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William Kelly, Vulcan, Mich.:—In the northern part of Bedford county, Pa., the county immediately south of Huntingdon, the Clinton measures appear along the eastern slope of Tussey mountain near its base. The only iron-ore bed that has been worked is in the upper part of the formation. Along the mountain this seam has a dip of more than 60°. At the outcrop the ore is soft and rich, but with depth it passes often abruptly into an almost pure limestone similar to that described by Dr. Rutledge. The soft ore extends deeper in the cross-gullies than it does under the higher gound between the depressions. The slates adjoining the rich ore have been weathered, but where in juxtaposition to lean ore and limestone they are hard. The alteration of the ore-bed is evidently the result of the conditions of drainage in quite recent geo-

Jan 1, 1910

By John A. Mathews

D R. CHARLES W. ELIOT, the great educator and philosopher-he of the five-foot book shelf-recently gave expression to a thought I had long been cherishing as a private opinion, when he said: "It is obvious that standardization has become a dangerous adversary of progress in both education and industry." This idea must have been more widespread than either of us knew, for some five years ago a writer of verse for one of the comic papers dealt with it at great length. I will quote only a few of his stanzas to illustrate his understanding of "A Standardized Existence" : A visitor at large, I stand Beneath a standard sky- Where everything is standardized To please the standard eye. Each tree is of a standard height, Each building is the same; Each man is uniform in height, And has a standard name. Above there is a standard star Beside a standard cloud, And a standard weather here prevails To please a standard crowd. With standard joy, and standard gain, The standard people live; And if there is one bit of pain T?is such as standards give.

Jan 1, 1926

Members whose deaths were reported from April 7, 1924 to April 7 1925 Elected Died 1923 ANDERSON, ANDREW ELMER 1924 1919 ANDERSON, JOHN EDWARD 1924 1923 BENKISER, WILLIAM JACOB 1924 1900 BROOKS, ALFRED H 1924 1900 BROWN, CONY T 1925 1910 BROWN, GILMOUR E 1924 1894 ChAPPELL, HOWARD F 1924 1882 CLARK, W A 1925 1918 CLEAVES, DANIEL LUNT 1924 1883 COLBY, ALBERT LADD 1924 1886 CORNING, C R 1924 1911 CRABTREE, FRED 1925 1875 CREMER, J H 1924 1921 CRONIN, JAMES 1925 1904 DANIEL, WILLIAM B 1924 1891 DOUGHERTY, JOHN W 1924 1920 ESCARDO, HECTOR FLORENCIO 1924 1921 FRANK, PAUL MELVILLE 1924 1920 GILES, ROBERT 1924 1922 GILLETTE, LEWIS SINGER 1924 1918 HARRIS, J W 1924 1902 HARTMAN, T F 1923 1912 HERRMANN, CHARLES E 1924 1892 HILLES, JOSEPH T 1924 1882 HOFMAN, H O 1924 1905 HOVEY, EDMUND O 1924 1923 KIME, EDWIN R. 1924

Jan 1, 1923

Feb. 18 to. 21, 1918 Committee on Arrangements J. E. JOHNSON, JR., Chairman BRADLEY STOUGHTON, Vice-Chairman A. R. LEDOUX RALPH W. DEACON F. T. RUBIDGE L. W. FRANCIS E. M. SHIPP MRS. S J. JENNINGS J. V. N. DORR A. L. WALKER G. D. VAN ARSDALE R. M. RAYMOND Finance Committee ALBERT R. LEDOUX, Chairman WALTER H. ALDRIDGE J. H. JANEWAY GEORGE D. BARRON CHARLES F. RAND WALTER DOUGLAS BENJAMIN B. THAYER

Jan 4, 1918

By E. W. Davis

THE large iron-ore producers on the Mesabi Range are able to maintain the silica in their shipping products at from 8 to 10 per cent by mixing ores of various grades, some assaying 4 per cent silica and some as high as 18 per cent silica. For each ton of 4 per cent silica ore mined, a ton of 14 per cent silica ore can be mined and mixed with it and the average grade maintained at 9 per cent. This mixing operation has made possible the utilization of large cluantities of ore too lean to be used alone. and herein lies the advantage of the producers who operate a number of mines at the same time. As the grade of the ore from one of the properties falls off, a little high-grade ore from another property can be mixed with it and the average maintained, while if one property alone were being operated all of the ore below grade would be left behind.

Jan 1, 1930

By C. A. Hartnagel

The production of petroleum in New York in 1940, totaling 4,999,000 bbl., was only slightly under the amount produced in each of the previous three years. The year 1940 started auspiciously with a posted price on Jan. I of $2.75 a barrel. Four price reductions, beginning in May, resulted in August in a low of $1.85 a barrel, after which two increases brought the year's closing price to $2.15 a barrel. The favorable crude price at the beginning of the year stimulated an increased drilling program, especially in the water-flooding districts. In the Allegany County region, which accounts for about two-thirds of the state's oil production, 886 wells, including water-intake wells, were drilled; 200 more than in the preceding Year. During the closing months of the Year there was a marked decline in the number of wells drilled. The unfavorable position in which the industry found itself before midsummer was due largely to the loss of export markets for its high-grade lubricants, constituting approximately 25 per cent of its business. As a result of this situation, runs to refineries were curtailed as much as 30 Per cent at the middle of the Year. Improvement in market conditions toward the end of the Year found the stocks of available crude at an almost record low. Deep DRILLING with the gradual exhaustion of some of the important natural and flood-oil-produc-ing areas of the Allegany and Bradford pools, overproduction will not be a serious problem in the future. The possibility of finding new territory or deeper producing sands has been further lessened by the drilling of additional deep wells for gas in and about the present oil fields. Many of these wells drilled to the Oriskany sand-stone were over 4000 ft. deep and have tested the entire thickness of the Devonian formation, the upper 2000 ft. of which contain all the important oil-producing strata in the state. Water-flooding It is thus evident that the problem of the New york oil producers is not one of find-ing new supplies but of obtaining as much 6 oil as possible from the old developed fields that during the 60 years of their life have 1 produced I 3o,ooo,ooo bbl. of oil. Although a few floods were in operation before I9I9, when the production of oil by flooding was 1 made legal, the output for that year amounted to only 85I,000 bbl. From 1919 I on there has been an almost constant increase, which during the past four years has averaged well above 5,000,000 bbl. annually. During the last 22 years, which constitutes the period of important flooding operations, 651337,000 bbl. of oil have been produced in the state. Careful estimates indicate that between one-third and one-half of the oil fields are being flooded or are already watered out. Some of the flooded and watered-out areas include territory with unusually thick sands, which were highly productive during the early history of the fields. From a recent study of operations in the New York oil fields, it is estimated that about 65,ooo,oo bbl. of oil

Jan 1, 1941

By C. A. Hartnagel

The production of petroleum in New York in 1940, totaling 4,999,000 bbl., was only slightly under the amount produced in each of the previous three years. The year 1940 started auspiciously with a posted price on Jan. I of $2.75 a barrel. Four price reductions, beginning in May, resulted in August in a low of $1.85 a barrel, after which two increases brought the year's closing price to $2.15 a barrel. The favorable crude price at the beginning of the year stimulated an increased drilling program, especially in the water-flooding districts. In the Allegany County region, which accounts for about two-thirds of the state's oil production, 886 wells, including water-intake wells, were drilled; 200 more than in the preceding Year. During the closing months of the Year there was a marked decline in the number of wells drilled. The unfavorable position in which the industry found itself before midsummer was due largely to the loss of export markets for its high-grade lubricants, constituting approximately 25 per cent of its business. As a result of this situation, runs to refineries were curtailed as much as 30 Per cent at the middle of the Year. Improvement in market conditions toward the end of the Year found the stocks of available crude at an almost record low. Deep DRILLING with the gradual exhaustion of some of the important natural and flood-oil-produc-ing areas of the Allegany and Bradford pools, overproduction will not be a serious problem in the future. The possibility of finding new territory or deeper producing sands has been further lessened by the drilling of additional deep wells for gas in and about the present oil fields. Many of these wells drilled to the Oriskany sand-stone were over 4000 ft. deep and have tested the entire thickness of the Devonian formation, the upper 2000 ft. of which contain all the important oil-producing strata in the state. Water-flooding It is thus evident that the problem of the New york oil producers is not one of find-ing new supplies but of obtaining as much 6 oil as possible from the old developed fields that during the 60 years of their life have 1 produced I 3o,ooo,ooo bbl. of oil. Although a few floods were in operation before I9I9, when the production of oil by flooding was 1 made legal, the output for that year amounted to only 85I,000 bbl. From 1919 I on there has been an almost constant increase, which during the past four years has averaged well above 5,000,000 bbl. annually. During the last 22 years, which constitutes the period of important flooding operations, 651337,000 bbl. of oil have been produced in the state. Careful estimates indicate that between one-third and one-half of the oil fields are being flooded or are already watered out. Some of the flooded and watered-out areas include territory with unusually thick sands, which were highly productive during the early history of the fields. From a recent study of operations in the New York oil fields, it is estimated that about 65,ooo,oo bbl. of oil

Jan 1, 1941

By Charles H. Fulton

ONE of the events of note in mineral industry education circles during the year was the summer school for engineering teachers, devoted to mining and metallurgical engineering, which was conducted by the Society for the Promotion of Engineering Education in co¬operation with the University of Wisconsin. It was in charge of Prof. Harry P. Hammond, director of the summer school, and Prof. Richard S. McCaffery of the University of Wisconsin. It was attended by 63 people, and practically every educational institution offering mineral industry courses had representatives present. The session was successful and those in attendance spoke highly of the pro¬gram and results obtained. The Mineral Industry Education Division cooperated with the S.P.E.E. in this project. Prof. Hammond will discuss the purpose and results of this session at the February meeting.

Jan 1, 1934

By P. R., Bradley

THE Juneau gold belt is divided into ore-bands of poor definition. The most easterly workings on the , belt, those of the Alaska Gastineau Co., disclosed three separate bands: the Footwall or Ground-hog band, 70 ft. wide; the Perseverance band on which the recent mining was done, also 70 ft. wide; and the No. 2 band, 100 ft. wide. These bands, aggregating 240 ft., are found over a width of 2000 ft. Going toward the west into the adjoining Alaska Juneau ground, four bands have been found which have a total 'right-angle thickness of 755 ft. These bands are convergent in their westerly trend and terminate on the plane of Silver Bow fault. The four bands have better definition at the fault plane than at the eastern boundary line where they enter the property. -Along the property line, the width of the bands and intervening country is 1600 ft., and at the Silver Bow fault this width is reduced to 1300 ft. The distance from the eastern property line to Silver Bow fault is 2400 ft. The bands are slate or slate with metagabbro intrusions, together with gold-bearing quartz masses, stringers, and gash veins. The bands themselves are not all ore, but all commercial .ore is found within the bands. They have no uniform width either in horizontal or vertical section. The ore has no hard and fast boundary except where cut by faults, and profitable mining ceases on a vague and

Jan 1, 1929

By Max Kraut

UNTIL VERY RECENTLY the flotation process has not found much application in the treatment of gold ores. No appreciable improvement has been made lately in the technology of this application; but the possibilities of flotation have been more fully appreciated. Excellent results were obtained long ago, but few operators paid much attention to them. For instance, in 1915 extensive experiments were carried out by Mr. Beauchamp and Minerals Separation on ores from the Dutch-Sweeney mine near Jimtown, Calif. The ore contained gold-bearing pyrite and laboratory tests indicated a 10c. tailing on a $6 head. In 1918 a 300-ton flotation mill using Minerals Separation machines was built based on the results obtained. However, when the mill began full-scale operation, mill heads did not come up to expectation, being only $4; also the-tonnage was considerably less than had been expected. Flotation mill tailing assayed 15c., indicating a recovery of over 96 per cent, so that excellent metallurgical results were obtained. The operation was a success but the patient died.

Jan 1, 1932

By D. S. Flett, A. W. Fletcher

Equilibrium studies on the extraction of nickel and cobalt with kerosine solutions of naphthenic acid have shown that an exchange extraction reaction occurs at pH 5.5. The nickel/cobalt separation factor is constant at 1.8 for constant total metal molarity and varying nickel/cobalt ratios. The separation factor decreases with increasing total metal molarity in the organic phase beyond 0.2 M and also decreases with increasing temperature. From the equilibrium data, it has been possible to derive a mathematical model for the separation of nickel from cobalt by exchange extraction in multistage systems. Experimental data from a continuously operated multistage mixer/settler apparatus has shown a reasonable correspondence with computer-calculated data. The effective separation of nickel and cobalt in sulfate solution remains a problem in hydrometallurgy and the hope that this would be solved by solvent extraction has not yet been fulfilled. With chloride solutions, advantage may be taken of the ability of cobalt to form anionic complexes with the chloride ion. It can then be readily separated from nickel, which does not form stable chloro complexes, by extraction with a suitable long chain amine. However, in hydro metallurgical operations, sulfate solutions are generally obtained in which no extractable anionic species are present. Thus, the possibility of using cationic extractants must be considered, and in this paper attention is directed to the use of carboxylic acids. The method of separation studied has been termed exchange extraction, which involves replacement of a metal in the organic phase with a more acidic metal in the aqueous phase. Thus, (BR2).+ (Az+)aqt=(AR,).+ (B2+)aq (I) where metal A is more acidic than metal B, R represents the acidic radical derived from the acid RH, and the subscripts e and aq refer to the organic and aqueous phases, respectively. Ashbrook and Ritcey' have used this method for the separation of cobalt from nickel using the sodium salt of di-2 ethyl hexyl phosphoric acid, which preferentially extracts cobalt. Some nickel is coextracted, and this is removed by exchange with cobalt ions in the feed solution by suitable countercurrent operation in a pulsed column. Much work has been carried out by a number of workers in Russia on the general use of exchange extraction for the separation of metal ions using car-boxylic acids. Gindin et aL a have demonstrated that this technique could be applied to the separation of nickel from cobalt using a C--C. carboxylic acid and have applied the technique to the production of high purity cobalt solutions for electrolysis. Further worka was concerned with the development of a process for the separation of nickel from cobalt in a pulsed column. This system permitted the separation of iron and copper from nickel and cobalt in one system. The procedure involved center feeding with acid backwashing at the top and alkali addition lower down the column. Thus the system operated under a pH gradient and the metals were distributed in the column in the order of their basicities. A similar application was studied by Gel'perin et al,4,5 for the removal of copper and iron impurities from a nickel anolyte by means of a C10-C,12 fatty acid fraction. Ginden et al,' and Fletcher and Wilson' have studied the effect of pH on the extraction of a number of metals with carboxylic acids. These studies showed that metals such as iron, copper, lead, zinc, nickel cobalt, and manganese are extracted at pH values close to the pH of hydroxide precipitation. Nickel is extracted at a slightly lower pH than cobalt and thus the nickel/cobalt separation factor has a value not much greater than 1. More basic work on complex identification has been reported by Fletcher and Flett: by Tanaka; and Jay-cock and Jones." These studies have suggested that at low loadings in the organic phase, the nickel and cobalt carboxylates appear to be dimeric and solvated by free carboxylic acid molecules. As the concentration of metal in the organic phase increases, the complex changes and larger polymeric species are formed. In order to permit assessment of the potential of carboxylic acids as extraction reagents for separation of

Jan 1, 1971

By T. M. Olson, B. G. Lewis

The adsorption of selenite on bentonite, kaolinite, and an iron--coated illite was studied to determine the importance of several soil variables on selenite removal from uranium mill tailings pond seepage. Adsorption capacities of the clays of selenite varied by orders of magnitude and decreased in the following order: illite > kaolinite > bentonite. Maximum adsorption of selenite on the clays was observed between pH 2.5 and the clay's zero-point-of-charge. Substantially less selenite was adsorbed on these clays in actual mill tailings solutions than in model systems. Virtually all selenite was removed from the tailings at pH 7. The principal removal mechanism at this pH is suggested to be the adsorption of selenite on freshly precipitated metal hydroxides. It is concluded that selenite can be removed from tailings seepage in soil or in clay liners in the presence of kaolinitic clays and iron oxides. Selenite would also tend to be removed from tailings seepage in calcareous strata.

Jan 1, 1984

By W. Bonfield

The microstrain characteristics of a polycrystal-line Cu 1.9 wt pet Be precipitation-hardening alloy have been determined for various conditions of aging. The friction stress remained constant for all the conditions investigated, whereas the microscopic yield stress (the stress to produce a plastic strain of 2 x 10-8 in. per in.) and the three-stage stress-strain curve in the microstrain region were sensitive to changes in dislocation and precipitate distribution. Correlations between the measurements of microplasticity and electron-nzicroscope observations of substructure are considered. ALTHOUGH the macroscopic mechanical properties of Cu 1.5 to 2.0 wt pet Be precipitation-harden ing alloys were established' in some detail, there has been no previous investigation of the nature of microyield-ing in these alloys. This paper describes a high-sensitivity extensometer determination of microplasticity in polycrystalline Cu 1.9 wt pet Be, in which the friction stress, the microscopic yield stress (the stress to produce a plastic strain of 2 x 10-6 in. per in.), and the rate of strain hardening in the micro-strain region were measured for various conditions of precipitation. The structural changes accompanying aging in this alloy were examined using transmission electron microscopy, a study which differed from previous investigations as, in order to minimize grain boundary precipitation effects,' the solution-treated alloy was cold-rolled to 40 pet reduction prior to aging. Hence the extent of recovery and recrystalliza-tion, as well as the variation of precipitate morphology and distribution, were assessed. From these results possible correlations between the microstrain characteristics and the observed precipitate and dislocation structure are considered. EXPERIMENTAL PROCEDURE The material investigated was a commercial copper beryllium alloy (Berylco 25), which had a com- position of 1.9 wt pet Be and 0.2 wt pet Co. The alloy was solution-treated at 800°C, quenched in water, and then cold-rolled to 40 pct reduction. Tensile specimens of gage length 1 in. and rectangular cross section of 0.18 by 0.06 in. were prepared from the solution-treated, cold-rolled material and aged for 15 min, 2, 24, and 100 hr at 315°C and 24 hr at 425°C to produce a range of precipitate structure. The hardness values associated with these conditions are listed in Table I. It can be seen that a maximum value is obtained after 2 hr at 315oC, which decreases with continued time at temperature to a minimum after 24 hr at 425°C. For comparison some as-solution-treated specimens were also aged for 2 hr at 315°C. The specimens heat-treated to a given condition were examined in two ways. First, the nature and distribution of the precipitate and dislocation structure was characterized using transmission electron microscopy. Thin foils were obtained from the specimens by electrolytic polishing in a 30 pet nitric acid-alcohol solution at -20oC, and were examined in an RCA EMU 3 electron microscope. Second, the mi-croplastic behavior of the specimens was measured with a Tuckerman strain gage, using the load-unload technique previously described2, 3 to determine the friction stress, the microscopic yield stress, and the variation of plastic microstrain with stress. RESULTS 1) Structural Changes During Aging. a) Annealing Processes. The solution-treated, cold-rolled Cu 1.9 wt pet Be had an irregular dislocation-cell structure,

Jan 1, 1968

By John G. Hall

The unstable metal market during 1949, with resulting lower metal prices, has focused every mine operator's attention on the problem of reducing operating costs. Improvement in mining, methods, use of modern mechanical mining equipment, and increasing the efficiency of the labor force are the tools with which we will have to work. Careful planning is necessary to coordinate all phases so that no one phase is overdone. A mine may become over-mechanized if, for instance, capital charges against new equipment exceed the savings in labor costs, or where a large enough tonnage is not produced. The cooperation, of labor is essential to any mechanization program. There have been too many instances where mechanization and improvements have done nothing more than make up for a decrease in labor efficiency, thus bringing the production of labor back to its old standard. The operator has gained little and labor has gained only a "softer job." In any mechanization program there are gains to be had by both the operator and labor. By the efficient application of modern equipment and improved mining methods the operator should gain by decreased costs, and labor may profit by receiving a share of these decreased costs.

Jan 1, 1950

By J. A. Danko, C. D. Pears, L. D. Schmidt, J. P. McGee

This paper describes a pilot plant built on the campus of West Virginia University by the Federal Bureau of Mines station at Morgantown, West Virginia, for gasifying pulverized coal in a mixture of oxygen and steam at pressures in the gasifier up to 450 psig. The work upon which this report is based was done under a cooperative agreement between the Bureau of Mines and the West Virginia University. The goal of Bureau of Mines work at Morgantown is development of a low-cost process for producing mixtures of carbon monoxide and hydrogen for the modified Fischer-Tropsch synthetic-fuel plants, which may be shifted to produce hydrogen for coal-hydrogenation plants. Gasification with oxygen offers the inducement that the gas may be generated at the pressure at which the gas will be utilized in a gas-synthesis plant. Since the optimum pressure for the synthesis appears to be about 400 psig, the gas should be produced at approximately 450 psig to take care of pressure drops in the purification train and control valves. If the gas is generated at the pressure of utilization, only the oxygen need be compressed, not the raw synthesis gas. This means a saving in power of 5 hp per hour per 1000 cu ft (CO + H2), which is approximately a saving of 4 cents per gallon of gasoline. For example, consider a commercial plant generating 18,000,000 standard cubic feet per hour of raw gas that would produce approximately 10,000bbl of liquid product per stream-day. Assume that this gas would be 85 pd CO + H2 and that the oxygen required would be 320 cu ft per 1000 cu ft of CO + H2. The following estimate is based on a commercial centrifugal compressor. If the 18,000,000 std cu ft per hour of synthesis gas is compressed to 450 psig with 74 pd efficiency, 107,000 hp is required for compression. If the synthesis gas is generated at 450 psig pressure, only

Jan 1, 1953

By G. Sachs, G. Espey

SIMPLE methods can be used for the determination of the residual stresses in thin-walled tubing if the stresses consist of high tensile stresses at the one surface and high compressive stresses at the other surface Such a stress distribution is approximated in sunk tubing and in deep-drawn shells It is possible to cut sections from such articles in such a manner that a major part of the residual stress is relieved by a bending of the part that is separated from the adjacent metal The circumferential stress is evaluated from the change in diameter D, occurring on splitting a length of tubing (Fig Ib),1-5 or from deflection resulting from the cutting out of a circumferential tongue (Fig Ia) G The bending moment M released by such a flexure is [ ] The release of this bending moment corresponds to the release of stresses, which, in a thin section, vary linearly from one surface to the other, and have the following value in a particular fiber a certain distance (zx from the surface [ ] where C is the section modulus and d is the thickness of the section, the ratio AI C being d 2 for a rectangular section* The maximum stress values at the surfaces are [ ] For most purposes the simpler equations [ ] will be satisfactory, where Dm is the average of the mean diameters of the tubing

Jan 1, 1941

By V 7. 0 / 300 dpi

WHEN the copper smelters were built, in Montana, all of the refractory products which were used in their construction were shipped in from Eastern factories. It was apparent that if a material suitable for the manufacture of these products could be found within the State, a saving of freight could be effected and a new industry built up. Prospecting for such materials was started and experiments were made with samples from numerous deposits. Considerable effort and funds were expended in an attempt to manufacture silica brick from Dillon quartz, a light colored sandstone that is found near Dillon, Mont., on the Oregon Shortline railroad. As a brick material the Dillon quartz was a failure, but it has proved very satisfactory as a silica cement. It is now being used in laying silica brick and for reverberatory furnace bottoms. A bed of quartzite that is particularly suited to the manufacture of high-grade silica brick -was finally discovered at Browns Spur, 6 miles west of Anaconda. The material from this deposit is now being used in the manufacture of the Anaconda silica brick, which have gained a wide reputation for heat-resisting and lasting qualities. The analysis of all average sample of this quartz is: SiO2,, 96.7; Fe203, 0.3; Al203, 2.5; CaO, 0.3 per cent. The very low percentage of fluxing ingredients makes this a most refractory material. All of the Anaconda silica brick are hand molded. Various types of brick machines have been tried, but the hand-mold process proved the best suited to the manufacture of silica brick from this material. The silica is first put through a jaw crusher and is then clumped into wet pans, where 4 per cent. of lime paste is added, to produce a bond. Without the lime the. material would not be plastic enough to mold. After a few minutes' grinding in the wet pans the material is conveyed to the molder, who forces it into the molds by hand. The brick are then dumped on pallets and placed in the drier, where they are left until dry enough to be set in the kilns. Some of the brick are re-pressed before being dried. They are burned about five days, in round down-draft kilns. It is not necessary to have as much heat in the kilns as the brick will be subjected

Jan 9, 1913

"The Midvale. Plant of the United States Smelting, Refining and Mining Company, situated twelve miles south of Salt Lake City, consists of mills for concentrating lead-zinc ores and a custom lead smelter.The milling department includes a 475-ton gravity mill for ores from the United States Mines at Bingham, a 100-ton Huff electrostatic zinc plant and a 60-ton pilot flotation mill for differential separation of lead and zinc. The gravity mill and electro¬static plant are being replaced by a 600-ton differential flotation plant, now under con¬struction, for differential separation of lead, zinc and iron. This new mill will have cap¬acity for treating custom ores in addition to ores from the company's mines at Bingham.The smelting department is equipped to handle 1600 tons of charge per day through six blast furnaces, 48 inches by 160 inches at the tuyeres. All gases from both blast furnaces and roasters are filtered through baghouses, which remove the dust from the gases so effectively that even when the plant is running at full capacity no smoke can be seen coming out of the 450-foot brick stack handling rca2ter gases, nor out of the two shorter steel stacks which take the blast furnace gases. On this account the Midvale plant has come to be known as the ""smokeless smelter.""The blast furnace gases are filtered through 832 woolen bags, 33 feet 6 inches by 18 inches in diameter, and 1200 woolen bags, 28 feet by 12 inches in diameter."

Jan 1, 1925

By J. C. Smock

THE magnetic iron ores of New Jersey are found in the northern part of the State, in the Highland Mountain range, which runs from the New York line on the northeast, to the Delaware River, near Easton, at the southwest. The same range continues across Orange County to the Hudson River, and towards the southwest it is known in Pennsylvania as the South Mountain. It is more properly an elevated table-land, quite deeply furrowed by several narrow, longitudinal valleys, and shorter cross-valleys or gaps. The ridges or lines of elevation, as well as the lower valleys, conform in their general direction very closely to the general trend of the whole belt or table-land, that is, from northeast to southwest. This also agrees with the prevailing strike of the rocks. This great uniformity in the altitudes of the hills and ridges, and the direction of the lines of depression corresponding to the strike of the strata, point to an original table-land, which, through the long action of denuding agents, has been quite deeply eroded, giving rise to the present surface configuration, so that some of the former and uniform features have been partially obliterated. The very few cross-valleys or depressions are much more irregular in their course, and serve as outlets through which the drainage is carried either into the Kittatinny Valley on the northwest, or to the broad, red shale and sandstone plane bounding the highlands on the southeast. The area of this highland

Jan 1, 1874

By P. LEROY FOSTER

G EOPHYSICAL prospecting was presented in its several aspects and discussed with much vigor at two sessions during this year's annual meeting of the Institute. The first session was devoted entirely to the presentation and discussion of various technical papers, while the second meeting took the form of a round table conference on the advisability of revising the existing mining laws to recognize the results of geophysical prospecting. This conference was immediately followed by further consideration of technical papers. Each session was well attended and great interest was displayed by everyone present.

Jan 1, 1929