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By ARCHIBALD DOUGLAS

AT various times during the past quarter century proposals have been made that the basic Federal mining law of 1872 be repealed or amended, and that in its place a new and simpler law be enacted to provide for the entry upon, working, and the taking up of claims on the unallotted Federal mining lands in our western states and in Alaska. Serious discussion and study have been given such proposals but little has resulted there from, except perhaps a lively interchange of opinion and the conclusion that though the Apex law of 1872 is in many ways highly unsatisfactory and frequently a fomenter of strife and trouble, it still bids fair to remain with us. Under this act a greater part of the non-ferrous mining industry of the United States has developed. With all its short-comings it is the legal bridge that has carried over the innumerable caravans of adventurers and prospectors who explored our mining frontiers. For without any amendments of substance this act has for fifty-eight years been the guide in the location of our western Federal mineral claims and has stood unchanged during the most important period of our mining history. While Federal and state acts and amendments have been ground out by thousands and tens -of thousands the mining act of 1872, with a :strange tenacity, has remained as constant as the Rock of Gibraltar, and under it states, mining districts, and local customs have developed different codes for its application but its fundamentals have been unaltered. "Use doth breed a habit in a man"; until now the application of the law of 1872 has become a second mining nature.

Jan 1, 1930

By W. C. Knopf, G. Samsel

For several years International Minerals & Chemical Corp. has used a radiation method to assay potassium content of products from potash and feldspar beneficiation. The procedure is rapid, accurate, and inexpensive and is easily handled, if necessary, by nontechnical personnel. Data are presented to show the accuracies that may be expected if the technique is used for control of pilot plants or large- scale plants. Natural potassium is composed of three isotopes -K39, K40 and K41. Five other isotopes, artificially produced, have been detected. In natural potassium only the K40 isotope, with a half life of 1.4 x 109 years, is radioactive. Its modes of decay are beta and gamma rays, positrons, and x-rays. Only the more abundant beta rays, however, are important in radiation measurements using geiger tubes.

Jan 10, 1958

By William H. Spice

Exploratory drilling in South Central Texas for the year 1944 showed a marked increase over that of 1943 and resulted in a similar increase in new fields discovered. In this area, which comprises the 30 counties included in district No. I, Oil and Gas Division, Railroad Commission of Texas,? 61 exploratory wells were drilled during 1944 as compared with 29 exploratory wells drilled during 1943, or an increase of over 100 per cent. Three new oil fields, two new gas fields and one gas-distillate field were discovered during the year, as compared with one new oil field and one new gas field discovered during 1943. These new fields were the result of exploratory drilling throughout the district along the Wilcox trend and the deeper Edwards lime trend, which was started during the previous year. The Wilcox trend yielded the new Loma iilta-Wilcox oil field and the San Caja gas-* tlistillate field, both in McMullen County. The Charlotte field, in Atascosa County, was discovered along the deeper Edwards lime trend. These three discoveries were of considerable importance and subsequent development should indicate the desirability of continued exploration along these trends. The other three discoveries, United oil field in Guadalupe County, Pederson gas field in Milam County and Van Cleve gas field in Zavalla County, were of minor importance. Charlotte Field, Atascosa County, was discovered by the Humble Oil and Refining Company's No. 3 Pruitt, completcd on Aug. 9, 1944, flowing 176 bbl. per day, 3/16-in. choke, 710 lb. tubing, 475 lb. casing pressures, 37.7º A.P.I. gravity, from the top of the Edwards lime from 6917 to 6923 ft. Two oil wells were completed during the year in this field. This discovery is 14 miles southwest of the same company's Imogene field, also producing from the Edwards lime but with considerable difference in reservoir characteristics. The discovery of this field is the result of surface geology and subsequent seismograph survey of the area. Loma Alta-Wilcox Field, McMullen County, was discovered by the Atlantic Refining Company's No. I Atkinson, completed on June I, 1944, flowing 102 bbl. per day, 9/64-in. choke, 1900 lb. tubing pressure, 37º A.P.I. gravity, from Wilcox sand from 6866 to 6869 ft. after being drilled to a total depth of 7185 ft. This discovery is the result of subsurface geology and an extensive seismograph survey of the entire area. Sun Caja Field, McMullen County, was discovered by Edwin M. Jones No. 2-C Ezzell, completed on June 2, 1944 as a dual completion in the Wilcox sands, flowing 1,740,000 cu. ft. gas with 53 bbl. distillate, 1/4-in. choke, 2035 lb. tubing pressure, 53.2º A.P.I. gravity, from sand 6416 to 6453 ft. and flowing 2,000,000 cu. ft. of gas with 127 bbl. distillate, 1/4-in. choke, 2500 lb. tubing pressure, 50º A.P.I. gravity, from sand 6889 to 6916 ft., after being drilled to a total depth of 7264 ft. Three gas-distillate wells were completed during

Jan 1, 1945

Jan 1, 1942

By R. R. Angel

Drilling rate is a parameter that should be considered in determining the volume requirements for air and gas drilling. The use of past methods which ignore the effects of the solids content upon the pressure and velocity of the annulus flow stream can result in undercalculation of the required volurne by as much as 50 per cent. A vertical-flow equation is presented for determining volume requirements. This equation includes the effect of the solids that are transported up the annulus in the flow stream by incorporating the drilling rate as one of the parameters. The effect of down-hole temperature on required circulation rates is also ana-lvzed. A simple approximate method of determining volume requirements is presented. This method is more accurate than the methods used in the past. Hole cleaning difficulties are analyzed for a recent air drilling job where past methods indicated that - excess air was being used. Sample curves of calculated boitom-hole pressures are presented for air and gas drilling in several hole sizes. INTRODUCTION In certain areas the use of air or natural gas as a circulating medium for drilling oil and gas wells is becoming a common practice. Large increases in penetration rate and bit life are achieved through the use of these media in preference to mud or water. Drilling rates as high as 90 ft/hr have been obtained in shales. The importance of maintaining adequate circulation rate is generally recognized; however, much disagreement exists among drilling operators as to what constitutes "adequate" circulation rate. In quarry drilling, where annular velocities can be accurately determined, an annular velocity of 3,000 ft/min of standard air is required for best results in rocks having approximately the same density as those commonly penetrated in drilling oil or gas wells'. Although this standard air velocity has proven satisfactory for quarry drilling, some oil and gas well drilling operators believe that an equivalent annular velocity of more than 4,000 ft/min is required; others believe that as little as 2,000 ft/min . is sufficient. Much of this disagreement results from determining the required circulation rates with methods which fail to incorporate the drilled solids in an equation which is applicable to vertical flow. Hughes Tool Co. Bulletins No. 23' and 23-A3 present data for determining circulation rates based on the Weymouth formula. These data do not include the drilling rate as a parameter and, therefore, neglect the effect of the solids being transported up the annulus. In spite of this apparent defect and the fact that the Weymouth formula is not applicable to vertical flow, the Hughes data have well served the drilling industry in many areas and are important and timely contributions to the science of air and gas drilling. The Hughes data purposely omit a correction for increasing down-hole temperature. At slow drilling rates this effectively compensates for the use of a formula which is not valid for vertical flow; however, volumes determined by the Hughes method are not sufficient to support rapid drilling rates at moderate and great depths. For example, Phillips Petroleum Co.'s Cauthorn "D" No. l in the Vinegarone field for Val Verde County, Tex., was air drilled from 1,500 to 9,300 ft using a compressor delivering 1,400 cu ft/min. The 8 3/4-in hole was drilled with 5-in. drill pipe, and drilling rates as high as 90 ft/hr were obtained between 7,000 and 9,300 ft. No water or caving hole was encountered. At 7,728 ft it was necessary to wash-out 60 ft of cuttings to reach bottom after a trip to change bits. At 8,130 ft a twist-off occurred and the drill col-lars were stuck in drill cuttings. These difficulties indicate that the 1,400 cu ft/min of air was not sufficient to keep the hole clean. Hughes data indicates that 1,180 cu ft/min is sufficient to produce an annular ve-

Jan 1, 1958

By H. C. Schultz

CERTAIN local conditions were known to govern in large measure the successful adaptation of liquid-oxygen explosives to the large-scale blasting at Chuquicamata. The wide variation in hardness of the rock at this mine makes necessary the use of several types of explosives. A locally manufactured, relatively cheap black powder is used in blasting the softer waste and capping material, where a thorough displacement, breaks the ground sufficiently. Before the introduction of L. 0. X., an ammonia dynamite of about 65 per cent. strength was being used exclusively in the harder underlying orebody, where a strong disruptive as well as a displacement effect is required for breaking the ore. The L. 0. X., as developed for quarry work in the United States, has a practically pure carbon cartridge material, and the explosive has an extremely high rate of detonation, which should therefore cause it to usefully develop its full disruptive effect in hard ground. The individual blasts at Chuquicamata are large, black-powder shots which dislodge masses of rock averaging 250,000 tons each, and dynamite shots which dislodge masses averaging 80,000 tons each. It was desirable, therefore, to attempt to displace with L. 0. X. the faster, higher-cost ammonia dynamite used in the smaller blasts. It was not considered practical to attempt to displace the low-cost black powder with L. 0. X., as estimated costs showed no probable saving if this were accomplished. Since it was desirable to continue shooting relatively large blasts for effective operation, it was recognized that larger storage facilities than had been in use would be needed for the liquid oxygen. Because of the difficulty of transporting and discharging large storage containers of efficient design, the better plan appeared to be storage and discharge of the liquid at the place of manufacture, and transportation of the filled soaking boxes to the blast.

Jan 1, 1928

By H. C. Schultz

CERTAIN local conditions were known to govern in large measure the successful adaptation of liquid-oxygen explosives to the large-scale blasting at Chuquicamata. The wide variation in hardness of the rock at this mine makes necessary the use of several types of explosives. A locally manufactured, relatively cheap black powder is used in blasting the softer waste and capping material, where a thorough displacement breaks the ground sufficiently. Before the introduction of L. 0. X., an ammonia dynamite of about 65 per cent. strength was being used exclusively in the harder underlying orebody, where a strong disruptive as well as a displacement effect is required for breaking the ore. The L. 0. X., as developed for quarry work in the United States, has a practically pure carbon cartridge material, and the explosive has an extremely high rate of detonation, which should therefore cause it to usefully develop its full disruptive effect in hard ground. The individual blasts at Chuquicamata are large, black-powder shots which dislodge masses of rock averaging 250,000 tons each, and dynamite shots which dislodge masses averaging 80,000 tons each. It was desirable, therefore, to attempt to displace with L. 0. X. the faster, higher-cost ammonia dynamite used in the smaller blasts. It was not considered practical to attempt to displace the low-cost black powder with L. 0. X., as estimated costs showed no probable saving if this were accomplished. Since it was desirable to continue shooting relatively large blasts for effective operation, it was recognized that larger storage facilities than had been in use would be needed for the liquid oxygen. Because of the difficulty of transporting and discharging large storage containers of efficient design, the better plan appeared to be storage and discharge of the liquid at the place of manufacture, and transportation of the filled soaking boxes to the blast.

Jan 1, 1928

By completing a double-track railroad cut-off, involving a large volume of cut and fill, in addition to a half-mile bridge spanning an important French river, engineers in the zone of the Services of Supply have opened up a route by means of which hours of valuable time are being saved in transporting men and materials to combat areas. Its most valuable feature is that it provides a means for by-passing a certain city where several, French railroad lines converge and where, consequently, congestion of traffic has been responsible for delayed train movements. To avoid a double-track turnout, which would have involved a cross-over cutting one of the French tracks, the two track connections of the cut-off are taken off from opposite sides of the French right-of-way. This involved running one of the new lines of the cut-off out from the main line track on a fill to a point where it could be brought back and over the French track on a steel girder bridge. Beyond this bridge the two tracks of the cut-off converge and straighten out in the standard type of double-track construction. The new cut-off is about 5 3/4 mi. (9 km.) long and has required 160,000 cu. yd. of cut (122,329 cu. m.) and 414,000 cu. yd. (316,527 cu. m.) of fill. In the biggest continuous fill a-yardage of 180,000 has been placed; the road-bed in this section-being-about 40-ft. (12 m.) above the original ground surface. The bridge portion of the cut-off, 2190 ft. (667.5 in.) long, is made up of ninety-nine 14-ft. (4.3 m.) timber spans and sixteen 50-ft. (15.3 m.) steel girder spans. This is the longest bridge which engineers of the American Expeditionary Forces have built in France. The timber spans are supported by pile trestle bents, while the longer steel girders rest on clusters of 43 piles. Two pile drivers of the steam-hammer type worked from each -end of the bridge toward the center of the river, while a drop hammer worked westward from the shore end. In this structure nearly two thousand piles 50 ft. or so in length had to be driven.

Jan 12, 1918

By J. D. Price, W. M. Bertholf

W. J. PARTON*—I have not had the opportunity to read this paper, and I do not have a written discussion. However, I thought it might be interesting for me to relate some of the experiences we had with equipment similar to the vibrating filter as described by the' authors. At the Tamaqua flotation plant of the Lebigh Navigation Coal Co. approximately 40 tons per hour of froth concentrate carrying 60 pct by weight moisture are produced. The major problem encountered at this plant is the dewatering of this coal froth so that a satisfactory product can be sent to market. In the original design of the plant a centrifuge of solid bowl type was included for de-watering this material. The centrifuge did not work out as well as we had hoped. High maintenance costs and moisture content in the cake were obtained. A Robbins dewatering screen was installed at a later date with the idea of using it in conjunction with the centrifuge. The froth concentrate from the flotation cells was fed directly to the Robbins dewatering screen. The cake from the screen carried approximately 55 pct of the feed solids. Moisture in the cake was approximately 24 pct by weight. The underflow from the screen carried 45 pct of the feed tonnage at about 80 pct moisture by weight. The underflow product was then pumped into the centrifuge with the idea of using the cen-trifuge for recovering the tonnage lost through the screen. This circuit did not operate as satisfactorily as we expected. The only benefit derived was in the reduction in the power consumed by the centrifuge. The maintenance on the centrifuge was approximately the same as previously. The next step in our experiments was to pump the underflow from the screen into a cyclone thickener which was mounted directly over the vibrating screen. This thickener increased the concentration of the solids to approximately 60 pct by weight and dropped the mate- rial back 011 the filter cake which had formed toward the discharge end of the screen. Unfortunately, the screen was not capable of handling this additional tonnage, and our experiments stopped at that point. We have been considering installing a second screen to make possible the complete mechanical dewatering of this product by the use of the dewatering screen and the cyclone thickener. Another possibility under study is to pump the underflow from this screen to a thickener which is available in the flotation plant, and to combine this thickeued underflow with the original feed going to the screen. Again, however, a second dewatering screen will be required to handle the total tonnage. 0. R. LYONS*—I had an opportunity to read this paper ahead of the meeting, and I did a little pencil engineering on it. As Mr. Bertholf said, it is very difficult to make a comparison and to carry the results of work at one plant over to what might be expected at another. What I did was to find information on filtering operations more or less comparable to the type of operation that Mr. Bertholf has with his vibrating filter. The only information that I was able to find was for drum type filters, and I found the operating characteristics of the vibrating filter and the drum type filters were very similar. The moisture contents of the cakes were almost identical. The output per square foot was about the only way that I could compare their capacities— using square foot of screen area against square foot of filter area—and I found the capacity of the vibrating filter to be slightly greater per unit area than the capacity of the drum-type filters. W. H. NEWTON†—Do I understand that the only escape for the solids is by overflowing the thickener? That is, does the filter have a chance to recover all the solids except that lost in the thickener overflow ? W. M. BERTHOLF (authors' reply)— Actually, the only escapc from that part of the circuit is over the top of the thickener. There are other places the fines could be lost in the washery. but once they get into that part of the circuit, they must go over the top to escape. W. H. NEWTON—I would like to ask Mr. Lyons if, in the study of rotary filters, he has any basis for comparison of operating costs? 0. R. LYONS—No, I had no information on costs. The only information I was able to find was on screen size, moisture content, and tonnage output per unit area. W. L. McMORRIS*—Are you wasting that overflow water or re-using it? W. M. BERTHOLF—Right now, we are not re-using it. D. R. MITCHELL† —What is the approximate per capita cost of one of these units? W. M. BERTHOLF—It appears to be somewhere in the neighborhood of $200, for the screen. W. H. NEWTON—The cost would be about $2500 for the complete unit including the vibrating power unit. G. A. VISSAC‡—I do not like to come on the floor after I have been talking so long, but I thought you might be interested in our experience in dewatering, as well as drying our very fine coals. We have used both centrifuge and vibrating screens. The type of vibrating screens we have used in Canada are called the Zimmer. That is a screen of German construction, and I guess it is along the same lines as the dewatering screens you are using now. We use wedge wires, and the minimum size opening is a quarter of a millimeter. In our experience, the cheapest way is still a dewatering bin. A dewatering bin takes 48 hr to do work that takes 20 min in a dewatering screen. We use old wedge wire from our driers which we cover with brattice cloth, and

Jan 1, 1950

By J. W. Downey, M. V. Nevitt

The phase boundaries for the 950" isothermal sections in the ternary systems Zr-Co-0 and `Zr-Ni-0 have been determined for the composition range from 50 to 100 at. pct Zr. The two systems show very similar phase relations, having no extensive solid solution phase fields. Each contains a ternary phase. These phases are apparently isostructural, but their structure has not been determined. Some aspects of the phase relations are discussed in terms of the alloying behavior of transition metals. THE work described in this paper is the outgrowth of a recent study of the occurrence of phases having the Ti2Ni-type structure (structure-type E9,) in certain ternary systems involving Ti, Zr, or Hf with another transition metal and O.", In the Zr-CO-0 and Zr-Ni-0 systems no Ti2Ni-type phases were found to occur. However, there are several interesting aspects of the phase relations in the two systems which have significance from the point of view of the alloying behavior of transition metals. The results of this investigation may also have some importance in studies of the oxidation of Zr-Co and Zr-Ni alloys. In both the Zr-Co-0 and Zr-Ni-0 systems only the 950" isothermal sections were investigated and, as a further restriction, the study was limited to the composition range from 50 to 100 at. pct Zr. A tentative Zr-Co binary diagram has been published by Larsen, Williams, and Pehin. In the composition range pertinent to the present work they report a eutectic at 980°C and 75.9 at. pct Zr, the products of which are the terminal solid solution based on /3 Zr and the compound Zr2Co, and a eutectic at 1080" and 64.8 at. pct Zr whose products are Zr,Co and ZrCo. The solid solution based on /3 Zr is shown to decompose eutectoidally at 826°C into a Zr and Zr2Co. The limits of solubility of Co in a and /3 Zr have not been established. The structure of Zr2Co is not identified in the publication just cited. Dwight has reported that ZrCo has the CsC1-type strcture. The Zr-rich portion of the Zr-Ni diagram has been determined by Hayes, Roberson, and Paasche." The phase relations are very similar to those of the ZrCo system. A eutectic reaction whose products are /3 Zr containing 2.9 at. pct Ni and Zr,Ni occurs at 961°c, and a eutectic between Zr,Ni and ZrNi is found at 985". The solid solution based on /3 Zr decomposes eutectoidally at 808°C. The solubility of Ni in a Zr is not known accurately but is believed to be very small. Smith, Kirkpatrick, Bailey, and Williams7 have found that Zr2Ni has a tetragonal structure of the A1,Cu-type and that ZrNi is orthorhombic. Domagala and McPherson8 have published a constitution diagram for the system Zr-ZrO,. At 950" their diagram indicates that the solid solution of 0 in 0 Zr is stable from 0 to 0.5 at. pct while the phase field of 0 in a Zr extends from 6 to 29 at. pct. These solubility limits were adopted in the present study and no binary Zr-0 alloys were made. No previous data on the phase diagrams of the ternary systems are known to exist. EXPERIMENTAL PROCEDURE The experimental details involved in the preparation of alloys in this laboratory by arc melting have been described in several previous papers"3 and they will not be repeated here. Information concerning the purity of the metals used is given in Table I. Oxygen was added in the form of reagent grade ZrO,. All of the cast specimens in both alloy systems were annealed in air-atmosphere tube furnaces at 950 3' for 72 hr and water quenched. The specimens were protected from oxidation by wrapping them in Mo foil and sealing them in quartz tubes that had been evacuated at room temperature to a pressure of 1 x 10B mm of Hg. The phase boundaries were determined by metallography, and identification of the phases was accomplished primarily by X-ray diffraction methods which employed a powder camera having a diameter of 114.6 mm. The diffraction techniques which are in use in this laboratory have been previously described.' An etchant that proved satisfactory for most of the alloys consisted of 5 pct by vol of AgNO

Jan 1, 1962

By C. D. Woodward

PRIOR to 1902, the tramming of ore from the stopes to the shafts, in the Butte mines, was done by man or animal power, but the demand for greater tonnage and the need for more improved methods of tramming the ore resulted in the installation of the compressed-air locomotive in a few mines. Some of the objections to animal haulage were thus eliminated, but this locomotive was not generally adopted, because of a number of limiting features. It was superseded by the electric trolley locomotive. The early types of trolley locomotives were not satisfactory from the operators' viewpoint, but. they had many economic advantages and after a number of years, in which improvements were constantly made in the structural details, they became dependable, so that the use of animals for main haulage in the mines has now been practically abandoned. There are now operating in the Butte mines of the Anaconda Copper Mining Co., 185 trolley-type locomotives, each of which has replaced five animals. It cost approximately $50 per month to keep an animal, hence the economies that resulted fully justified the expenditure of electrifying the haulage systems. The haulage conditions in this company's mines possess many advantageous features that are not always found in underground mine workings. The drifts and crosscuts are large, approximately 5 ft. (1.5 m.) wide by 7 ½ ft. (2.3 m.) high, and have curves of no less than 18 ft. (5.5 m.) radius; and the roadbeds of the drifts and crosscuts have a uniform grade of 0.5 per cent. toward the shaft, or in favor of the loaded trips. In all of the mines, except two, the track gage is 18 in. (45.7 cm.), and all tracks in the main haulageways are laid with 25-lb. (11.3 kg.) rails. The stations at the shaft are large, well-lighted, clean, and cool. The average temperature of ,the stations, however, is about 75° F. (24° C.), while the average temperature in some of the drifts and crosscuts is 92° F. (33.5° C.).

Jan 2, 1922

By Alan Morris

In a previous paper1 the results of cutting tests on free-cutting brass rod were reported. Investigation was made of the effects of variation in lead content, microstructure and cold drawing. The author's reply to the discussion of that paper includes a study of the directional cutting properties of drawn and annealed rod. The present paper records the results of tests made on series of samples in which the tin, iron and copper contents have been varied. The apparatus used and method of testing are described in detail in the previous paper. The machine is of the pendulum-operated milling type used and described by Airey and Oxford.2 Angular readings of the height to which the pendulum rises after falling from a fixed position, both when a cut is made and when the pendulum swings freely, give the basis for calculation of the energy consumed in making a cut. Careful weighing of the sample before and after cutting gives a measure of the amount of metal removed. The results are expressed in footpoiinds per cubic inch of metal removed, and have been called "unit cutting energy." In the course of the discussion of the author's earlier paper, W. B. Price reported large-scale tests involving some 50,000 lb. of material. These tests indicated that the addition of as much as 0.6 per cent of iron and 0.25 per cent of tin had apparently no adverse effect on the highspeed cutting characteristics of the rod. The rod also contained a small amount of nickel. The test results reported here tend to confirm his observations. Effect of Variation in Tin Content The castings for this series were made 2 by 1 by 9 in. and were processed as follows: 1. Castings were annealed at 500" C. for 7 hr. 2. Cold-rolled to 0.700 in.

Jan 1, 1933

By H. Herbert Hughes

ECONOMISTS have predicted that the present business depression ultimately may pay big dividends to industry through the cumulative savings resulting from technical improvements and merchandising advances that might never have been developed under normal conditions. Waste prevention is a sound medicine for economic ills. In theory, this prescription may be applied not' only to raw materials, but also to labor, fuel, over- head, and other phases of production. Actually, how- ever, regardless of the efficiency of operating practices, waste is inevitable in the production of many commodities. The problem then becomes one of profitable utilization of waste rather than prevention.

Jan 1, 1932

The Library of the above-named Societies is open from 9 A.M. to 9 P.M. on all week-days, except holidays, from September 1 to June 30, and from 9 A.M. to 6 P.M. during July and August. The Library contains about 55,000 volumes, including sets of technical periodicals and the publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library can render valuable service through correspondence; letters requesting information will receive special attention. The Library is prepared to furbish references and copies of articles on mining and metallurgical subjects; to determine the existence of mining-maps, and to furnish general information as to the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape. The members of the Institute can be of service to the Library by forwarding copies of mining-reports, maps privately issued, and similar material, which will be classified, indexed, and made available to other members. Suggestions for additions to the Library, either by purchase or personal solicitation as gifts, will be welcomed. It is hoped that members while in the city will use the Library freely, and assurance is given that most careful service will be rendered to them.

Jan 10, 1913

By T. S. Fuller

THE work of D. J. McAdam1,2 at the U. S. Naval Engineering Experiment Station, Annapolis, Md., on what has been called by him "corrosion fatigue" has focussed the attention of the engineering profession in general, and of those interested especially in the study of corrosion in particular, on the importance of making tests which will indicate as nearly as possible what can be expected from a given material in service. Pitting is unquestionably the chief agent operating so tremendously to reduce fatigue limits, but in the light of previous work3, 4, 5, 6, 7, 8 it is fair to assume that absorbed hydrogen resulting from the action of the corroding medium upon steel may, under certain conditions, have a perceptible influence. The experiments described in this paper deal more precisely with stressless corrosion, or "prior-corrosion fatigue, "9 and have been carried out to test such an assumption, to segregate, if possible, the effect of pitting from that of absorbed hydrogen, and although very preliminary in nature they indicate results which are striking.

Jan 1, 1929

By Horace R. Graham

CHEMICAL nitrogen and the "nitrates" of commercial significance are derived mainly from three basic sources: (1) the natural deposits in the form of nitrate-bearing earth and clay, which, being largely water-soluble, can exist only in the most arid portions of the earth; (2) coal, which yields not only nitrogen but also the additional by-product hydrogen required for the synthesis of ammonia and its compounds; (3) the atmospheric air, which contains 75.5 pct by weight of pure nitrogen gas. NATURAL NITRATE DEPOSITS Occurrence Although natural nitrate deposits consisting principally of the salts of sodium and potassium have been reported in Egypt, South Africa, Mexico, Argentina, Colombia, Peru and the USA, the only known natural nitrate resources of commercial importance are the vast deposits found in the Atacama, Tarapaca and Antofagasta regions of northern Chile, lying in a narrow strip 10 to 50 miles wide and roughly 450 miles long, between latitudes [19O] and [26OS]. In addition to yielding nitrates of sodium and potassium, these deposits are the source of the major portion of the world's supply of iodine. The nitrate-bearing ores known in Chile as caliche are variable in composition and may contain from 5 to 30 pct each of nitrate, chloride and sulphate. While the deposits are present chiefly in the form of the sodium salt, potassium, magnesium and calcium also occur in percent- ages from 0.1 to 5; usually as double salts with sulphate, which are but slightly soluble in nitrate leach solutions. These double salts are bloedite(Na2S04.MgS04.4H,0), glauberite (Na2S04.CaS04), polyhalite (K2SO4.- MgS04.2CaS04.2H20). Some deposits contain up to30 pct of their ni-

Jan 1, 1949

By R. W. Fountain, John Chipman

The solubility of nitrogen in Fe-B alloys (0.001 to 0.91 pet B) is determined by the Sieverts' technique for temperatures of 950° to 1150°C. The activity coefficient of nitrogen is decreased by boron. The three-phase equilibrium between ? iron, BN, and gas is established and also the four-phase equilibrium between iron, BN, Fe2B, and gas. The above equilibria are calculated for a iron. The relation of these data to hardenability and strain aging of boron-treated steels is discussed. BORON additions are known to enhanbe the hardenability of heat-treatable steels and to assist in the control of strain aging in sheet steel for deep drawing. The increase in hardenability is explained by the theory that adsorption of boron on austenite grain boundaries reduces their free energy and thus retards ferrite and upper bainite nucleation.l,2 Digges and Reinhart3 have shown that the full effectiveness of boron in commercial steels is achieved only when strong nitride formers such as titanium and zirconium are also present. The influence of nitrogen on eliminating the boron contribution to hardenability was also demonstrated by Shyne and Morgan.4 These workers prepared Ni-Mo steels containing either nitrogen or boron or nitrogen plus boron. The nitrogen-plus-boron steels showed the lowest hardenability which was attributed to the presence of stable nucleating particles, presumably nitride. Morgan and Shyne5-7 have shown that boron in the amount of 0.007 pet will completely eliminate strain aging due to nitrogen in low-carbon, open-hearth steels. In addition, by proper control of the boron additions, a rimming steel can be produced. Since the effectiveness of boron on hardenability and eliminating strain aging is influenced by the amount and distribution of the nitrogen in the steel, the present study was. undertaken to determine the influence of boron on the solubility of nitrogen in iron. EXPERIMENTAL PROCEDURE The solubility of nitrogen in Fe-B alloys was measured by the method of Sieverts, which consists of determining the amount of gas dissolved by the metal in a constant volume system. The apparatus employed in this investigation and the experimental details have beendescribed previously.B AMcLeodgage was added to the apparatus to allow measurements at very low pressures. The alloys were melted at reduced pressure in a basic-lined induction furnace using electrolytic iron and ferroboron. Ferroboron was added after the primary deoxidation of the iron with carbon. Since it was difficult to attain a constant low level of oxygen by this procedure, silicon was added after the carbon deoxidation and prior to the ferr obor on addition. The alloys were castas 2-in. sq ingots, heated in argon at 1050loC, and forged to 1/4-in. plate. After forging, 1116 in. was machined from each side of the plate to remove any possible contamination, and it was then cold-rolled to 0.010-in. sheet. The sheet was cut into approximately 1/4-in. squares and pickled in an inhibited H2SO4 solution to ensure a clean surface. In the case of the boron alloys, a hydrogen treatment could not be used for surface cleaning because boron losses resulted. The composition of the alloys is given in Table I. For a solubility determination, a 75-g sample was inserted in a quartz tube and sealed in place in the apparatus. The entire system was evacuated at room temperature and leak tested for 24 hr. If no leaks were observed, the system was heated to the temperature of measurement and again leak tested for 24 hr. If no leaks were detected, the hot volume and solubility determinations were begun. The hot volume was determined at a constant temperature for each run by admitting successive amounts of argon and recording pressure vs volume, which, in all cases, resulted in a straightline relationship. The argon was then removed and the procedure repeated with nitrogen. Successive additions were made until the desired nitrogen content of the metal and equilibrium pressure of the system were obtained. The

Jan 1, 1962

The Library of the above-named Societies is open from 9 A.M. to 9 P.M. on all week-clays, except holidays, from September 1 to June 30, and from 9 A.M. to 6 P.M. during July and August. The Library contains about 55,000 volumes, including sets of technical periodicals and the publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library can render valuable service through correspondence; letters requesting information will receive special attention. The Library is prepared to furnish references and copies of articles on mining and metallurgical subjects; to determine the existence of mining-maps, and to furnish general information as to the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape. The members of the Institute can be of service to the Library by forwarding copies of mining-reports, maps privately issued, and similar material, which will be classified, indexed, and made available to other members. Suggestions for additions to the Library, either by purchase or personal solicitation as gifts, will be welcomed. It is hoped that members while in the city will use the Library freely, and assurance is, given that most careful service will be rendered to them.

Jan 9, 1913

By T. S. Fuller

The work of D. J. McAdam, Jr.1,2 at the U. S. Naval Engineering Experiment Station, Annapolis, Md., on what has been called by him "corrosion-fatigue" has focussed the attention of the engineering profession in general, and of those interested especially in the study of corrosion in particular, on the importance of making tests which will indicate as nearly as possible what can be expected from a given material in service. Pitting is unquestionably the chief agent operating so tremendously to reduce fatigue limits, but in the light of previous work3, 4, 5, 6, 7, 8 it is fair to assume that absorbed hydrogen resulting from the action of the corroding medium upon steel may, under certain conditions, have a perceptible influence. The experiments described in this paper deal more precisely with stressless corrosion, or "prior-corrosion fatigue,"9 and have been carried out to test such an assumption, to segregate, if possible, the effect of pitting from that of absorbed hydrogen, and although very preliminary in nature they indicate results which are striking.

Jan 1, 1929

By T. S. Fuller

The work of D. J. McAdam, Jr.1,2 at the U. S. Naval Engineering Experiment Station, Annapolis, Md., on what has been called by him "corrosion-fatigue" has focussed the attention of the engineering profession in general, and of those interested especially in the study of corrosion in particular, on the importance of making tests which will indicate as nearly as possible what can be expected from a given material in service. Pitting is unquestionably the chief agent operating so tremendously to reduce fatigue limits, but in the light of previous work3, 4, 5, 6, 7, 8 it is fair to assume that absorbed hydrogen resulting from the action of the corroding medium upon steel may, under certain conditions, have a perceptible influence. The experiments described in this paper deal more precisely with stressless corrosion, or "prior-corrosion fatigue,"9 and have been carried out to test such an assumption, to segregate, if possible, the effect of pitting from that of absorbed hydrogen, and although very preliminary in nature they indicate results which are striking.

Jan 1, 1929