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By AIME AIME

0 N March 5, at Carnegie Hall, Cleveland, the Ohio Section held a joint meeting with the Cleveland Engineering Society, and the local sections of the American Chemical Society, American Society of Mechanical Engineers, and the American Society for Steel Treating. Prior to the meeting there was an informal dinner attended by 50 men. Then followed an address, "The Principles of Corrosion Protection," by Ulick R. Evans, the well-known British specialist in this problem. There were 266 present, presided over by Zay Jeffries, president of the American Society for Steel Treating and a member of the Cleveland Engineering Society. The address was well received and some discussion followed

Jan 1, 1929

By Frederick M. Becket

AFTER all the chronology that has been given, what is the present status of chromium steels? For the purpose of this discussion the different types of chromium steels can be divided into three classifications-those containing relatively low , percentages of chromium, say 5 per cent or less; the medium-chromium steels containing up to about 18 or 19 per cent chromium; and the steels containing still higher percentages of chromium, and some of the special alloys. Chromium has some unique effects in steel, so it is well to make a few generalizations. The affinity of chromium for carbon is great and the metal is unique in the manger in which it supplements and enhances the effects of carbon. Chromium retards -considerably the thermal transformations on cooling and exerts an opposing influence both on the absorption and precipitation of the carbides in steel. These statements make it easy to understand the fact that chromium .steels are capable of producing a hardened product at a much slower rate of cooling than is, true of plain carbon steel, and that chromium carbide or -the mixed carbides of iron and chromium do not contribute to brittleness to as great a degree as does iron carbide.

Jan 1, 1929

By PALMER H. TYLER

WHEN the Mid-Continent Section of the A. I. M. E. met at the roof garden dining room of the Tulsa Club on Monday evening, May 13, most of the members present came prepared with a credulity-stretching yarn of some sort or other, gathered from actual experience. Perhaps it was not realized at the time that such anecdotes would eventually burst into print, but while the excellent dinner was appeasing the inner man the word was passed around that informality and spontaneity of expression would characterize the meeting, with the result that the shackles of convention were eventually cast aside and the meeting waxed better and better until the hour grew ,late, and the chairman, L. G. E. Bignell, originator of the idea, brought to a close what was agreed to be a profitable and entertaining evening. The ball was started rolling by Paul Ruedemann of the program committee, who offered the following:

Jan 1, 1929

By GUY C. RIDDELL

THE recent purchase by an American investment trust of a substantial block of shares in a British owned Venezuelan copper operation directs attention to mining activities that have been quietly gaining momentum in that country for a number of years. We hear so much of oil work in Venezuela that attention to its metal-mining activities is in most quarters casual. In gold and copper the country has made some interesting mining records, and two of the old districts are ,digging in for a come-back. Copper Copper production centers in the state of Yaracuy. The Aroa-Cumaragua mining region has had a long and eventful history. The Aroa mine itself, 50 miles from the coast in West-Central Venezuela, was discovered in 1605. First mined in 1632, owned at one time by Simon Bolivar, it has been reopened many times and is now , the basis of substantial operations by the South American Copper Syndicate, Ltd. of London. The latter has operated the property profitably, off and on, for a number of years, paying heavy dividends on a small investment-at times over 300 per cent annually.

Jan 1, 1929

By CARL B. SNYDER

PERHAPS the most extraordinary thing about business, the trade and production of the country as a whole, is its amazing continuity and growth, its momentum and energy. It goes on year after year, growing steadily, almost without breaks, in spite of every kind of disturbance. We have been grossly deceived into the idea that business is highly variable. We have taken a few things like pig iron, and the like, constructional activity broadly, and imagined that these are a trustworthy measure of trade. Actually they are the worst that we could find. They do not apply to more than 10 per cent or, at the most, possibly 15 per cent of the total of the country's industrial activity. The other 85 or 90 per cent, or even more, goes on growing surely and steadily just like the growth of population and the steady advance in technique, invention, discovery, and improved methods of production Let me give you what seems to me one of the most remarkable examples of this amazing momentum and regularity. You know that 90 per cent or more of the business of the country is done 'by means of checks. About seven-eighths of the total of all checks drawn are reported regularly every week in the newspapers. Let us follow these reports from week to week, just as they come, and plot them up against the correspond- ing weeks of last year, and the year before, and the gear before that, as far back as you would like to go. Take especially the figures for 140 selected cities out- side of New York.

Jan 1, 1929

By R. A. RAGATZ

THE preparation of specimens for microscopic examination from metal articles of relatively large cross-section offers no particular difficulty. It often happens, however, that articles submitted for examination are so thin that specimens satisfactory for microscopic examination can not be successfully pre- pared by the methods commonly employed when working with larger articles. Ordinarily, the preparation of metallographic specimens involves the following operations : (1) cutting the small specimens to be examined out of the larger mass of metal, (2) cleaning and electroplating, (3) mounting to furnish support during the grinding and polishing operations, (4) grinding and polishing to produce a scratch-free surface, (5) etching and drying. All of these operations must be carried out in such a manner that when the specimen is finally examined under the microscope, the structure seen is a true and well-defined representation of the structure that the larger mass of metal possesses at the place where the small specimen was removed. It is important that the deformation involved in cutting out the specimen be as slight as possible, in order that the subsequent grinding and polishing operations will completely eliminate the cold- working effects in the vicinity of the cuts. It is also important that the specimen never be allowed to attain a temperature high enough to alter its structure; the maximum permissible depends on the metal being handled. With some metals, zinc for example, consider- able care must be taken to avoid heating; with other metals, annealed steel -for example, no particular pre- cautions need be observed because there is no tendency for structural change to occur at relatively low temperatures.

Jan 1, 1929

By AIME AIME

THE petroleum economics session," held on Wednesday morning, Feb. 20, 1929, presided over by Campbell Osborn, chairman, proved to be of un- usual interest and resulted in serious and constructive discussion of the papers presented. The first paper on the program, "Gasoline Economics and Refinery Operation," was by H. J. Struth, petroleum economist of the Gulf Publishing Co., Houston, Tex. While this paper was intended to cover the re- finery situation, it also presented the author's reasons for believing that the oil producer should give cognizance to gasoline demand as a most reliable barometer by which to parallel the production of crude petroleum. The discussion which followed brought out some interesting points in connection with the immediate outlook for the industry as a whole during the present year. Some advanced the opinion that, regardless of the out- come of proration efforts, the refiner is in a position to conduct his operations on a reasonably profitable basis, provided that he exercises control over them. This would mean running less crude and resorting to wider utilization of cracking to produce the gasoline demand. Thus, if the refiner uses diligent care in scheduling his still runs, the producer will be obliged to carry over a large stock of crude this year, unless he is able to keep production below the limits prescribed by the demand for gasoline.

Jan 1, 1929

By Howard S. Bryant

FROM the viewpoint of the oil producer, the oil refiner, the oil marketer, and the investor, in oil securities, a brief picture of the crude oil supply and demand in the present critical season of the year will be timely and interesting. Although crude oil production has been in a comparatively poor statistical position this year, increased sales and sustained refinery and crude oil prices have allowed increased profits for many oil companies. The large amount of crude oil going into storage during the present period of peak consumption, just previous to the major yearly fall decline in consumption, has caused oil producers to make plans to leave the oil in the ground for the present in several of the areas of large flush production. The present moment is looked on as the turning point in the current year.

Jan 1, 1929

By L. W. WALLACE

IN an engineering fashion we have made an assay of the engineering profession, using as a. sample the engineers listed in "Who's Who in America" (1928-1929). We are aware that some will say it is an unfair sample; that it came from the best mine. This is readily admitted, with this qualification: that all engineers and architects by virtue of their training and experience have been freed of most of the dross to which mankind is heir. They are -a selected group to begin with, having all the potentialities those in the sample possess. We are also aware that some will say a part of those included in the sample are not engineers. Our answer to that criticism is this: An engineer is no less an engineer because for the time being he is president of a bank, a university, an opera company, or a hotel company. Moreover, he is no less an engineer because he is a governor of a commonwealth, a United States senator, a member of the Cabinet, or the President of the United States.

Jan 1, 1929

By William F. Boericke

THERE was a time when the selection of fire brick was .left to the judgment of the head bricklayer of the plant, whose choice was not unaffected by a box of Christmas cigars from a friendly salesman. But the days are past when it was generally believed, with complacent philosophy, that bricks were bricks without much distinction, and should be bought on a price basis alone. Gone, too, is the belief that in certain types of industrial work the eventual failure of refractories was assured. Modern metallurgical practice, with its trend toward handling larger tonnages at higher temperatures, demands the use of refractories that cannot be supplied by random guess. The logical development is to inquire into the properties of the brick to be purchased, and this resolves itself into the use of specifications. In 1925, the General Refractories Co., with the active support and hearty cooperation of some of its larger customers, established a laboratory, at its Baltimore plant, for testing and research in refractories. This was the outgrowth of a growing appreciation of the value of research in the refractory field. Since then the work has become more involved' and the aims more ambitious, so that the present laboratory now employs a staff of 11 men working, under the direction of trained refractory technologists, on problems of research as well as the routine control of manufacture. It is believed s that `this type of laboratory is a comparative novelty among refractory manufacturing plants. It handles the testing and research work for all the 15 plants of the organization. Being at one of the works has the advantage of making it possible to carry on large scale plant tests on new products after the preliminary laboratory tests have been successfully completed.

Jan 1, 1929

By Thomas T. Read

THE official title of our topic for today is "Resources of Metals and Other Strategic Minerals," but in accepting the invitation to open this discussion I claimed the privilege of being allowed to talk about problems other than resources for the two reasons that a great deal has already been said about resources and because we can never discuss them with the degree of certainty that an engineer likes. Resources are uncertain for many, reasons. One is that we do not know what is in the earth. It is four thousand miles to its center and although oil wells 1 ½ miles deep are becoming common and engineers are now talking of drilling holes 2 miles deep, even when they do they will have advanced only one two-thousandth part of the total distance. Only a relatively few mines are over a mile deep as yet. We know certainly that it is comparatively expensive to work at such great depth, but it would be a very foolish man who would assert it will be' impossible, one or two hundred years from now, for engineers to obtain from great depths mineral supplies that are now being obtained at or near the surface. As long as- I can remember I have been hearing that our petroleum resources were in imminent danger of speedy exhaustion, and yet the yearly output is now of the same order of magnitude as the total resources were once estimated, with ' the cry of over-production the loudest it has ever been. Tapping progressively deeper and deeper sources of supply, has produced this result. Even in the thin layer that we are now working much-exploration still remains to be done. .

Jan 1, 1929

By F. G. Clapp

IT is to be hoped that no casual reader will erroneously refer to the latest publication' of the Division of Public Relations of the American Petroleum Institute, as being "Petroleum Facts and Fancies." The facts are so faithfully derived and the figures are so authentically sponsored by the highest sources that no person can read this valuable volume (287 pages and numerous tables) without being convinced that every- thing therein set forth is "the truth and nothing but the truth." Yet, having read the volume from the perspective of the world's petroleum industry and with a critical attitude that comes from years of study of the subjects discussed, I find myself tempted to cogitate and to envisage a few of the fancies that come to mind as a fitting sequel.

Jan 1, 1929

By FREDERICK MCAKCCOY

THE production of tin from Mexico has never reached the point of being considered a national industry, but the distribution of tin ores is so widespread that there are possibilities that one day it may become of importance. Of the twenty-seven states of the Republic, tin claims have been taken up in sixteen. In all there had been taken up to the end of 1926, two hundred and twenty-five claims, of a total area of about 7400 acres. The first historical mention of tin in the Americas is found in a letter of Cortez to the Emperor, Charles the Fifth, of Spain, which is as follows: Speaking of his manufacture of some small cannon, he says: "For these reasons I took considerable pains to get copper from some provinces of this country, and bought it at a high price in order to get it quicker.

Jan 1, 1929

By O. E. Kiessling

THIS announcement of the topics relating to production control, which the Committee hopes to have discussed at the February meeting, supplements the preliminary announcement published in the November number of MINING AND METALLURGY. In the previous article, the writer indicated the kaleide-scopic nature of the questions involved in obtaining better coordination in industry, and that, as a matter of practical expediency, the discussion in February would be limited to the more obvious difficulties in industry which need attention and to those questions which the Committee thinks would be of greatest interest to members of the Institute. But while practical considerations necessitate limiting the program, free discussion of all phases of the subject is urged by 'the Committee. In a preliminary consideration of the production control problem, there loom up two questions which have to be faced: (1) First, there is the question of the extra industrial capacity necessary to meet demand during the ordinary fluctuations of business, commonly characterized as `the "business cycle." Anyone who tries to formulate a program pertaining to productive capacity must decide whether he wishes to discuss the control of business cycles. While this question may eventually lend itself to treatment, the Committee does not feel that it can be considered at present with much profit. (2) The second question arises from the existence of over-stimulated capacity above and beyond peak demands in boom times. Discussion of this topic, it is felt, would be most fruitful. How to prevent capacity from being over-stimulated to an extent beyond any hope of possible demand is a

Jan 1, 1929

By E. L. BROKENSHIRE

FLUORSPAR, a little known non-metallic mineral, referred to technically as fluorite, chemically as calcium fluoride, is a compound of calcium and fluorine in the ratio of one molecule of calcium to two of fluorine. By weight it is composed of 51.3 per cent of calcium and 48.7 per cent of fluorine. Its specific gravity is 3.2. It is brittle, has a hardness of four and can be easily scratched with a knife. It weighs about 200 Ib. per cubic foot and has a melting point of 1650" F. The color of fluorspar ranges from pure white and opaque white, according to its purity, to various hues of yellow, green, pink, lavender, blue and brown, to bluish black. Although the lumps have color, when ground the fluorspar becomes pure white. The reason for this is because the mineral usually carries no fixed pigment, the color being produced by the re- fraction of light rays within the crystal structure and small quantities of organic matter which readily oxidizes. It crystallizes in the isometric system with perfect octahedral cleavages.

Jan 1, 1929

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 AIME AIME

THE non-ferrous alloys have been placed in the same class with steel by metallurgical research on hardening, and hardenable alloys of all metals except zinc are now manufactured. The hardening of the non-ferrous alloys is accomplished by a process of heating, quenching and ageing. R. S. Dean, head of the research department of the Western Electric Co., told of the results of this research in 'a lecture on "Recent Advances in the Art and Science of Fabricating Metals," given before the Missouri Mining and Metallurgical Association on Jan. 24, 1929.

Jan 1, 1929

By O. A. Carson

Introduction Although the equilibrium conditions of the copper-tin alloys have been the subject of a ?great amount of research, the equilibrium diagram is still in doubt. The first systematic investigation of the series was made in 1894 by Le Chatelier, who published a freezing-point curve. In 1895, Roberts-Austen and Stansfield published the complete liquidus and partial solidus curves, which they modified somewhat in 1897. Their liquidus as given in 1897 is essentially that accepted today (Figure 3). Haycock and Neville also published a liquid us curve in 1897. In 1898, William Campbell published a series of micrographs showing the changes in microstructure which accompanied the thermal changes of Stansfield? s diagram. The classic work on the bronze series was published by Heycock and Neville in 1903. Their diagram was based on both thermal and microscopic evidence, and is the first for this series of alloys which can be considered nearly complete. Further, it was the first bronze diagram in which any attempt was made to apply the phase rule in the interpretation of the thermal and microscopic results. That portion of Heycock and Neville's diagram covered by the present work is reproduced in Figure 7.

Jan 1, 1929

By C. W. Davis

THE name fuller's earth, which was derived from its early use in "fulling" or removing grease from woolen goods, is a term that is generally considered to designate mineral matter, containing hydrous aluminum silicates of the clay group, which has a high capacity for removing colors from oils, whether of animal, vegetable, or mineral origin. Fuller's earths are usually dried and may be "tempered" by heating or may be treated with water or reagents to improve their efficiency. For our purpose the term "acid-treated earths" will include those products from the partial decomposition of mineral water by acid which are equal to or more efficient than an untreated fuller's earth from Quincy, Fla., when used in bleaching mineral oil by the "contact" process. In general, the contact process for treating oils consists of heating and agitating a mixture of oil and finely divided adsorbent, the latter being subsequently removed by filtration. The term "adsorbent" is used because, although there has been a great deal of controversy over the mechanism of removal of impurities from oils by mineral matter, there is no doubt that adsorption, which involves the surface of the solid, plays a major part.1 The properties that make fuller's earth useful in the treatment of petroleum products by "percolation" and in the purification of edible oils by the contact process have long been studied, but the comparatively recent adaptation of the contact process to the bleaching of petroleum products has made desirable the further investigation of fuller's earth and other adsorbent earths.

Jan 1, 1929

By C. K. Leith

IN telling the story of Canada's minerals many interesting and spectacular details will be passed over to permit pointing out some of the significant inter- national aspects. No country now has enough of all minerals for its own use. The problems of satisfaction of both national and world demands under these conditions have become international in scope, and history supplies no obvious solutions. The minerals of Canada are coming to play a prominent part in such problems. Production and Reserves In the last decade Canada has rapidly advanced in mineral production. In 1928 the total value of mineral products from Canadian sources reached 273 millions of dollars. Canada ranks first in production of nickel, first in asbestos, second in cobalt, third in gold and silver, fourth in lead and copper, and sixth in zinc.

Jan 1, 1929