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By T. A. Rickard

"The chief aim in style ought to be absolute precision", said Flaubert. "There is only one noun that can express your idea, only one verb that can set that idea in motion, and only one adjective that is the proper epithet for that noun." Let this be your motto. The engineer tries to be exact in all his measurements; he should measure his language with similar exactness. The technical term is a word of precision. It is not only precise, it is a word-saver. To the unscientific the earth is "a ball slightly flattened at the poles, something like an orange". To the scientific it is "an oblate spheroid". A similar contrast between the precision of the technical term and the vagueness of common words is afforded by a conversation between Ivanhoe and Rebecca: "' What device does he bear on his shield?' asked Ivanhoe. 'Something resembling a bar of iron, and a padlock painted blue on a black shield.' 'A fetterlock and shacklebolt azure', said Ivanhoe "-using the technical terms of heraldry. It is good style in writing, however, to adapt your manner of expression to the intelligence and experience of the person or persons to whom the writing is addressed. The description of a mine should be worded differently according as it is intended to inform a mining engineer, a director, or a bishop. REMEMBER THE READER. It is as incorrect to write in a technical way for a non-technical reader as to write in a popular way for a technical or scientific reader. That style is best which enables the writer to place himself in the closest mental touch with his reader, to establish the maximum of sympathetic understanding. Let your precision be\ proportioned to your accuracy. You should not try to be precise in matters that do not admit of

Jan 1, 1931

By WILFRED SYKES

IT is with particular pleasure that I welcome the members of the Open-hearth Conference of the I American Institute of Mining and Metallurgical Engineers to this meeting, as I feel this is one of the most useful activities of the Institute in the field of ferrous metallurgy. For the information of our other members I might say the Open-hearth Conference was organized by Mr. Reynders when he was president, and is made up of open-hearth superintendents and metallurgists. All the plants are invited to send representatives, and practically all do, with the exception of the U. S. Steel Corporation. It meets twice a year to discuss various problems in connection with the manufacture of steel, and its minutes are published for the benefit of those attending, the expense being defrayed by the participating companies. This conference, .1 believe, should be a model for activities in the other branches of the work covered by this Institute. It works, not by reading formal papers, which we all know is not a very satisfactory method to bring out the experience of others, but rather by a round-table method of discussion. The spirit of the meetings is such that each member feels perfectly free to state his experience, and he gets as much as he gives. A series of topics for, discussion is brought to the attention of the chairman and after one is exhausted the next point is taken up. In this way there is a real interchange of ideas and experiences which cannot fail l to be of the greatest benefit to those attending. That these meetings are beneficial is evidenced by the "continued growing attendance and lively discussions at these half-yearly meetings.

Jan 1, 1930

By R. D. Rubright, Owen J. Hart

In the Bingham district over a span of more than 90 years, 43,947,104 tons of "non-porphyry" copper, lead, zinc, gold, and silver ore have been mined from a folded and faulted alternating series of Pennsylvanian and Permian limestones and sandstones and from some Tertiary intrusives. This ore came from six major mine areas located east, south, and west of the Bingham stock, site of Kennecott's porphyry copper deposit. The sediments were affected by varying degrees and types of metamorphism within 2000 feet or more of the Bingham stock. The intrusives consisting of the mineralized Bingham and the unmineralized Last Chance stocks and numerous dikes and sills of granite and monzonite were intruded into the asymmetrical northwest-trending and plunging Bingham syncline. Extrusives, although present, contain no ore. The bulk of the non-porphyry ore in the district was found above the Midas thrust. The primary ores are found in three major types of deposits: concordant bedding fissures, crosscutting fissures, and replacement deposits. These deposits consist of both copper and lead-zinc ore bodies that contain various amounts of gold and silver. These are in places roughly zoned both laterally and vertically and have been mined for up to 10,000 feet outward from the center of the Bingham stock and up to 5000 feet vertically below the surface. Secondary ore was of minor importance and was found in and under the oxidized zone at shallow depths. Genetically the Bingham stock, the ores, and related phenomena have had a common source.

Jan 1, 1968

By David P. Shoemaker, Clara Brink Shoemaker

The I phase was discovered by Bardos, Malik, Spiegel, and Beck1 in the V-Ni-Si system at 1100°C and in the Mn-Co-Si and Mn-Ni-Si systems at 1000°C. Kuzma and Hladyshevskii2 and Kuzma, Hladyshevskii, and cherkashin3 have reported a new phase, which they named the S phase, in the Mn-Co-Si and the Mn-Ni-Si systems at 800°C at approximately the I phase compositions. The powder diffraction diagrams of the I and S phases, compared by Bardos el al.,1 are related but show distinct differences in relative intensities. Professor Paul A. Beck kindly sent us a specimen of the (v-Ni-Si) I phase for single-crystal study. Precession and Weissenberg diagrams taken with a tiny single-crystal fragment showed that the structure is monoclinic with a large unit cell. The cell dimensions were refined from a powder diffraction diagram taken with CrKa radiation in a 57.3-mm camera with our computer program LSCELP4 using only the indices of those reflections that were observed on Weissenberg diagrams (hnl, with n = 0 through 9 and n = 12) and precession diagrams (Okl, lkl, Izk0, hkl, hk2). Table I shows the agreement obtained between the l/d values calculated with the final values for the cell dimensions and the l/d values observed by Bardos et al .1 for I(V42Ni33Si25), by US for I(V41Ni36Si23), and by Kuzma and Hladyshevskii2 for S(MnpCoSi). The powder patterns contain many broad and diffuse lines. In fact practically all powder lines observed are near-superpositions of several reflections. The refinement program is not set up to handle several reflections contributing to one observed line: the position of each line is refined with the aid of one set of indices only. The final values for the cell dimensions were obtained from the lines of strong or medium intensity with the indices indicated by asterisks in Table I: a0 = 13.403(6), bo = 23.336(15), co = 9.129(6)A ß = 99.11(6) deg The standard deviations (given in parentheses) are those calculated by the refinement program from least-squares theory and do not take into account that the lines included in the refinement may not have been correctly indexed in every case or that the position of a line may also be partly determined by the overlapping reflections. The agreement between the calculated and observed I phase patterns is fairly good, although some discrepancies occur. Not all observed lines could be indexed with the incomplete set of sin-

Jan 1, 1968

By J. M. GLEDHILL

(Washington Meeting, May, 1905.) A Discussion of Mr. J. M. Gledhill's paper, read by title at the Lake Superior meeting, but presented first at the New Yolk meeting of the Iron and Steel Institute (October, 1904), and here published under a mutual agreement. Between the two Institutes. Discussion. MR. E: WINDSOR RICHARDS, Past-President, said that at a recent meeting of the Institution of Mechanical Engineers a paper was read on tool steel, and he called the attention of the members to the high-speed tool steel at the Bethlehem Works. They would have the pleasure of seeing those wonderful works and would see 60, 70, 80 and 100 tons oil lathe with half-a-dozen of these high-speed tools running. PROP. H. M. HOWE (Columbia University) said that they all looked upon these high-speed tool steels as of very great importance, particularly to the machine shop. One point occurred to hire : Had it really been shown that Swedish steel is necessary, or better than equally pure steel that is not Swedish; and is cemented steel really necessary, and is there any advantage in using that, rather than equally pure open-hearth steel'! It might be well if the author could indicate the kind of evidence on which lie bases his assertion that it is necessary to have cemented Swedish steel. Many were hoping for the development of high-speed steels from elements which exist in great quantities, such as silicon, manganese and chromium, rather than from rarer metals like molybdenum, vanadium and tungsten, the supply of which is likely to be soon exhausted. If the high-cutting speed was to last more than a generation, it. seemed to him that they would have to draw upon the common ele¬ments and not upon the rare ones. MR. Tom WESTGARTH (Middlesbrough) said he fully appreci¬ated what had been said about the advantages of using high-speed steel, because great benefit had been derived from the

Mar 1, 1905

By Nicholas J. Grant, John S. Benjamin

A series of composite alloys containing a high volume of NiAl, Ni3Ah or CoAl, bonded with 0 to 40 vol pct of a ductile metal phase, were prepared by powder blending and hot extrusion. The binder metals were of four types: pure nickel or cobalt, near saturated solid solutions of aluminum in nickel and cobalt, type 316 stainless steel, and niobium. Sound extrusions were obtained in almost all instances. Studied or measured were the following: interaction between the alunzinides and the binders, room-temperature modulus of rupture values, 1500° and 1800°F stress rupture properties, hardness, structure, and oxidation resistance. Stable structures can be produced for 1800°F exposure, with interesting high-temperature strength and good high-temperature ductility. Oxidation resistance was excellent. A large number of experimental investigations have been made of the role of structure on the properties of cermets and composite materials. Gurland,1 Kreimer et al.,2 and Gurland and Bardzil3 have indicated the preferred particle size in carbide base cermets to be about 1 µ, with a hard phase content of 60 to 80 vol pct. The optimum ductile binder thickness was noted to be 0.3 to 0.6 µ.1 Complete separation of the hard phase particles by the binder is important in reducing the severity of brittle fracture.' The purpose of the present study was to produce structures comparable to the conventional cermets, using a series of relatively close-packed intermetal-lic compounds rather than carbides as the refractory hard phase, and to study the effects of binder content and composition on both high- and low-temperature properties. The selected intermetallic compounds were particularly of interest because of the potential they offered in yielding room-temperature ductility. The highly symmetrical structures are known to possess high-temperature ductility and room-temperature toughness. Based on a ductile binder, the alloys were prepared by the powder-metallurgy route to avoid melting and subsequent alloying of the matrix, and were extruded at relatively low temperatures. It was expected that the composite alloy would retain useful ductility. In contrast, infiltration and high-temperature sintering led to alloying of the matrix and to decreased ductility. The systems Ni-A1 and Co-A1 were selected for this study. In the Ni-A1 system the compounds NiA1, having an ordered bcc B2 structure, and Ni3Al(?1), having an ordered fcc L12 structure, were chosen. In the system Co-A1 the intermetallic compound CoAl with an ordered bcc B2 structure was used. ALLOY PREPARATION The intermetallic compounds, see Table I, were prepared by using master alloys of Ni-A1 and CO-A1, with additions of either cobalt or nickel to achieve the desired compositions. The master alloy in crushed, homogenized form, was melted with pure nickel or cobalt in an inert atmosphere, cold copper crucible, nonconsumable tungsten arc furnace. The resultant intermetallic compounds were homogenized at 2192°C in argon, crushed, and dry ball-milled in a stainless mill to -100 and -325 mesh for the Ni-A1 compounds and to -325 mesh for the CoAl compound. Finer fractions were separated for some of the composite alloys. Several ductile binders were utilized. These included Inco B nickel, 5µ ; pure cobalt, 5 µ, from Sher-ritt Gordon Mines, Ltd.; fine (-325 mesh) niobium hydride powder; fine (15 µ) type 316 stainless-steel powder; and near-saturated Ni-A1 and Co-A1 solid-solution alloys, also in fine powder form. The niobium hydride was decomposed above about 700°C in processing of the compacts in vacuum to produce niobium powder. The Ni-7.1 pct A1 and the Co-5.3 pct A1 solid-solution alloys were prepared from pure nickel or cobalt and pure aluminum by nonconsumable tungsten arc melting under an inert atmosphere. The ingots were homogenized, lathe-turned to fine chips, and dry ball-milled in air to -325 mesh powder. These solid-solution alloys are designated NiSS and CoSS; see Table I. Subsequently the hard and ductile phases were dry ball-milled as a blend. Experiments clearly established the need to coat the hard particles with the ductile binder to optimize subsequent hot compaction by extrusion. Ordinary dry mixing usually resulted in nonhomogeneous alloys which were quite brittle. Conventional cermets are consolidated by liquid phase sinteiing or infiltration, which resulis in undesirable and uncontrolled alloying of the binder phase. For this study, a loose (unsintered) powder-extrusion process was emploved, minimizing reactions between binder and hard particle, thereby permitting much greater control of composition and structure. The constituent powders were first mixed in the desired

Jan 1, 1967

By George M. Fowler, F. E. Gregory, William M. Agar, Joseph P. Lyden

The fact that most of the zinc-lead ores of the Tri-State district are associated with abundant chert in the Boone formation has led us to give much consideration to the manner of occurrence of the chert throughout the formation and to its relationship to the structural and other geologic features having bearing upon the sulfide mineralization. Necessarily the question of the source and the manner of deposition of the chert has come up in the course of these studies. We do not pretend to have arrived at the answer to all the questions regarding the chert. However, we have made a very large number of field observations, which present certain facts about the chert in this district that may be worth elaboration. Whatever theories may be drawn upon to explain the presence and distribution of the chert must necessarily be capable of reconciliation to these facts. The more important theories that have been presented are briefly summarized, and some of them discussed, in this paper. This paper is in three distinct parts, each complete in itself, wherein is recorded the evidence gained from three separate methods of attack. In an earlier paper,(3)‡ we briefly described the chert and its relation-ship to the ore deposits. Chertification, as used in this paper, means the replacement of limestone by introduced silicic acid. It is a common phenomenon in many widely distributed limestones. The products of chertification may be chert, cotton rock, or tripoli, depending upon the extent to which the replacement has been carried. Chertification is used instead of silicifica-tion in order to reserve the latter for the siliceous emanations so common in connection with the sulfide ore deposits of this and many other districts. Broadly, it is meant to include all silicification in this district prior to the introduction of the jasperoid, the latter being contemporaneous with the ore-bearing solutions.

Jan 1, 1935

By William M. Agar, F. E. Gregory, Joseph P. Lyden, George M. Fowler

The fact that most of the zinc-lead ores of the Tri-State district are associated with abundant chert in the Boone formation has led us to give much consideration to the manner of occurrence of the chert throughout the formation and to its relationship to the structural and other geologic features having bearing upon the sulfide mineralization. Necessarily the question of the source and the manner of deposition of the chert has come up in the course of these studies. We do not pretend to have arrived at the answer to all the questions regarding the chert. However, we have made a very large number of field observations, which present certain facts about the chert in this district that may be worth elaboration. Whatever theories may be drawn upon to explain the presence and distribution of the chert must necessarily be capable of reconciliation to these facts. The more important theories that have been presented are briefly summarized, and some of them discussed, in this paper. This paper is in three distinct parts, each complete in itself, wherein is recorded the evidence gained from three separate methods of attack. In an earlier paper,(3)‡ we briefly described the chert and its relation-ship to the ore deposits. Chertification, as used in this paper, means the replacement of limestone by introduced silicic acid. It is a common phenomenon in many widely distributed limestones. The products of chertification may be chert, cotton rock, or tripoli, depending upon the extent to which the replacement has been carried. Chertification is used instead of silicifica-tion in order to reserve the latter for the siliceous emanations so common in connection with the sulfide ore deposits of this and many other districts. Broadly, it is meant to include all silicification in this district prior to the introduction of the jasperoid, the latter being contemporaneous with the ore-bearing solutions.

Jan 1, 1935

The fact that most of the zinc-lead ores of the Tri-State district are associated with abundant chert in the Boone formation has led us to give much consideration to the manner of occurrence of the chert throughout the formation and to its relationship to the structural and other geologic features having bearing upon the sulfide mineralization. Necessarily the question of the source and the manner of deposition of the chert has come up in the course of these studies. We do not pretend to have arrived at the answer to all the questions regarding the chert. However, we have made a very large number of field observations, which present certain facts about the chert in this district that may be worth elaboration. Whatever theories may be drawn upon to explain the presence and distribution of the chert must necessarily be capable of reconciliation to these facts. The more important theories that have been presented are briefly summarized, and some of them discussed, in this paper. This paper is in three distinct parts, each complete in itself, wherein is recorded the evidence gained from three separate methods of attack. In an earlier paper,(3)‡ we briefly described the chert and its relation-ship to the ore deposits. Chertification, as used in this paper, means the replacement of limestone by introduced silicic acid. It is a common phenomenon in many widely distributed limestones. The products of chertification may be chert, cotton rock, or tripoli, depending upon the extent to which the replacement has been carried. Chertification is used instead of silicifica-tion in order to reserve the latter for the siliceous emanations so common in connection with the sulfide ore deposits of this and many other districts. Broadly, it is meant to include all silicification in this district prior to the introduction of the jasperoid, the latter being contemporaneous with the ore-bearing solutions.

Jan 1, 1935

By F. E. Gregory, George M. Fowler, William M. Agar, Joseph P. Lyden

The fact that most of the zinc-lead ores of the Tri-State district are associated with abundant chert in the Boone formation has led us to give much consideration to the manner of occurrence of the chert throughout the formation and to its relationship to the structural and other geologic features having bearing upon the sulfide mineralization. Necessarily the question of the source and the manner of deposition of the chert has come up in the course of these studies. We do not pretend to have arrived at the answer to all the questions regarding the chert. However, we have made a very large number of field observations, which present certain facts about the chert in this district that may be worth elaboration. Whatever theories may be drawn upon to explain the presence and distribution of the chert must necessarily be capable of reconciliation to these facts. The more important theories that have been presented are briefly summarized, and some of them discussed, in this paper. This paper is in three distinct parts, each complete in itself, wherein is recorded the evidence gained from three separate methods of attack. In an earlier paper,(3)‡ we briefly described the chert and its relation-ship to the ore deposits. Chertification, as used in this paper, means the replacement of limestone by introduced silicic acid. It is a common phenomenon in many widely distributed limestones. The products of chertification may be chert, cotton rock, or tripoli, depending upon the extent to which the replacement has been carried. Chertification is used instead of silicifica-tion in order to reserve the latter for the siliceous emanations so common in connection with the sulfide ore deposits of this and many other districts. Broadly, it is meant to include all silicification in this district prior to the introduction of the jasperoid, the latter being contemporaneous with the ore-bearing solutions.

Jan 1, 1935

Following the suggestion of Engineering Council and at the direction of, the President, representatives from each of the Federal Government bureaus interested in map-making were called into a conference for the purpose of coordinating all of the Government's map-making activities. This conference has now reported back to the President the results of its findings, which indicate that Engineering Council's recommendation in this matter was well founded. While the conference report states that its members were of the opinion that little duplication of effort existed, it recommends the formation of a permanent Board of Surveys and Maps. An extended review of the map-making activities, which is given as an appendix to the report, indicates that this recommendation is a logical step. The conference recommendations concerning this Board of Surveys and Maps are as follows: (1) the Board is to he com-posed of representatives of mapping bureaus to be assisted by outside engineering organizations, which have been named above; (2) the estab-lishment of an information office in one of the Government bureaus, preferably the Geological Survey, which is to be under the supervision of the Board and is to be a mapping information clearing house for the Government and outside engineering organizations; (3) copyright laws are to be so changed that copies of all. maps made in the United States and with Governmental authority, will go to the central information office; (4) the Government departments are to receive orders to cooperate, with the Board; (5) future topographic maps of all kinds are to conform with specifications for the standard topographic map; (6) the U. S. Coast and Geodetic Survey to have supervision of final adjustment of all important control data under specifications approved by Board of Surveys and Maps; (7) surveys in the form of maps and publications are to be issued as soon as possible after field work has been completed; (8) program of the Interdepartmental Committee on Aerial Surveying was approved. Outside technical and scientific organizations that are called in for consultation are to operate in an advisory capacity only, responsibility for action on Governmental work is. to rest solely with the Governmental agencies.

Jan 12, 1919

By George J. Young

(San Francisco meeting, October, 1911.) THE nature of slimes handled in the treatment of gold- and silver-ores has been discussed in technical literature to a considerable extent. The subject of slime-filtration from the practical worker's stand-point has also received much comment, and scattered through the literature of the subject are descriptions of many slime-filtration installations. Articles of this nature serve a valuable purpose and assist materially in the design of new and the improvement of old plants. The subject of the physics of slime-filtration has been touched upon to only a slight extent. The underlying principles are worthy of more intensive study and experimentation than they have received, and the main purpose of this paper is to present the results of such study and experimental work as will serve to make clear in part at least many of the principles which control the filtration of slime. Nature of Slime. Much has bean written concerning an accurate definition of the term ? slime," but no comprehensive definition seems to be generally accepted. The reason for this is clear. A slime consists of at least three different substances, each, when separated, possessing distinctly different physical and to a certain extent chemical properties. These substances are extremely fine sand, a colloidal material which may be and generally is in a coagulated condition, and a colloidal material which is in a non-coagulated condition. Suspending a slime in a relatively large volume of water by shaking and allowing sedimentation to take place, results in the fine sand settling out with comparative rapidity, followed by the coagulated material, which settles much more slowly and finally a certain portion remains

Nov 1, 1911

By Joseph Hyde Pratt, Douglas B. Sterrett, CHAPEL HILL

I. DESCRIPTION. MONAZITE is one of the minerals which, for a long time, was considered rather rare in its occurrence, but, upon a commercial demand arising for it, prospectors and engineers soon located large deposits of it in the Carolinas and Brazil, and the supply has always been able to meet the demand. During 1908 further sources of supply of monazite have been discovered and developed in Idaho. North and South Carolina, however, are the only States that have thus far put any monazite on the market. Monazite is essentially an anhydrous phosphate of the rare-earth metals, cerium, lanthanum, and didymium (Ce, La, Di)PO;. There is nearly always present a varying but small percentage of thoria, ThO2, and silicic acid, SiO, which are very probably united in the form of a thorium silicate, ThSiO4 Some monazites contain but a fraction of a per cent. of thoria, while others have been recorded that showed the presence of from 18 to 32 per cent. ; but the majority contain from 3 to 9 per cent. of this oxide. It is the presence of the thorium oxide that gives the monazite its commercial value. The analysis occasionally shows also the presence of other constituents, as the yttrium and erbium oxides, zirconia, alumina, magnesia, lime, iron oxides, manganese oxide, and titanium oxide. Monazite is light-yellow, honey-yellow, reddish-, brownish-, or greenish-yellow in color, with a resinous to vitreous luster, and is translucent to subtransparent. It is brittle, with a conchoidal to uneven fracture, and is from 5 to 5.5 in hardness, and from 4.64 to 5.3 in specific gravity. It crystallizes in the monoclinic system, and some crystals have been observed that were 6 in. in length. The more perfect crystals are, however,

Jun 1, 1909

The materials used for pump construction vary according to the nature of the solution handled. The pump materials in use are the result of extended experiment and are all giving satisfactory results. Research is still in progress, particularly with stainless steel and rubber lining, both of which show considerable promise. Following are the materials used: For tank-room acid, carrying about 100 grams per liter free sulphuric acid, hard lead is used. Stainless steel is under investigation. Duriron is satisfactory, but requires very careful handling to prevent mechanical breakage. For pulps containing low acid (10 grams per liter), abrasive solids, ferric iron, copper, etc. pumps are made of hard lead. Stainless steel is satisfactory. For pulps containing no acid but carrying abrasive materials and copper, bronze is used. Pulps containing acid (10 grams per liter), copper, iron and nonabra-sive solids require lead pumps. Rubber linings are under investigation. Clear neutral solutions containing copper are handled in bronze pumps; neutral solutions free of copper, acid, abrasive material, etc., in iron or bronze. The hard lead used contains 13 per cent antimony. The stainless steel has the following analysis: Cr, 20.0 per cent; Ni, 7.0; C, 0.25; W, 4.0; Cu, 2.0.

Jan 1, 1937

By Murray Kaufman

Using en; 41 for a base alloy, 15 modifications were made in sheet form. The elements Al, Ti, C, Mo, Co, and Cb were varied. The effects on the phases formed and their temperature dependence, the aging characteristics, tensile and stress-rup- ture properties, and weld cracking were determined. The A1-Ti content and balance is the most important factor influencing the major sCrengthening phases [Ni,Ti and Ni,(Al, Ti)] and, consequently, mechanical properties. THE mechanical properties, fabricating and joining characteristics, dimensional stability, and so forth, of alloys containing secondary phases are largely determined by the phases present, their distribution, and their temperature dependence. The phases in the basic ternary and quaternary Ni-Cr-Al-Ti combina- tions have been investigated thoroughly.'* The phase behavior of many commercial nickel-base alloys has been determined also. In some cases, for example U500, 5 the effect on mechanical properties has been found. However, little systematic work has been done to clarify the action of each of the important alloying elements in controlling the phases formed in complex commercial alloys and their behavior. The effect of molybdenum on the carbides formed in M252 was investigated by Beattie and verSnyder.6 Application of the results provided by that work

Jan 1, 1963

By J. R. Morison, M. P. O’Brein, J. W. Johnson, S. A. Schaaf

The force exerted by unbroken surface waves on a cylindrical object, such as a pile, which extends from the bottom upward above the wave crest, is made up of two components, namely: 1. A drag force proportional to the square of the velocity which may be represented by a drag coefficient having substantially the same value as for steady flow, and 2. A virtual mass force proportional to the horizontal component of the accelerative force exerted on the mass of water displaced by the pile. These relationships follow directly from wave theory and have been confirmed by measurements in the Fluid Mechanics Laboratory of the University of California, Berkeley. The maximum force exerted by breakers or incipient breakers is impulsive in nature, reaching a value much greater than that produced by unbroken waves but enduring for only a short time interval. This impulsive force represents the ultimate development of the accelerative force and is produced by the steep wave front and large horizontal acceleration at the front of a breaker. This impulsive force greatly exceed. the drag force computed from the particle velocities of the breaker. The reader is cautioned that these preliminary results are applicable only to single piles without bracing and are likely to be modified somewhat where multiple piles are driven, one within the influence of the other or where multiple piles are connected by submerged bracing. This paper is essentially a preliminary report submitted at this time because of the current importance of wave forces in the design of offshore structures. An extended series of additional experiments is planned for the near future. Theoretical Relationships For the sake of simplicity of treatment, the theory will be developed from the equations for waves of small amplitude. The horizontal displacement of a water particle is described by the equation 2p cosh — (d + z) H L 2pt X =----------------------sin ----- . , (1) 2 2pD T sinh------ L The horizontal component of the orbital velocity is obtained by differentiation with respect to time as 2p cosh — (d + z) pH L 2pt u = ------------------- cos— .... (2) sinh- L The acceleration of the water particles at any position is obtained by again differentiating with respect to time as 2p cosh — (d + z) 9 u -2vH L 2pt -----=----------------------------sin ----- . . (3) 3 t T2 2pd T sinh------ L where H = wave height — ft L = wave length — ft d = still water depth — ft z = depth below the still water measured negatively downward — ft. T = wave period — sec t = time — sec The force exerted on a differential section, dz, in length is pD2 s u pD 1 dF= [CM (p/4) st + Cn/2 u2] dz • • (4) where D = pile diameter — ft p = water mass density — slugs/ft3 C, = coefficient of mass C,, = coefficient of drag Substituting for a s u/s t arid u2 from Eqs. (3) and (2), the force per unit length at any position z is dF p2 pD H2 &apos; / = — [- fM sin ? ± fD cos2 ? ] . . . (5) dz 2T2 fM D fD 2pt Cm = pA/H:CD = A2;? = T [+ cos2 ? for 0 < ? < p/2 cosh— (d+z) 3p L — < o < 2p Sin L -cos2 ? for p/2 <? <3p/2 The sin 9 term (inertia) i- negative for 0 < 0 < p and positive for p < ? < 2p. Values of A and A&apos; appear in Fig. 1

Jan 1, 1950

By M. Bevis, E. O. Fearon, P. C. Rowlands

Fe-Ni and Fe-Ni-C martensite specimens have been deformed in compression at room temperature and the habit planes of operative deformation twins determined by two-surface optical trace analysis. The full orientations of the martensite crystals were determined from divergent X-ray beam diffraction patterns. The experimental results are in excelled agreement with predicted twinning modes. In particular, the habit planes of some deformation twins in bcc martensites are consistent with a "Type XI compound&apos;&apos; twinning mode with Kl, Kz, 71, 77~ elements given by {5, 8, 11) {ioi}, (33) (ill) Tetragonal derivatives of this mode are operative in bct martensites. UnUSUAL deformation twinning modes have been reported by Richman&apos; to occur in Fe-Ni-C martensites with bcc and bct structures. The twin habit planes were determined by single-surface trace analysis (pole locus method) and the remaining twinning elements were determined from the geometry of twin-twin intersections. The indices assigned to the observed habit planes are (3 101, "(089)" and "{0, 1,13)" or "{1,2,7} ", and only in the first case do the twinning elements correspond to a predicted twinning mode. This is mode 1.4 in the paper by Bevis et al. The results presented in Ref. 2 indicate that previously unpublished bcc and bct modes should be operative in preference to the (130) mode and anomalous modes reported by Richman. In view of these results and the uncertainties involved in determining habit planes from single-surface trace analysis and twinning elements from twin-twin intersections5 a two-surface trace analysis of deformation twins in Fe-Ni and Fe-Ni-C martensites has been carried out. EXPERIMENTAL PROCEDURES Two alloys with compositions Fe-23 pct Ni-0.6 pct C and Fe-30.4 pct Ni were prepared from 4N pure materials by induction melting under a vacuum of 10"5 mm Hg. The alloys were homogenized at 1350&apos;~ for 5 days. Both of these alloys are austenitic at room temperature with M, temperature - — 50"C. The aus-tenite grain size of the Fe-Ni-C alloy was approximately 300 to 400 p. The Fe-Ni alloy was remelted in a vertical tube furnace and the melt lowered slowly from the hot zone of the furnace to produce s ingle -crystal austenite specimens. Specimens approximately 10 by 5 by 5 mm were cut from the ingots and quenched to various temperatures below the Ms temperature. The specimens were elec-tropolished in a 10 pct perchloric acetic electrolyte before being deformed in compression at room temperature. Martensite plates which exhibited profuse deformation twinning were selected for analysis and the specimen polished on a second surface such that the two surfaces which contained the martensite plate enclosed an obtuse angle of approximately 145 deg. The specimens were then electropolished to reveal the traces of the deformation twins on both surfaces. The full orientations of the martensite crystals were determined using a divergent X-ray beam technique (Kossel line technique) employing an AEI SEM2 electron probe microanalyzer. Details of this technique which include a detailed description of the Kossel camera attachment to the microanalyzer used in the present experiments have been discussed elsewhere.3 Only additional details relevant to this investigation are discussed here. The specimens were mounted with one surface normal to the incident electron beam as illustrated schematically in Fig. 1. The martensite plates to be analyzed were located using the normal scanning equipment of the microanalyzer. The position of the electron beam and hence the position of the source of divergent X-rays generated within the crystal could be located to within 1 p. Exposure times of approximately 8 to 10 min were required for back-reflection Kossel patterns and it was found that useful diffraction patterns could be obtained consistently from heavily deformed martensite plates. A reference line (carbon contamination mark) produced on the two surfaces of the specimen by scanning the electron beam in a direction having a known relationship with the reference !ine in the X-ray camera enabled the full orientation of the crystals to be determined. Martensite plates with widths as small as 8 p could be oriented using this procedure. The Kossel line patterns were interpreted using the charts developed by Rowlands and ~evis~ as generally

Jan 1, 1969

By G. W. Josephson

VIRTUALLY every year inventors find one or more startling new uses for one of the varied products of the nonmetallic mineral industries. For example, in November a major step toward positive control of rainfall was made when an experimenter converted a cloud to snow by dropping a few pounds of solid carbon dioxide into it. Other examples of ingenuity in the development of markets and production methods are noted in the following pages. For most of the industrial mineral products one of the outstanding features of 1946 has been the high level of production. There are exceptions, such as quartz crystal and lithium, whose production capacity during the war outgrew current peacetime needs, but they are few. Some technical men point out that this prosperity is not an unmixed blessing to technologic progress, because so much effort must go into day-to-day production problems that relatively little opportunity is left for the pursuit of new developments.

Jan 1, 1947

By W. J. Romanow

RECENT papers by Williams, Sherwood, and Boothby,1 Seybolt et al.2 Heikes; and Roberts4 attest to the increasing importance of the hexagonal ferromagnetic compound MnBi. Since the magnetic properties of MnBi crystals are highly anisotropic, it is useful and necessary to have appropriate aids for determining their orientations—a (00.1) standard stereographic projection and a corresponding table of crystallographic angles for this structure. The tables of crystallographic angles for the hexagonal system available in the literature5 are computed for c/a ratios greater than that of MnBi and cannot satisfactorily be used to find the crystallographic angles of MnBi. A table of angles between the crystallographic planes (HK.L) and (hk.1) was calculated for MnBi from the formula0 F=are cos Hh+Kk+ 1/2(Hk+hK) + 3/4 (a/c)2Ll/v(H2 + K2 + HK + 3/4 (a/c)2L2) (h2+ k2+hk + 3/4 (a/c)2l2) on an IBM Type 650 Magnetic Drum Data Processing machine. The lattice constants used are listed in Table I and are those determined by Willis and Rooksby7 at 20°C. More recently published values obtained by both X-ray and neutron diffraction"&apos; show no difference from these significant to the calculation. From the crystallographic angles between the basal plane (00.1) and the general plane (hk.1) in Table I, an (00.1) standard stereographic projection was made for MnBi which is shown in Fig. 1. Acknowledgments The author wishes to thank R. G. Treuting and J. N. Hobstetter for their technical assistance, and Miss D. P. Booth for programing the IBM machine for the calculations. He appreciates the opportunity to read the paper of B. W. Roberts of General Electric Co. prior to its publication. References 1H. J. Williams, R. C. Sherwood, and 0. L. Boothby: Bulletin Amer. Physical Soc., 1956 vol. 1, p. 132. 2 A. U. Seybolt, H. Hangen, B. W. Roberts, and P. Yurcisin: AIME Trans., 1956, vol. 206, p. 605: Journal oF Metals, May 1956. 3R. R. Heikes: Physical Review, 1955, vol. 99, p. 446. .B. W. Roberts: A Neutron Diffraction Study of the Structures of Manganese B.W.Roberts:ANeutronDiffractionBismuthide, Physical. Review, 1956, vol. 104, p. 607. 5 A. Taylor and S. Leber: AIME Trans., 1954, vol. 200, p. 190; JouRNal of Metals February 1954. « C. S. Barrett: Structure of Metals, 2nd Ed., p. 635. McGraw-Hill Book Co. New York and London, 1952. 7B. T. M. Willis and H. P. Rooksby: Proceedings Physical Soc., London, 1954, vol. 67B, p. 290.

Jan 1, 1958

By Y. L. Yao

A scale based on existing data for the mutual solid solubilities of metals in binary systems has been compiled. This scale is useful for estimating the relative magnitude of two solubilities, provided that these two metals do not form a continuous series of solid solutions. In his classic work on the theory of metallic solid solutions, Hume-Rothery proposed that, other things being equal, a metal of lower valency should be regarded as more likely to dissolve one of higher valency than vice versa. He called this the "relative valency effect". Later he found that the application of this general principle was limited to the three univalent metals: copper, silver, and gold. In dealing with alloys of these metals with metals of higher valency, Hume-Rothery stated, it is usually found that the solid solution of the univalent metal is of the greater extent.&apos; The question of whether there is a systematic trend in comparing the relative magnitude of mutual solubilities, if valency is not considered a criterion, naturally arises. The present paper proposes a "mutual solid solubility" scale on an empirical basis. The order of its arrangement is determined by the relative magnitude of mutual solid solubilities. Some applications of and inferences from this scale are given. ORIGIN AND SCOPE OF THE SCALE An extensive survey of over 400 binary phase diagrams shows that, with certain exceptions and within certain limitations, metals can be arranged in the following order: Na Zn Cd Ga Bi Ge Sb As Hg Sn Si Mg Li Ba In Tl Pb Al Ca Be Mn Cr Re W Mo Cu V Ta Fe Ru Cb Co Ti Hf Ni Os Zr Ir Pt Au U Rh Ce Pd Ag Th so that a metal higher on the scale tends to have a higher solubility in a metal lower on the scale than vice versa. some experimental solubility data are given in Table I. These data, unless otherwise specified, are taken from Hansen and Anderko.6 Throughout this paper, the term "solubility of A in B" is taken to mean the maximum solid solubility of A in B in atomic percent, while the maximum solid solubility of B in A in atomic percent is called "reciprocal solubility". The exceptions found in the above-mentioned survey are: Al-Ag system, 20.34 at. pct Al in Ag, 23.8 Ag in Al; Mg-Pb system, 5.9 Mg in Pb, 7.75 Pb in Mg; As-Sn system, vanishingly small amount of As in Sn, a large As primary solid solution; Cd-Hg system, Cd in Hg <Hg in Cd; Mg-T1 system, 5(?) Mg in ßT1, 15.4 T1 in Mg; W-Ti system, -21 W in ßTi, -25 Ti in W; Zr-Ag system, probably small amount of Zr in Ag, 20 Ag in ßZr.7 Considering the large number of examples, the exceptions are few. It is remarkable that metals may be so arranged without considering other factors such as size, crystal structure, electronic structure, and so forth. A limitation to the use of the scale is the fact that it cannot be tested for two metals forming a continuous series of solid solutions. It is interesting to point out that when the continuous solid solutions have a miscibility gap the critical composition is

Jan 1, 1961