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The State Mining Bureau of California under the direction of Fletcher Hamilton, State Mineralogist, is starting a field campaign to report on the economic minerals of California, which have an important industrial and military bearing on the present war situation. Particular interest and value attaches at the present moment to our available supplies of chrome, coal, iron, magnesite, manganese, molybdenum, quicksilver and tungsten. Trained geologists and engineers of the Bureau's staff are being sent, out to obtain information with relation to the latest developments. Advance notices will be sent to the local newspapers, from time to time, of the arrival of the engineers in the various districts. All persons interested in the minerals mentioned are earnestly urged to cooperate with the State Mining Bureau by meeting the field men while in their districts or by communicating direct with the State Mineralogist at his office in the Ferry Building, San Francisco. The State Mining Bureau has just issued Bulletin No. 72 on The Geologic Formations of California. It was written by Prof. James Perrin Smith of Stanford University, and contains a complete bibliography and resume of all of our present knowledge relative to the geological formations occurring in California. It also contains much previously unpublished data, and six tables showing geologic columns. It covers 41 pages.

Jan 6, 1917

By I. R. Kramer

[The final paper in the diffusion symposium was given by I. R. Kramer. The author called attention to the diffusion characteristics of chromium deposited on the surface of steel by treatment with chromium chloride and alloyed with the surface layer of the steel by thermal treatment. As the data cited were previously published in the paper " Chromizing of Steel," by I. R. Kramer and Robert H. Hafner (Metals Technology, October 1942, and in the Transactions, volume 154, 1943, pages 415-420), it is unnecessary to reproduce these data here. The following paragraphs are taken from the author's presentation.— Editor.] Aside from the well-known practical application of the diffusion phenomena to carburizing and calorizing, -diffusion also finds application in adding alloying elements to the surfaces of steel parts. The chromizing of steels is a process by which the surface of a low-alloy steel may be enriched with chromium to form a highly corrosion-resistant case; This chromized case differs from an electroplated coat in that it is a diffused layer integral with the base metal and has all of the properties of a high-chromium steel. Recently a method of chromizing has been developed in Germany by Daeves, Becker and Steinberg in which gaseous chromium chloride and hydrogen are passed over the steel at temperatures of 1650° to 1800°F. The chromium chloride reacts with the iron to give chromium and iron chloride. The chromium atoms are deposited on the surface and diffuse in as the iron atoms diffuse out, forming a layer rich in chromium. The principal role of hydrogen is to remove the carbon from. the surface of the steel. Of the two mechanisms, chemical reaction and diffusion, the one operating at the slower rate will determine the rate of formation of the layer. In this case, diffusion is slower and therefore any factors influencing its rate will affect the process. The rate of diffusion is influenced by the temperature and crystal structure of the parent metal. Depth-concentration studies show that the concentration falls off gradually for a considerable distance and then drops sharply at about 13 per cent chromium, the point coincident with the boundary of the gamma loop. The influence of the composition of the base metal upon diffusion is quite important. The depth of penetration of the chromium decreases as the carbon content increases and, of more importance, the chromized layer becomes brittle and is likely to spa11 if the carbon content is too high. It appears that in order to chromize successfully the carbon must be fixed by strong carbide-forming elements such as chromium or molybdenum, which decrease the diffusion of carbon. If this is not done, the carbon will diffuse from the interior faster than the chromium can diffuse inward, thus forming a carbide barrier. The corrosion resistance of the chromized layer is high, and these steels offer some unique advantages over other corrosion-resisting coating or alloys. While chromizing is not meant to replace stainless steels, it may serve in the saving of alloying elements. The chromizing process uses soft or low alloyed steels that can be easily hot or cold formed and since the chromized layer is soft and firmly adherent, chromized parts can be subjected to cold deformation without spalling or chipping and without loss of corrosion resistance.

Jan 1, 1944

By I. R. Kramer

[The final paper in the diffusion symposium was given by I. R. Kramer. The author called attention to the diffusion characteristics of chromium deposited on the surface of steel by treatment with chromium chloride and alloyed with the surface layer of the steel by thermal treatment. As the data cited were previously published in the paper " Chromizing of Steel," by I. R. Kramer and Robert H. Hafner (Metals Technology, October 1942, and in the Transactions, volume 154, 1943, pages 415-420), it is unnecessary to reproduce these data here. The following paragraphs are taken from the author's presentation.— Editor.] Aside from the well-known practical application of the diffusion phenomena to carburizing and calorizing, -diffusion also finds application in adding alloying elements to the surfaces of steel parts. The chromizing of steels is a process by which the surface of a low-alloy steel may be enriched with chromium to form a highly corrosion-resistant case; This chromized case differs from an electroplated coat in that it is a diffused layer integral with the base metal and has all of the properties of a high-chromium steel. Recently a method of chromizing has been developed in Germany by Daeves, Becker and Steinberg in which gaseous chromium chloride and hydrogen are passed over the steel at temperatures of 1650° to 1800°F. The chromium chloride reacts with the iron to give chromium and iron chloride. The chromium atoms are deposited on the surface and diffuse in as the iron atoms diffuse out, forming a layer rich in chromium. The principal role of hydrogen is to remove the carbon from. the surface of the steel. Of the two mechanisms, chemical reaction and diffusion, the one operating at the slower rate will determine the rate of formation of the layer. In this case, diffusion is slower and therefore any factors influencing its rate will affect the process. The rate of diffusion is influenced by the temperature and crystal structure of the parent metal. Depth-concentration studies show that the concentration falls off gradually for a considerable distance and then drops sharply at about 13 per cent chromium, the point coincident with the boundary of the gamma loop. The influence of the composition of the base metal upon diffusion is quite important. The depth of penetration of the chromium decreases as the carbon content increases and, of more importance, the chromized layer becomes brittle and is likely to spa11 if the carbon content is too high. It appears that in order to chromize successfully the carbon must be fixed by strong carbide-forming elements such as chromium or molybdenum, which decrease the diffusion of carbon. If this is not done, the carbon will diffuse from the interior faster than the chromium can diffuse inward, thus forming a carbide barrier. The corrosion resistance of the chromized layer is high, and these steels offer some unique advantages over other corrosion-resisting coating or alloys. While chromizing is not meant to replace stainless steels, it may serve in the saving of alloying elements. The chromizing process uses soft or low alloyed steels that can be easily hot or cold formed and since the chromized layer is soft and firmly adherent, chromized parts can be subjected to cold deformation without spalling or chipping and without loss of corrosion resistance.

Jan 1, 1944

"In 1899 the American Refining and Smelting Company obtained control of the East Helena Smelter, and have added improvements from time to time.The plant is four miles east of Helena, on the Northern Pacific and Great Northern railroads, with hourly street car service from Helena.Electric power is obtained from Canyon Ferry dam, twelve miles east on the Missouri river, and about 800 h-p. is used in the blowing engines, crushing machinery, cranes and locomotives.Besides the Montana ores convenient to the above railroads, a large part of the ore supply comes from the Coeur d'Alene district, Idaho, and is mainly lead ore and concentrates.A modern automatic sampling mill, with Vezin samplers and a capacity of 50 tons per hour, was completed in 1912.Three blast furnaces, each 48 inches by 136 inches, are now in continuous operation, and the monthly production of silver-lead bullion is six thousand tons.A part of the ore roasting is done in Godfrey furnaces, in connection with the Huntington-Heberlein process, 12 pots being in use, with a capacity of 300 tons per day.Four Dwight-Lloyd sintering furnaces, each 42 inches by 264 inches, and a smaller experimental machine, with a combined capacity of 440 tons per day, are in steady operation, and are successfully roasting ore as well as sintering flue dust. These machines are in great favor and results are being carefully watched.Three bag houses are used in connection with the 1,800 brick flue chamber, and each bag house contains 1,260 cotton bags, each 18 inches in diameter by 30 feet long, suspended on vertical roads. The product saved by the bags contains about 50 per cent lead and is retreated in the blast furnace after sintering.About 450 men are employed."

Jan 1, 1913

IN order to make his work easier, every master of any art whatever keeps always to the road that he has learned or that his skill or good judgment has shown him to be the best. Although there are various methods used in making moulds for guns, depending on whether they are large or small, nevertheless almost the same road is traveled in all. You must first know that it is necessary to make a pattern of wood or clay exactly as the gun is to be, with those ornaments of cornices and rings that you wish to be in the bronze. Let us suppose that you wish this pattern to be of wood. You must try to have for this a piece of fir as long and thick as you wish, dry, solid, and well seasoned, with few or no knots if possible. This should be longer than the gun by the length of the head and foot rests where it is pivoted [83v] so that it can be turned as on a lathe. On the end where the mouth is to be it should project out enough so that you can attach a feeding head at the top of the casting. You can make or have this pattern made round, fluted, spiral, or half fluted, as you like best, making the measurements exactly correct with all care and attention. Then two bearing trestles must be fixed firmly in the ground, one at the head and one at the foot, as is usually done with roasting spits and as you see drawn here. This done, if it is fluted, put the cornice pieces at the place where you wish the mouth to be and at the foot where the fire is applied. These are

Jan 1, 1942

By Jerome Alexander

IT is an outstanding fact of Nature that many of the practical properties of substances are dependent, not on their ultimate chemical composition, but on the kind and degree of aggregation of their constituent particles. Thus, a granite boulder is unmoved by wind or water, but if reduced to a fine dust it will be blown about by the wind and washed away by the rain. Carbon in one crystalline state of aggregation (diamond) is the hardest known substance, whereas in another crystalline state (graphite) it is so soft that it is used as a lubricant. Laying too much stress on the mere chemical analysis of substances is apt to obscure the fact that the nature of the aggregation of their particles is always a factor of importance, and sometimes the most important factor. Colloid chemistry deals with matter in. a very fine state of subdivision; its sphere begins with particles just a little smaller than a wave length of light-and extends clown until they blend into molecular dimensions. With particles of this size; such phenomena as surface tension and adsorption, which depend on the development of free surface, become enormously magnified. Thus a cube of 1 cm. edge has a surface of only 6 sq. cm.; but if it is reduced to colloidal dimensions by being cut up into cubes each having an edge of 0.01 , (0.00001 mm.), it will yield one million, million, million (1,000,000,000,000,000,000) such cubes, having a combined area of 600 sq. in., or 21,274 sq. ft. The tiny force with which a drop of rain clings to the window pane becomes a. factor to be reckoned with, if the surface involved is increased millions of times. From the colloid-chemical viewpoint, metals and alloys may be regarded as jellies or sponge-like structures, the viscosity or stiffness of which at ordinary temperatures is exceedingly great; and like all jellies their properties are dependent on the composition and degree of dispersion of their constituent phases. These, in turn, depend on chemical composition, mutual solubility, speed of chilling, subsequent mechanical and heat treatment, etc In fact, in preparing metals and

Jan 2, 1919

Jan 1, 1928

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Jan 1, 1928

Jan 1, 1934

Jan 1, 1934

Jan 1, 1921

Various Abstracts

Jan 10, 1978

Jan 1, 1948

Jan 1, 1902

Jan 1, 1902

Jan 1, 1906

The members of the Institute will recall the account given in the March Bulletin of the inauguration exercises of the Engineering Foundation which was inhibited by an initial gift of $200,000 by Mr. Ambrose Swasey, to be administered by the United Engineering Society as trustees. The Engineering Foundation Board is now constituted as follows: GANG DUNN, Chairman, EDWARD D. ADAMS, Vice-Chairman FREDERICK R. HUTTON, Secretary, JOSEPH STRUTHERS, Treasurer, American Society of Civil Engineers. J. WALDO SMITH, CHARLES WARREN HUNT.

Jan 12, 1915

Jan 1, 1915

By George Haworth

ELECTRICAL illumination of shafts, stations, and haulageways has been successfully practiced for many years, but its use in drifts and stopes where mining operations are carried on has- been limited. The large underground drifts of the Tri-State field present a lighting problem that is not satisfactorily solved by the use of the carbide lamp. It has, for some time, been the policy of the Anna Beaver mine to provide ample lighting throughout the underground haulage drifts and working faces. This has, in the

Jan 6, 1928

W. H. BASSETT, * Waterbury, Conn.-Manganese should not be expected to remedy all the defects that are due to poor melting practice. It is undoubtedly valuable in helping to eliminate porosity in many of the alloys. In the copper-nickel alloys, its use is becoming almost universal, for, beside helping to make sound castings, it tends to hold the carbon in solution in the solidified alloy. GWILLIAM H. CLAMER,? Philadelphia, Pa.-I have found that manganese copper is satisfactory for eliminating sulfur and that it works very well in the crucible and when you have reducing conditions; but in a large reverberatory charge, where the conditions are oxidizing, we were not able to eliminate the sulfur.

Jan 1, 1919