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By Leslie C. Richards

The competitive position of producers of industrial minerals depends upon the delivered price of their product. Freight charges are a major factor in the sales to consumers. A comparison of freight rates on movements of limestone and silica rock in the Pacific Northwest shows a wide variance in mills per ton mile for like hauls, thereby favoring some localities over others. Introduction: Sooner or later the potential miner of industrial minerals reaches the conclusion that of the various factors he must consider, the marketing of his product is. the most important. The sooner he realizes this the better, as successful industrial mineral producers .will confirm. Herein lies a difference between i.ndustria1 mineral mining and metal mining. Often in the latter, technical problems of mining or concentrating are equal to or even surpass those of marketing. This is not meant to imply that there are no problems in mining and beneficiation of industrial minerals, but these usually are outweighed by the problem of marketing. Recentlv. an official of a nationally known corporation :i the elecl.ro-metallurgical industry made an industrial mineral survey in the Pacific Northwest. In the course of his investigation he interviewed producers and potential producers of the various industrial minerals scheduled for use in the plant now being constructed in this area. He stated that he was interested in only three factors: namely, (1) Can your product meet our specifications? (2) Are you able to supply our tonnage requirements? and (3) What will be the delivered price? If there are several sources of supply of sufficient grade and tonnage, as is often the case in the Northwest, then the third factor becomes the important and deciding one. While industrial minerals are usually sold f.0.b. cars with the freight being paid by the buyer, it is the delivered and riot the f.0.b. price that determines the competitive position of the producer and his industrial mineral product. Unfortunately for both the consumers and producers of industrial minerals in the Northwest, the sources are generally a considerable distance from the markets. This necessitates long rail hauls, for which transportation charges make up the largest share of the delivered cost and the delivered price of the product. Is it any wonder then, that rail rates play such an important part in the marketing of industrial minerals? In order to sell his product, the producer must be able to deliver to the market at a competitive price. It must be remembered that his largest cost factor is rail transportation, and that he is limited to markets that he can reach competitively. Since the cost of rail transportation is so important, let us compare various freight rates in the Northwest and attempt to determine their influence on marketing. A study of all rates on all industrial minerals transported in this area, is beyond the scope of this paper. For the purposes of comparison, let us consider limestone (broken, crushed, or ground), and silica rock. These are widely used industrial minerals, and are carried by several different rail routes from.the sources of supply to the centers of consumption in the Pacific Northwest. Markets and Sources of Supply: Limestone has a number of uses in western Oregon and Washington. Among them are agricultural lime for the soils of the Willamette Valley and southwestern Washington; paper rock for the mills in such cities as West Linn, Oregon City, Newberg, St. Helens, and Salem, Oregon, and Camas and Everett, Wash.; chemical and metallurgical-grade limestone for the metallurgical plants centering around Portland, and the Tacoma-Seattle areas'; and sugar rock for the sugar refineries at Toppenish, Wash., and Nyssa, Oregon. Since limestone for cement manufacture is generally processed near the quarry, transportation

Jan 1, 1951

By C. F. Dietz

WHEN thinking of industrial relations, we must not confine the term to what is ordinarily called "welfare work;" viz., organizing baseball teams, departmental parties, athletic contests, and such things. These are all of interest but not very helpful in solving the problems of industry. We must think of industrial relations as that understanding developed between workers and management that permits of harmonious progress because of a mutual understanding of each other's problems. Most of the industrial unrest, discontent, mistrust, or antagonism is due to misunderstanding; and that misunderstanding is the direct result of not having taken the workers into our confidence. If they are merely cogs in a machine, employed to do certain things, and have no interest in anything but the receipt of the pay envelope, we cannot expect intelligent harmonious progress. There are still some people who think that the interests of management, or capital invested in a business, and the interests of the worker are diametrically opposed. That is an unfortunate belief; the interests are identical. If the worker does not understand what his part of the work represents, what the management's part represents, and what the invested capital's part represents, he is bound to have a misconception, of the matter and will think only in terms of the pay envelope. The methods used for producing a better understanding between workers and management do not much matter so long as the end is attained. Some plants prefer shop committees; others attempt to work through the foremen in the various departments; others, by personal contact-between the management and the men, especially if a shop is small. It does not really matter how the end is attained as long as the object is accomplished. The best type of industrial relations can probably be attained when the mystery is taken out of industry-when the workers understand what they. are a part of, what their function is, what they are contributing. They should also understand something of fundamental economics-that it is not just a question of getting all they can and giving just as little as possible but that their contribution makes for expansion, progress, and permanence, and opens a field of activity for themselves that other-wise would probably be blocked.

Jan 6, 1925

By R. E. Allen

THERE was once a time when a practical oil man would appraise or buy a producing property on the basis of from $200 to $500 per barrel of average daily settled production. Curtailment-has, for the present at least, caused a virtual abandonment of the "barrel -of settled production" as a yardstick of, oil property value and in its place has come the "barrel of allowable production," which, although an artificial thing, is nevertheless now the principal factor governing the rate of ?pay out? or investment return. The potential production of a well, settled or otherwise, is of less importance in determining the present worth of a well than is the rate at which it may be produced. Speaking only of true potential for the moment, it is obvious that of two similar wells having the same potential, the one having the highest rate of allowable production would be worth proportionately more than the one of lesser allowable. The discount factor for deferred return and risk can easily vary the present values of the two wells by as much as 20 per cent when allowable rates are not greatly different.

Jan 1, 1934

By Richard P. Rothwell

THE anthracite coals of Pennsylvania are all mined from large veins. A seam less than four feet. in thickness is generally considered as unworkable, those from which most of the coal now comes being from 8 to 30 feet thick. The system of mining employed is, almost without exception, that known as "chamber and pillar work;" that is, the coal is taken out of chambers of from 18 to 30 feet in width, and pillars of from 12 to 20 feet are left between these to support the roof. In general, the entire thickness of the seam, even

Jan 1, 1875

By Richard P. Rothwell

The anthracite coals of Pennsylvania are all mined from large veins. A seam less than four feet. in thickness is generally considered as unworkable, those from which most of the coal now comes being from 8 'to 30 feet thick. The system of mining employed is, almost without exception, that known as " chamber and pillar work;" that is, the coal is taken out of chambers of from 18 to 30 feet in width, and pillars of from 12 to 20 feet are left between these to support the roof. In general, the entire thickness of the seam, even

By Thomas T. Read

Readjustment of the industrial world to a peace basis after more than 4 years of war will involve many fundamental and far-reaching changes that cannot as yet be clearly foreseen or definitely provided for. Such problems may be subdivided, in the vocabulary of war, into those involving material and those centering about personnel. Of the two, the latter group is the more difficult and obscure, as the factors involved are less clearly understood and the methods to be followed are not yet tested and standardized. When it is said that the market is weak, stocks large, and demand light, every business man understands clearly what is meant and what course he should adopt to adjust himself, so far as possible, to such conditions. But when it is said that the rapid spread of Bolshevism in Europe is a danger to industrial organization in this country, it is difficult to have any assured sense that all that the statement may mean is clearly understood or that the means to be followed to meet such a situation are definitely known. Since Bolshevism is primarily a mental phenomenon and since the rupture it brings about in industrial organization should be prevented, if possible, it is my purpose to restrict this discussion of the activities of the Committee on Industrial Organization to some of its mental aspects, as the chairmen of the sub-committees, from their special knowledge of their own fields, can best set forth recent progress in the lines with which they are especially concerned. The first requisites of success in industrial organization, as in the biological organism of which it is the social counterpart, are unity of purpose and coordinated activity. Typical good and bad examples of this' are the relative parts that the United States and Russia have played in the great war. These two factors are primarily mental, and it is not difficult to view the mental aspects of all problems of industrial organization as the most important ones. Unless we can attain unity of purpose and coordinated activity in industry, the provision of comfortable homes at reasonable rent, the assurance of steady work at good wages, the elimination of industrial accidents, and provision against want in old age or in case of disability will have brought us no nearer to our real goal.

Jan 1, 1919

By H. R. Drullard

TO obtain the best results from hammer drills, close attention must be paid to two factors in drill maintenance, which are of equal importance; one is lubrication, the other is the shank. With the exception of stoping drills, most modern rock drills require both oil and grease. The oil ports are in the lubricator, on or behind the hammer cylinder; the grease port for the lubrication of the chuck sleeve and rotating mechanism is on the chuck end. Ordinary machine oil is not adapted to rock drills; a heavier more gelatinous oil such as castor machine oil or liquid grease should be used. The lubricators should be filled once for every 12 or 14 ft. (3.5 to 4 m.) of hole drilled. Grease guns should be used to fill the port in the chuck end once a shift; a medium (No. 3) grease is well adapted to this purpose. Hard grease must not be put into the lubricators, as it will not flow through that part. Contrary to the popular belief, oiling a machine once or twice a shift does not provide sufficient lubrication; the drills should be oiled once for every 12 or 14 ft. of hole drilled. The rotating handle of a stoping drill is an oil reservoir and is provided with a port for oiling. The rotating handle is packed with wick-ing, or similar material, which causes the oil to feed slowly from the handle to the other parts of the machine. Stoping drills require oil at least twice a shift; lighter oils than castor, such as Arctic Ammonia, may be used. Drills used in shaft sinking can be oiled satisfactorily by placing a good-sized, drop, sight lubricator on the station above the sinking operations and connecting it with the air-line supplying the sinking drills. If this lubricator is properly filled and adjusted, a uniform oiling of the sinking machines will be effected without the necessity of oiling the drills individually. The grease end should be filled at the station or surface before each drilling period. The shift boss should see that the machines are greased and also that the lubricators at the station function properly. The life of the air-drill hose is somewhat shortened by this method, as oil attacks the inner tube; but as some oil is always present in the compressed air, this is not a serious objection to the method.

Jan 1, 1922

By Lucien Eaton

The use of filling in mines is less common in the United States than it is in Europe, where in some places it is required by law. In most cases the filling is placed by hand, and the material used for this purpose is the waste from development and that sorted from the ore in the stopes. When these sources provide an insufficient supply, additional rock must be quarried on surface or mined underground, or some other material must be used. In different parts of the world sand, clay, gravel, culm, granulated slag, mill tailings, and even ashes, have been used as filling material in place of or in conjunction with rock. Of all the materials used for filling the best is probably clean sand. Gravel, finely crushed rock, granulated slag and coarse mill tailings are almost as good, and the methods used for placing and confining sand will apply equally well to any of these. The advantages of sand are its comparatively slight compressibility and the ease, economy and convenience with which it may be placed. On account of the voids, which necessarily occur in fills made of coarse waste, such fills will compress 10 to 25 per cent before they develop their full strength, whereas clean sand seldom compresses more than 5 per cent. Sand is especially desirable when practically complete filling is required, and sand derived from mill tailings, especially when not thoroughly cleaned, has been remarkably effective in sealing off and extinguishing mine fires. When natural sand is available on surface, or when it can be obtained from the mill tailings or tailings dump, the cost of using this material for fill will probably be considerably less than that of rock. In this paper it is not proposed to discuss all methods of filling, but to describe some of the methods used for placing sand fill and to make a brief comparison of their merits. Methods of Placing Sand Sand may be transported and placed underground by several methods, which may be classified as follows: 1. By Hand.—The sand, which must be comparatively dry, is taken down the shaft in cars on cages and is distributed to its destination in these cars, or it is dumped down raises and is drawn off and distributed by means of cars, wheelbarrows or scrapers.

Jan 1, 1932

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

Discussion of the paper of H. M. WARREN, A. S. BIESECEKER and E. J. POWELL, presented at the New York meeting, February, 1916, and printed in Bulletin No. 110, February, 1916, pp. 181 to 193. R.. V. NORRIS, Wilkes-Barre, Pa.-For many years the power requirements of breakers designed in the Anthracite. Region have been based on calculations made from indicator diagrams taken during operation, with various sections of machinery idle; these, while giving reasonably accurate figures, gave no intimation of the peak loads which have been shown so clearly in the paper. The high-speed flywheel for breaker rolls is new and shows a remarkable saving in peak power required, besides eliminating the stalling of the rolls from overload. The figures given are so far in advance of anything previously published that they will undoubtedly be used as a basis for future breaker design. It is to be hoped that the authors will continue this investigation and extend their paper by a description of the motors found best suited for this work. WILLIAM KENT, Montclair, N. J.-I notice on p. 187 reference is made to one of the difficulties being the starting torque, and it is proposed to use roller or ball bearings in order to decrease the high starting torque. I suggest that. before the roller or ball bearings are put in, an investigation be made as to the amount of the starting torque, as shown by wattmeter measurements and as to what the starting torque ought to be, theoretically, according to the energy formula; that is, how much starting torque is required to accelerate the rotating mass in a given number of seconds up to full speed. Having secured this information it may be found the amount to be saved by roller bearings is not very great. If it appears that roller bearings will not greatly decrease the starting torque, the next thing to be done is to have a special design of motor in which there is a field that can be made very strong at the start, by the use of extra poles or other means, and the next thing that may be done is to increase the speed from 10,000 r.p.m. to 25,000, which can be done with wire-wound flywheels, especially if the wires are made of vanadium steel.

Jan 5, 1916

By R. T. Pepper

DURING an investigation into the effect of heat-treatment on the creep properties of the magnesium alloy ZW1, (1 pct Zn, 0.6 pct Zr), the previously published methods of final polishing were found to be unsatisfactory. A new diamond-polishing technique has been developed to facilitate the study of fine precipitates in this and other magnesium alloys, and is described in this note. The sectioning and coarse grinding techniques are those of Fox and Hall,' and Hess and Cieorge.' Pre- liminary mechanical polishing is done with 6-µ, and 1-µ( grades of diamond compound on 'Microcloth' using a lubricant of 'Hyprez' oil. When the conventional technique is used with a 1/4- µ diamond wheel for the final polishing of magnesium alloys, scratching is likely to result from the abrasive action of the 'Microcloth' nap on the soft metal surface. This problem has been overcome by the use of a cream on the wheel in order to separate the specimen surface from the polishing cloth. To prepare this cream, a solution of 6-ml tri-ethanolamine in 75-ml water is stirred into 12.5 g stearic acid at a constant temperature of 80° to 90°C. The cream is allowed to cool, and is then 'whipped' to a smooth consistency with 100-ml 'Hyprez' oil. Before polishing, the diamond loaded 'Microcloth' is moistened with a few drops of 'Hyprez' oil, then a small amount of cream is worked into the nap. For the best results a wheel speed of 500 rpm should be used for polishing, and the specimen should be held by hand with a light pressure while being rotated in the opposite direction to the wheel. After polishing it is necessary to swab the specimen thoroughly in methylated spirits to remove residual cream and oil from the surface in order to avoid uneven etching and drying stains. Fig. 1 shows the surface finish obtained on a specimen by polishing on a 1/4- ° diamond wheel using the cream, and Figs. 2 and 3 the precipitate observed in ZW1 after polishing, and etching for two seconds in nitric acid 15 pct in ethylene glycol. This new diamond-polishing technique has made a valuable contribution to the programme of metal-lographic research on ZW1 and has become a routine laboratory practice for other low alloy content magnesium alloys.

Jan 1, 1961

AS I told you in the chapter on salts, saltpeter is a mixture composed of many substances extracted with fire- and water from arid and manurial soils, from that growth which exudes from new walls or from that loosened soil that is found in tombs or uninhabited caves where the rain cannot enter. It is my belief that it is engendered in these soils from an airy moisture that is drunk in and absorbed by the earthy dryness. Considering its effects, I do not know how to decide and say exactly what the nature of saltpeter is. The learned and very wise physicians find it salty and with a subtle sharpness both in taste and in their medical experiments. Considering its strong biting qualities, they decide to say that it is of a hot and dry nature; on the other hand when they see that it is engendered from the air and that when touched by fire it becomes inflammable and vaporous, and rises with a fearful impetus when mixed in powder for military guns, it manifestly shows itself to be of a hot and moist airy nature. And then when they see that it is shining and transparent with whiteness and is fusible in every fire in a manner corresponding to a thing of a watery nature, and since it. is heavy, it seems that it can be said to be watery in nature. To this is added the experience of touch and of the great cooling action which it has on water in summertime when wine is to be cooled, and since it crushes and breaks with but little pressure, it might be thought to be earthy in nature; especially when it is seen to change into a hard, white stone when burned with an equal amount of sulphur. Thus it seems that every one of the elemental qualities is predominant in it. Now the ancients called this, or a similar thing, nitrum. [150] Pliny, in Book XXXI of his Natural History, has said that it was a thing not much different from salt, that doctors do not seem to have yet known its nature, that it is found in various places, and that the best is found in Macedonia. But among the moderns and especially in our regions, it is not known today what it is that Pliny and other writers refer -to, since according to the aforesaid Pliny and other ancient writers it is a natural mineral. Some say that in place of, the natural kind the artificial will serve for the same medicinal purposes, since it has the same nature and is perhaps more powerful.

Jan 1, 1942

By R. N. Thurston, E. A. Nesbitt, G. Y. Chin

A general relalionship between the amount of glide shear (due to slip) and the macroscopic shape change has been developed. Since the deformation can be large, finite strain analysis is employed. In this treatnzent, the shape change is expressed by a deformation gradient matrix, F - [axi/aXj1, where X and x refer to the initial and final positions of a particle. This matrix is readily evaluated in terms of the amounl of glide shear, a , and the direction cosines of the slip-plane normal and the slip direction for a single active slip system. In the case of deformation from slip on several systems, the product F(a) of the several deformation gradient matrices is first calculated. Then, by assuming that the final configuration is reached by a long series of small shears of magnitude a, occurring more or less alternately in the several slip sys- IN problems of crystal plasticity, it is often necessary to relate the amount of glide in the operating slip systems to the macroscopic strain components. This relationship is relatively simple when only small strains are considered. In this case the separate strain contributions from several slip systems are additive. Such a procedure is incorrect in the case of large plastic deformation. To the authors' knowledge, no general treatment of the latter problem has appeared in the literature. In specific instances, Mark, Polanyi, and schmid3 have derived the relationship between glide and axial elongation during tensile pulling of a single crystal when only one slip system is active. A similar relationship for duplex slip was worked out by v. Goler and Sachs.4 Taylor and Elam5 have also studied in detail problems of large plastic deformation. Due to uncertainties as to the slip systems at the time, terns, the final deformation gradient matrix can be obtained. Mathematically, the problem is reduced to finding the limit of F(dN as N — m while a — 0 in such a way that the Product Na = 0, a ftnite conslant designatzng the accunzulated amount of shear. It turns out that this limit is simply , where F, is the matrix whose elements are the coefficients of a in the F(a) matix. Application is made of the present treatment to a fcc crystal of Perlrzalloy compressed on the (110) plane and contrained to elongate zn the [112] directzon. In addition, it is shown that one rnay readily obtain from the general analyszs the well-known formulas relating elongation, amount of glide shear, and amount of lattice rotation for crystals deforming by single and double slip under tension. however, they were mainly concerned with proving that slip occurs on {111}(110) systems in fcc metals. The present general treatment arose out of recent investigations of magnetic anisotropy in cold-worked Fe-Ni alloys6 as well as some related problems in strength anisotropy of single crystals.' Detailed application of the general analysis will be provided in the case of a Permalloy single crystal compressed on the (110) plane and constrained to elongate only in the [112] direction. It will be seen that, as expected, the small strain approximation leads to significant errors after moderate straining. It will also be shown that the present general treatment yields the formulas of Mark et al. and of v. Goler and Sachs in those specific cases. GENERAL CONSIDERATIONS Consider a homogeneous deformation in which a material point initially at moves to both positions being referred to the same set of Cartesian axes. Such a deformation can be

Jan 1, 1967

By E. P. Abrahamson, S. L. Lopata

A general relalionship between the amount of glide shear (due to slip) and the macroscopic shape change has been developed. Since the deformation can be large, finite strain analysis is employed. In this treatnzent, the shape change is expressed by a deforlnation gradient matrix, F - [axi/aXj/ where X and x refer lo the initial and final positions of a particle. This matrix is readily evaluated in termas of the amounl of glide shear, a , and the direction cosines of the slip-plane normal and the slip direction for a single active slip systena. In the case of deforma tion from slip on several systems, the product F(a) of the several deformation gradient matrices is first calculated. Then, by assuming that the final configuration is reached by a long series of small shears of magnitude a, occurring more or less alternately in the several slip sys- IN problems of crystal plasticity, it is often necessary to relate the amount of glide in the operating slip systems to the macroscopic strain components. This relationship is relatively simple when only small strains are considered. In this case the separate strain contributions from several slip systems are additive. Such a procedure is incorrect in the case of large plastic deformation. To the authors' knowledge, no general treatment of the latter problem has appeared in the literature. In specific instances, Mark, Polanyi, and schmid3 have derived the relationship between glide and axial elongation during tensile pulling of a single crystal when only one slip system is active. A similar relationship for duplex slip was worked out by v. Göler and Sachs.4 Taylor and Elam1 have also studied in detail problems of large plastic deformation. Due to uncertainties as to the slip systems at the time, ! terns, the final deformation gradient matrix can be obtained. Mathematically, the problem is reduced to finding the limit of F(aN as N — m while a — 0 in such a way that the Product Na = a finite conslant designatzng the accumulated amount of shear. It turns out that this limit is simply eafF1, where F, is the matrix whose elements are the coefficients of a in the F(a) twatrzx. Application is made of the present treatment to a fcc crystal of Permalloy compressed on the (110) plane and contrained to elongate in the [112] directzon. In addition, it is shown that one rnay readily obtain from the general analyszs the well-known formulas relating elongation, amount of glide shear, and amount of lattice rotation for crystals deforming by single and double slip under tension. however, they were mainly concerned with proving that slip occurs on {111}(110) systems in fcc metals. The present general treatment arose out of recent investigations of magnetic anisotropy in cold-worked Fe-Ni alloys6 as well as some related problems in strength anisotropy of single crystals.' Detailed application of the general analysis will be provided in the case of a Permalloy single crystal compressed on the (110) plane and constrained to elongate only in the [112] direction. It will be seen that, as expected, the small strain approximation leads to significant errors after moderate straining. It will also be shown that the present general treatment yields the formulas of Mark et al. and of v. Goler and Sachs in those specific cases. GENERAL CONSIDERATIONS Consider a homogeneous deformation in which a material point initially at moves to (xl,xz,x3), both positions being referred to the same set of Cartesian axes. Such a deformation can be

Jan 1, 1967

By George Wolff

To THE average person, the purport of the items and figures on the balance sheet of a mining company are hazy and the real financial condition of the company is cloaked in obscurity. It is also likely that the satisfaction of the stockholder in his investment, as well as the determination of the prospective investor, rests more on the reputation of the company, his confidence in the management, the stated earnings per share and the dividends paid, than on a comprehension of the information contained in the balance sheet. The balance sheet of any company at best can only closely approximate the true financial condition as of a given date. Any item of asset, except cash, can probably be altered if another's viewpoint is applied. It is difficult and expensive to drill and explore an orebody to determine the entire tonnage of ore therein. Those inherent difficulties render it practically impossible to prepare an absolutely correct balance sheet of a mining company. It is possible, however, to present the facts of a mining company more intelligently and comprehensively than is usually done. With this in mind, a balance sheet of an imaginary mining company is submitted, with supporting schedules. The same fundamental principles hold true whether we consider a large or a small company. Less complexity is involved in dealing with the affairs of a smaller company. Therefore, for this purpose, the assumed company operates but two mines and a smelting plant. It has been deemed advisable to introduce the features of the operation of a mine acquired prior to March 1, 1913 and one after that date. The presentation therefore is concerned in one mine with the appraisement as of March 1, 1913 and in the other with the appraisement by reason of discovery. A consequential factor pertains to dividends paid from depletion reserves and therefore free of surtax to the stockholders. While supporting schedules, when necessary, give details of certain items on the balance sheet, it seems desirable to give further explanations with respect to some of them. This seems to be important because some mining companies do not treat the items as indicated on the statements submitted.

Jan 1, 1928

By George Wolff

To THE average person, the purport of the items and figures on the balance sheet of a mining company are hazy and the real financial condition of the company is cloaked in obscurity. It is also likely that the satisfaction of the stockholder in his investment, as well as the determination of the prospective investor, rests more on the reputation of the company, his confidence in the management, the stated earnings per share and the dividends paid, than on a comprehension of the information contained in the balance sheet. The balance sheet of any company at best can only closely approximate the true financial condition as of a given date. Any item of asset, except cash, can probably be altered if another's viewpoint is applied. It is difficult and expensive to drill and explore an orebody to determine the entire tonnage of ore therein. Those inherent difficulties render it practically impossible to prepare an absolutely correct balance sheet of a mining company. It is possible, however, to present the facts of a mining company more intelligently and comprehensively than is usually done. With this, in mind, a balance sheet of an imaginary mining company is submitted, with supporting schedules. The same fundamental principles hold true whether we consider a large or a small company. Less complexity is involved in dealing with the affairs of a smaller company. Therefore, for this purpose, the assumed company operates but two mines and a smelting plant. It has been deemed advisable to introduce the features of the operation of a mine acquired prior to March 1, 1913 and one after that date. The presentation therefore is concerned in one mine with the appraisement as of March 1, 1913 and in the other with the appraisement by reason of discovery. A consequential factor pertains to dividends paid from depletion reserves and therefore free of surtax to the stockholders. While supporting schedules, when necessary, give details of certain items on the balance sheet, it seems desirable to give further explanations with respect to some of them. This seems to be important because some mining companies do not treat the items as indicated on the statements submitted.

Jan 1, 1928

By C. L. Magee, H. W. Paxton

PREVIOUS workersl'% ave found that as-quenched ferrous martensites can be plastically deformed at low stresses. They have also found that the stress to obtain small strains can be significantly increased by aging at temperatures up to 150°C. This behavior has been interpreted in two ways: 1) that the deformation at low applied stress is due to internal stresses and thus the aging phenomenon is due to relaxation of the internal stresses;' 2) that the microdeformation arises through the motion of unpinned dislocations and the aging process is the diffusion of carbon to the dislocations to pin them.293 In a recent paper,4 we have shown that under certain conditions the dominant microdeformation mechanism of as-quenched Fe-31Ni marten-site-austenite aggregates is the transformation of retained austenite. Our results on resistance changes during deformation and temperature dependence of the deformation also established that, at temperatures above 300° K, the microdeformation was not due to this transformation. The purpose of this note is to report results of experiments which indicate that explanation 1 is appropriate for this deformation. All results presented here are from conditions where transformation does not make a measurable contribution to the microplastic deformation, in Fe-31Ni-0.002C, or in Fe-29Ni-0.02C-0.25Ti. The experimental techniques that were used for measurement of the plastic deformation are described4 and analyzed5 elsewhere. Fig. 1 shows the microplastic response of 100 pct austenite at 300" and 350° K. The microplastic response of an austenite-martensite aggregate is also given in Fig. 1 and it is seen that, after formation of martensite, the initial plastic deformation occurs at lower stresses. Thus, the softness is not entirely due to retained austenite—the quenched structure can be deformed at lower stresses despite the fact that the macroscopic strength is significantly higher. A result which allows a distinction to be drawn between the alternative explanations for this behavior is derived from aging experiments on the low-carbon alloy containing titanium. We have previously shown4 that the presence of titanium in this alloy reduced the free carbon to a sufficiently low level that thermal stabilization of the austenite-martensite transformation was not detected. Despite this, Fig. 2 shows that the microplastic response is decreased by aging treatments. A similar aging effect in Fe-ZONi, with some titanium, has previously been reported by . Thus, carbon is not necessary for the aging process and explanation 2 is at best incomplete. Since internal stress relief can occur independently of carbon (any temperature dependence of the flow stress can result in decreased internal

Jan 1, 1969

By R. W. Raymond

THE death of Privy Councilor Bruno Kerl, on March 25, 1905, terminated a distinguished and useful career. Bruno Kerl was born March 24, 1824, at St. Andreasberg in the Harz, and entered in 1840 the mining school of Clausthal, where he studied for three years, working at the same time in the mines and stamp-mills. After an additional year of practice in the silver-reduction and iron-works of the Upper Harz, he passed his examination as a metallurgical graduate, and studied for a year at Göttingen under WV filer in chemistry, Hausmann in mineralogy, and eminent teachers in other branches. In 1846 he was employed at the Oker works, but very soon left this post, to become a tutor in chemistry, metallurgy, etc., at Clausthal, where he continued to labor until 1867. During this period the Clausthal school became a completely equipped Mining Academy, and Kerl was made in 1862 a full professor. Meanwhile, in addition to the work of instruction, he discharged, simultaneously or successively, the duties of many responsible official positions in the Royal Hanoverian administration of mines and smelting-works, and also published many valuable books and treatises. Among these were professional guide-books to the Upper and Lower Harz, and their characteristic metallurgical processes; a manual of qualitative and quantitative blow-pipe analysis; another of metallurgical assaying ; and, most important of all, a Handbook of Metallurgy in four volumes, the second edition of which was issued in Leipzig, 1861-1865. This book was speedily recognized as the leading authority in its field. In this country, the English translation and revision, by Crookes and Röhrig, published about 1869, had a large circulation. In addition to these literary labors, Prof. Kerl became in

Jul 1, 1905

By E. J. Bruderlin

A metallurgical process to be economically successful must be carried on under proper conditions of control and equipment. The question of equipment is always of primary importance. In the distillation process for the recovery of zinc by retorting, the retort is the all-important piece of equipment. Each retort in a working blóck must function as a separate unit. Over-all block efficiency is the result of the ability of the individual retort to withstand the severe conditions of operation for a maximum period of time. Therefore retort manufacture has been an ever present problem with the operator of a zinc-retorting plant. During recent years the zinc-plant operator has been faced with rapid changes in the character of the ores and concentrates. Operating costs have increased as a result of the introduction of the flotation process and the amount of flotation concentrates to be handled. To counteract increasing costs, the operator has found it necessary continually to attempt heavier loading of retorts, until a 45 to 50-lb. charge per cubic foot of retort space has become common practice. Heavy loading has brought about severe firing conditions, which, in turn, have emphasized the necessity for further improving the quality of the retort. Increasing percentages of detrimental impurities in the retort charges have also added to the operator's difficulties. Amarillo Silicon Carbide Retorts At the Amarillo plant of the American Smelting and Refining Co. a retort made of a suitable plastic clay grogged with silicon carbide has been found to best meet the present-day requirements. Retorts of this kind have been in use at Amarillo for 8 years and have shown an average furnace life of approximately 175 calendar days. The Amarillo retort is cylindrical in shape and after burning is approximately 83/4 in, inside diameter by 60 in. over-all length. The wall thickness is 136 in., except for the butt of the retort, which is approximately 2½ in. thick. The retort mud has a shrinkage of 3 per cent, or approximately % in. per foot. The silicon carbide retort after being properly dried weighs about 211 lb. When the retort is fired and ready to go into use the weight decreases to approximately 203 lb.

Jan 1, 1937

By Stanley C. Herold

A few hates on the occurrence and significance of mud volcanoes in Colombia may be of interest at the present time, owing to the renewed activity in geological exploration of the coastal regions bordering the Caribbean Sea. The best-known volcanoes are found a few miles from the seacoast. One is situated to the south of Puerto Colombia; the second, to the east of Cartagena near the village of Turbaco; and the third, near the village of Puerto Escondido south of the Sinu River. Others are reported in more inaccessible localities. Usually they stand 2 1/2 or 3 ft. (0.762 or 0.914 m.) above the surrounding ground at the crater, though several craters from 10 to 20 ft. -(3.04 to 6.09 m.) "apart will often build up an extensive mound at low gradient. The shallow mound may cover 1/2 or 3/4 acre (0.2 to 0.3 ha.) with an elevation of 12 or 15 ft. (3.65 or 4.57 m.) at the, center. The craters are formed of hardened blue clay; the inside diameters vary from 14 to 24 in. (35.56 to 60.96 cm.). The rim is continuous, except on one side where there is usually a cut 3 or 4 in. deep, thus allowing an overflow. The craters are filled to the' rim-cut with a thick mixture of blue clay mud and water, which is kept in agitation by escaping gas. Fig. 1 shows the bubble in the act of bursting and Fig. 2 the appearance of the surface of the viscous fluid a second or so later. The frequency of the explosions is determined by the weight of the column of fluid in the neck of the volcano, consequently, such explosions are not synchronous in a group of craters. Ordinarily, there arc two or three explosions in about 3 minutes. The supply of gas is small but steady and sufficient pressure must accumulate before the bubble can enter the column of fluid. The water is derived from the surface and enters the scdirnentary strata not far distant from the volcano. During long dry seasons, as the supply of water fails the volcano dries and geyser action ceases. The temperature of the muddy fluid is normal; the gas is dry and inflammable. - No petroleum products come with the gas. On the surface of the fluid, there is sometimes a dark brown streaky scum, which

Jan 1, 1920