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By Walter Crafts, C. M. Offenhauer

IN a previous study' of the carbide phase of chromium steels, it was shown that chromium carbide (Cr7C3) is a more stable carbide than cementite (Fe3C) at tempering temperatures above about 500°C. in quenched steels containing from about r1to 7.5 per cent chromium. Below this temperature the carbide phase was found to consist of cementite in all of the steels examined. In the present investigation it was found that a similar change in the carbide phase takes place in molybdenum and in chromium-molybdenum steels at approximately the same tempering temperatures. The approximate ranges of occurrence of the alloy carbides Cr7C3, Cr4C, and Mo2C have been determined in steels containing up to 5 per cent chromium, 1 per cent molybdenum and 0.60 per cent carbon. The experimental steels were made in small high-frequency furnaces from Armco ingot iron, low-carbon ferrochromium and calcium molybdate and were poured into 2-in. ingots, which were forged to 1-in. round bars. Sections of the bars were heated to the carbide-solution temperature and cooled rapidly to induce austenite transformation at relatively low temperatures. The steels were subject to some segregation, therefore comparatively high temperatures were necessary to dissolve all of the carbides. The microstructure of the quenched specimens was examined to verify the belief that the carbides had been dissolved, and also to determine the nature of the nonmartensitic structure of incompletely hardened steels. Ferrite and pseudomartensite were present in some of the specimens, but all specimens were quenched at such a rate that pearlite was not formed, in order to ensure the formation of the carbides at temperatures lower than about 500°C. It had been found previously' that in chromium steels the chromium carbide could be produced by transformation of austenite in the pearlite range above 500°C., and, in order to start the tempering treatment with the carbide present as cementite, the absence of pearlite was considered to be essential. The specimens were tempered for 64 hr. to permit the formation of the stable carbide. After tempering, the specimens were submitted to microscopic and X-ray examination. The carbides were separated either electrolytically in a 5 per cent HCl electrolyte or with an acidified copper-potassium chloride solution. The crystal structure of the carbide phases was determined by the Debye-Scherrer type of X-ray patterns. The X-ray patterns obtained from specimens near the boundaries between two types of carbides were generally weak and diffuse as compared with the other patterns. For this reason, and because the more soluble components may be masked, the boundaries between the phases could not be determined precisely. However, the X-ray analysis of electrolytically separated carbides has given consistently reproducible results

Jan 1, 1943

We did install one 100% brick bottom in our #33 furnace which is basically the same design as Inland's furnace. We had previously embarked on a program of replacing all bottoms in our 300 ton furnaces every 2nd campaign which would be about every 2000 - 2300 heats. This had been necessitated by the effect of our rather high oxygen blowing rates and our desire to maintain a minimum bottom interval level. This meant that we were able to compare bottom performance of various types of materials on a realistic bas is. Since furnace availability is critical to our operation, we are organized to employ every piece of equipment and all the necessary man power to complete a rebuild in the shortest possible time. A 300 ton furnace requires 7.5 days to rebuild. If a new bottom is to be installed an additional 2.5 days is added - 24 hours for tear out and 36 hours for bricklaying - making a total of 10 days.

Jan 1, 1972

[ZAY JEFFRRIES, Vice-chairman PAUL D, MERICA, Chairman W, M, CORSE, Secretary Executive Committee J. It, FREEMAN, JR., Local Section S. SKOWRONSKI, Papers Committee R. S, ARCHER, Non-ferrous Data Sheets H, C, JENNISON, Membership Committee E, C, BAIN, Journal Committee L, W. SPRING Local Section Committee J. R, FREEMAN, JR,, Chairman R. J, ANDERSON, Cincinnati R. L. DOWDELL, Minneapolis R. S. WILLIAMS, Boston G, H, CLAMER, Philadelphia W. A. SCHEUCH, Chicago R, F, WOOD, New York]

Jan 1, 1928

By Herbert R. Hanley

THE One Hundred and Twenty-sixth meeting-of the Institute, held in San Francisco, Sept. 25 to 29, 1922, was a success in every way. Character-istically, San Francisco presented climate suited, to the occasion, while the Committees on Arrangements left nothing undone that would contribute to the interest and entertainment of the members and their wives. There was a registration of over 230, and all sections, save three, were represented. In the technical meetings, under the leadership of Albert Burch in the mining session and C. W. Merrill in the milling session, the greatest interest was manifested in ore-hunting geology and modern ore-dressing methods. The general geologic phase developed numerous discussions and had for its aim the study and correlation of known data and the application-of these to the finding of commercial orebodies. The geologic features of the Comstock and their significance to the development of the present orebodies were discussed. This brought out matters of much technical interest as well as those of romantic nature in the history of the early life of that camp. The profitable application of modern milling methods to ores, non-commercial a short time ago, was discussed with much interest. The recent work on the Comstock ores occupied a conspicuous part in these discussions. Basic principles delineated by mathematical study of mechanical devices for the milling of ore came in for a prominent part in the program as well as the physical-chemical side of the processes devised for the winning of precious metals as a profit.

Jan 11, 1922

By W. R. Crane

While professiorlally engaged in the oil- and gas-fields of Kansas, in measuring the pressure and flow of gas-wells, and studying the phenomena attendant upon the production of both oil and gas, I noticed in the flow of gas a peculiar and interesting feature. That there are actual lines of flow in liquids (non-compressible fluids) discharged through an orifice, or a short section of pipe, is shown by the external shape of the discharge—the vena contracts. Such lines of flow are not observable in the discharge of gas from an orifice. It can hardly be questioned that they exist. That they are not apparent is probably due to the very small weight of the gaseous particles, which climinishes the momentum of their movement in a given direction, acquired before they issue from the orifice, and also to the expansion of the gases, which would exert a powerful influence in overcoming any such tendency in their flow. Gas flowing from an orifice, supplied by a large reservoir or blowing-engine, exhibits almost the reverse of what is noticed with liquids. Namely, the gas assumes the form of an inverted truncated cone, of large angle: with its apex-end at the orifice. (See BB, Fig. 1.) This external ahape assunled by the flow of gas shows, however, marked differences under varying conditions of volume and pressure. For instance, a large volume of gas under high pressure, flowing through a 2- or 3-in. pipe, as in the case of a natural gas-well, assumes a more definite conical form, the angle of which increases as the pressure falls. Moreover, outside of the well-defined inverted cone is a thin conical heath or zone of gas, A A, the angle of which is considerably greater than that of the main cone, and increases with +1UNIVERSITY OF KANSAS, LAWRENCE, KANSAS.

Jan 1, 1905

By K. V. S. Sastry, V. P. Mehrotra

A laboratory investigation was carried out to study the influence of asphalt, bentonite, and corn starch binders on the pelletization kinetics of coal fines and on the quality of the resulting pellets. Pellet quality was evaluated in term of the compression strength, impact resistance (drop test), abrasion resistance, and resistance to severe weather conditions. The amount of binder addition did not significantly influence the pellet growth kinetics. However, the pellet quality varied markedly depending upon the type and the amount of binder wed. Experimental results are explained on the basis of the mechanism of interaction between the coal particles and the binders. Of the three binders tested, corn starch proved to be the best in all respects but for the resistance to water penetration. Finally, a combination of corn starch (imparting strength) and asphalt emulsion (imparting resistance to water penetration) was found to yield the best quality coal pellets.

Jan 1, 1983

By H. N. Thomson

GENERAL. THE Tooele plant of the International Smelting & Refining Co. is situated at the mouth of Pine canyon, Tooele county, Utah. It is connected with the main line of the San Pedro, Los Angeles & Salt Lake railroad by the Tooele Valley railway, and is about 7 miles from Tooele Junction. Fig. 1 is a general view of the plant. FIG. 1.-TOOELE PLANT OF THE INTERNATIONAL SMELTING & REFINING Co. The copper plant has been in operation since July, 1910, and the first blast furnace at the lead plant was blown in on Feb. 29, 1912. The location of the plant was selected on sloping ground with the idea of using gravity to the fullest extent and thus keeping labor at a minimum. Practically the entire plant is constructed of steel, reinforced concrete, and brick. Bingham ores, both lead and copper, are received over the Utah Consolidated Aerial Tramway. The tram buckets, each containing

Jan 7, 1913

By E. N. Harshman

The Wind River Formation of Eocene age is the host rock for large high-grade uranium deposits in the Shirley Basin. The major deposits are in a northwest-trending belt of sandstones that were deposited in stream channels and that were lithologically favorable for uranium accumulation. Paleotopography influenced the character and position of the belt. The major deposits within the belt are at, or near, the margins of large tongues of altered sandstone formed in the most transmissive parts of thick sandstone beds. At least two tongues of altered sandstone are present in the belt, one of which is 5 miles long, 3 miles wide, and 70 feet thick; the other tongue is somewhat smaller. Ore bodies consist of a few hundred tons to several hundred thousand tons of material containing from 0.10 to about 2.00 per cent U3O8. The ore mineral is uraninite associated with pyrite, marcasite, hematite, and calcite. Deposition is believed to have taken place when neutral to slightly alkaline, oxidizing, uranium-bearing ground water, on entering the basin, encountered a reducing environment. The reductant may have been H2S of biogenic origin. Geology played an important role in discovery, exploration, and development of ore in the Shirley Basin.

Jan 1, 1968

By Earl R. Parker, Ralph Hultgren

DURING the past year publications in physical metallurgy have not been abundant when compared with the output of prewar years. Nevertheless, some noteworthy contributions have been made to the literature. Because of the necessity for war production, much of the metallurgical effort has been directed towards the solution of problems of production processes. The limited amount of time devoted to other problems is reflected in the small number of papers devoted to nonapplied research, though a few excellent contributions have been made to the fundamentals as will become evident in the following pages. Results of many of the government-sponsored research investigations have been released to the public and are being published in the technical journals. Many more of these papers may be expected to appear in the 1946 publications.. Public distribution of information obtained in the course of these investigations should be of great value to American industries in the postwar era. Continued activity in research of all kinds is apparently assured because of intense

Jan 1, 1946

By W. T. Cardwell

This paper presents a theory for estimating the rate of gravity drainage of a liquid out of a sand column. Account is taken of the variation in permeability to the liquid as the saturation in the upper part of the sand becomes less than 100 pct. The theory is confirmed by previously published experimental data. Introduction Petroleum engineers have expressed the need for 4 theory of gravity drainage. Brunner,' in particular, has pointed out that some type of mathematical theory is necessary to begin the application of laboratory data to field problems. Muskat and his associates2'3-4 have recently made contributions to the theory of gas-drive behavior and have indicated an intention to apply their methods to water-drive systems. No theory of gravity drainage rates has been developed, however, and it seems desirable to formulate one at this time. Differential Equations of Capillary Flow The flow of liquids in partially saturated porous media has been studied by many investigators.6-10 Richards6 presented derivations of fundamental differential equa- tions governing two-phase capillary flow; and used simplified forms of those equations in solving a steady-state problem. Muskat and Meres6 presented and used equations different from those of Richards. Their equations did not explicitly involve capillary pressure gradients; but included, on the other hand, terms expressing the effects of the evolution of gas from the liquid phase during flow. Leverett8 stated in 1940 that "previous work on the flow of fluid mixtures in porous solids [had] failed adequately to account for all of the three influences that cause motion of the fluids: capillarity, gravity, and impressed external pressure differentials." Leverett's basic equations, however, were specialized forms of the general equations of Richards,5 which had actually taken account of the three influences mentioned by Leverett, but had not been used in a problem involving all three. The fact is that our knowledge of capillary flow and our ability to express this knowledge in differential equations exceed our ability to solve the equations except in a few cases. General differential equations have usually been of little more than formal value. In solving practical problems, it has been necessary to develop specific equations, preserving terms that involved the factors important in those problems, and purposefully neglecting other terms that were not of predominating influence. This is the method followed here. It is believed that the solution of the particular problem and the scheme of the solution itself are new.

Jan 1, 1949

By J. F. Enrietto

It is shown that one cannot approximate the broad internal friction Peaks observed in the Fe-Mn-N system as the sum of a number of subsidiary Peaks and still vetain the concept of a single relaxation time. Furthermore, the approximation of manganese affectirg only nearest neighbor interstitial sites is shown to be incompatible with the experimental results. The results of this experiment show that the influence of manganese in the ferrite lattice extends over 3 to 4 atomic distances. NUMEROUS experiments have shown that the presence of relatively small amounts of substitutional alloying elements can profoundly affect the profile of the damping spectrum in the vicinity of the Snoek peak in bee metals.1-7 Dijkstra and Sladekl observed this phenomenon in Fe-Mn-N alloys where it appeared as a broadening and shifting of the Snoek peak to higher temperatures. The authors interpreted this as being the result of a superposition of two damping maxima—the normal Snoek peak, located at its usual position and having a normal half-width, and an interaction peak having a normal half-width, but occurring at a somewhat higher temperature. They prclposed that the interaction peak was caused by nitrogen atoms jumping from Fe-Mn sites to Fe-Fe sites, the Fe-Mn interstitial sites having one manganese and one iron atom as nearest neighbors, and the Fe-Fe sites having two iron atoms as nearest neighbors. They further suggested that the Fe-Mn sites had a lower energy than the normal Fe-Fe sites because of the presence of the adjacent manganese atoms. From the relative heights of the two postulated damping peaks, the dif-

Jan 1, 1962

By Yasushi Ishikawa

The fact that the degree of granulation and the state of granulated particles of sinter raw mixtures are the influential factors in ensuring coke combustibility and permeability during sintering has been clarified. Based on this knowledge, Nippon Steel developed the divided coke-addition process and the technology to utilize binder, and applied them on a commercial scale. Productivity and sinter quality are thereby greatly improved with a significant reduction in fuel consumption.

Jan 1, 1977

By David J. Mack, T. V. Philip

The effects on the Cu-A1 eutectoid transformation of the addition of a third element from the second long period and from Group IIB of the periodic table, were studied by isothermal transfomation techniques. The valency of the third element shows the most pronounced effect on the eutectoid decomposition. With some exceptions, the atomic size factor of the third element shows some consistent effects on pearlite nucleation and growth. The atomic concentration or the electronegative valency of the third element shows wo consistent effect on the eutectoid decomposition. Addition of the third element helps spheroidization of pearlite. SINCE the pioneering work of Davenport and Bainl on the eutectoid decomposition in steel by the isothermal transformation technique, an enormous amount of data has been accumulated on the eutectoid transformation characteristics of commercial steels. While the eutectoid reaction in steel is of tremendous industrial importance, it appears to be quite unique among the eutectoid reactions. Though the metal-lographic structures developed in the Fe-C and Cu-A1 eutectoids are similar, it is now evident that the two eutectoid reactions are quite dissimilar. The eutectoid decomposition in the Cu-A1 system is more complicated partly due to the appearance of transitional phases in addition to the equilibrium phases. * The first isothermal studies of aluminum bronzes were made by Smith and Lindlief2 and later by Mack,3 Klier, and Grymko,4 and recently Hayne 5,6 A few other systems, structurally analogous to the above, have been studied by the same technique.7-10 Kasberg and Mack1' studied the effects of iron on the transformation of commercial aluminum bronze. The effects of manganese and nickel on this aluminum bronze and those of iron, manganese, and nickel on the binary Cu-A1 eutectoid have been recently studied.12 The object of the present investigation was to study, by isothermal transformation techniques, the effects (with respect to the fundamental factors of alloy formation) of the addition of a third element on the transformation of a Cu-Al eutectoid alloy, 11.8 pct Al. The third elements chosen for the purpose were silver, cadmium, indium, tin, and antimony from the second long period, and beryllium, zinc, and cadmium from group 11B of the periodic table. They were added in nominal amounts of 0.5, 1.0, and 2.5 pct by weight to a eutectoid Cu-A1 alloy. These third elements were expected to show the effects of electron valency, atomic size factor, and electronegative valency effects on the binary eutectoid transformation. PFLEPARATION OF ALLOYS AND PROCEDURE All alloys were made as 400-g heats by induction melting in a graphite crucible with a graphite lid. The molten alloy with a layer of graphite powder on top was stirred at regular intervals by a graphite rod. When the melt was judged to have acquired sufficient superheat, a pinch of common salt was sprinkled on top and any crust scraped off to one side. It was then chill cast into a 5/8 in. rod. The alloys with silver were prepared by remelt-ing the high-purity Cu-A1 eutectoid alloy used by Mack3 with high-purity silver (99.99 pct pure from Hardy and Harmon, Inc.). In the preparation of all the other alloys, polished electrolytic copper shot (from Belmont Smelting and Refining Co.) and high-purity aluminum (99.99 pct pure from Aluminum Co. of America) were used.

Jan 1, 1962

[ARIZONA Established July 10, 1915 ROBERT W. HUGHES, Chairman CHARLES R. KUZELL, First Vice-Chairman GILBERT C. DAVIS, Second Vice-Chairman W. CLARK MASON, Secretary-Treasurer Inspiration Cons. Copper Co., Inspiration, Ariz. LYLE BARKER ROBERT HIGH T. G. CHAPMAN P. D. I. HONEYMAN GEORGE M. COLVOCORESSES WALTER C. LAWSON EDWIN H. CRABTREE, JR. W. H. LOERPABEL WALTER I. GARMS ALBERT MENDELSOHN WESLEY P. Goss CARL E. MILLS H. C. HENRIE JOSEPH A. WILLCOX C. F. WILLIS]

Jan 1, 1946

By R. M. Brick, R. G. Treuting

DESPITE the basic importance of slip in the plastic deformation of metals, and the considerable experimental investigation, thought, and speculation that have been devoted to the fundamental nature of these processes, surprisingly few data have been reported regarding the microscopic appear- [ ] ance and distribution of slip lines,[$] the external manifestation of the slip process. Photographs hitherto reproduced in the literature are in general at low or unspecified magnifications with no correlation to the prior shear. A single-crystal cylindrical tensile specimen of alpha brass about ½ in. in diameter, one of many previously prepared by H. L. Burghoff,1 was available for study. A plane about 3/16 in. wide, parallel to the specimen axis and normal to the plane containing the slip direction and the specimen axis, was ground and metallographically polished along the entire 5-in. gauge length. Heavy etching produced a surface free of both scratches and flow. The specimen was strained in tension until slip markings first became visible on the polished surface (Figs. I and 2). Restressing the crystal caused additional markings to appear at an initially lower [ ] stress than previously was required. Stretching the specimen to produce a dense concentration of slip lines caused such variations in level in the polished surface (normal to the slip direction) that microscopic study at higher magnifications became impossible. After annealing 15 hr. at 850°C., the specimen recrystallized to form two grains with a boundary approximately normal to the specimen axis and about midway along its length. Each was X-rayed, and two planes were again polished along the length of the specimen, in this case each parallel to the slip direction in one of the two crystals. A light longitudinal scratch parallel to the specimen axis was drawn down the center of each plane. A Huggenberger extensometer was attached to the crystal A, whose slip plane would have the higher resolved shear stress of the two, and the specimen was again strained in tension.

Jan 1, 1941

By H. K. Birnbaum, H. B. Aaron

he authors suggest that a number of the types of yield phenomena which have been observed in high-purity fcc metals are due to dislocation interactions bccurring at the surface of the crystals rather than due to volume effects. Since rather different inter-pretationS2,7,12,14,15,21-23 of these effects have been suggested, it is of some importance to ascertain the role of the surface in these yield phenomena. It should be first noted that the high-purity fcc metals appear to exhibit several distinct types of yield phenomena. The "unloading yield point" which is observed on reloading the specimen after removing the applied load has been found to be independent of the time of holding in the unloaded condition. If however the specimen is aged while under load and re-tested without removing the load, a yield point is observed which does depend on the aging time and tem-perature. Feng and Kramer suggest that the removal of the unloading yield point on removing sufficient material from the surface of the specimen indicates that the effect is associated with dislocation interactions at the specimen surface. Their observations are counter to those of Haasen and Kelly5 and Birnbaum.12 Since the unloading yield points are extremely small (-2 pct of the flow stress) the results of the surface removal will depend on whether the material is removed uniformly over the gage length. The introduction of small etch pits or the removal of more material from one portion of the specimen than from another will result in preferential yielding and obliteration of the yield point. With the normal electropolishing techniques it would be difficult to avoid these effects. The data obtained by Aaron and Birnbaum, Fig. 10, on aluminum polycrystalline specimens indicate that, although the unloading yield point and the strain-aging yield point are not simply additive, a time- and temperature-dependent yield point is observed under conditions where no creep is observed. This does not agree with the results of Feng and Kramer but does agree with the results on copper15 and gold.7~23 The source of the discrepancy may be the procedure used by Feng and Kramer to correct their time-dependent yield points for the effect of creep. Since the strain-aging yield point is not independent of the pre-aging strain rate, Fig. 11, the effects of creep cannot

Jan 1, 1967

By John M. Lovejoy

CURRENT production of petroleum on such a vast scale presents many interesting problems- the solutions of which are important not only to those directly interested in the business, but to the nation as a whole. The industry is relatively young. Until the discovers of the Lucas gusher at Spindletop in 1901 petroleum production had not exceeded 60,000,000 bbl. per year compared with 1,100,000,000 bbl. in 1936. In 36 years then, the modern oil business, production, transportation, refining, and marketing has developed. I will first present a brief history. of oil production as a background for consideration of the present situation.

Jan 1, 1937

By R. S. Shoemaker, R. M. Darrah

Expanded markets for copper in the past few years and a consequent search for new ore bodies have revitalized the widely known but seldom applied method of producing copper called heap leaching. Heap leaching is defined here as the process applied to oxide ores which have been mined solely for the purpose of leaching. In this case, all costs of mining the ore become a part (and a substantial one, as will be shown) of the cost of the copper produced, whereas in dump leaching the mining cost has already been accounted for as a stripping cost for the sulfide ore. Of course, with newly opened ore bodies, stripping costs may be divided through accounting procedures, between the copper produced by the mill and that obtained by leaching, but in general this type of operation must be economic on the basis of the sulfide ore alone. Heap Leaching Requires Low Capitalization Heap leaching, as a beneficiation method, is unique in that it is the only process used for the recovery of a metal in which the time involved from mining the ore to metal production is measured in months instead of hours or at the most, days. Then too, after the ore body has been depleted and mining has ceased, metal production will continue for some substantial period of time. Heap leaching is also unique because unlike any other method of beneficiation, metal recovery cannot be accurately forecast ahead of time and recovery will never approach that of a conventionally milled sulfide ore or even that of a vat leached oxide ore. Counter-balancing this drawback, however, is the relatively low capital expenditure necessary to put a heap leaching operation into production and the consequence that smaller ore bodies which would not support the higher capital cost involved in a vat leaching plant can be made into producers. Stated more simply, in heap leaching the operator accepts low recovery in exchange for low capital costs and low break even point. Whether the operator chooses vat leaching with its higher recovery and higher capital costs, is a mater of economics which depends in part on the nature of the ore to decide. For instance, an ore that will vat leach in 7 to 10 days using 7 pounds of sulfuric acid per pound of copper produced might use double or triple that amount of acid during the months that are required for heap leaching.

Jan 12, 1968

By J. D. McBeth, G. M. Potter, Ramon Pizarro

Heap leaching is used by the Carlin Gold Mining Co., Carlin, Nev., to supplement conventional processing of gold ore by agitation-leaching and countercurrent decantation. Selected open-pit ore containing about 0.072 oz Au per ton is crushed to 3/4 inch, dumped by truck on an asphalt pad, and leached by sprinkling with dilute cyanide solution for 7 days. The heap is then drained and removed by front-end loader to tailings disposal. About 70 percent of the gold is dissolved. Leach solution from the heap joins the pregnant solution from countercurrent decantation for gold recovery by zinc precipitation. Four leach pads, each with a capacity of 1,400 tons of ore, are in use. About 10,000 tons of ore are heap leached monthly from about April through October. Heap leaching is recessed during freezing weather. Labor, equipment, and reagent requirements for heap leaching are presented.

Jan 1, 1974

By B. Silliman

THESE ores occur in the Laurentian rocks in the town of Clifton, St. Lawrence County, New York. The Clifton Mining Company have opened these magnetites upon their estate of 23,000 acres, on the waters of the Grasse River, an affluent of the St. Lawrence, which flows for about nine miles across the estate, exposing a section of the formation, and affording ample water-power at numerous points. In approaching this district from De Kalb Junction, upon the Watertown and Ogdensburg Railway, the observer passes from the zone of the specular ores, which abound to a great extent in Jefferson County, across a belt of non-metal-liferous limestones, continuing for some miles intermingled with metamorphic rocks, and gradually giving place to heavy beds of granitic and porphyritic gneiss, the weathered surfaces of which present a gray and rough appearance, from the washing out of the feldspar; leaving the quartz very prominent, and completely disguising the real character of the rock, which, when freshly broken, has a lively reddish appearance from the predominance of flesh-colored and red feldspar. Beds of fine-grained quartzite appear also intercalated in the granitic gneiss. These are the dominating rocks of the magnetite region, but the magnetite is always found, so far as the speaker's observation extended, associated with beds of calcite, carrying hornblende, black and green, biotite, and brown garnet interspersed with yellow and magnetic pyrites. The strike of these rocks is about northeast, and their dip about 40° to 45° southeast.

Jan 1, 1873