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By L. D. Godshall

The extreme difficulty of obtaining a short and, at the same time, exact method for the determination of gold and silver in copper-materials has been well illustrated in "Assays of Copper and Copper-Matte," and its discussion, by Dr. A. R. Ledoux and other leading authorities on this subject.* Two general methods were used by the numerous assayers who took part in the symposium initiated by Dr. Ledoux, and whose results are given in the paper and discussion. One of these is the dry or fire-method, consisting of scorification and cupellation, the former being repeated if the percentage of copper is very high, all slags and cupels being assayed and the results so obtained added to the ordinary assay; and the copper retained by the silver buttons being determined and deducted from the combined weight of the buttons obtained from the assay of the original material, the scorification-slag, and the cupel. The other is the wet or combination-method, which, while not involving so much work, requires a longer time. Briefly, it is as follows : The material to be assayed is dissolved in nitric acid, the solution is diluted, and the fine undissolved gold is collected by means of sulphate of lead, formed by the addition of lend acetate and sulphuric acid to the solution, After standing from 12 to 24 hours, the precipitate is filtered off, and the silver in the filtrate is precipitated as a chloride or bromide, and collected by means of sulphate or bromide of lead. The solution containing this precipitate in suspension is again allowed to stand until the precipitate has settled. It is then filtered; both precipitates, containing the gold and silver, are dried, ignited and scorified, either separately or together, and the result is cupelled in the usual way.

Jan 1, 1901

By H. L. Luo, W. Klement

By rapidly quenching Ag-Pt alloys from the melt, a continuous series of solid solutions has been obtained. At equilibrium''2 these fcc elements form a peritectic system, Fig. 1. Weighed amounts of silver and platinum powder (325 mesh, purity greater than 99.9 pct) were mixed for 24 to 120 hr, pressed into compacts, sintered at 1000°C in a hydrogen atmosphere for at least 16 hr, and then furnace-cooled. Because of the difficulty in achieving homogeneity in alloys containing more than about 40 at. pct Pt, the sintered compacts were induction-melted under hydrogen in alumina crucibles and then cold-rolled into wires. Small amounts ("30 mg) of alloys cut from various sections of the sintered compacts or rolled wires were heated to at least 50' ~ above the liquidus in an alumina insert held within an induction-heated graphite crucible; then the molten alloy was ejected by a blast of helium onto a lightly polished copper strip held on the inner periphery of a rotating wheel. The flakes thus obtained were typically 1 sq mm in area or often slightly larger for the silver-rich alloys. X-ray diffraction patterns were obtained with nickel-filtered copper K radiation in a 114.6-mm-diam Debye-Scherrer camera with rotated specimens. Lattice parameters and associated uncertainties were estimated from extrapolations against the Nelson-Riley function. High-angle lines were always resolved and spacings were computed relative to r(CuKa!,) = 1.540508 The details of these techniques have been discussed previously.s'6 Lattice parameters of the solid solutions are plotted in Fig. 2, together with the data of Schneider and Esch,' Johansson and Linde,' and Novikova and pudnitskii. Each of the present lattice spacings represents two or more independent determinations. The alloys were homogeneous within 2 at. pct of nominal composition as estimated from the uncertainties in the lattice spacings. Many of the mechanisms involved in the achievement of metastable solid solutions by rapidly quenching from the melt have been previously discussed. There is some evidence" that such solid solubility cannot be obtained when the liquid alloys are cooled

Jan 1, 1963

By W. G. Wender

The North Central Texas district, as known to the oil fraternity, is the area producing from sands and limes of Pennsylvanian age, roughly embracing the territory lying between Fort Worth and Abilene in an east-west line, and between the Red River and the Llano Mountains in a north-south line. The history of oil development in North Central Texas during the year 1927 is briefly reviewed in the following paragraphs. Brown County New discoveries and development in Brown County centered mainly around the Fry pool, located in the west central portion of the county. Important discoveries for the year were: Shoupe No. 1 John Byler, discovery well of the Byler pool, located 2 miles south of the Fry pool which camc in early in February, 1927, at 1262 ft. for 90 bbl. in the Fry sand of upper Strawn (Pennsylvanian) age. Rosenfield No. 1 P. Davis, discovery well of the Smith-Ellis pool located 1 1/2 miles northeast of the Fry pool, came in March 7, in the Fry sand from 1277 to 1279 ft. for 30 bbl. initial. Pandem Oil Corpn. No. 1 Mrs. T. Hutton, located 1 mile east of the Smith-Ellis pool, came in in December in the Fry sand from 1119 to 1130 ft. for 45 barrels. The Fry pool passed its daily production peak of 25,000 bbl. during the first part of June, and declined to a daily production of 5100 hhl. by the close of the year. The oil recovery from the Fry pool up to Jan. 1, 1928, slightly exceeded 4,000,000 bbl., averaging 4700 bbl. to the acre. over the entire pool. The Smith-Ellis pool passed its daily production peak of 5300 bbl. in Octohcr, 1927, and dropped to 3600 bbl. by the close of the year. The possibilities of the Byler pool will be unknown until the area is fully drilled up. In the Blake pool, production passed 2,500,-000 bbl. for the year. The per acre recovery in this pool up to lkc. 31, averaged slightly over 5000 barrels.

Jan 1, 1928

By John Mathews

DURING the prosecution of the aircraft-production program in 1917 and 1918, the writer visited many plants engaged in the manufacture of motors, planes and parts, in carrying out his duties as chairman of the Committee on Aircraft-engine Forgings. On several occasions, when the question of expansion was discussed, it was noted that there was confusion in the use of the terms: the true coefficient of expansion, a physical constant, and distortion in hardening. One engineer, referring to a steel shown in the accompanying table; stated that he could not consider it for crankshafts because of its excessive coefficient of expansion, while another steel, also listed in the table, as said to be especially good because it had no coefficient of expansion, since it came out of the oil bath perfectly straight. Many years ago one of our employees designed anew oil furnace; when asked what became of the products of combustion, he replied: "There ain't any, we burn them all up." While the coefficient of expansion is not without its effect in volume changes in hardened steel, it is not a determining factor in the matter of distortion and going out of shape. Irregular heating, uneven furnace bottoms, and carelessness in withdrawing the part from the furnace, as well as the manner in which the part enters the quenching bath are of greater moment. Generally speaking, also, steels of relatively low hardening temperature will distort less than those requiring higher hardening heats. The coefficient of expansion must be considered in engineering design most frequently when different metals or alloys are used in the same construction. For example, the difference of expansion between a steel crankshaft and an aluminum crank-case might be of real importance and a steel with no coefficient of expansion would be much less desirable than one with the normal coefficient. About 15 years ago, the writer made many determinations of the coefficient of expansion at low temperature ranges, usually between 20° and 100° C. Among the materials tested were: Pure forged electrolytic iron, 11.73 parts per million for 1° C.; cast aluminum (99.93 per cent. Al.),

Jan 2, 1920

By M. S. King

A series of cross-hole acoustic measurements have been performed in a columnar-jointed basaltic rock mass around an underground opening mined by the drill-and-blast method. The purposes of the test program were: to evaluate the rock mass characteristics around the opening; to determine the zone of blast damage; and to evaluate seismic methods for anomaly detection ahead of mining in this type of rock. The cross-hole measurements were made between four 76-mm diameter horizon- tal boreholes diamond-drilled 12 m into a wall of the underground opening. Repetitive pulses of compressional (P) and shear (S) waves of frequencies in the range 3 kHz-100 kHz were propagated from a transmitter sonde through the rock mass to a receiver sonde, both of which were clamped hydraulically to the borehole wall. After amplification the received P- and S-wave signals were digitized at the surface by a digital oscilloscope and stored on floppy discs. The results indicate considerable reductions in P- and S-wave velocities at distances less than 2 m from the face. Clearly these low values are associated with blast damage. Beyond 2 m, the velocities in a vertical direction indicate almost constant values. The velocities in the horizontal direction beyond 2 m appeared erratic, but showed a general tendency to increase as a function of distance from the face. Their maximum values remained, however, still lower in value than the corresponding velocities in the vertical direction. Near the face, the differences in velocities were considerably greater: with horizontal velocities considerably lower in value than those vertical. Results of the spectral analyses of the received signals indicated that Q-values were strongly influenced by the vertically- oriented sets of joints. Only for waves travelling in the vertical direction was the effect observed of the blast-damaged zone immediately around the opening. The acoustic data obtained are clearly indicative of an anisotropic jointed rock mass, with a greater intensity of jointing for travel paths in the horizontal than the vertical direction. The vertical, columnar joints are probably less tightly closed than those oriented in the horizontal plane.

Jan 1, 1984

By Paul Bechtner

THE name bentonite formerly was applied solely to a peculiar clay occurring in Wyoming and South Dakota, which was distinguished from other clays by its unctuous feel when wet and the property of swelling in water. In the last decade scientific studies of clay have recognized that bentonite is composed mainly of the clay mineral montmorillonite and the name bentonite has been extended to cover the entire family of clays that have montmorillonite as their chief constituent. Montmorillonite has the chemical formula of A1203-4Si0-xH2O, With Fe203 and MgO replacing part of the A1203. The montmorillonite crystal is an Si-Al-Si clay mineral, being formed of two silicon-oxygen sheets with an aluminum-oxygen sheet sandwiched between them. In contrast, kaolinite-the chief clay mineral of most clays other than bentonite-is Si-Al, one silica and one alumina sheet. The unit crystal of montmorillonite is much thinner than that of kaolinite, with greater surface area. These differences in crystal structure patterns are leading factors in the dissimilar properties and commercial uses of bentonite compared with other clays. Mineralogically, bentonites are 85 to 90 pct montmorillonite with fragments of feldspar, gypsum, calcium carbonate, quartz and traces of other minerals. They vary in color; the widely used Wyoming type is creamy white when dry and a light shade of tan when wet; the low-swelling bentonites of the southern United States and elsewhere are found in many shades of gray, blue, yellow, red, and brown. Pure white bentonites are rarer and generally of the medium or low-swelling type, though there are a few exceptions to that general rule. PROPERTIES Bentonites may be divided into two general classes: (1) those that adsorb large quantities of water, "swelling" greatly in the process, and that remain in suspension in thin water dispersions; (2) those that adsorb only slightly more water than ordinary plastic clays or fuller's earths, do not swell noticeably, and settle rapidly in thin water dispersions. Another distinction is that some varieties of the No. 2 type

Jan 1, 1949

EDUCATION for the mineral industry was at first a single comprehensive curriculum, but it was early recognized that the main basis of mining is physics, while that of metallurgy is chemistry. The first school to offer curricula leading to degrees in mineral industry education in the United States (1853) had separate ones in mining and metallurgy. The Columbia School of Mines (the fist really successful one) had only a single curriculum when it opened in 1864, but within a few years had so reorganized its work that it offered curricula in mining, metallurgy, geology, chemistry, and civil engineering. Interest in the metallurgy or geology curricula was slight at fist, and for the next 30 years the great majority of Columbia students took the mining curriculum, probably partly because it contained nearly as much geology as the geology curriculum, practically all the metallurgy, and most of the chemistry, and partly because of the degree awarded for it. Other schools kept their mining curricula equally broad, and as late as 1900-1910 men were graduating as mining engineers who were practically as well prepared to make geology or metallurgy their life work as they were for mining. Gradually, however, the subject matter of mining geology and metallurgy became so enriched through research and development that separate curricula in them became worth while; their progressive development is the subject of another chapter. Mining curricula also began to be somewhat diversified, and schools in areas where coal mining was of outstanding importance began to offer options in coal mining, the earlier curricula having been chiefly aimed at metal mining. The petroleum industry began its meteoric rise about the same time as mineral instruction in this country, but little more of applied science attended its birth than had attended such ancient practical arts as copper and iron

Jan 1, 1941

By J. J. Bodmer

The four different modes, more or less practiced for subdividing slag (that is, producing slag sand), are the following: 1. Crushing the slag from the lump in Blake's crusher, by edge runners or other suitable means. 2. Blowing water, steam, cold or hot air, into the stream of viscous slag whilst it runs from the furnace. So treated, the slag takes

THE Annual Fall Meeting held in Chicago in conjunction with the celebration of a Centennial of Engineering brought forth a round of field trips and symposiums which did much to add to the store of information of the 240 who registered for the gathering. Instead of a scattered program, technical papers were grouped together in organized symposiums, where the particular importance of each report was enhanced by presentation in context. Despite the heavy accent on technical papers and informative field trips, those attending the meeting had ample time to enjoy the benefits of a visit to Chicago. The AIME dinner dance was held at the Palmer House, in the Red Lacquer Room. The Chicago Section played host Friday evening at dinner. The MBD held four sessions at the meeting headquarters, the Palmer House, September 4 and 5. Featuring the meetings was a review of taconite concentration and new theories on comminution. The first session opened with a paper on the Structural Features Which Effect the Concentration of Iron Formations, presented by F. J. Tolonen. The paper was centered upon the various members of the low grade iron formations of the separate Michigan districts. The study correlated macrostructure, microstructure, and concentration tests. [ ] Beneficiation Characteristics of Michigan Low Grade Iron Ores, presented by F. X. Tartaron, cochairman of the session, reviewed the work of his laboratory on the beneficiation of low grade ore taken from various strata of a deep shaft on the Marquette Range. The paper included data on flotation, gravity separation, magnetic separation, and combinations of these processes. The economics of low grade ore treatment generated great interest. Ty. Maki offered a compilation and correlation of field results with magnetic separators in ferrosilicon and magnetite medium recovery circuits. Following the morning session, 130 persons attended a luncheon, followed by a brief business meeting. Later, a film illustrating the grinding, separation, and pelletizing steps investigated by the Mines Experiment Bureau, was presented by H. H. Wade. T. E. Ban, and L. J. Erck gave a report on pelletizing which evoked much discussion. R. A. Limons presented a paper on the Mineralogy of Blast Furnace Sinter, for its author, H. M. Kraner. Friday sessions featured a new hypothesis for high speed drill rod milling and a new technical approach to comminution. Jack Myers commented that Consolidated's large rod mill was a hammer mill turned inside out. Steve Erickson described the use of Cyclones for Heavy Media Concentration of Iron Ore Fines. Bob Meaders gave a Progress Report on the Aerofall Mill. Shiou-Chuan Sun described an improved high frequency analyzer for studying the conductivity of suspensions of various minerals. L. A. Roe discussed a magnetic reflux condensor which enabled him to determine the degree of liberation of magnetic iron ores. Roy A. Johnson described a function of the hydroscilator in which the fan rake was eliminated in favor of a conical bottom. The Industrial Minerals Division sessions held September 5 and 6 and were well attended. The Friday morning session was particularly concerned with developments and advances in industrial minerals with special emphasis on the Chicago area. The first two papers dealt with transportation on the Great Lakes and fuel movement into the Chicago area. The third paper proved to be of great interest, turning the spotlight on the fairly new hydraulic mining methods introduced by a silica company in the Ottawa, Ill. field.

Jan 1, 1952

Jan 1, 1930

By S. D. Michaelson, Eric Sinkinson

Many of the magnesite ores of the western part of the United States contain such large amounts of silica and hydrous silicate minerals that the value of the ores is either low or nominal. Expensive and carefully controlled mining methods are necessary to prevent excessive dilution of the higher grade ores by introduction in mining of small pieces of the hanging walls or footwalls of the deposit. This difficulty is further complicated by the various states of decomposition of the country rock of the deposits in which many of the ores occur. The problem the authors attempted to solve arose from a request to float an impure magnesite containing varying proportions of siliceous gangue with calcium carbonate. The ore is normally enclosed in serpentine masses, somewhat decomposed, and in mining it wall rock is incidentally added, so that variable amounts of siliceous material occur in the samples. The silica, alumina, and iron oxide are so closely associated with the magnesium carbonate in the magnesite that ordinary mechanical separation at coarse mesh sizes is of no avail. It is well known that calcium carbonate can be floated by suitable reagents, therefore it seemed reasonable to suppose that magnesium carbonate minerals would behave in a similar manner, but experimental trial proved that this supposition was unfounded. Therefore the first step in the problem was to find out what differences of behavior there were between magnesium and calcium carbonates under flotation conditions, or when suspended in water. In water at 18" C. magnesium carbonate is slightly more soluble than calcium carbonate; in fact, MgCO3 is soluble to the extent of 0.0106 grams in 100 c.c. of water at 18" C. and CaCO3 to the extent of 0.0013 grams. However, magnesium carbonate in water gradually changes to the basic carbonates of a composition (3MgCO3.Mg(OH)23H2O) or (4MgCO3.Mg(OH)25H2O), depending upon conditions, and calcium carbonate to calcium hydroxide, Ca(OH)2. The relative solubilities of these hydroxides in water are the reverse of the solubilities of magnesium and calcium carbonates. The range in published figures for solubility

Jan 1, 1938

By S. D. Michaelson, Eric Sinkinson

Many of the magnesite ores of the western part of the United States contain such large amounts of silica and hydrous silicate minerals that the value of the ores is either low or nominal. Expensive and carefully controlled mining methods are necessary to prevent excessive dilution of the higher grade ores by introduction in mining of small pieces of the hanging walls or footwalls of the deposit. This difficulty is further complicated by the various states of decomposition of the country rock of the deposits in which many of the ores occur. The problem the authors attempted to solve arose from a request to float an impure magnesite containing varying proportions of siliceous gangue with calcium carbonate. The ore is normally enclosed in serpentine masses, somewhat decomposed, and in mining it wall rock is incidentally added, so that variable amounts of siliceous material occur in the samples. The silica, alumina, and iron oxide are so closely associated with the magnesium carbonate in the magnesite that ordinary mechanical separation at coarse mesh sizes is of no avail. It is well known that calcium carbonate can be floated by suitable reagents, therefore it seemed reasonable to suppose that magnesium carbonate minerals would behave in a similar manner, but experimental trial proved that this supposition was unfounded. Therefore the first step in the problem was to find out what differences of behavior there were between magnesium and calcium carbonates under flotation conditions, or when suspended in water. In water at 18" C. magnesium carbonate is slightly more soluble than calcium carbonate; in fact, MgCO3 is soluble to the extent of 0.0106 grams in 100 c.c. of water at 18" C. and CaCO3 to the extent of 0.0013 grams. However, magnesium carbonate in water gradually changes to the basic carbonates of a composition (3MgCO3.Mg(OH)23H2O) or (4MgCO3.Mg(OH)25H2O), depending upon conditions, and calcium carbonate to calcium hydroxide, Ca(OH)2. The relative solubilities of these hydroxides in water are the reverse of the solubilities of magnesium and calcium carbonates. The range in published figures for solubility

Jan 1, 1938

By A. B. Kinzel

Advance in the art of slag control has been very rapid in the past few years. The viscosimeter method for slag-reaction rate and composition, together with the phosphorus and other methods mentioned by Dr. Herty, allow the steelmaker to rectify and control the slag in the finish period of the heat with much greater precision that ever before. However, the steelmaker's problem is more complex, and in order to make steel of proper analysis in the most economical manner the constitution of the initial slag that has formed immediately after the lime is up in the furnace is of prime importance, as it is one of the factors that determine the carbon content of the charge as melted. Many heats melt with high carbon and some with carbon much lower than is expected so that, on the average, increased furnace time is necessary before reaching the finishing period. The problem, therefore, is to so regulate the slag-making additions that a suitable initial slag will be formed at once. Where all cold metal charges are involved, particularly where the iron and scrap are selected, this may be done with a fair degree of regularity. This regularity results not only in better conditions at the beginning of the heat and during the carbon drop, but also the need for smaller slag-modifying additions toward the end of the heat. The above has been well demonstrated by the work reported by Reagan in the past few years. Where large amounts of cold pig or hot metal are used, the problem becomes more involved. It is much more difficult for the steelmaker to be sure that for any given furnace the heat will form the desired initial slag. Observations of many heats indicate that the pig iron is a dominating factor in the constitution of the slag formed. The scrap is also a factor but in general could be roughly classified and a correction made therefor. The necessity, therefore, arises for a method of correlating the pig-iron charge and type of slag formed for any particular furnace, which resolves itself into a measure of those qualities of the pig iron which affect the slag. The amount of silicon, manganese, phosphorus and sulfur in the pig iron will probably have some effect on the type of slag formed, but

Jan 1, 1935

By A. B. Kinzel

Advance in the art of slag control has been very rapid in the past few years. The viscosimeter method for slag-reaction rate and composition, together with the phosphorus and other methods mentioned by Dr. Herty, allow the steelmaker to rectify and control the slag in the finish period of the heat with much greater precision that ever before. However, the steelmaker's problem is more complex, and in order to make steel of proper analysis in the most economical manner the constitution of the initial slag that has formed immediately after the lime is up in the furnace is of prime importance, as it is one of the factors that determine the carbon content of the charge as melted. Many heats melt with high carbon and some with carbon much lower than is expected so that, on the average, increased furnace time is necessary before reaching the finishing period. The problem, therefore, is to so regulate the slag-making additions that a suitable initial slag will be formed at once. Where all cold metal charges are involved, particularly where the iron and scrap are selected, this may be done with a fair degree of regularity. This regularity results not only in better conditions at the beginning of the heat and during the carbon drop, but also the need for smaller slag-modifying additions toward the end of the heat. The above has been well demonstrated by the work reported by Reagan in the past few years. Where large amounts of cold pig or hot metal are used, the problem becomes more involved. It is much more difficult for the steelmaker to be sure that for any given furnace the heat will form the desired initial slag. Observations of many heats indicate that the pig iron is a dominating factor in the constitution of the slag formed. The scrap is also a factor but in general could be roughly classified and a correction made therefor. The necessity, therefore, arises for a method of correlating the pig-iron charge and type of slag formed for any particular furnace, which resolves itself into a measure of those qualities of the pig iron which affect the slag. The amount of silicon, manganese, phosphorus and sulfur in the pig iron will probably have some effect on the type of slag formed, but

Jan 1, 1935

DISCUSSION, G. Derge and D. J. Girardi presiding N. A. Gokcen (Michigan College of Mining and Technology, Houghton, Mich.)—While the authors present very interesting results on the effect of sulphur upon the solubility of oxygen, they have not established convincingly the lines of two-fold saturation (the valleys in Fig. 2) and the ternary eutectic point. Their contention that sample S-7, upon melting at

Jan 1, 1954

By F. W. DeVries

The subject article is an excellent comparison between two potential oxidants, molecular oxygen and hydrogen peroxide, as used in the Palangana field at the time of the trials. The tests showed no advantage to using hydrogen peroxide; however, it would be unwise to generalize that the experience in these trials was universally true. During the time of the work cited, extremely high levels of an unusual impurity were recycling in the lixiviant, which substance was a catastrophically destructive catalyst for peroxide. Since this material was not removed before recycle, it was not surprising that much of the peroxide fed was decomposing in the feed piping and never made contact with the uranium mineralization. Under these conditions, indeed, peroxide showed no improvement over oxygen. This is, however, perhaps the most adverse environment encountered to date in US in-situ uranium leaching. In other operations, peroxide has proved advantageous where two factors have been exploited: 1.Despite the tendency for Hz02 to decompose to water and oxygen in the in-situ leach environment, its higher redox potential before decomposition has provided higher leach rates. In some formulations, overloading beyond the O2 saturation equivalent with peroxide has allowed higher oxidant levels, and higher leaching rates, when overloading with molecular O2, led to vapor-locking.

Jan 1, 1983

By Arnulf Muan, Klaus Schwerdtfeger

Activity-composition relations in Pt-Cr and Pd-Cr alloys of low chromium concentrations UCr < 0.3) have been determined in order to ascertain quantitatively the extent of reactions to be expected between Cr2O3-containing oxide phases and platinum or palladium crucibles used as containers in studies of oxide equilibria at low oxygen pressures. This work is a continuation of similar work previously

Jan 1, 1965

By E. P. Whelan

A recent investigation1 into the origin of "ghost boundaries" in dilute Cd-Mg alloys has indicated the persistence of a segregated solidification substructure in spite of a homogenizing treatment designed to remove such segregation. Although no grain growth experiments have been reported on these segregated alloys, the homogenizing treatment used in grain growth studies on other dilute alloys2-7 is similar in

Jan 1, 1968

By C. L. Colburn

Discovery is the first step in the location of the claim. The provision of the Revised Statutes (2320) is, " No location of a mining claim shall be made until the discovery of the vein or lode within the limits of the claim located." Strictly speaking, discovery may be defined as the finding of ore or metalliferous rock in place in a well-defined vein. This definition was too strict, so discovery extended later to cover such indications of the pregence of ore, within rock in place, as would justify an experienced miner in spending his time and money with a reasonable expectation of finding ore in paying quantities. According to Colorado statutes a discovery must show a well-defined crevice; in Arizona, a lode, deposit, or mineral in place; in Montana, a well-defined crevice or valuable depositi; in Nevada, a lode or deposit of mineral in place. It is wrong to require a discovery. An honest prospector, wishing to obey the law, finds himself compelled, in most cases, to evade this point. In Clear Creek district, Colorado, a quartz seam will constitute a discovery; in Butte, a red capping; in Leadville or Ely, it is any place where a man can find a piece of vacant ground big enough upon which to sink a . 10-ft. hole. If the vein or deposit outcrops a man can show a discovery, but if it does not outcrop it is foolish to compel him to show one; and this point has been gently side-stepped. Any hole 10 ft. deep now constitutes a discovery. It is no use having laws that the people cannot consistently ob_ey. No sane man will dig unless he expects to find mineral, and he should be protected while digging. He should be required to show that he has mineral ground only when he comes to patent.

Jan 1, 1915

By H. Bernstein

WHILE the beryllium -copper (2 pct Be) alloy is nominally nonmagnetic, the presence of iron impurity causes variations in the magnetic proper- ties which, at times, attain excessive proportions. This investigation was carried out to establish the effect of small amounts of iron on the susceptibility of the material and to determine if the effect could be minimized. Beryllium-copper is an age-hardening alloy which

Jan 1, 1959