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By W. Rostoker

A STUDY of the titanium-oxygen system' involved an associated series of measurements of the lattice parameters of the a and TiO phases. The results permit some interesting deductions which are herein reported. A comprehensive survey of the physical PI-operties of the phases in this alloy system has been made by Ehrlich.2 However, only impure titanium was available at that time, so that some revision of his measurements is to be expected. The lattice parameters were calculated from the high angle lines of Debye-Scherrer patterns taken in a 14 cm camera and using filtered CuKa radiation. The specimens were prepared largely by crushing and screening of lump samples which had been quenched from elevated temperatures. Only in the case of low oxygen contents was it necessary to resort to filing and annealing. The results of the lattice parameter studies are graphically presented in Figs. 1 and 2. It will be seen that oxygen produces a pronounced distortion of the c parameter of the a phase (hexagonal close-packed). The trend is in general agreement with Ehrlich's work, although the divergence of actual parameter values strongly suggests that his titanium was very impure. It will be noted that the a phase of titanium can tolerate the unusually high saturation solubility of about 34 atomic pct 0. By virtue of this unique effect, it is possible to make a calculation of the effective atomic diameter of oxygen when dissolved in a lattice with metallic bonding. This has not been possible before. Ehrlich's2 density measurements demonstrated that oxygen occupies interstitial positions in the a lattice and the trend of the lattice parameters would certainly support this. In a hexagonal close-packed unit cell the largest interstitial positions lie at (2/3, 1/3, 1/4) and (2/3, 1/3, 3/4). Accordingly, if both of these positions were occupied, the ratio of titanium to oxygen would be 1:1. The extrapolated c parameter may be taken as between 4.93 and 4.99?. The a parameter appears to reach a constant value of 2.955? at low oxygen contents. The distance of the center of a titanium atom site from the [vc2/16+a2/3-1.448] Then the atomic diameter of the oxygen atom is represented by the function: where the radius of the titanium atom is 1.448A,

Jan 1, 1953

By Bruce A. Kennedy

The long awaited new Mining Engineering Handbook is taking shape under the leadership of A. B. Cummins, Chairman of the Editorial Advisory Board for the SME Mining Engineering Handbook, and Ivan Given, Editor-in-Chief. The last Mining Engineers' Handbook, the Peele edition, published by John Wiley and Sons, was last revised in 1941. This book was and still is a virtual mine of information although a good deal of its content, especially the cost tables, is becoming rather antiquated. The new one-volume work will contain approximately 1600 pages and be divided into 36 sections. A brief summary of the sections follows: The Place and Contribution of Mining, Mining Costs: Mining Geology-Minerals and Mineral Deposits; Minerals Discovery-Prospecting and Exploration Methods and Equipment; Site Exploration and Selection; Minerals-Mining Design; Soil and Rock Mechanics; Design of Excavations; Opening and Development: Underground Mining Systems and Equipment; Roof and Ground Control; Groundwater and Groundwater Control: Open-Pit and Strip-Mining Systems and Equipment: Underwater and Ocean Mining; Fragmentation-Cutting, Drilling, Blasting; Underground Haulage: Hoists and Hoisting Systems; Surface Haulage, Hoisting. Lowering Pumping and Drainage; Ventilation: Mine Surveying; Ore and Coal Processing; Mill Design; Industrial Minerals-Specifications and Markets: Power; Maintenance plant and Equipment; Supply Service; Health and Safety; Reclamation and Surface Restoration: Administration and Management; Operations Optimization (Systems Engineering) : Mint, Costs and Control: Mine Examination. Valuation. Reports; Engineering Terms: and Consulting Engineering.

Jan 1, 1970

By James W. Neill

Discussion of the paper of H. 0. Hofman, presented at the Canal Zone meeting, November, 1910, and printed in Bulletin No. 42, June, 1910, pp. 473 to 497. JAMES W. NEILL, Pasadena, Cal. (communication to the Secretary *) :-Professor Hofman's paper brings the art up to . date. As I was one of the pioneers in this business, I beg to give the following incomplete data regarding my efforts in this line. In the year 1883, while I was in charge of the smelting-operations at Mine La Motte, Mo., there was at the concentrator an unusually large production of a middle product, locally called "iron," which carried considerable values in nickel and cobalt, and which it was desirable, for this reason, to treat by itself. The works could not spare a furnace for the purpose; and to handle this product I improvised a "roast-hearth " from an old " lead-hearth." This was a small cast-iron furnace of the usual construction, about 2 by 4 ft. in dimensions, with a hollow cast-iron back, through which the wind circulated before entering the tuyeres. I had a cast-iron grate made to fit this hearth, and placed it flush with the lip, or apron, and above the tuyeres. On this grate, which had round holes about 0.25 in. in diameter, and a total surface of about 20 by 40 in., I roasted the nickeliferous pyrite product; starting the fire with kindling, then adding charcoal, and then gradually feeding the sulphides with a shovel, so as to cover the fire, choke down blow-holes, and get an even bed. Blast at a pressure of 3 or 4 oz. was supplied by a fail-blower. When a cake of roasted material had formed, it was removed with a steel bar, or fork, to the lip of the furnace, and thence into a wheel-barrow.. The fine material which had remained unmelted, but very hot, on top of the cake would promptly ignite when the cake was broken up and removed. The fire would then be covered with fresh material and * Received Aug. 29, 1910.

Apr 1, 1911

E. P. Pfleider, University of Minnesota I would like to ask Bob Merrill whether he considers that horizontal concave curvature of a slope has any stabilizing effect, such as Jenike 1 suggested several years ago. R. H. Merrill, U. S. Bureau of Mines, Denver Federal Center The stabilizing effect is due to the restraint offered to radial movement by the curvature. We found in laboratory tests that if we constrained the rock with the same stresses as those measured in the pit then it would sustain a maximum stress about two or four times greater than when the same rock type was unconstrained. We are therefore definitely of the opinion that a constrained situation in a slope is favorable towards stability. G. A. Leonards, Purdue University I was interested in Mr. Lane's observations concerning the correspondence between rate of slide movement with rise of reservoir. Perhaps the most interesting feature is that the rate of movement at the time the rock slope failed was less than the rate at an earlier time when it did not fail. This is difficult to explain from current slope stability theory. K. S. Lane, U. S. Army Corps of Engineers I believe that reduced rate of movement is the result of the progressive type of failure, such as described by Patton and Deere. which occurs along the sliding surfaces. It is difficult to analytically define the progressive failure condition for inclusion in slope stability conditions, but its existence should be recognized in design. We should also realize that many apparently stable slopes undoubtedly contain overstressed regions. To design a slope with no overstressed region would be uneconomical and conservative. D. H. Deere I would pose the question-"What is the meaning of a factor of safety of one?" We were involved in the design of a large, irregularly shaped, underground cavity with an unsupported span of several hundreds of feet. Tests on rock specimens indicated a strength of 1300 lb per sq in. The RQD would have been between 90 to 100 percent indicating excellent structural continuity. In-situ stress determinations indicated an approximately hydrostatic state of stress at a level of 1400 lb per sq in. Calculation of stress concentrations at the walls indicated that the stresses there would be about 3000 to 4000 lb per sq in. Admittedly the rock is in a confined condition everywhere except at the very skin of the wall and the rock walls would thus on the average be somewhat stronger. Allowing for the effect of restraint the factor of safety was found to be less than 0.5 over a region several feet into the wall. Construction was started, using rockbolts only to support the walls. Failure around the immediate skin occurred after each

Jan 1, 1967

By H. l. Burghoff, A. I. Blank

The state of knowledge bearing on the stability of copper under stress at elevated temperatures is generally known to be in need of revision and extension. The present investigation, dealing with the creep characteristics of a deoxidized copper of low residual phosphorus content, is intended to contribute in some small measure toward this end. The experimental data presented herein have been correlated by methods of evaluation and interpretation familiar to those who are concerned with crecp of metals. In practice it is common, if not requisite, to use structurally stable materials at elevated temperatures. It is frequently desirable, however, to test materials under conditions that produce structural change, in order to determine the extent of such change and its effect on physical properties, thus making it possible to establish accurately the limiting conditions to which such materials may be safely exposed. The creep characteristics of the drawn copper wire of this investigation arc directly associated with its structural instability at elevated temperatures. Complete realization of this fact is essential to the evaluation of its creep resistance under various conditions. Creep results should apply to steady deformation under equilibrium conditions, but these are seldom attained in only one or two thousand hours. It will be shown that steady creep rate for copper at useful stresses does not usually begin until considerably more time has elapsed. A wholly satisfactory substitute or shortcut for extensive creep testing does not appear to be evident in the application of mathematical analyses to limited experimental data. Material A single lot of phosphorized copper wire was drawn down to 0.125-i11. diameter with a final reduction of 84 per cent. After mechanical straightening, a portion of this wire was annealed to an average grain size of 0.013 mm. in a controlled-atmosphere furnace. The composition and initial properties of the copper in these two conditions are listed in Table I. Photomicrographs of the original structure are shown in Fig. I.

Jan 1, 1945

By Albert Sauveur

AT the New York meeting of the Institute, February, 1914, Professor Hopkinson and Sir Robert Hadfield presented an important paper entitled Research with Regard to the Non-Magnetic and Magnetic Conditions of Manganese Steel.1 Any contribution on manganese steel by its discoverer necessarily carries with it much weight and is entitled to serious and close consideration. The momentous discovery of that alloy by Sir Robert Hadfield some 30 years ago was the signal for great activity in the field of alloy steels; and the remarkable results obtained in the last two decades probably constitute the most important modern advance in the metallurgy of steel. The authors of the paper referred to above are unable to reconcile with the allotropic theory the interesting results obtained by them in heat treating manganese steel. When they speak of the allotropic theory, however, I understand that they have more especially in mind the existence of beta iron. It is not my understanding that they question the occurrence of iron in the two allotropic varieties known as gamma and alpha. If I am wrong, I trust they will correct me. A careful consideration of the experimental results reported and discussed by the authors leads me to believe that on the contrary they can be very satisfactorily explained in terms of allotropy and that, in the light of our present knowledge, they cannot be accounted for in any other way. The physical properties of non-magnetic manganese steel described by the authors are those pertaining to iron-carbon alloys in which iron is present in the gamma condition, or, in other words, to austenite. The metal is then characterized by great tenacity and ductility and low elastic limit, while its hardness, mineralogically speaking, is not excessive, but of a special kind termed "tough hardness" by the authors. Even when subjected to the restraining influence of a large amount of manganese and of considerable carbon, however, relatively rapid cooling

Jan 9, 1914

New York Meeting, October 16 and 17, 1913.-The One Hundred and Sixth meeting of the Institute for the reading and discussion of professional papers will be held in New York City, on Thursday and Friday, October 16 and 17, 1913. Headquarters will be at the Institute office in the Engineering Societies Building, 29 West 39th Street. The sessions will be held in one of the assembly rooms of the building. Because of the many valuable papers on iron and steel obtained with the assistance of the Iron and Steel Committee, which papers could not appropriately be presented and discussed at the Montana meeting, this October meeting of the Institute is held for the purpose of reading and discussing these papers, most of which will be printed and distributed in advance. The members of the following societies have been invited to attend the meeting, and several have accepted and declared their intention of taking part in the proceedings: American Society for Testing Materials, American Iron and Steel Institute, American Society of Mechanical Engineers, American Society of Civil Engineers, American Institute of Electrical Engineers, American Foundrymen's Association. The meeting will be conducted under the auspices of the Iron and Steel Committee, and the latest revised program of the proceedings will be found on page xi, under the notes of this Committee.

Jan 10, 1913

By GEORGE D. RAMSAY

ABOUT three miles west of Fontana San Bernardino County, California, and fifty miles east of Los Angeles, the Kaiser Co., Inc., has built an integrated steel plant. By integrated, I mean that from its wholly owned iron ore and coal supply, the Kaiser Co. is producing in its own mills iron and steel products. Pig iron to meet the West Coast needs has been produced at Fontana since Jan. 1, 1943; steel ingots were first poured there May 14, 1943; and steel plate for ships was first rolled Aug. 15, just sixteen months after ground was broken. Briefly, the plant consists of: (I) Two batteries of by-product coke ovens, totalling ninety ovens, carbonizing about 1740 tons of coal per day at capacity; with by-product facilities for the production of tar, ammonia, and ammonium suIphate, light oil distillates, and tar distillates. (2) One blast furnace producing at

Jan 1, 1944

By Kazutami Imai

Effects of heavy metal ions on the growth and the activities of iron and sulfur oxidation of Thiobacillus ferrooxidans were investigated. Mercuric, silver, and stannous ions inhibited both of the growth and the iron- oxidizing enzyme system of the bacterium. On the other hand, uranyl ion inhibited the growth, but it gave almost no effect on the iron-oxidizing enzyme system. The inhibitory effect of uranyl sulfate on the growth of the bacterium is intensified on lowering the cultivating ' temperature from 28 ºC to 7 ºC. In the concentration of 10-3M, cadmium and copper ions inhibited colloidal sulfur-oxidizing activity of the cells 69 and 52 %, respectively, though they did not inhibit the iron-oxidizing activity at all in the concentration. On the contrary, stannous chloride did not givr any effect on the sulfur-oxidizing activity of the cells, though it inhibited the iron-oxidizing activity 55 % in the concentration of 10-3M. Several differences were observed among the cytochrome systems of cell-free extracts of the cells grown on iron and on sulfur.

Jan 1, 1976

By Rodolfo V. de la Cruz

The in situ deformability of rock masses is determined by relating the applied load to the radial displacements of points on the borehole wall that are outside of the loaded surfaces. The external displacement method includes the steps in which: a) radial displacement sensors are installed to measure the change in length of a diameter of a borehole; b) unidirectional self- equilibrating pair of forces perpendicular to the direction of radial displacement measurements are applied on opposite sectors of the borehole wall, and; c) using elastic theory, the in-situ deformability of the rock mass can be related with the applied loads and measured radial displacements. The displacements outside the loaded surfaces are comparatively smaller in magnitude than displacements inside the loaded surfaces. These displacements, however, are sufficiently large and can be measured precisely by commercially available linear displacement sensors. Loads are applied by a conventional borehole jack. Existing methods for measuring the in situ deformability of rock masses yields unreliable results due to complex boundary stresses, small and varying contact areas, and the existence of fractures. It was shown that in the external displacement method, the effect of boundary pressure distribution and contact area are negligible. Also, since the displacements measured in the external displacement method were due to materials that are deeper inside the rock mass, borehole fractures have less influence on the calculated deformation modulus.

Jan 1, 1982

By B. S. Tani, R. V. Schablaske, M. G. Chasanov

MEASUREMENTS of the solubility of scandium in liquid cadmium from 349" to 606°C by Chasanov, Hunt, Johnson, and eder' led to the isolation and characterization of the intermetallic compound ScCQ. The solid phase found in equilibrium with a saturated solution of scandium in liquid cadmium above 422°C is ScCQ. The equilibrium solid phase below this temperature has not as yet been characterized. Hexagonal needles of ScCG were isolated from a 5 wt pct Sc alloy which had been ice-quenched from 500°C. Free cadmium was leached away from the intermetallic with saturated ammonium nitrate solution. The concentration of cadmium in successive leaches was followed polarographically and the leaching process was terminated when the rate of cadmium dissolution decreased markedly. Chemical analysis of the intermetallic thus isolated is as follows: 11.5 wt pct Sc and 88.3 wt pct Cd. The composition of ScCQ is 11.8 wt pct Sc and 88.2 wt pct Cd. X-ray diffraction powder photographs of ScCds taken in a 114.6-mm Debye-Scherrer camera with CuKa, radiation can be indexed on the basis of a hexagonal nit cell. Lattice coonstants are a. = 6.330 ± 0.001A to 6.324 i 0.001A and co = 4.853 i 0.001A. The a0 has a slight range with the lower value seemingly associated with the cadmium-rich terminus of the phase. With eight atoms in the unit cell the calculated intermetallic density is 7.54 g per cu cm; the density as determined by a liquid-displacement method is 7.7 g per cu cm. Powder-diffraction data for ScCQ are recorded in Table I. Stoichiometry, symmetry, unit-cell dimensions, and the number of atoms per unit cell indicate the MgsCd (D019) type structure for ScCQ; space group is D,&-P6,/mmc. Atomic coordinates are:

Jan 1, 1964

By Henry Fernald

THE accounting system or bookkeeping methods of any company are principally the concern of that company and of those who are in control of its affairs. Its published financial report is, however, primarily intended for those who are not already fully informed regarding its operations and finances. Whatever may be the advantages of standardization of accounting and bookkeeping methods, it must be admitted that a company has a certain right to handle its accounts and keep its books and records in whatever manner may seem to it best adapted to its affairs, even though such methods may differ materially from those generally adopted by others. In its financial reports it should not, however, either ask or expect that the statements it makes or the terms which it uses will be given in its case a meaning and interpretation different from that which they are ordinarily considered to have in similar reports and statements of other companies. The particular form and arrangement of such reports is a matter concerning which there may be much difference of opinion. It is of little importance whether current assets come first or last in the Balance Sheet, but it is important that there should not be included under this designation any items which are not properly current assets within the generally accepted meaning of that term. The extent to which stockholders or others interested are to be made acquainted with the full details of a company's business is a question which the proper authorities must in each case decide. It should, however, be recognized that there are certain facts regarding a mining com-pany which must be set forth in a financial statement if it is fully to cover the conditions and affairs of the company. For example, a financial, statement which does not include or is not accompanied by a statement, of the ore reserves of the company does not fully set forth its financial condition. This is true whether the absence of such a statement of ore reserves is because it is not desired to make public the figures or whether it is because the ore reserves themselves are not definitely known, or accurately measured.

Jan 1, 1928

By E. P. Chartkoff, W. P. Sykes

In 1926 one of the authors published researches on the determination and description of the iron-tungsten and iron-molybdenum systems,' including the equilibrium diagrams. In 1929, further work was carried on, including the examination by X-rays, which is recorded here. Meas-urements were made of changes in lattice parameters in the solid solutions. Precipitation from the solid solution and the accompanying changes in hardness were studied as well as the formation of the intermetallic com-pound phases upon sintering a mixture of metal powders. Materials All the specimens were prepared from the same quality of metals and by the same methods as were described in the determination of the constitutional diagrams. The metal powders as mixed and pressed were sintered or fused in a hydrogen atmosphere and subsequently treated as indicated in the titles of the figures. The formation of the iron-rich solutlon in the solid was accomplished by sintering in hydrogen for a period of 20 to 30 hr. at a temperature 25' to 50' C. below the melting point of the eutectic. The tungsten-rich and molybdenum-rich solid solutions of iron were prepared by adding the iron as a solution of iron ammonium oxalate to the oxide of tungsten or molybdenum, followed by a hydrogen reduction. This method results in a homogeneous alloy after sintering the pressed metal powder for 20 to 30 hr. at a temperature slightly below that of the peritectic reaction in the system involved. For X-ray examination the specimens were variously prepared, depending on the nature of the sample and what it was desired to show. For example, the iron containing tungsten or molybdenum in solid solution was cut with a file, the chips were put through bolting cloth, and this powder of filings formed the specimens for comparative study. The

Jan 1, 1930

By JOHN D. SUMMER

THE Premium Price Plan for copper, lead, and represent, the approach of the Office of Price Administration to the urgent of wartime problem of securing increased output of nonferrous metals. Some of the problems encountered in too operation of the Plan and the considerations which led to it?s adopt it will here he reviewed. The Plan provides for extra payment by the Metals Reserve Co., to mine operators who exceed established quotas of production. Producers are thus directly, compensated for the higher costs of working ores that are not commercial at the ceiling price, although the metal obtained from these ores is directed into regular channels of distribution at the established prices for copper, lead, and zinc. Higher-cost metal is thus available to fabricators and to the government agencies at the regular ceiling price and the dual objective of increased production and table pries is achieved.

Jan 1, 1943

By Edgar S. Cook

At the close of the Bethlehem Meeting, the writer was experimenting with large fuel-charges, 4000 Ibs. basis, as compared with 2000 Ibs., hot had not made sufficient progress to draw any safe conclusions. Previously me had always used 2000 Ibs. fuel, the ore-burden being proportioned to this as a basis. I could never persuade myself that there was any advantage to be derived from following the more popular method of larger fuel-charges. Our men were accustomed to the old way of filling ; and we did not care to run the risk of the errors likely to follow any alteration in routine work, particulary as I could not, by my course of reasoning, discover ally compensating gain. Nevertheless, after reading Mr. Gordon's discussion of Mr. Birkinbine's paper, '' Operations of Warwick Furnace from August 27th, 1880, to September 1st, 1885" (Transactions, xiv., 833), I determined to test by actual experiment the value of large fuel-charges : the change was made in the week commencing March 28th, 1886, and continued until July 25th, about four months. The fuel and ores remained during the trial the same as had been used before, and have been used since. For the first two weeks, the furnace worked with great regularity, giving excellent results, exceeding those of the two weeks immediately preceding. But for my remembrance that the furnace had on former occasions worked with equal uniformity for longer periods without any apparent reason, I should doubtless have concluded that this improvement was due to the different method of filling and congratulated myself that a means had at last been found to prevent inconvenient "dirt" accumulations. Before abjuring my previous skepticism, however, I resolved to pursue the trial further. The fourth meek developed the peculiar conditions that had prevailed previous to the change; and these continued with more or less frequency during May, June and July. At last, finding no improvement over the smaller charges—no change in fact for better or for worse—I commenced filling the 2000 lbs. fuel-charge in the latter part of July, and have continued it up to present writing, September 4th.

Jan 1, 1887

By AIME AIME

ANDREW FLETCHER, newly elected Treasurer and Director, has spent his entire mining career in the employ of the St. Joseph Lead Co. and brings to the Institute Board a career rich in financial experience and varied in interest and accomplishment. "Drew" Fletcher was born in New York City on Feb. 6, 1895. After graduating from the Sheffield Scientific School of Yale in 1916 as a mechanical engineer, he became a shipyard mechanic in Wilmington, Del. The next thirteen years saw. him gradually enlarging his responsibilities until he ultimately became the head of the W. & A. Fletcher Co., in Hoboken, N. J., ship repairers. In 1929 his program for merging the Fletcher plant with five other New York shipyards was finally consummated in the formation of the United Dry Docks, Inc., which subsequently was purchased by Bethlehem Steel, with the result that today the old Fletcher yard and organization has been expanded into one of the finest ship repair units in the United States.

Jan 1, 1944

By T. B. Counselman, T. B.

Continuous countercurrent decantation calculations have always been a headache to the cyanide man (and the chemical engineer) because of the simultaneous equations involved. These are tedious to solve, and there is considerable opportunity for mathematical error. This paper presents a shortcut method for making these calculations, which has been in successful use for twenty years by the author, and which is particularly valuable in selecting the best of several possible flowsheets, or evaluating the effect of various assumptions.

Jan 1, 1950

By V. O. Struebing, K. A. Johnson, F. H. Ellinger, C. C. Land

The system Pu-Ce-(Pu,Ce)Co2 has been investigated by thermal, micrographic, and X-ray diffraction methods. The principal characteristics of this system were found to be: 1) a "eutectic" valley extending across the phase diagram from the 6 Pu/Pu3 Co eutectic at 408°C to the 7 Ce/Ce24Co11 eutectic at 42Z°C, the maximum temperature in the valley being 443°C; 2) three ternary inter mediate phases, each having an appreciable mutual solid solubility for plutonium and cerium; 3) eleven four-phase equilibria comprising one eutectic, four peritectics, and six Class II reactions; 4) a pseudobinary section between the ternary phase A and the y Ce solid solution, and another such section between the 6 Pu solid solution and the 77 phase (Pu3 CO) containing cerium in solid solution. ALLOYS of plutonium that are completely molten at temperatures in the vicinity of 500°C are of interest for use in the liquid state as fast reactor fuels. Since exploratory work1,2 on Pu-Ce-Co alloys had indicated that a "eutectic" valley extended across the ternary system between the Pu-co[6 Pu/n (Pu3co)] and the Ce-CO[? Ce/? (ce24co11)] binary eutectics, thus allowing alloys of any plutonium concentration to be selected within the temperature limitation, the present investigation was begun for the purpose of accurately defining the "eutectic" valley. However, when the existence of three ternary intermediate phases and the consequent complexity of the liquid-solid equilibria were discovered, the investigation was expanded to cover the complete system, except for the corner between the isomorphous series PuCo2-CeCo2 and pure cobalt. 1) EXPERIMENTAL The purities of the alloy components are given in Table I. Alloy buttons, each weighing about 5 g, were prepared by arc melting the accurately weighed components (±0.1 mg) under a purified He-Ar atmosphere. Weight loss as a result of melting was usually less than 1 part in 1000; therefore, the buttons were not chemically analyzed. One half of each button was re-melted by induction heating in vacuo in a magnesia crucible and furnace-cooled, so as to produce a somewhat coarser microstructure than that of the rapidly cooled arc-melted button. About 20 g of each alloy to be examined by thermal analysis were remelted in vacuo in a tantalum crucible of the inverted thermocouple well type. The thermal, X-ray diffraction, heat treating, and micrographic methods used in this investigation were essentially the same as have been described in earlier reports.3,4 Two etchants for these alloys were found to be satisfactory: A) 8 (parts by volume) orthophosphoric acid, 5 ethanol, and 5 glycol; B) 7 tetraphosphoric acid, 36 water, and 57 2-ethoxyethanol. Etchant A was used at 5 to 6 v for 15 to 20 sec, and etchant B was used at 10 v for 10 sec. 2) THE LIMITING BINARY SYSTEMS 2.1) Plutonium-Cerium. The phase relationships of this system have been investigated by Ellinger, Land, and Cramer,5 and by Selle and Etter.6 The over-all agreement of their phase diagrams is good, but there are some discrepancies in the positions of some phase

Jan 1, 1967

By Frank Firmstone

IN the early decades of the past century the method of starting iron blast-furnaces by "scaffolding-down" seems to have been in universal use for coke-furnaces and, at least in this country, for charcoal-furnaces also. It was likewise used at some of the early anthracite-furnaces, as is stated in the important "Reminiscences" printed by the late Samuel Thomas. I It had been generally superseded in Great Britain as early as 1850, by some variations of the plan now used, and was rarely used when Percy wrote.' On the Continent it was still followed in the 60's,3 and was elaborately described by Valerius in 1852. I have never read any statement as to when and by whom '4 scaffolding" was first dispensed with, but the following extracts from journals of my father seem to fix an authentic date for an instance in this country:

Mar 1, 1907

By Henry M. Howe

In discussing the classification of iron to-day, we are to leave out of consideration the general division into non-malleable or cast iron and malleable iron, as to the adequacy of which no question has been raised; and to confine ourselves to the subdivisions of malleable iron. This has been classified, according to the extent to which the properties imparted by carbon are present (viz., resilience, hardness,strength, and, above all, the capacity for being hardened by sudden cooling from a high temperature), into (1) wrought iron which cannot be hardened, and (2) steel which can be hardened; and this classification I shall, for briefness, term the carbon classification. Until within a few years all authorities, both metallurgical and general, have concurred in explicitly recognizing the carbon-given qualities, and preeminently the capacity for being hardened, as the essential qualities of steel; this is laid down with clearness by every writer on the subject. For several years this old classification has not been sufficient to meet all our needs, since the genius of Bessemer, Siemens, and, I may add, Holley, has produced wrought iron which has been perfectly melted, and thus freed from certain mechanical adhering impurities. This causes what we call homogeneousness for want of a better word, and gives rise to many important qualities which the old wrought iron had not; qualities universally recognized, though not readily described. I shall, for briefness, style them the fusion qualities, and a classification based on them, a fusion classification. These qualities render the new product so vastly superior, for most purposes, to the wrought iron formerly known, that it is neces-