this plant revealed its grain elevator heritage. Overlooked at the time of design or, perhaps more accurately, not fully recognized, were the dramatic differences between grain and minerals in both operating conditions of the system and the physical characteristics of the material to be conveyed. This inevitably caused problems, but from the ashes of these problems rose solutions. The Edison plant became a proving ground from which came two significant developments by Thomas Robins-the first conveyor belt designed specifically for impact loading and abrasive materials and the three-roll conveyor idler. As an installation with more than 50 conveyors in widths of 20-30 in. and belt centers of up to 500 ft, the plant was a landmark, for it established the belt conveyor as a vital method of trans- porting heavy, abrasive materials.

Jan 1, 1971

By ANDREW CARNEGIE

Although the noble building provided in New York City by Mr. Carnegie for the United Engineering Society has been pushed to about half-completion, the ceremony of laying its corner-stone was not performed until Tuesday afternoon, May 8, 1906. The stone lies just back of the southeast corner of the building, on the north side-of West 39th Street. Among those present were Mr. and Mrs. Carnegie, Miss Whitfield, the sister of Mrs. Carnegie, Ralph W. Pope, Secretary of the Institute of Electrical Engineers, Frederick R. Hutton, Secretary of the. Society of Mechanical Engineers, Rossiter W. Raymond, Secretary of the Institute of Mining Engineers, Charles H. Haswell, the first Chief Engineer of the United States Navy (1836-1851), now in his ninety-seventh year, John Fritz, of the Bethlehem Steel Company, William H. Fletcher, President of the Engineers' Club, E. E. Olcott, President of United Engineering Society, and other interested friends. After an inspection of the interior of the building, the group formed about the corner-stone, which had been draped with the American flag. The exercises were opened by Mr. Olcott, who appropriately welcomed Mr. Carnegie, and briefly expressed the essential value of the building, saying, in part " The societies to be housed underneath this roof have as their aim the pre¬serving and putting in tangible form of the records of scientific accomplishments so as to avoid the repetition of mistakes. The possibility of finding the records of these results all at one center, so near the great Public Library of our city, will be an inestimable advantage to all professions. It is an occasion of no ordinary moment, therefore, when we can welcome Mr. Carnegie and have him lay for us the corner-stone of this great building which his liberality has provided." Mr. Carnegie responded in happy vein, thanking the committee for their greeting, and expressing his pleasure. in being able to do what he had done to further so worthy a cause. Among other things, he said

May 1, 1906

By Hans Lundberg

Jan 1, 1927

By John C. Smock

The fire-clays of New Jersey belong in two geological ages, the cretaceous and quaternary, or post-tertiary. Three very small deposits of plastic clays have been discovered within the limits of the Archæan rocks. These are not refractory and of little importance, excepting in a geological consideration. They have resulted from a decomposition of the feldspars of the rock in situ, and they have been classified as inferior kaolins.

Jan 1, 1879

By C. D. Ramsden

During the war years of 1941 to 1945, maintenance of mine locomotives and other mine equipment took the form of rebuilding rather than of renewing. Purchase of new parts became increasingly difficult and mine operators found it necessary to maintain equipment by salvaging old parts. Mine-locomotive wheels, although not representing a high cost per pound of material, contain a considerable amount of steel and without rebuilding would have to be scrapped long before even a moderate percentage of the steel in the wheel is actually consumed. Many mine operators have been rebuilding locomotive wheels for several years with automatic open are-welding equipment. In 1927, the Pittsburgh Coal Co. started such a program, using a single Westinghouse automatic welding head. Since that time, many refinements have been added, until in 1944 the setup was operating very efficiently. A desire to increase wheel life and to hold down rising costs led the company in 1944 to investigate the possibilities of the under-flux are-welding process for wheel rebuilding, although at that time, little or no work had been done on multiple pass or "build-up" welding with the underflux arc. Work with this process had been confined largely to welding together flat plates in a "down hand" position. Possibilities for savings were intensified by the fact that the company has 300 locomotives in operation, using actively or as spares 1200 sets of wheels. During 1942 and 1943, about 500 sets of wheels were sent each year to the company's maintenance shop at Library, Pa., for rebuilding. Based on having 800 sets in service (many of the company's heavy locomotives have three sets of trucks), the average life of a set of wheels was approximately 19 months. Anything that could be done to increase wheel life promised sizable annual savings. Open Arc Welding With the open arc process, a set of wheels could be rebuilt for about 40 pet of the cost' of new wheels. Underflux arc welding gave promise of greatly increased welding speeds, more homogeneous, dense deposits and the chance for use of a wider range in welding-wire compositions. Against this was ranged the higher cost of materials and the cost of developing the process from the theory to a practical reality. Since 1927, when a single open arc head was placed in operation, fixed welding procedures had been gradually developed, a positioner for handling a set of wheels was built, and a second head was placed in operation in order to weld two wheels simultaneously. The fixture, or positioner, which was built to position and turn the wheels under the two welding heads, included a motor drive, controlled by a rheostat, which rotated the wheels through a double set of speed reducers and a removable jaw coupling attached to one end of the axle of the wheel truck.

Jan 1, 1947

By C. D. Ramsden

During the war years of 1941 to 1945, maintenance of mine locomotives and other mine equipment took the form of rebuilding rather than of renewing. Purchase of new parts became increasingly difficult and mine operators found it necessary to maintain equipment by salvaging old parts. Mine-locomotive wheels, although not representing a high cost per pound of material, contain a considerable amount of steel and without rebuilding would have to be scrapped long before even a moderate percentage of the steel in the wheel is actually consumed. Many mine operators have been rebuilding locomotive wheels for several years with automatic open are-welding equipment. In 1927, the Pittsburgh Coal Co. started such a program, using a single Westinghouse automatic welding head. Since that time, many refinements have been added, until in 1944 the setup was operating very efficiently. A desire to increase wheel life and to hold down rising costs led the company in 1944 to investigate the possibilities of the under-flux are-welding process for wheel rebuilding, although at that time, little or no work had been done on multiple pass or "build-up" welding with the underflux arc. Work with this process had been confined largely to welding together flat plates in a "down hand" position. Possibilities for savings were intensified by the fact that the company has 300 locomotives in operation, using actively or as spares 1200 sets of wheels. During 1942 and 1943, about 500 sets of wheels were sent each year to the company's maintenance shop at Library, Pa., for rebuilding. Based on having 800 sets in service (many of the company's heavy locomotives have three sets of trucks), the average life of a set of wheels was approximately 19 months. Anything that could be done to increase wheel life promised sizable annual savings. Open Arc Welding With the open arc process, a set of wheels could be rebuilt for about 40 pet of the cost' of new wheels. Underflux arc welding gave promise of greatly increased welding speeds, more homogeneous, dense deposits and the chance for use of a wider range in welding-wire compositions. Against this was ranged the higher cost of materials and the cost of developing the process from the theory to a practical reality. Since 1927, when a single open arc head was placed in operation, fixed welding procedures had been gradually developed, a positioner for handling a set of wheels was built, and a second head was placed in operation in order to weld two wheels simultaneously. The fixture, or positioner, which was built to position and turn the wheels under the two welding heads, included a motor drive, controlled by a rheostat, which rotated the wheels through a double set of speed reducers and a removable jaw coupling attached to one end of the axle of the wheel truck.

Jan 1, 1947

By Richard Moldenke

The author discusses some economic conditions which have made the career of the cast-iron pipe industry in the United States a checkered one. He next describes the two new developements in the manufacture of cast-iron pipe-both along the lines of centrifugal casting. The advantages and disadvantages of both processes are presented in some detail. Finally, statistics on the production of pipe in the United States at the present time are given, as well as the plants-and their capacities-so far as these are situated in the South. No SINGLE branch of the foundry industry has been brought to a production basis of huge tonnage, low manufacturing cost, and producing material of a remarkably high quality, as has the making of cast-iron pipe. The pipe shop is an excellent illustration of the fact that repetition work in specialties leads to mechanical equipment and manipulation that lower production costs to an. astonishing degree. Hence cast-iron pipe, in dull times, has been sold at a few dollars a ton over the selling price of the pig iron used. On the other hand, these same pipe, shops make fittings .of many varieties, and in much smaller quantities, where the cost is high, and when pipe may be sold, say, at $50 a ton, the fittings on the same shipment will be sold for nearly double that price. The history of pipe-making, in the United States, is a checkered one the mortality of plants is high and, from the nature of the industry, plants must be large to live. In spite of the fact that the best processes must be used to turn out this rather strict specification material, pipe is easy to make and a pipe plant is more of a tonnage mill than the really high-class specialty foundry it should be. Every time, therefore, that the demand for pipe is strong new shops spring up, only to close when the demand has ceased, but the financial damage to the more permanent plants has been done. Both the South and the North have had abundant experiences of this kind, and when recently a northern Public Service Corporation gave its order to France, the pipe plants thus adversely affected were content to have this occur rather than see-a plant started to supply the surplus demand.

Jan 9, 1924

By H. W. Reid

One of the outstanding features of the year was a further marked decline in the footage drilled. This is estimated at 169,000 ft., as against 218,000 ft. for the previous year, and 372,500 ft. in 1930. Owing to repair work and improved production methods, there was an increase of about 4.25 per cent in the amount of oil won, the production being estimated at 10,160,000 bbl., or an increase of 400,000 bbl. over 1931 and nearly 750,000 bbl. more than in 1930. (See Table 1.) At the end of November there were 28 rigs in operation. During the first 11 months of the year 54 new wells were started; the average depth of those completed was 2476 feet. Owing to the continued restriction of drilling programs there has been little of outstanding interest in the way of new plant or technique. The use of the acid bottle, for testing the verticality of wells while drilling, has increased considerably, and this is now in use in practically every well except the very shallowest. During the last six months of the year fairly extensive use has been made of electrical coring. The number of wells started in the Colony up to the end of November, 1932, was 1894. The average number of producing wells during the year was 789, or 41.7 per cent of the total. Of these, 214 were flowing wells, 473 pumping, 80 bailing or swabbing, and 22 were produced by air or gas-lift. Although the last category represents less than 3 per cent of the total, there has been a marked increase in the use of air or gas-lift as compared with 1931. During the year there were 16 companies engaged in producing oil, as compared with 14 in the two previous years. In addition to one small refinery which started to operate at the beginning of the year, the five existing refineries worked continuously. At the latter very little has taken place in the way of extensions, except at one in the Parry Lands—Pitch Lake—Point Fortin area, where extensive alterations and additions are in progress, including the building of a deep-water pipe-line pier. When this is completed there will be five loading terminals, all situated in the sheltered Gulf of Paria, or west, coast, capable of accommodating ocean-going tank steamers. There

Jan 1, 1933

By Charles Kumke

THE "slot" system of mining in use at the Golden Queen mine, Mojave, Calif., does not involve any new mining methods. It is, how-ever, a, new combination and adaptation of several stoping systems in common practice. The first plans for stoping operations at the Golden Queen mine called for ordinary shrinkage stopes. The hanging wall of the vein, where exposed, is a very hard felsite with a dip varying from 50° to 70°. The vein itself is quartz, shattered and fractured enough to make it easy to drill and blast to a clean hanging wall. There is no well defined footwall. The footwall limits had to be determined by assays as the metal content faded out into the felsite. Two shrinkage stopes, each approximately 200 ft. long, were laid out and started on the 200-ft. level. One of these stopes, varying in width from 8 to 18 ft., was carried on up to the top limits of the ore, approxi-mately 120 ft., without a break in the operation. The shrinkage system proved entirely satisfactory and low costs resulted from-this operation. In the final drawing of this stope, two timbermen followed down on the ore, scaling the hanging wall clean of small fragments and placing an occasional long stull from foot to hanging wall where it was deemed necessary. Few such stulls; however, were required. The hanging wall stood up very well until the stope was entirely emptied of ore. Waste fill was then put into the stope by the glory-hole method, through a waste raise that had previously been run to surface from the middle of the stope. The second shrinkage stope ran into difficulties about 35 ft. above the sill floor. Up to this point the maximum width of the ore had been about 15 ft. The ore suddenly widened into the footwall to a distance of 40 ft. in the north end of the stope. In extending the stoping operations over this width, it was soon found that the vein material would not arch and support itself. Drilling in this end of the stope was then entirely too hazardous, and all operations were stopped. The ore was drawn through the chutes below as rapidly as possible and as soon as the stope was entirely

Jan 1, 1937

By J. O. Lewis, Carl H. Beal

Introduction ............................... 492 Theories Relating to the Recovery of Oil.................. 493 Methods Commonly Employed for the Estimation of Future Production..... 495 Saturation Method........................... 495 Production Curve Method....................... 496 Production per Acre Method.....................: 496 Appraisal Curves.............................. 498 Derivation and Construction...................... 498 Comparison of Appraisal Curves of the Osage and Nowata Fields...... 505 Use of Appraisal Curves........................ 506 Accuracy of the Apprais?l Curves and Their Sources of Error........ 508 Relation Between Future Productions of Wells of Equal Output....... 510 Use of Appraisal Curves for the Derivation of Generalized Future Decline Curves. 513 Theory of Generalized Curves Showing the Decline in Production...... 513 Suggested Methods for Making Closer Estimates.............. 517 Use of Logarithmic Coordinate Paper.................... 518 Summary................................ 520 Introduction Oil wells usually reach their maximum daily output shortly after they are completed. From that time they decline in production, the rapidity of decline depending on the output of the wells and on other factork governing their productivity. The production curve of a well shows the amount of oil produced per unit of time for several consecutive periods; if the conditions affecting the rate of production are not changed by outside influences, the curve will be fairly regular, and, if projected, will furnish useful knowledge as to the future production of the well. By the aid of this knowledge the value of a property maybe judged, and proper depletion and depreciation charges may be made on' the books of the

Jan 1, 1918

By Sterry Hunt

The American Institute of Mining Engineers, and American science in general, have sustained a great loss in the death of Prof Benjamin Silliman, deceased at New Haven, Connecticut, on the 14th of January, 1885, at the age of sixty-eight. But a month has passed since, as one of the pall-bearers, I paid the last tribute to the remains of my old friend and honored master.

Jan 1, 1885

By Ta M. Li

This article draws freely on the experiences of the engineering and operating staff of P.T. Inco and its parent firm Inco Ltd. In addition, information was derived from papers presented during the recent International Laterite Symposium, held in conjunction with the 1979 AIME Annual Meeting, New Orleans, La., February 19-21. The author wishes to acknowledge all contributors and, in particular, Roy Aitken, president and managing director, P. T. Inco.

Jan 7, 1979

By James E. Mills

In the work of exploring certain gold-bearing gravels in the American Valley, Plumas Co., California, entrusted to my charge by Prof. A. Agassiz, of Cambridge, and Q. A. Shaw, Esq., of Boston, it became necessary to sink a shaft through loose materials containing in some layers large quantities of water, and I have been compelled to devise a new method which has proved successful and may be of service elsewhere.

Jan 1, 1885

By R. E. Shinkosk

This paper outlines the development of a program for increasing the life of woolen bags used for filtering Dwight-Lloyd gases by treating the bags and gases with hydrated lime. Methods and apparatus are described for determining alkalinity of dusts, acidity and breaking strength of bag cloth. Procedure and results, based on several years of operation, are presented. DURING 1939, additional facilities were constructed in the Dwight-Lloyd Blast Furnace and Baghouse departments at the Selby, California, Plant of the American Smelting and Refining Co. In order to handle adequately the increased volume of gases from the resultant increase in production, it was necessary to increase gradually the amount of water used for cooling gases ahead of the sinter machine baghouse. As a result of this increased water cooling, the average bag life dropped from 27 months in 1939 to 14 months in 1941. (Table I). This drop in life meant an increased. bag cost, as well as lower recovery of dust and some curtailment of operation. During 1941, it was found new bags showed as high as 0.3 pct acidity* after two weeks of opera- tion and as much as 2.0 pct acidity after some months of operation. This high acidity was present in spite of the fact that free oxide or relative alkalinity of the unburned dust ran from 5 to 6 pct. In view of these circumstances, a twofold program was started in Nov. 1941.t Part one of this program consisted of vigorously dipping all new bags in a weak lime solution, containing 50 lb of hydrated lime per 50 gal of water. Part two consisted of feeding fine, dry, hydrated lime into the gas stream intake of the sinter baghouse fan. Apparatus for feeding this lime is shown in fig. 1. All baghouse chambers are shaken in rotation about once each hour. On alternate hours, the baghouse operator places 50 lb of hydrated lime (one sack) into the lime feeder, starts feeder and immediately starts the bag shaking machinery. The rate at which lime is fed is set to coincide with the approximate time necessary to shake all sinter bag-house chambers, or about 15 min. It is felt this method of lime addition is most effective for getting lime into the woolen bag fabric. The amount of lime so fed averages about 600 lb per day. The amount of lime fed per day is varied to keep a minimum relative alkalinity of 9 pct in the unburned sinter dust. A daily dust sample is taken for alkalinity by allowing dust to accumulate in a sample pipe over a 24-hr period. This sample pipe, placed in any chamber cellar, is 2 in. in diam, 4 ft long, is sealed on the inner end, and capped on the outer end. It has a 1/2 in. slot cut for 18 in. along the tip end. This slot faces upward and allows the pipe to fill gradually with dust as bags are shaken. Breaking strength of bags has, in most cases, been the deciding factor in bag replacement. Bags that normally test 100 psi breaking strength when new are replaced when they test under 35 lb. The method for determining breaking strength is shown in the description accompanying fig. 2. Since the start of the liming program in 1941, bag life has increased from 14 months to an average of over 23 months, with a consequent material decrease in bag cost per year. Acidity, as per cent sulphuric acid, may be determined by means of a Beckman pH meter as follows: From a piece of bag cloth. which has been thoroughly cleaned of dust, a 5 g sample is weighed on a balance. Cut the sample into fine pieces and place in a 400 cc beaker. Add 100 cc (measured) of distilled water and stir vigorously. Filter on suction funnel, holding cloth pulp in beaker with a stirring rod. Wash cloth sample and filter wash water four additional times, each time with 20 cc distilled water, the last time squeezing cloth pulp over funnel. Discard pulp and rinse funnel and filter paper. Pour wash solution jnto measuring graduate and make up to exactly 300 cc with distilled water. Place into clean 600 cc beaker and measure the pH on meter. The per cent acid in bag cloth is read from the following table:—

Jan 1, 1951