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By E. S. Moore

ALTHOUGH nickel was in use in alloys long before the Christian era, the metal was not discovered until 1751, when Cronstedt recognized it in niccolite from Sweden. The Chinese apparently used a nickel alloy, known as "pahfong" thousands of years ago and Persian coins dating farther back than 200 B.C. consist of a copper-nickel alloy similar to some of those now in use in coins. The pure metal was first prepared about 1775 and the metal was refined for commercial purposes some years later. The nickel industry did not attain much prominence until the ores in New Caledonia were discovered. Exports of ore from that country began in 1875 and since that date there has been an ever-increasing world output of nickel and a great expansion in the uses of the metal except during short periods of commercial and industrial depression. Previous to 1875, for a number of years, Norway was the chief producer, although the metal was mined also in Sweden, Finland, Italy, Germany, Austria, France, China, the United States and other countries. With the dis-covery of nickel deposits in the Sudbury district, Ontario, a new factor was introduced into the nickel industry and Sudbury has since become the overwhelmingly dominant feature in the world's nickel markets. Although nickel was first discovered in Canada as early as 1848 near the north shore of Lake Huron and nickel-copper sulfides were found in 1856 by surveyors working close to the present location of the important mine at Creighton, in the Sudbury field, it was not until 188.3 that any importance was attached to this field. In that year copper sulfide attracted attention where the main line of the Canadian Pacific railroad was being projected across Canada to the Pacific coast. Mining began near this discovery in 1889 but in the meantime operations had begun in 1886 in other parts of the field and by 1890 about 100,000 tons of ore had been raised. In the Sudbury field, as in Norway and at the old Lancaster Gap mine in Pennsylvania, the ore was first mined for its copper content and difficulty in the refining of the copper led to the discovery of the important proportions of nickel in the ore. No. 3 property of the Inter-national Nickel Co., now known as the Frood, the greatest deposit in the

Jan 1, 1932

COMMITTEES Committee on Arrangements DAVID H. BROWNE, Chairman BRADLEY STOUGHTON, Vice-Chairman LAWRENCE ADDICKS BURR A. ROBINSON PERCY E. BARBOUR E. MALTBY SHIPP GEORGE D. BARRON JOSEPH STRUTHERS J. V. N.. DORR E. B. STURGIS J. R.. FINLAY T. T. READ Louis D. HUNTOON R. H. VAIL

Jan 4, 1916

By John V. Beall

HEAVY-DENSITY separation processes, a commercial application of the sink-float test used in mineralogical laboratories for the separation of mineral particles by their difference in specific gravity, are the biggest development in mineral dressing since flotation, which was at about the same stage of development thirty years ago. The scope of their application has broadened and, though still in the development stage, they are being accepted in a constantly increasing number of commercial installations. This progress in mineral beneficiation is especially satisfying when we realize that our high-grade ore deposits are fast disappearing and a big factor in determining whether a hole in the ground is being sat upon by a liar or an honest citizen is how economically the ore dressers can concentrate comparatively low-grade ores. As early as the middle of the nineteenth century attempts were made to use aqueous salt solutions in a heavy-liquid separation for cleaning coal. But the original and recovery costs of these liquids were high and further, the fact that they were corrosive, unstable, and toxic added to the difficulty in using them.

Jan 1, 1948

By J. A. Morgan

IN the art of roasting sulfides it is well known that the lower the temperature and the higher the pressure of SO, the larger will be the amount of sulfate present in the product. However, the mechanism of sulfate formation is not generally understood. The following experiment" demonstrates in a direct way that, in the roasting of Cu2S, the sulfate forms from the reaction of Cu2O, formed by the oxidation of Cu2s, with gaseous SO, (or SO3) and 0,. Thus, the sulfate does not form at the sulfide surface. The reaction at the sulfide surface is the same whether or not sulfate is formed. Using an indirect method, Ong, Fassell, and Wadsworth' infer that sulfate forms after oxidation, during the roasting of sphalerite, agreeing with the observations of this paper. The method presented here of demonstrating that sulfate forms after formation of Cu2O is to roast a sample of Cu2S and then to locate and identify the phases formed.' A solid cube of cuprous sulfide, made by melting Fisher reagent grade Cu2S powder and measuring about 1.5 cm on edge, was placed on a Nichrome wire grid suspended over the top of an Alundum combustion boat. The assembly was placed in a tube furnace at 600°C and oxygen gas, flowing at 0.60 liters per min, was passed around the specimen for 24 hr. The furnace tube diameter was 1.5 in. The partially roasted sample was removed from the furnace and impregnated with resin No. BR 0014, obtained from the Palmer Products Co., and the impregnated sample was then mounted in Lucite. A cross section was obtained by grinding and the surface was prepared by the following steps: 1) grinding—60 grit, 3M disk, dry; 2) preliminary polishing —60 through 600 grit, 3M disk, dry; 3) polishing— 8 µ diamond putty, silk cloth; and 4) final polishing —1evigated magnesia in isopropyl alcohol, Selvyt cloth. The color micrograph of the polished surface is shown in Fig. 1. The layers present in the micrograph are given along the side. The comwositions of the various layers were established by Debye-Scherrer patterns. From this evidence the following sequence of reactions which occur in the roasting of Cu2S is inferred: 1) The oxidation of Cu2S occurs with oxygen which has been transported through the oxide-sulfate layer by either gaseous or solid state diffu- sion. The products of this reaction at the Cu2S surface are Cu2O and SO,. 2) The SO, diffuses out through the pores in the Cu2O and finally reaches a position in the Cu2O where the oxygen pressure and the SO, pressure have values such that the thermodynamic conditions for the formation of CuSO4 are fulfilled. Then, the mixture of SO2, SO3, and oxygen reacts with the Cu2O to form CuSO1. 3) The CuSO, decomposes by the evolution of SO,, or SO, and O2, to form the basic sulfate. This is reasonable, since the SO, gradient will decrease toward the oxygen gas phase from the CuSO4 layer. 4) For this same reason the basic sulfate will decompose to form CuO. The above sequence of events is based on the assumption that diffusion through the oxide and sulfate layers, rather than the reaction at the sulfide-oxide interface, is rate-determining. This assumption is supported by the observation that these oxide and sulfate layers combined are almost nonperme-able to the flow of gases through them. Acknowledgments This research was supported by the U. S. Air Force, through the Office of Scientific Research of the Air Research and Development Command. The authors wish to acknowledge the helpful suggestions of Ralph Wells of the Applied Research and Developmeit Laboratory, U. S. Steel Corp. References E. A. Peretti: A New Method for Studying the Mechanism of Roasting Reactions. Discussions Faraday Soc. (1948) 4, p. 174. - J. N. Ong, Jr., M. E. Wadsworth, and W. M. Fassell. Jr.: Kinetic Study of the Oxidation of Sphalerite. Trans. AIME (1956) '206, pp. 257-263; Journal OF Metals (February 1956).

Jan 1, 1957

By E. S. Moore

Although nickel was in use in alloys long before the Christian era, the metal was not discovered until 1751, when Cronstedt recognized it in niccolite from Sweden. The Chinese apparently used a nickel alloy, known as "pahfong" thousands of years ago and Persian coins dating farther back than 200 B.C. consist of a copper-nickel alloy similar to some of those now in use in coins. The pure metal was first prepared about 1775 and the metal was refined for commercial purposes some years later. The nickel industry did not attain much prominence until the ores in New Caledonia were discovered. Exports of ore from that country began in 1875 and since that date there has been an ever-increasing world output of nickel and a great expansion in the uses of the metal except during short periods of commercial and industrial depression. Previous to 1875, for a number of years, Norway was the chief producer, although the metal was mined also in Sweden, Finland, Italy, Germany, Austria, France, China, the United States and other countries. With the discovery of nickel deposits in the Sudbury district, Ontario, a new factor was introduced into the nickel industry and Sudbury has since become the overwhelmingly dominant feature in the world's nickel markets. Although nickel was first discovered in Canada as early as 1848 near the north shore of Lake Huron and nickel-copper sulfides were found in 1856 by surveyors working close to the present location of the important rnine at Creighton, in the Sudbury field, it was not until 1883 that any importance was attached to this field. In that year copper sulfide attracted attention where the main line of the Canadian Pacific railroad was being projected across Canada to the Pacific coast. Mining began near this discovery in 1889 but in the meantime operations had begun in 1886 in other parts of the field and by 1890 about 100,000 tons of ore had been raised. In the Sudbury field, as in Norway and at the old Lancaster Gap mine in Pennsylvania, the ore was first mined for its copper content and difficully in the refining of the copper led to the discovery of the important proportions of nickel in the ore. No. 3 property of the International Nickel Co., now known as the Frood, the greatest deposit in the

Jan 1, 1932

By René de Batz

From 1754 to the end of 1895 the production of gold in Russia had been approximately as follows: Kilogrammes. Russia proper (Finland and the Caucasus),. .. 890 The Ural Region,........505,386 Western Siberia,........116,937 Eastern Siberia,........1,218,372 Total,.........1,841,085 of the value of more than $1,200,000,000.

Jan 1, 1899

By O. M. TUPPER

REQUIRING a finer ground clay than that obtainable with a dry pan or hammer mill, the Clay Corporation of California installed a five-roller, low- side Raymond impact mill at its Lincoln plant in 1925 and since then has been economically grinding fire clay with a moisture content as high as 15 per cent. This was one of the first, if not the first, of this type of mill to be used in the grinding of clay on the Pacific coast. The pulverizer consists of a die-ring, lying in a horizontal plane, enclosed in a sheet-iron housing. A vertical shaft supports a spider from which five rolls are suspended in such a way as to always have them bearing on the die-ring. The vertical mill shaft is driven by means of beveled gear and pinion from a horizontal shaft which is connected by belt with a 60-hp. motor with suitable pulleys to give a speed of 175 r.p.m. A large fan which has a speed of 1100 r.p.m. and is belt connected to a 40-hp. motor is connected to the mill housing. The discharge end of the fan is in turn connected to a cyclone dust collector.

Jan 1, 1929

By R. A. Corley, W. R. Wilcox, J. R. Teviotdale

Chemical vapor deposition of hafnium carbide yielded whiskers, needles, dendrites, faceted crystals, and adherent coatings. The gas stream compositiom and the mass transfer conditions determined the habit of the deposit. The deposits were obtained at temperatures ranging from 1100" to 1800°C. HAFNIUM carbide has the highest melting point of any binary compound; therefore, its various potential applications are a subject of vital interest to the aerospace industry. The experiments described herein were performed to investigate the chemical vapor deposition of hafnium carbide with particular interest being placed upon the possible production of high-strength single-crystal whiskers for composite materials. In 1931 Moers 1 used a gaseous mixture of HfC14, Hz, and toluene to vapor deposit crystalline hafnium carbide on a tungsten filament heated to 2400°to 2800°C. More recently Lepie 2 deposited hafnium carbide on graphite using HfC14 and methane in a helium gas carrier. The pyrolytic depositions described here were accomplished in graphite tubes by using various gas mixtures and dopants. The resulting crystal habits included whiskers, needles, needle dendrites, bulbous dendrites, faceted crystals, and smooth, adherent poly-crystalline layers. EXPERIMENTAL The depositions were carried out in an induction-heated graphite tube, 1.2 cm ID, which was contained in a vertical 9-cm-ID quartz tube. (A more detailed account of the experimental procedures and results is given in Ref. 3.) Refractory oxide fiber and tubes and graphite felt were utilized jointly and singly for therma1 insulation. A typical temperature distribution is shown in Fig. 1. The reactant gases were introduced at the top and removed at the bottom of the tube. Table I summarizes the experimental conditions and results. Many deposition habits were obtained. X-ray analyses showed that they possessed the hafnium carbide structure. Almost invariably these formed well above the point of maximum temperature in the graphite tube. The habit depended strongly on the gas composition. In a series of runs (e.g., run A) using HfC14 and toluene in H 2, hafnium carbide coatings, Fig. 2, were reproducibly obtained at the position where the tube wall was 1400°C, and bulbous dendrites, Fig. 3, were

Jan 1, 1969

J. H. HEGINBOTHAM, a, metallurgist of the General Engineering Co., talked on "Current Milling Practice at Kirkland Lake," at the December meeting of the Utah Section. The ore is enough alike through the whole district so that some generalizations and comparisons may be made. The question as to whether or not the flotation process should be used in the flowsheet for extracting gold by cyanide solutions is still being vigorously debated, and it will seemingly need some years for a definite answer to be given. Most of the gold is either free, though much of it is finely dispersed in quartz, or occurs with pyrite. At times there may be 2 per cent of telluride compounds in the ore, but the amount of gold telluride present is small and has not been definitely established. It has been shown by Dr. Haultain and others that though gold tellurides may be so finely disseminated that it is necessary to grind the ore exceedingly fine, the compounds themselves are not difficultly soluble. (An increase in temperature helps to dissolve tellurides, and also to settle pulps.) It is likely that if the ore were ground through 400 mesh, practically all of the gold would be soluble. As it is, with 96 to 98 per cent of the ore ground to minus 200 mesh, and some 70 per cent minus 325, the cost of

Jan 1, 1934

By E. Martinez

The effect of ultrasonic energy transmitted through a liquid on chrysotile asbestos was investigated. Ultrasonic energy was effective in fiberization of chrysotile crudes as well as standard grades of milled asbestos fibers. Treated samples of several grades of milled fibers had increased wet bulk volumes and decreased settling and filtration rates compared to untreated fibers. Ultrasonics may be a method for fiberization of chrysotile without decreasing length or use of chemical additives that alter surface properties. Cavitation of the liquid on the surface of fiber bundles is believed to be the cause of the fiberization. It was found that ultrasonic energy greatly increased the rate of precipitation of latex on asbestos. When chrysotile asbestos fibers require additional opening or fiberization, the usual method employed is some type of high speed impact or grinding to open the fibers and produce a larger surface area. These methods always cause some degradation in length due to breaking of fibers. In addition, the efficiency of mechanical methods decreases as the diameter of fiber bundles decreases. Chemical methods have been proposed and it is claimed that fiberization down to individual fibers of 200-300 A diam is possible with some wetting agents. However, large amounts of reagent are required, approximately EDWARD MARTINEZ is with Central Research Laboratories, American Smelting and Refining Co., South Plain-field, N.J. TP 63H226. Manuscript, Aug. 12, 1963. Discussion of this paper, submitted in duplicate prior to Mar. 15, 1964, will appear in SME Transactions, September 1964, and AIME Transactions, 1964, vol. 229. 50 pct of the weight of fiber treated, and some of the wetting agent remains on the surface of the chrysotile and cannot be removed by any solvent which does not destroy the asbestos.' This investigation was directed at determining whether ultrasonic energy transmitted through a liquid would be effective in fiberizing chrysotile asbestos. Samples of asbestos crudes and commercially milled fibers were treated; settling and filtration rates of treated and untreated milled fibers were obtained. EQUIPMENT A Westinghouse Corp. ultrasonic cleaning system WEHH was used in this investigation. See Table I for a breakdown of this ultrasonic unit. RESULTS AND DISCUSSION Fiberization of Chrysotile Crudes: Samples of chrysotile crudes were pulled apart with tweezers so that coarse bundles of fiber approximately 1/16 in. in diam were obtained. The bundles were put into a bottle with 200 ml of methanol and the mixture placed into the ultrasonic tank for 30 min at a power output of 1200 w. The test was repeated using water instead of methanol. During the irradiation it was noted that the surfaces of the bundles were being fiberized. The liquid eventually became cloudy with dispersed solids. Fig. 1 is an electron micrograph of the fibers, some reduced to unit dimensions, and a fine material released by the ultrasonic energy. The platy particles in Fig. 1 were identified by electron diffraction and differential thermal analysis as brucite, Mg(OH)2, which must have been intergrown in the chrysotile crudes. Electron micrographs of bulk specimens of chrysotile have shown a fine material filling the interstices between tubular fibers.2,3 Electron diffraction patterns of the fine material collected after ultrasonic treatment indicate that it is amorphous. After decanting the solution, bundles of chrysotile remained somewhat decreased in diameter. Continuing the ultrasonic irradiation of the remaining material resulted in additional fiberization. The opening of the fibers occurred in both methanol and water. Cavitation of the liquid by the ultrasonic energy is undoubtedly responsible for the fiberization. When sound waves are transmitted through a liquid at a

Jan 1, 1963

By J. W. Halley

RIMMING steels derive their name from their action during solidifica-tion in the molds. As a result of incomplete deoxidation, gas is evolved during freezing, and the metal has a characteristic rolling action. The metal rises along the mold walls and descends in the center of the ingot. This action keeps the top of the ingot open and the advancing rim of solid metal can be seen. The rim grows until the rolling action is insufficient to prevent the top of the ingot from freezing or until the action is stopped by capping the ingot with a heavy plate. The violence of the reaction and its characteristics, such as growth or drop ill the molds, are deter-mined by the Composition, the furnace practice, and the deoxidation in the ladle and in the molds. Though rimming steels represent a large proportion of the amount of plain carbon steel made, they have received comparatively little attention in the technical literature. The manufacture of rimming steels has been described by Hibbard,1,2 Fleming,3 Pierce4 and Jackson.5 The reactions occurring during rimming have been considered from the theoretical point of view by Chipman and Samarin.7 The structure of rimmed-steel ingots has been discussed by Nead and one of the present authors.6 Meyer,8 in studying segregation, investigated the distribution of carbon, sulphur and phosphorus in rimmed-steel ingots by analyzing the rim and core of blooms. In their studies of segregation, the Joint Committee of the Iron and Steel Institute and the British Iron and Steel Federations studied distribution in one billet and one ingot of rimmed steel. A detailed study of the distribution throughout the ingot has not been published. The present investigation was undertaken to determine accu-rately the distribution of carbon, manganese and sulphur in normal rimmed ingots and the general distribution of other common elements present. The study included some work on the effect of pouring condi-tions and furnace practice on the distribution, though there is still much to be done in this direction.

Jan 1, 1938

By Arthur Bell

(San Francisco Meeting, September, 1915) . PRIOR to 1908 the oil production in the State of California, had been almost entirely a heavy fuel, oil, with a high flash point, hut changed within a-short period to a large percentage of refining oil with a low flash, by reason of the coming in of the Santa Maria field, the Midway field, and the increased production of the Fullerton field. This is clearly shown in the following tabulation of California's production: Year Barrels . Below -20° Be, Above 20° Be,, Per Cent_ Per Cent. 1905 48,307,000 90 10 1910 77,698,000 SO 20 1912 90,075,000 6o 31 1914 10:3,600,000 47 53 The bringing in of these high percentage's of light oil with their dangerous low flash and the increasing demand for the refined products necessitated the devising of some cheap and efficient means of quickly separating the lighter elements either in the field or at the main distributing points; also it became necessary to remove the excessive percentage of water which many of the light oils carried in emulsion.

Jan 9, 1915

By Charles M. Cooley

A NOTED Prospector Passes-Stories of the grizzled old prospector that discovered what turned out to be a famous and highly profitable mine, only to die in poverty through the shenanigans of "the Interests," are legion. It is pleasant, therefore, to be able to report that the discoverer of one of Canada's most famous mines was more fortunate.

Jan 7, 1953

Frank Clemes Smith, Deadwood, 8. D. (communication to the Secretary): The reading of Mr. Chance's interesting paper suggests a few ideas relative to his discussion of certain Black Hills gold-ores. Mr. Chance refers to his examination, in 1897, of " the (Carboniferous) limestone plateau-country which encircles the central area of the Black Hills," and says that " it had been generally assumed that the mineralization of this formation was confined to the northern area;" further, that he "found, however, a general mineralization, extending in zones or belts throughout the region," and that the ores, being more or less specially

Jan 1, 1900

By F. T. Davis

Many contributors have added to the fund of knowledge in the basic sciences related to mineral dressing during the past year. During 1964, the French edition of the Proceedings of the VIth International Mineral Processing Congress together with discussions was printed. Also, complete Preprints of papers delivered at the VIIth IMPC were published in September1. Over a third of the papers presented at VIIth IMPC dealt with fundamentals. COMMINUTION It has been postulated by Ponceleta that flaws need not exist before a stress is applied but rather the flaws are created at the tip of a propagating crack at a stress well below the theoretical breaking stress.

Jan 2, 1965

By Robert H. Leach, C. H. Chatfield

This paper gives a brief summary of the process of manufacture of sterling silver, and some of its more important physical properties, as observed in conlmercial production of rolled sheet and wire. Although papers have been published by Turner and Smith,1 Rose,2 Sperry3 and Jordaq4 there are few technical data available, and unfortunately the time allowed for the preparation of this paper has not been sufficient to make it as comprehensive as the title might indicate. Analysis of Steeling Silver Fine or pure silver is too soft for coinage and the manufacture of articles in which strength and resistance to wear are desired. From the earliest times of which we have record, copper has been the metal generally used to harden silver. Analyses of coins and silver articles from ancient tombs show varying amounts of copper, and old Roman silver objects in the British Museum have approximately the same ana,lysis as our sterling. The first authentic record of the establishment of a standard alloy is during the reign of Henry I1 in England. During the twelfth and thirteenth centuries, the people in the Eastern Provinces of Germany had a reputation for the standard and purity of their silver coinage, and it is said that Henry II employed some of these Easterlings, as they were called, to improve and standardize the English coinage, which had become debased. The peculiar standard adopted is probably accounted for by the system of weights used. A troy pound contains

By J. B. STEWART

T HE position of each hole of any series of holes was carefully located by the surveyor, plotted in plan and elevation, and numbers assigned to them. The second series was staggered halfway between the first and so on for each succeeding series. Two and a, half to three months was frequently required to grout a series of holes calculated to insure safety for sinking a distance of 10 meters or say 33 ft. Naturally the initial operation called for drilling and grouting two series of holes but thereafter each sinking campaign required only one series of holes as shown in Fig. 8. The pump handling about 75 gal. per minute corresponds to 46 tons of grout or 6 tons cement delivered as a fair over-all average for the 24 hours. Thus 600 to 800 tons of cement was used for a single section of 33 ft. depth of shaft. One campaign used nearly 1100 tons of cement. Some holes were effectually sealed with as low as 30 tons, while many required 60, and some 80 to 90 tons.

Jan 1, 1926

By F. W. Bowdish

Analysis of data on the equilibrium exchange of sodium ions from salt solutions for calcium ions, from various fractions of an oxidized calcareous iron ore from Lorraine, France, strongly suggests that the calcium may be attached to the solid by only one of its bonds. Nearly equal values were found for the equilibrium expression from data covering concentration ranges of 1000 fold for the salt and 235 fold for the ion-exchangeable calcium. Differences indicated between the exchangeable calcium contents of the slime and the sandy portions of the ore, as well as the equilibrium relationship itself, are of importance in the flotation of the ore. During an experimental program on the flotation of oxidized calcareous iron ores from Lorraine, France, ion-exchangeable calcium was found in the ore. Because this source of calcium ions, if not controlled, could thwart all efforts at flotation, an extensive study was made of the phenomenon. The part of that study reported here was to obtain data on the equilibrium established between ore solids and solutions of sodium chloride, and to analyze the data to try to understand better the physical chemistry of the exchange. The ore contains oolites of goethite and quartz grains embedded in a matrix consisting of calcite and a brown cement believed to be the residue from oxidation of the silicate minerals found in fresh unoxidized ore. When ground, a substantial fraction of the ore becomes a fine slime in which is concentrated more than half of the alumina content of the ore. It is believed that the alumina occurs as unidentified clay minerals with which most of the ion-exchange capacity of the ore is associated. A preliminary experiment on the exchange of ions from the ore for sodium ions from solutions of NaCl showed that calcium was about ten times as abundant as magnesium in the exchange solutions. Thus calcium was the predominant ion in causing difficulties with flotation, and it was the only one for which data was obtained in this study. It is believed that the omission of magnesium ion exchange from consideration does not invalidate the results. It is possible, however, that inclusion of magnesium in the analyses and calculations or its prior elimination from the samples would have improved the consistency of the results. EXPERIMENTAL Data about the equilibrium exchange of sodium from solutions for calcium from the solids were obtained using two different samples of material. The solids

Jan 1, 1963

By H. M. Howe

A Discussion of the paper of Professor Howe, presented at the London Meeting, July, 1906, and printed in Bi-Monthly Bulletin, No. 14, March, 1907, pp. 169 to 274. SECRETARY'S NOTE.-M. Beutter's introductory remarks, being simply a resume of Prof. Howe's paper, with a disclaimer of the intention to criticise it, have been omitted, and the remainder of this contribution has been somewhat condensed, without omitting any essential statements. M. BEUTTER, St. Etienne* (communication to the Secretary-+):-Professor Howe observes in paragraph 47 of his paper that the fluid-compression of steel. diminishes piping by forcing the liquid and viscous metal, while the pipe is forming, or after it has formed, into the space so produced, and proceeds to study the different systems of compression, alluding to the four principal ones: Whitworth, Illingworth, Williams, and Harmet. Having now for many years had in use the last-named process, that of M. Henri Harmet, I shall attempt to explain the difference between it and the three other processes named. The Harmet process does not diminish or close the pipe after it has formed, but prevents it from forming; and I may add that it is the only one of the four which produces this result. It is true that the Whitworth process diminishes the interior hollow by localizing it around the central axis of the ingot, which is afterwards removed by trepanning the hollow forgings for which this process has been, I believe, always exclusively used. The Illingworth and Williams processes, which, in my opinion, are applicable only to small ingots, of necessity allow the pipe to form, or (to use the expression of Professor Howe) they allow the surface of the lake of liquid steel to sink into the interior of the ingot, since they involve waiting a certain time before compression, so that (in the case of the Williams process) the ingot-mold can be opened without dan¬ger, or (in the case of the Illingworth process) so as to avoid the risk that the steel may enter the grooves produced by the removal of the distance-bars. During the time required for

Jul 1, 1907