Search Documents

By Courtenay DeKalb

Revision of the United States mining law is needed chiefly because of the following reasons: 1. The conceptions as to the characteristics of orebodies that were held at the time the statute of 1872 was enacted have since proved to be in many respects erroneous. 2. The operation of the existing law has been found to work unnecessary hardship upon many claimants to mineral land. 3. The existing statute fails in large degree to encourage development of mineral resources. 4. The existing law often produces conflict between placer and lode-claim rights, working unnecessary injustice to placer claimants. 5. The methods of establishing the rights of locators on United States mineral land are defective, and are not uniform throughout the States within which such lands exist. Law of the Apex The objections to the so-called "law of the apex" are so well known as to require no detailed statement. It is sufficient to point out that the apex rule was based upon the notion that ore deposits consisted of well-formed veins included between definite walls, like the slice of ham in a sandwich. The fact is that veins conforming to that simple type are rare. Irregularity is the rule, and the chief metal production of the United States comes from mass? which bear no resemblance to the tabular form of vein. Manifestly the law of the apex fails completely in such cases. Moreover, the tendency is constantly toward the exploitation of ores of lower grade than could formerly be worked, and such deposits exist mainly in the form of large irregular impregnated zones and masses, so that the future development of our mineral resources would be continuously embarrassed by shadowy claims to extra-lateral rights by the locators of so-called apexes.

Jan 1, 1915

RichaRd PeaRce, Argo, Colo.: This contribution upon the very interesting subject of the origin of the gold of certain lode-formations offers many subjects for thonghtful consideration. The explanation, for instance, of the perplexing features of thin lava dikes seems to me to be in harmony with facts as I have myself observed them elsewhere. At Marshall basin, near Telluride, Colorado, there is an extensive lava-flow. The material of this formation contains a large proportion of fragments of foreign matter in the form of angular pieces of rock. The latter show no signs of having undergone metamorphism, such as would be expected to be due to the direct effects of heat; and the evidence in this particular case would certainly lead me to suppose that the flow was due to causes analogous to those suggested by Mr. Rickard. It was, I believe, a moving mass of material, having a temperatrire considerably below the actual melting-point of the rock of which it is composed. In regard to the theory which the author has built up from the existence of the iodide of gold in sea water, I cannot consider it untenable ; but I would put the question whether any investigations have been made with a view to determining whether gold and silver occur in the beds of rock-salt, formed, as is generally allowed, by the evaporation of bodies of salt water. At Stassfurt, in Germany, there is a very remarkable series of alternating beds of rock-salt and anhydrite, the uppermost members of which are covered with deposits of potash salts. The question occurs to me, why should not gold and silver have been discovered in these deposits? Iodine and bromine, I believe, have been found in the salts last deposited by

Jan 1, 1894

OPEN-HEARTH refractories are not merely an accessory to the furnace. They themselves ore the furnace, to all intents and purposes. The steel work of the main structure is merely a frame which helps to support the refractories; and the regenerators, a necessary part of the furnace system, consist almost entirely of refractories with very little supporting structure. Not only do refractories constitute the essential part of the furnace, but they also carry the liquid steel all the way to the point where it begins to solidify. On leaving the furnace the liquid passes through a refractory runner into a refractory-lined ladle, then through a refractory nozzle closed by a refractory stopper on the end of a refractory- protected rod. The liquid is sometimes sent through an additional refractory-lined tun-dish, a supplementary ladle, or a refractory runner for bottom pouring, until it finally enters the iron mold in which it solidifies. Even in the mold, refractory materials are sometimes used to provide a non-conducting "hot top." These materials, from ladle to hot top inclusive, are often referred to as the "pouring-pit refractories." CAUSES OF FAILURE Compared with the equipment used in most industrial processes the open-hearth furnace has a relatively short life. The most important quality of an open-hearth refractory, therefore, is its rate of failure. The discussion here of the individual refractory materials will therefore keep uppermost the question "Why, how, and where does it fail?" The principal causes of failure of open-hearth refractories are, in their order of importance: 1. Reaction with iron oxides. 2. Reaction with slag. 3. Flow and failure under load. 4. Melting. 5. Spallimg. 6. Mechanical breakage. Reaction with Iron Oxides and Slag. This is by far the most important cause of failure. Liquid iron oxide comes very near to being the

Jan 1, 1944

Jan 1, 1901

By Edgar C. Bain

Of the important phenomenon of the hardening of steel, Professor Sauveurl says: It would seem as if the methods used to date for the elucidation of this complex problem have yielded all they are capable of yielding and that further straining of these methods will only serve to confuse the issue, the point having been reached when this juggling, no matter how skilfully done, with allotropy, solid solutions, and strains is causing weariness without advancing the solution of the problem. The tendency of late has been to abandon the safer road of experimental facts and to enter the maze of excessive speculations, in which there is great danger of some becoming hopelessly lost. The conclusion seems warranted that new avenues of approach must be found if we are to obtain a correct answer to this apparent enigma. With some degree of fitness we may say this of other problems. It seems likely that one of the new avenues of approach to many metallo-graphic problems is the study of crystal structure, or more accurately, the atomic arrangement, by means of the x-ray spectrometer. The crystal structure of some materials has been carefully worked out by the mineralogist, but his methods are, in general, unsuited to commercial metals and a method that yields even better information is at hand as the result of work on the diffraction of x-rays by Laue and the Braggs2 and later by HullI3 St. John, and others. It should be understood that the contour of free crystals, which is the subject of measurements by the crystallographer, is the result of the atomic structure and, in general, bears a simple and obvious relation to it. The use of the x-ray spectrometer4 has been described frequently, so the procedure will not be given here.

Jan 1, 1923

By Edgar C. Bain

Of the important phenomenon of the hardening of steel, Professor Sauveurl says: It would seem as if the methods used to date for the elucidation of this complex problem have yielded all they are capable of yielding and that further straining of these methods will only serve to confuse the issue, the point having been reached when this juggling, no matter how skilfully done, with allotropy, solid solutions, and strains is causing weariness without advancing the solution of the problem. The tendency of late has been to abandon the safer road of experimental facts and to enter the maze of excessive speculations, in which there is great danger of some becoming hopelessly lost. The conclusion seems warranted that new avenues of approach must be found if we are to obtain a correct answer to this apparent enigma. With some degree of fitness we may say this of other problems. It seems likely that one of the new avenues of approach to many metallo-graphic problems is the study of crystal structure, or more accurately, the atomic arrangement, by means of the x-ray spectrometer. The crystal structure of some materials has been carefully worked out by the mineralogist, but his methods are, in general, unsuited to commercial metals and a method that yields even better information is at hand as the result of work on the diffraction of x-rays by Laue and the Braggs2 and later by HullI3 St. John, and others. It should be understood that the contour of free crystals, which is the subject of measurements by the crystallographer, is the result of the atomic structure and, in general, bears a simple and obvious relation to it. The use of the x-ray spectrometer4 has been described frequently, so the procedure will not be given here.

Jan 1, 1923

By A. J. Phillips, C. G. Grant, Wm. B. Price

ADMIRALTY nickel is a new corrosion-resisting and heat-resisting white metal alloy composed of 70 per cent. copper, 29 per cent. nickel and 1 per cent. tin. It has been given the trade name "Adnic." In 1924, Wm. B. Price1 described this alloy and its successful use as a diaphragm metal. The physical properties of Adnic at ordinary and elevated temperatures were given in Mining & Metallury.2 A patent3 was granted on Adnic, April 28, 1925. Work was first started on this alloy during December, 1921. An investigation of the patent situation in this country and abroad, and also a search of the literature, did not reveal any work on the ternary diagram, copper-nickel-tin; and the only wrought copper-nickel-tin alloy found was that known as "Newloy," composed of copper, 64 per cent.; nickel, 35 per cent.; tin, 1 per cent. This was being manufactured and sold by Wm. Gallimore & Sons, Ltd., Sheffield, England, for unplated spoon and fork stock, and first came to our attention in January, 1922. The preliminary work in connection with the development of Adnic was started by casting four binary copper-nickel alloys of the compositions shown in Table 1. Various amounts of tin were added to each of these mixtures, to produce the series of ternary copper-nickel-tin alloys also given in Table 1. A 200-gm. sample of each of these was cast by melting in a clay graphite crucible and allowing the melt to slowly cool with the furnace. A longitudinal section from each of these castings was polished and etched for examination. The castings were not homogeneous solid solutions, but showed the usual cored structure associated with cast alloys. However, from an examination of these sections we roughly determined

Jan 1, 1928

By Robert P. Burrows

In preparing this paper the object has been to set forth facts relating to illumination problems, which, judging from the results realized in the iron and steel and other industries somewhat similar to mining, will tend toward furthering safety, production, and contentment of employees, as well as economy of operation in mines. By applying the principles of illumination with the assistance of modern appliances, the full benefits in efficiency may be derived from improvements already made in other details of mine operation. The lighting of a typical coal mine may be*divided into four distinct parts: 1, The lighting of the buildings about the top; 2, the lighting of the working faces; 3, general illumination at the bottom; and 4, special applications of lighting. The lighting of buildings about the top may be treated in the same manner as that of any other industrial plant, for we have a boiler room, an engine and generator room, a forge, a machine shop, and a hoist room. These can be well and efficiently lighted by the use of 100-watt tungsten-filament multiple lamps with proper reflectors so spaced and suspended that a power consumption of from ¼ watt per square foot in the boiler room to 1 watt per square foot in the machine shop is obtained. The methods that apply to this kind of lighting have been ably treated by a number of authors,' and for this reason a detailed discussion is unnecessary. The lighting of the working faces is usually done by means of portable lamps, of which there are four types in use: The oil torch, the acetylene Iamp, and the oil and the electric safety lamps. The different types have been fully described in numerous papers and articles and will not be covered here, although a few figures on the cost of operation will no doubt be

Jan 1, 1916

By J. J. Jakosky

A REVIEW of the progress in applied geophysics during the recent depression years reveals marked advances "over the methods employed several years ago. Of late, geophysical work has been curtailed to a con-siderable extent in the fields of oil and base-metal exploration, its especial domains a few years ago. Greater attention has been directed toward the use of geophysical technique in other engineering problems. Constantly maintained research programs have developed new instruments and per-fected better field, laboratory and interpretation techniques based on experience and skill acquired from years of application in the older geophysical field. During the past two years, geophysical methods have been employed in problems that required information on thickness of fill materials and subsurface bedrock contours. Considerable success has been attained, with subsequent drilling checking the predicted depths within one to five per cent. In general, these problems were similar as far as the fundamen-tal physical and geological conditions were concerned, but they have varied widely in specific detail and in engineering aspects. Character-istic of the different problems are: (1) yardage and bedrock profile in gold-placer mining; (2) water supply, involving underground drainage and storage conditions; (3) bedrock contours in dam-site and other structural investigations; (4) gravel and fill yardage, and other structural features along rights of way and in rock and gravel quarrying. Of particular interest, perhaps, to mining men are the problems of gold placer deposits and water supply. Geophysical work on gold placers is of especial interest because of the present expanded activity in all phases of gold mining. The development of a suitable water supply at, an economical cost is often of prime importance in insuring a successful mining venture. Particularly is this true in the arid Southwest. How-ever, the use of geophysical work in water supply is not confined to the needs of mining development.

Jan 1, 1933

By Spurr

CONTENTS. [ ]

Jan 1, 1913

By H. L. Hopkins, L. W. Kempf

Aluminum alloys, in common with most other metallic alloys exhibit slight density changes with variations in temper achieved by heat-treatment, which usually are the result of the variation with temperature of the solid solubility of the various alloy constituents in the solvent metal. Changes in density are, of course, most marked in conditions that exhibit the maximum variation in solid solubility of the constituents. In aluminum alloys these conditions usually prevail when alloys are quenched from just below the melting point and are subsequently reheated to some lower temperature. Since commercial heat-treatments may be of this type, the density changes, although small (of the order of 0.3 per cent which may be compared with the density change of about 1.5 per cent involved in the transformation, at ordinary temperatures, of gamma to alpha iron during the hardening of steel), may in some specific applications necessitate quantitative consideration. This phenomenon has been investigated extensively in the laboratories of the Aluminum Company of America over a period of years. A number of investigators '-5t have observed and measured the density changes accompanying the heat-treatment of aluminum alloys. In general, these changes have not been directly translated to dimensional changes and their significance has been overlooked to some extent by the practical user of aluminum alloys. It is the purpose of this paper to consider some practical aspects of these density and dimensional changes. These density changes were given some consideration in 1917 in connection with the use of aluminum-alloy pistons for aircraft engines. Investigations by Lea and Shakespear were reported in some confidential reports of the British Advisory Committee for Aeronautics, Light Alloys Subcommittee, during 1917 and 1918, which are not generally available in published form. In these reports the term "permanent growth" was applied to the dimensional changes occurring in the pistons at the tem-

Jan 1, 1936

By H. F. Silliman, Daniel R. Hull, John R. Freeman

In the normal operation of a brass-rolling mill, sheet and strip has, for the most part, been finished in comparatively thin gauges, involving a substantial amount of cold-work and a considerable number of anneals. This condition has been disturbed by the preponderance of cartridge brass, which is not rolled to thin gauges, and particularly by brass for artillery cartridge cases, on which the mill may finish its work at a thickness between 0.400 and 0.900 in. Obviously, the amount of rolling and the number of anneals to which such a product can be subjected are small compared with strip that is carried to a thickness of a few hundredths of an inch. As a result, critical examination into the internal condition of metal has been made on an extensive scale at a stage of manufacture that would not, in normal times, have been chosen for complete inspection. Under these conditions, a type of defect has been recognized that is not seen at thinner gauges. It might be more accurate to call it the appearance of a defect, since it refers to an apparently laminated, discontinuous structure, which, in fact, does not exist as such, and disappears after suitable treatment. For this reason it has been called a phantom lamination, which the authors consider an appropriate term. It is the purpose of this paper to describe the phenomenon and the conditions of its occurrence and, at least tentatively, to discuss its nature and cause. Great numbers of phantoms may be found in 2:r brass, either hot-rolled or cold-rolled. They are also found in 70-30 brass, sometimes when hot-rolled and generally when cold-rolled. It is not believed that phantoms are confined to these alloys but this paper is limited to them for the purpose of description. Hot-rolled 2:1 Brass For illustration, therefore, a typical cake of hot-rolled 2:I brass has been chosen. This was rolled to a slab 36 in. thick, from a casting 5 in. thick by 24 in. wide by 18 in. high, which was believed to have been sound. After hot-rolling and cooling, the slab was sheared and a portion of such a shear cut is shown in Fig. I. It would be difficult to convince anyone viewing this specimen that the metal was not unsound. The impression would be confirmed by the appearance of a tensile break, as shown in Fig. 2. This is an ordinary tensile-test piece from metal just described. Although there was nothing in its tensile strength or elongation that suggested unsoundness, it appeared run through with pipes and laminations. To question the reality of such a condition would imply questioning the obvious. But, considering the history of the metal, it would be difficult to believe that it could be so bad as it appeared. It seemed reasonable, though, that if the defects were what they appeared to be, they could be traced back from the sheared or broken face.

Jan 1, 1945

By M. R. Louthan

The susceptibility of titanium to stress orientation of hydride precipitates was investigated. It was determined that, when hydride precipitation occurred in titanium under an applied tensile stress of 30,000 psi, the hydrides precipitated on the titanium habit plane oriented most nearly perpendicular to the stress axis. Stress orientation of the hydride platelets occurred because the precipitation of the lower density hydride phase perpendicular to the stress axis caused expansion of the matrix in a direction that tended to relieve the applied stress. The Ti-H system has received considerable study in recent years, mainly because of concern over the effects of hydrogen on the mechanical properties of titanium. The amount of hydrogen present in commercial titanium is now quite low and should have no appreciable effect on its mechanical properties; however, many titanium applications require ex- posure to hydrogenous atmospheres under conditions in which hydrogen pickup is likely. In such cases continued exposures may cause the hydrogen content to increase to the extent that titanium hydride does precipitate as a second phase. The hydride phase has been shown 1,2 to have an adverse effect on the mechanical properties, particularly the impact properties, causing reductions in strength and ductility. BACKGROUND The behavior of titanium is often quite similar to that of zirconium and zirconium-base alloys, and the technology developed on one metal can often be applied to the other. Marshall and Louthan3,4 have shown that Zircaloy is susceptible to stress orientation* of zirconium hydride platelets, and that the platelet orientation has a pronounced effect on the mechanical properties of Zircaloy. They showed that when zirconium hydride precipitated in Zircaloy under an applied stress the hydride platelets tended to be aligned parallel to a compressive stress and perpendicular to a tensile stress. They also showed

Jan 1, 1963

By J. H. Craig

As a result of information that the Navy Department was questioning the advisability of raising the maximum allowable exposure temperature for zinc-coated steel parts from 500 to 750 F., it was decided to make a series of high temperature tension tests on several types of uncoated and zinc-coated steels. The objective was to determine at what temperature intergranular penetration of galvanized steel by zinc might take place under conditions of rapidly applied stress and temperature. Tests were conducted in the range from room temperature to 1400 F. In this range, low-carbon and high-carbon steels did not suffer any adverse effects due to zinc coatings. In fact, at 1400 F. the zinc coatings appeared to have a beneficial effect. In stainless steel, the coating had no effect up to 1000 F. Above this temperature, the zinc coating appeared to cause a marked loss in ductility and a less pronounced loss in strength. There was no visible evidence of zinc penetration of the stainless steel structure, but it was assumed that this was the cause of the adverse effect.

Jan 1, 1945

By C. Dalton, H. L. McGill

The purpose of this study was to develop a method for predicting the time delay created by metering a fluid through an annular restriction with translational motion of the boundaries. This time delay is utilized to control the opening of valves in various down-hole oilfield tools and forms the basis for the "hydraulic jar". The hydraulic jar is used to give upward impact forces to tubing or other tools that become lodged down-hole. The design of these jars has primarily been by trial and error; varying the clearances, fluid viscosities and dimensions of the jar until a satisfactory time delay was achieved. Obviously, a better understanding of the fluid flow characteristics is required to produce designs that are satisfactory and to eliminate the trial-and-error approach. Previous studies of flow in annular spaces were based on constant length of the annular restriction. Any motion of the boundaries of the annular space was confined to a rotational motion, like that encountered in journal bearing design. Consideration of the effect of translational motion of one boundary with respect to the other was necessary in applying this previous work to a time delay device. A prediction method was developed that takes into account this relative translational motion. Equations were developed to predict the relative velocity, the flow rate, and the time delay in a concentric annular space. The effect of eccentricity also was included. Experimental data were obtained and closely correlated with the prediction method. This correlation is presented graphically in terms of predicted and actual relative velocities for various annular clearances and pressure drops. This extension provides design equations which predict the performance of the hydraulic jar, thereby eliminating trial-and-error solutions and reducing the development time required for satisfactory designs. INTRODUCTION The design of down-hole oilfield tools which use hydraulic delay systems based on flow through annular orifices with relative motion of the boundaries is usually a trial-and-error process. The annular clearances, fluid viscosities and dimensions of the mechanisms were varied until satisfactory delay times were obtained. The development of these tools has been expensive, and a better understanding of the characteristics of annular flow with relative motion of the boundaries could result in superior and less expensive designs. The purpose of this investigation was to provide a method of predicting the performance of down-hole tools which use annular flow and, in particular, the performance of a down-hole tool known as the "hydraulic jar". The hydraulic jar is used to free pipe, packers and other tools that become lodged down-hole. The jar, located in the tubing string between the surface and the object which is stuck, releases the object though the repeated application of upward impact blows. The jar is basically a slip joint that is restrained in a collapsed condition until the desired tubing tension has been developed. The slip joint is then released and accelerates rapidly until it shoulders, delivering an impact blow or jar to the object. The delay obtained by metering the fluid through the annulus formed by the jar valve and housing provides the time delay necessary to stretch and apply tension to the tubing or pipe. Fig. 1A gives a schematic diagram of the hydraulic jar and brief details of its operation. The metering of the hydraulic jar begins when the tension force being applied to the jar by the pipe creates a pressure differential across the valve that is approximately equal to the force divided by the displacement area of the valve. This pressure differential induces flow through the annular restriction formed between the valve and housing. The valve moves with respect to the housing as the

Jan 1, 1969

By M. Friedman

Applications of rock mechanics to the design of engineering structures in rock involve the assumption that the stresses are due entirely to the present applied loads. For instance, it is assumed that the vertical normal stress in undisturbed rock free of topographic effects is equal to the weight per unit area of the overburden. In fact, vertical dilatational strains associated with stresses of more than 100 times the present overburden pressure have been measured by strain-relief methods on outcrops. 1,2 The notion of residual strain (stress) or latent stress3 seems unassailable; and indeed this has long been recognized by metallurgists. It is difficult, however, to assess the residual component of the in-situ state of elastic strain with conventional strain relief methods employed in mines or down boreholes. That is, in principle, the in-situ state results from the superposition of present applied loads (natural or man- induced) and potentially recoverable elastic strains (stresses) that exist in a given volume of material even though there are no external forces across the boundaries of the body (Voight,4 and Fig, 1). Accordingly, only in unloaded blocks can the true residual strains be measured by strain relief methods. Using X-rays, the elastic strains locked within the quartz grains or crystals of a rock can be measured. These strains are known to persist even when the rock is reduced to small chips but to vanish when the rock is disaggregated and the grains are powdered. Although we have just begun to investigate the mechanisms by which the strains are stored (see Preliminary Results), we believe that "pressure solution'' at grain boundaries, secondary cementation under load, permanent ("plastic") deformation, and temperature changes are possible processes. In any event, in our study of naturally deformed rocks, it is significant that we are work-

Jan 1, 1972

By W. F. Holbrook, T. L. Joseph

The problem of sulfur control is important in all blast-furnace operations but particularly for certain grades of steel because of the rigorous specifications. During the past decade the tendency has been to produce pig iron and hot metal of lower sulfur content. As most of the sulfur in the iron originates in the fuel, the use of high-sulfur coke demands modifications in practice to meet sulfur specifications. While it is generally known that high temperatures and more basic slags favor desulfurization, operators as a rule produce the most acid slag that will permit proper desulfurization. The viscosity of blastfurnace slag has been thought to be related to desulfurization and has been investigated by Feild and Roysterl, also McCaffery and his associates*, but apparently no systematic effort has been made to determine the relative desulfurizing powers of slags over the range of composition encountered in practice. Development of Testing Method Because slag and metallic iron are immiscible, the desulfurization reaction is heterogeneous, occurring only at the interfaces between slag and metal bodies. In the blast furnace the newly reduced iron, containing FeS, descends through the slag bath probably either as small drops or streams, at the interfaces of which desulfurization occurs. After its descent through the slag the iron collects to form a bath of metal, at the top surface of which desulfurization reaction probably occurs. These two steps have been thought to account for all desulfurization in the blast furnace. Kinney3 found that metal removed from the blast furnace just above the tuyeres contained three to four times as much sulfur as the iron at cast. Herty and Gaines4 conclude that most of the sulfur is removed while the metal is passing through the slag. Mund, Stoecker

Jan 1, 1936

By W. F. Holbrook, T. L. Joseph

The problem of sulfur control is important in all blast-furnace operations but particularly for certain grades of steel because of the rigorous specifications. During the past decade the tendency has been to produce pig iron and hot metal of lower sulfur content. As most of the sulfur in the iron originates in the fuel, the use of high-sulfur coke demands modifications in practice to meet sulfur specifications. While it is generally known that high temperatures and more basic slags favor desulfurization, operators as a rule produce the most acid slag that will permit proper desulfurization. The viscosity of blastfurnace slag has been thought to be related to desulfurization and has been investigated by Feild and Roysterl, also McCaffery and his associates*, but apparently no systematic effort has been made to determine the relative desulfurizing powers of slags over the range of composition encountered in practice. Development of Testing Method Because slag and metallic iron are immiscible, the desulfurization reaction is heterogeneous, occurring only at the interfaces between slag and metal bodies. In the blast furnace the newly reduced iron, containing FeS, descends through the slag bath probably either as small drops or streams, at the interfaces of which desulfurization occurs. After its descent through the slag the iron collects to form a bath of metal, at the top surface of which desulfurization reaction probably occurs. These two steps have been thought to account for all desulfurization in the blast furnace. Kinney3 found that metal removed from the blast furnace just above the tuyeres contained three to four times as much sulfur as the iron at cast. Herty and Gaines4 conclude that most of the sulfur is removed while the metal is passing through the slag. Mund, Stoecker

Jan 1, 1936

By Allen Rogers

THERE are few natural monopolies comparable with the nitrate industry. Perhaps the only other one is, curiously enough, also an essential fertilizer material, viz., potash, of which the Germans have heretofore held practically a-monopoly due to the existence in their territory of the most important known deposits of potash salts. And although nitrates in minute amounts are found in many desert regions, the only deposits callable of being worked commercially exist in Chile. Combined nitrogen in the oxidized form is an essential for plant life. Nature provides it mainly through the agency of nitrogen-fixing bacteria. But where lands are cropped artificially this supply is too small; and gradually the nitrogen supply becomes exhausted. In order to continue farming, it is necessary to furnish a supply of nitrogenous plant food, and this is clone by putting on various substances containing combined nitrogen. These consist of various animal wastes, ammonium sulphate, the ammonia of which is obtained in the destructive distillation of coal, and Chile saltpeter. The latter is immediately available as a plant food, the nitrogen being in the required form. The other substances must oxidize before they are available. Besides its use as a fertilizer, Chile saltpeter is the source from which the bulk of the nitric acid of commerce is derived. The use of nitric acid in the manufacture of almost, all modern explosives is, of course, well known.

Jan 2, 1918

By Tomoyuki Moritani, Atsuyuki Mizuno

A concentration of manganese nodule varies areally from 0 to 30 kg/m2 in the central-eastern deep sea bottom of Central Pacific Basin with depth of 5,600-5,900m, but generally it is low, mostly of the abundance order from 0 to less than some kilograms per square metres through the bottom. A high concentration over about l0kg/m is localized to the northwestern basin, besides "St. 414 Deep Sea Hill" and “GH 76-1 Trought”, and also it is likely related with the substratum of deep sea clay. Nodules are tentatively classified into nine types of Sr, SPr, SEr, Db, Ss/SPs, ISs, IDPs and V, in terms of morphology and surface feature. The types may be related with internal structure, nuculeus, mineral composition, chemical composition, occurrence and areal distribution, and might have resulted from various environmental factors of nodule genesis. The abundance of nodule at each station shows the interesting relation with acoustic records by 3.5KHz and seismic reflection profilings. In both the records, thick transparent layer over about 45m thick yield neither any nor significant amount of nodule. The layer less than 45m relates with abundant nodules up to 30kg/m2, though it yield also very little nodule in some cases. The relation suggests that the formation of nodule most likely could be related with the accumulation rate of the post-middle Eocene sedimentary sequence to some extent and also with other controlling factors. The relation can lead us to the tentative delineation of distribution of nodule deposits in the area. The comparative-consideration with the deposits in GH 74-5 area, just east- ward of the present area, shows the areal peculiarity of nodule genesis in deep sea bottom. The results of chemical analyses will be discussed elsewhere.

Jan 1, 1976