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Born, March 28, 1853 Died July 23, 1916 On July 25, 1916, the Board of Directors adopted the following minute and directed that it be entered upon the records of the Board & published in the Bulletin of the Institute, and thereof be sent to the family of Mr. Kirchhoff: Charles Kirchhoff was one of the oldest, most widely known and most highly esteerned members of the American Institute of Mining Engineers. On his return in 1875 from a European course of study, to begin a highly successful professional career, he joined the Institute, then just commencing to acquire both national and international recognition. He became at once, and-for more than 40 years continued to be, its earnest , and active supporter, serving it as Manager, Councilor or Director for terms aggregating 9 years,-as Vice-President for 2 years, and twice as President for a year. During the critical period of the erection of the United Engineering Society's building, and the transfer of the Institute to permanent head-quarters therein, Mr. Kirchhoff was its efficient representative in the United Engineering Society, and on the Building Committee. In 1910, amid the congratulations of colleagues, employees, and innumerable friends, Mr. Kirchhoff retired from active business as Vice- President and General Manager of a great technical publishing company. Yet he sacrificed of his well-earned leisure yet one more year, to serve the Institute as President through 1911.

Jan 9, 1916

Jan 1, 1959

By L. F. Stutzman, George Thodos

A new graphical method, which is a modification of that proposed by Buckley and Leverett', is presented for the determination of the displacing fluid saturation at breakthrough for frontal drive mechanisms. This method is applicable to all types of fluids, which may be either soluble or insoluble in the oil at reservoir and injection conditions. This adaptation has unique advantages in handling problems in which either liquids or gases are the displacing fluids. INTRODUCTION In the displacement of oil from a reservoir with water or gas injected into the formation or by the expansion of a gas cap, the determination of breakthrough or flood advance is important to define the initial and subordinate phases of the operation. Thus, the determination of the displacing fluid saturation at breakthrough is fundamental to the establishment of over-all reservoir production. Methods for analyzing this saturation and for calculating production rates have been previously reported1,'*".". All of these methods utilize the rate equation for linear flow developed by Buckley and Leverett1. xs = QT - Qn/A? (?fu/?Su) .....(1) Sp where f, represents the volumetric fraction of displacing fluid in the total flowing fluid within the reservoir as is defined by: fo = 1/1+ ku/kd µn/µn .......(2) Since the time, ?, necessary for the flood front to travel distance ?X is unknown, Eq. 1 cannot be solved directly for the determination of the breakthrough point. Therefore, it becomes necessary to solve Eq. 1 simultaneously with an equation representing a fluid bal-ance on the reservoir behind the flood front. To develop such a fluid balance equation, it has been assumed that the fluid composition is uniform in the reservoir behind the flood front. Based upon this assumption, the follow-ing equation can be derived from a material balance on the displacing fluid: x = (?X) s Dx ? x=0 [ Snx - Sn1 ] dx = QT - Qn/A? It is readily observed that the displacing fluid satura-tion behind the flood front, Snx, may be determined through the simultaneous application of Eqs. 1 and 3. Although the approach may vary, this objective re-mains the same for all of the previously mentioned graphical or analytical methods. After Sox is determined, it is then possible to calculate the gas-oil and/or water-oil ratios and the rates during the initial and subordinate phases of production, and thereby define the production history of the reservoir. In this presentation only the de-termination of Snx is considered, and the reader is re-ferred to the several texts in reservoir engineering2,4,5 for a complete discussion on the methods for establish-ing the production history of a reservoir. PROPOSED METHOD FOR DETERMINING Snx Since at any time the quantity, QT - Qn/A? is a constant, Eq. 1 may be expressed in differential form as follows: dxsn = QT - Qn/A? d (? fn/? Sn) sn .....(4) Eq. 4 may be substituted directly into Eq. 3 to obtain: ? fn/? Sn ? [ Snz - Sn] QT - Qn/A? d ( ? fn/? Sn) = QT - Qn/A? ...............(5) Eq. 5 simplifies to the expression: ? fn/? Sn ? [ Snz - Sn] QT - Qn/A? d ( ? fn/? Sn) = 1 ....(6)

Jan 1, 1958

By Edward J. Felten

THE oxidation resistance of chromium and Fe-Cr alloys is increased by small additions of yttrium or other rare earth metals.1,2 In addition, the presence of the additives increases the resistance of these alloys to spalling of the external oxide above 1000°C. This ability to prevent spalling appears to be related to the formation of an internal oxide in alloys containing yttrium or the other rare earth metals. The internal oxide is found in the form of a filamentary growth concentrated in the grain boundaries of the unoxidized metal. In alloys containing yttrium this internal oxide was found to be either Y2O3 Or YCrO3.' In an earlier report,' the growth of the external oxide was found to be controlled by diffusion through the oxide layer. Thermal balance studies were used to establish the kinetics of external oxide formation. In this related study the rate of growth of the internal filamentary oxide has also been studied. The results obtained indicate that the growth of the internal oxide is also diffusion controlled. Internal oxidation appears to occur in at least two ways. Using copper alloys containing small amounts of silicon, Rhines 3 found that between 600" and 1000oC a subscale was formed which consisted of particles of silica dispersed in the metallic matrix. The conditions requisite to internal oxidation as suggested by Rhines are: 1) a solubility of oxygen in the alloy, 2) the ability of oxygen to diffuse at an appreciable rate into the alloy, 3) the possibility of the formation by the alloying element of an oxide more stable than the oxide of the host metal, and 4) a relatively low solubility of this oxide in the metal. These conditions are fulfilled for a number of other copper alloys.3-5 Furthermore, the relationship between the depth to which the internal oxide is formed and the oxidation time follows the simple parabolic law.6 The activation energy for copper containing small amounts of silicon, germanium, iron, or manganese as calculated from Rhines data6 is about 48 kcal per mole. In some cases the internal oxide is found segregated at the grain boundaries, especially near the the surface. Observations of this type of oxide formation have been reported by stead,7 Rhines,* and Lustman. Evans" cites these cases as examples of the simultaneous movement of anions and cations during oxidation. Furthermore, Evans states that the presence of a minor constituent with a high

Jan 1, 1962

By Edward L. Beutner, Robert M. Crump

Benson Mines low-grade iron ore reserve is a replacement deposit within the Grenville gneisses of the Adirondacks. The average grade of the crude ore is about 23 per cent iron. The iron minerals are principally magnetite and hematite disseminated throughout the gneisses as discrete grains about 1 mm in size. Both the ores that are beneficiated by magnetic means and the non-magnetic ores that are treated by a gravity method of concentration are found in stratigraphically different positions but are mined from one open pit, which is about 2.5 miles long and 800 feet wide and are treated separately. The gneisses are described and named according to the distinctive mineralogy of each. Recognition of the gneissic types permits the interpretation of the structure as a northward-plunging syncline overturned to the west. A large subsidiary anticline-syncline complex occurs on the east limb of the major syncline. Iron minerals in sufficient quantity to be considered ore are confined to areas where the footwall rock has been overturned to become the hanging wall.

Jan 1, 1968

By Ta M. Li, Russell A. Carter

The first century of mining in northern Idaho's Couer d'Alene District will soon he drawing to a close. Like so many other great raining districts, it has been a period accompanied by a rich and colorful history. From its early days as a gold rush camp, the district has evolved into the leading silver producer in the US, but the going has not been easy: early-day labor disputes, the challenge of mining for profit in some of the deepest mines in the Western hemisphere, and the constant search for new reserves at great depths have taken their toll of mines-and miners-along the way. To these traditional mining problems have of late been added the burden of inflationary cost increases, pollution control, and reclamation. A recent visit to the district by MINING ENGINEERING, how ever, revealed that the deep commitment of the operating companies and the quiet competence and vitality of their engineering personnel are key factors in the continued prosperity of the district.

Jan 7, 1976

Jan 1, 1969

Jan 1, 1969

By S. S. PRENZ

Discussion held at the sessions of the Canal Zone meeting, November, 1910. [SECRETARY'S NOTE.-As a result of this discussion, an expression of opinion covering all points of unanimous agreement was adopted and signed by members of the Institute party as individuals. This statement, which was printed in the Bulletin of December, 1910, is reprinted below, as an introduction to ,the detailed report of the discussion. It should be clearly understood that it does not constitute an official declaration by the Institute, the rules of which forbid any such action. At the New Haven meeting of February, 1909, a free discussion of the plan of the canal took place, in which the critics of the present scheme had full opportunity to state their views. That discussion was continued at considerable length in the newspapers ; but the Institute was never committed to either side. In this latter instance, the situation is precisely similar. Certain members and guests of the Institute, having had the advantage of later developments and of personal inspection, have expressed the conclusions at which they have arrived on their own responsibility ; and these conclusions are published by the Institute, subject to further discussion, like any other part of its proceedings. The general statement referred to contained a promise that the full discussion, of which it was a result, would be subsequently printed ; and this promise is fulfilled, so far as practicable, in the subjoined report, concerning which I beg to offer the following explanations: 1. It is made up of the remarks of the members of our party, as subsequently written out and mailed to the Secretary. 2. In editing these contributions, I have condensed the material considerably by cutting out much repetition of opinions and phrases ; and in such excision, I, frankly confess, the authors whose communications were delayed, have been the sufferers. Nevertheless, there is a good deal of repetition left, as there must be, when so many persons had talked so much, and come to agreement upon so many points. 3. It has been found impossible to preserve in this report the actual order of the free and informal oral discussion represented. Consequently the several contributions have been arranged in alphabetical order under the names of their authors. References to "preceding speakers," etc., must therefore be construed as referring to other speakers, preceding or following.-R. W. R.] S. S. PRINZ AUGUST WILHELM, AT SEA, November 14, 1910. We, the undersigned, members and guests of the American Institute of Mining Engineers, after a visit to the Isthmus of Panama, and inspection of the work of the United States Isthmian Canal Commission, and after full discussion of our individual impressions, find ourselves in unanimous agreement as to the following conclusions:

Jan 1, 1911

For the benefit of those of our members who are considerable holders of securities,but owing to their isolated situations are not in close touch with the metropolitan market and current quotations, we are publishing two very interesting graphs, showing the course of the bond and stock markets in New York over a long period. These graphs are furnished through the courtesy of the financial department of the New York Tribune.

Jan 11, 1919

Jan 1, 1885

By T. S. Washburn

THE grades of commercial steel produced in large quantities can be divided into two general types from the standpoint of ingot structure-killed and rimmed. Killed steel covers a wide variety with carbon contents throughout the range of the steel portion of the iron-carbon diagram, and is the kind usually used in the production of alloy steels. Rimmed steel is normally associated with carbon ranges under 0.30 per cent, and is not yet used to a large extent in alloy practice, except for copper-bearing steels. The fundamental differences in the ingots made from these two types of steel can be seen most easily in Figs. 1 to 7. In the rimmed ingot shown in Figs. 5 to 7 there are two lines of blowholes approximately parallel to the sides and coming together at the top and at the bottom of the ingot. In the killed ingots shown in Figs. 1 to 4 these blowholes are not present. Also, the rimmed ingot has no well defined pipe, as com-pared to the deep pipe on the killed ingots, and there are numerous pri-mary blowholes in the lower portion of the rimmed ingot perpendicular to the surface and close to it, while on the killed ingot there are no blowholes of this type in the ingot shown in Fig. 1 and very small ones close to the surface in the lower part of the ingot shown in Figs. 2 to 4. With respect to the presence of pipe and the primary blowholes, the structure may vary considerably in both rimmed and killed ingots, therefore these cannot be considered as fundamental structural characteristics differ-entiating the two types of steel. The primary blowholes in rimmed ingots may be much less pronounced than those in the ingot shown in Figs. 5 to 7-as, for example, in "ingot iron," which is entirely free from them. An example of a cross section of an ingot-iron ingot is shown on page 16 of "Research and Methods of Analysis of Iron and Steel," published by the American Rolling Mill Co. (1920). A certain amount of pipe may also occur in rimmed ingots, though it is normally porous and not as well defined or deep as in the killed ingot of Fig. 1. In killed ingots, pri-mary blowholes may occur near the surface, as in Figs. 2 to 4, and

Jan 1, 1937

Jan 1, 1966

By William Priestley

The author has shown, by .practical experiments, how the rate of cooling steel in the mold governs ingotism, segregation, the formation of dendrites, and the distribution of intergranular material; and the resulting effect these conditions have on the physical qualities of the steel before annealing, after annealing, and after forging. The paper also describes how the structure of steel is affected by the design of the mold and the method of pouring. It is shown that the various constituents of carbon steel segregate differently under different rates of cooling. For the classes of steel covered in this paper, it is concluded that the best physical structure and the most uniform chemical composition is obtained by pouring the steel at a low temperature and solidifying as rapidly as possible in the mold. MUCH time has been devoted, by metallurgists, to the study of steel after solidification and remarkable strides have been made in the heat treatment of steel, but less knowledge is available of the thermophysical, activity of the constituents of steel prior to solidification in the mold. It is known that certain elements added to steel produce marked changes in physical properties, also that other elements added to steel produce similar changes, but we have only meager knowledge as to how these elements combine in steel under different conditions of solidification. It is not sufficient to know, from chemical analysis, that a certain element is present in steel. We should know how this element is in combination with the other elements and whether the combination is such as will give the greatest physical properties. Certain elements go into solid solution with the iron, while others segregate to the grain boundaries and combine with the impurities collected there. Until it is known where an alloy produces the most beneficial effect and a means, is determined for controlling its physical location by altering solidification conditions, or otherwise, we will not obtain the maximum value from our alloys.

Jan 2, 1924

Jan 1, 1970

By R. V. Norris

1. INTRODUCTION. THE anthracite coal trade, with a shipment averaging about 70,000,000 tons per year, differs essentially from other coal business, in the fact that the larger sizes, comprising about 65 per cent. of the total, are used almost exclusively for domestic purposes, principally during the winter months; and that for proper combustion close-sizing is imperative, so that eight sizes are made; broken, egg, stove, and nut, known as prepared sizes, and pea, buckwheat, rice, and barley, known as steam sizes. These sizes are made in the regular course of preparation, and but little variation in the natural percentage of each is practicable. Thus it is necessary either to work the collieries intermittently, or to dispose of all the varying sizes in their fixed proportions. Unfortunately, the market does not at all times absorb the coal in proper proportions, and rather than interfere with the regular operation of the mines it has been found economical to provide storage for the excess. While the cellars of the consumers are the great storage-plants of the country, this capacity is not under the control of the trade, except so far as reduced prices during the spring and summer months may tempt the use of this reserve. The same remark applies but with less force to the retail yards, which,, though usually small, store in the aggregate a large amount of anthracite. While every effort is made to utilize to the utmost the individual storage-capacity of the country, there still remains the necessity for taking care of the irregularities of the market by the construction of storage-plants under the direct control of the producers. Such plants are usually the property of the railroads, and are situated at points most convenient from a traffic stand-point.

Jun 1, 1911

Jan 1, 1970

By F. R. Morral

INDUSTRY has yet to find a universal solution to the problem of engineer personnel selection. Today, the choice of the right man for the right job is even more pressing than ever before. The age of the hard apprenticeship seems to have passed. In its place one finds the interviewer who must determine through personal contact and evaluation of college grades whether a graduate engineer will fit into his company's scheme. The problem, as it is constituted today, may be broken into four parts: Need for better use of human resources (there is a shortage of engineers, scientists, and skilled workers), productivity with higher efficiency, encouragement of personal pride in work performed, and employee's happiness on the job and away from it.

Jan 4, 1953

By George C. Stone

WHEN George C. Stone, a Director of the Institute, and so well known to our Members in connection with the Institute's many activities was abroad in 1.919, he secured an interesting collection of these coins, which appeared in Zinc, a publication by the New Jersey Zinc Co. Regarding this collection of coin, Mr. Stone says: "During the war, all gold and most of the silver disappeared, making small change very scarce. As the French Government was fully occupied by the war, it allowed various Chambers of Commerce and other bodies to issue money, both paper and coins. Many of the latter were made of zinc, and I secured several while in Paris. We had all heard of the Belgian and German zinc coins, but I imagine few knew how many different kinds there were. The accompanying plates show both sides of those I got. I took all that the dealer had; but he said that there were a number of others in existence. The coins in the bottom line were issued by the Germans in Belgium during the war and all are still in common use. The first two in the next to the bottom line are German. All of the others were issued by Chambers of Commerce or corporations. A few have been nickel plated; these look and wear much better than the others. "Coins" made of pasteboard were also issued by similar bodies, also notes.

Jan 1, 1920