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By Charles Frey

TIE fundamental principle of resistance thermometry lies in the determination of temperatures by the measurement of an electrical conductor subjected to various temperatures and the translation of the resultant changes, in ohms, into temperature equivalents. Such resistance measurements can be made with maximum precision by the use of a standard Wheatstone bridge and a reflecting galvanometer of high sensitivity. Under such conditions, results are obtainable that may be accurate within 0.1 or even 0.01 per cent., and the "idiosyncrasies" of heated electrical conductors can be studied with advantage and profit, even if the latter is not of a financial nature. The chief requisites for producing a serviceable -commercial instrument may be enumerated as follows: First, there must be a resistor or "bulb" that can stand the maximum temperature without deterioration and which has a pronounced temperature coefficient. Second, there should be constructed an "even" bridge, having two fixed arms of equal values, in ohms. Third, a rheostat, the maximum resistance of which will be equal to the total change in the resistance of the bulb, between temperature extremes, is required. Fourth, there must be a sensitive galvanometer which is aperiodic, or nearly so. Finally, there should be a fairly steady source of direct current. The general scheme of this type of apparatus, in its simplest form, can be readily understood by reference to Fig. 1. Resistors A and B are constructed of manganin, therlo, or some other resistance wire having a negligible temperature coefficient. The sensitive D'Arsonval galvanometer G has its zero in the center. R is a rheostat and X is a resistor or bulb made of insulated platinum wire, or else of nickel, copper, or some alloy, according to requirements. K is a battery, but a direct-current service line is often used instead, with sufficient ballast in series to properly reduce the current.

Jan 8, 1919

Our merchant marine is rapidly outgrowing our consular service, according to Edward N. Hurley, Chairman of the United States Shipping Board, who urges that steps be taken immediately to provide facilities abroad for handling the millions of tons of shipping which will be afloat under the American flag in peaceful trade when the war is over. When peace is restored and our present tonnage is scattered over world trade routes, the consular service will be inadequate to handle our ships: Besides, it will have to work against the handicaps of obsolete shipping regulations and, in many cases, lack of experience. There are nearly 100 pages in the United States consular regulations dealing with shipping platters. . Many of these regulations are based on old treaties and many of them are obsolete. There are also differences between treaties with various countries. Our consuls often lack authority to handle matters involving the interests of our sailors and shipowners. Before we can operate a modern merchant marine we must revise, standardize, and simplify this whole mass of regulations and bring them up to the efficiency of other nations' practice.

Jan 12, 1918

By James Chapman

THE observations here presented are those, not of an expert accountant, but of one who, while he has seen considerable service in the accounting departments of large companies, has spent more time in engineering and operating. This paper is intended to cover, in a measure, mine accounting for small mines, as distinguished from the elaborate systems, requiring many persons ;n the accounting department. I shall attempt to outline a system embracing the essentials of accounting, and simple enough in form to permit one or two persons to carry it on from month to month, in sufficient detail to be able to tell quickly the grade of ore, the prices received for metals, costs per ton for mining and milling, costs per foot for development, upward or downward tendencies in costs, ore settled or in transit, cash on hand, stocks of supplies on hand, efficiency of' labor, etc. As in all accounting, there are two main divisions: that of revenue received for what is sold, and that of disbursements made for what is bought, so in mine accounting we have to consider chiefly the income derived from sales of ore or concentrates, and the expenses incurred in producing the said ore or concentrates in a marketable condition.

Jan 3, 1916

By G. Knight

In most mines the major contribution to the dust exposure of miners arises from rock hand- ling. Scooptrams are frequently used and produce 8 to 1300 mg of respirable dust for each ton of ore loaded. It is shown that sprays at drawpoints are not fully effective in wetting the rock and suggestions for improved wetting techniques are given. Techniques for improved dust control by ventilation and local filtration are described. The problem of dust from ore- passes and dumps on tramming levels are outlined.

Jan 1, 1981

By G. Richards Gwinn

GRAPHITE is one of the so-called minor nonmetals that have become of major importance during the present conflict. Requirements of the domestic industry for graphite are relatively small and uses have changed so greatly in the past 25 years that different types, with few exceptions, are more nearly interchangeable in use. However, the quality of the graphite required for crucibles is exacting and under present manufacturing practices only a small part of the world production can be utilized economically by this industry. Graphite, for the domestic crucible industry, was supplied almost entirely by imports from Madagascar and Ceylon before the present war. The quantity required has been increased by the war and the greatest demand is for Madagascar flake. The fall of France to Germany in 1941 and the Japanese expansion southward threatened our supply of crucible-grade graphite, therefore the domestic industry was revived to supplement imports and to act as insurance in the event of complete stoppage of imports. Two plants were constructed for the Government, one at Ashland, Alabama, called the Crucible Flake Graphite Co., operated by Haile Mines, Inc., and one near West Chester, Pennsylvania, operated by the Benjamin Franklin Flake Graphite Co. Loans were made by the Reconstruction Finance Corporation to the Alabama Flake Graphite Co. at Ashland, the Ceylon Graphite Co., at Goodwater, Ala., and the Southwestern Graphite Co., at Burnet, Texas. However, by the end of 1943 the import situation had improved and it was no longer necessary to continue Government assistance to mine and stock-pile the high-cost domestic material. Graphite is found in virtually every country of the world. Most occurrences are of no economic importance because of their poor quality, prohibitive mining and milling costs, inaccessibility, and poor location with reference to the industrial centers where graphite is used. The principal commercial deposits are found in Ceylon, Madagascar, Chosen (Korea), United States, U. S. S. R., Canada, Germany, and Mexico. Graphite is a typical international mineral in that it is utilized mainly in countries noted for industrial activities, whereas the two islands, Ceylon and Madagascar, which produce the major part of the world's high-grade graphite, are virtually devoid of any manufacturing establishments requiring its use. The industry thus is violently disturbed by wars. TYPES of GRAPHITE USED IN CRUCIBLES Graphite of various kinds and from many countries has been used for making crucibles. Passau (Bohemian) flake was first used in Europe, but by the middle of the seventeenth century crucible formulas were established largely on Ceylon graphite and German Klingenberg clay. Ceylon graphite is granular and the grains are subdivided into more or less

Jan 1, 1945

By E. Just

The mining industry is guaranteed an important future because its products are indispensable. However, this can be anything from a brilliant, efficient, profitable future to one of being a heavy-handed, dull-witted claimant for public handouts, according to the caliber and training of the young men who enter the industry. Many views have been expressed about the type of education needed for today's mining industry. Criticisms have been aired to the point that further controversy amongst ourselves could be detrimental to both mining education and the mining industry. It is time we get together and start going somewhere. To canvass the various attitudes of mining educators, a questionnaire was sent to a group of these dedicated, intelligent men, whose primary interest is to help the industry and the profession. The following is a summary of their views.

Jan 9, 1961

By David B. Reger

Sharp declines of initial production of both oil and gas occurred in West Virginia during 1943. There was only a small decrease in the number of ncw wells, but these wells did not show the quantities of oil and gas that might have been expected. The same situation prevailed both as to routine drilling in old pools and as to exploratory wildcat wells. Out of 42 wildcats drilled, 19 resulted in small commercial gas wells, and 2 in small commercial oil. No new oil pools were discovered, but the proved limits of several old pools were considerably extended, giving 4200 acres of newly proved oil territory. Three new gas pools, resulting from discoveries made in 1942 and former years, came into definite activity. The newly proved gas territory in these and in various extensions of old pools is 39,000 acres or more. It is doubtful whether the newly proved reserves of either oil or gas will balance current withdrawals. The account of operations, as gathered from trade journals and other reporting services, shows that 696 new wells were drilled, resulting in 82 oil wells with 919 bbl. of daily new production; 475 gas wells with 454,735,000 cu. ft. of daily open flow, and 137 dry holes. Also, 57 old wells were drilled to deeper sands, with 3 bbl. and 11,484,000 cu. it. of added production. On the new wells, the oil average was 11.2 bbl. per well per day, and the gas average was 957,337 cu. ft. per well per day. On new wells the ratio of dry holes to completions was 19.68 per cent. On deeper drilling the ratio of failures was 14.03 per cent. The greatly decreased average initial gas-well production in 1943, as compared with 2,270,406 CU. ft. per well in 1942, is directly attributable to the abrupt decline of completions in the Charleston gas field, which reached its peak in 1942. Production of oil for the year was estimated by the U. S. Rureau of Mines as 3,349,000 bbl., as compared with 3,574,000 bbl. in 1942. Production of natural gas for the year is estimated by the author as 210,000, 000,000 cu. ft., compared with the U. S. Bureau of Mines final figures of 215,193,-000,000 cu. ft.* in 1942.

Jan 1, 1944

By David B. Reger

Sharp declines of initial production of both oil and gas occurred in West Virginia during 1943. There was only a small decrease in the number of ncw wells, but these wells did not show the quantities of oil and gas that might have been expected. The same situation prevailed both as to routine drilling in old pools and as to exploratory wildcat wells. Out of 42 wildcats drilled, 19 resulted in small commercial gas wells, and 2 in small commercial oil. No new oil pools were discovered, but the proved limits of several old pools were considerably extended, giving 4200 acres of newly proved oil territory. Three new gas pools, resulting from discoveries made in 1942 and former years, came into definite activity. The newly proved gas territory in these and in various extensions of old pools is 39,000 acres or more. It is doubtful whether the newly proved reserves of either oil or gas will balance current withdrawals. The account of operations, as gathered from trade journals and other reporting services, shows that 696 new wells were drilled, resulting in 82 oil wells with 919 bbl. of daily new production; 475 gas wells with 454,735,000 cu. ft. of daily open flow, and 137 dry holes. Also, 57 old wells were drilled to deeper sands, with 3 bbl. and 11,484,000 cu. it. of added production. On the new wells, the oil average was 11.2 bbl. per well per day, and the gas average was 957,337 cu. ft. per well per day. On new wells the ratio of dry holes to completions was 19.68 per cent. On deeper drilling the ratio of failures was 14.03 per cent. The greatly decreased average initial gas-well production in 1943, as compared with 2,270,406 CU. ft. per well in 1942, is directly attributable to the abrupt decline of completions in the Charleston gas field, which reached its peak in 1942. Production of oil for the year was estimated by the U. S. Rureau of Mines as 3,349,000 bbl., as compared with 3,574,000 bbl. in 1942. Production of natural gas for the year is estimated by the author as 210,000, 000,000 cu. ft., compared with the U. S. Bureau of Mines final figures of 215,193,-000,000 cu. ft.* in 1942.

Jan 1, 1944

By Paul Hett

The much-heralded Deep Ruth operation of Kennecott Copper Corp., at Ruth, Nev., is scheduled to become a producer by 1957. Inaugurated as a project in 1951, production was originally scheduled to start in 1953, but excessive water hindered shaft sinking. A revised schedule called for output by 1955, but again plans had to be changed. This time the change was to permit mining of an orebody that would have otherwise been lost because of block caving methods planned for the main deposit. The new ore is within the cave limits of the larger orebody, above the first production level. Ore will start coming from this new source in 1956, a year ahead of the principal operation. (See NEWS, page 344.) There is little doubt that current economic conditions and unforeseen expenditures for early shaft development will make the Deep Ruth a high-cost producer. Yet, some of the drawbacks of the Kennecott operation may be mitigated by the possibility that additional exploration will increase the already assured 25 million tons of 0.83 pet copper ore. While Kennecott is missing out on the current high copper market and is thus left with a potentially narrowed profit, the predicted demand for copper has created an optimistic feeling. Its development is certain to enlarge known U. S. copper reserves and significantly extend the life of Kennecott's Nevada operations.

Jan 4, 1955

ASSETS Working Fund Assets Cash-unappropriated $62,41294 Members' 1951 dues receivable 14,336 98 Accounts receivable Advertising, publications and miscellaneous $43,22055 Less-Reserve for delinquent accounts 12,775 76 $30,44479 Petroleum Branch-Special Projects Fund¬ Advances re Petroleum Conservation Volume 5,37085 35,81564

Jan 1, 1952

By Sherwin Kelly

THE need for geophysicists to adopt a uniform mode of expressing the electrical resistivity of geological formations has been stressed by Dr. A. S. Eve.1 The present paper is to emphasize the point he raised, to bring the weight of disinterested authority to bear on the matter, and to urge the adoption henceforth, save in exceptional cases, of a standard expression for resistivity; all in the hope that the needed reform will thus actually be brought about. The general definition of the resistivity of a material is the resistance in ohms between two opposite faces of a unit cube of that, material. No account need be taken here of the cases in which the unit volume is not a cube, and the units of length and cross-section are different, encountered principally when dealing with metallic conductors such as wires. The idea of the resistance of a unit volume of earth or rock has found expres-sion in geophysical literature in a number of forms and with a variety of units. Fortunately, the metric system has been adhered to in most cases, so ordinarily the meter or the centimeter, usually the latter, has been the measure chosen. The resistivity is then the resistance of a cube of the given rock, or soil, one centimeter on, an edge. This is far from always being the same thing, however, as the resistance of a cubic centimeter. A long thin wire could contain a cubic centimeter and have a high resistance, whereas the same volume formed into a flat plate would have an entirely different, and quite low, resistance between faces. Con-sequently, it is not proper to express resistivity in ohms per cubic centi-meter, inch, etc., as has been done occasionally by .some writers. In an effort to emphasize the idea of cubic volume, some geophysicists, the writer among them, have used the phrase, ohms per centimeter cubed. This is a graphic way of picturing the measure, but is not in favor among highly qualified authorities. In this connection, an appeal was made to the U. S. Bureau of Standards for advice, and the Director, George K. Burgess, kindly replied in detail as to the practice adopted by his Bureau: ." . .' such expressions as ohms per centimeter cubed' or any similar expressions are objectionable, because they certainly carry the implica-tion that the resistivity is found by dividing ohms resistance by the volume in cubic centimeters." Actually, of course, resistivity is found

Jan 1, 1932

Time Now For Thinking In these turbulous times a natural restiveness is created among the younger men of the mining profession. Many of them are veterans of World War II and the question is raised in their minds as to whether or not to go back into military service. There is time to think about this question now and it is advisable to do so in order that snap decisions may be avoided if war is declared.

Jan 2, 1951

A joint statistical report released by the U.S. Department of Commerce and U.S. Securities and Exchange Commission indicates that business investment in new plants and equipment is expected to total $81.8 billion during 1971. This figure is based on the findings of a survey conducted in late April and May and reflects about a 1 ½ % decrease in investments from the $83.1 billion projected in February. Mining, on the other hand, is still in a bullish mood and is expected to spend $1.99 billion in 1971 compared to $1.89 billion in 1970 and $1.86 billion in 1969. Based on figures quoted above, mining investment in 1971 should show a 5.2% increase over 1970. Carl E. Bagge, president of the National Coal Association, was the dedicatory speaker at the new Milton R. Young Station of the Minnkota Power Cooperative in North Dakota. This new power plant incorporates many innovations which have overcome the problems of using the low-cost lignite abundant in the area. According to Bagge, this development and President Nixon's recent request for an extra $10 million for coal gasification plants is helping the region lead the way in providing for the power needs of the future. He also maintains that gasification of coal can reconcile coal consumption with the demand for cleaner air, and also assure the nation of adequate pipeline gas.

Jan 1, 1971

By Roswell Johnson

THE prevailing system of wells on a rectangular basis, as shown in Fig. 1-A, has developed because of the exigencies of offsetting at boundary lines. When, however, a very large tract is, being drilled, it is often possible to abandon this inferior method for the superior arrangement C- PROPER STAGGERING FIG. 1.-THREE SYSTEMS OF SPACING WELLS. known as "staggering," which is illustrated in Fig. 1, B and C. The advantages of the triangular over the rectangular method are evident from Fig. 2, computed on the basis of one well to 10 acres (4 ha.). With the triangular system, no land is more than 409.4 ft. (124.8 m.) from a

Jan 8, 1918

By Albert A. Mathews

OUTCROPS of gypsum rock near the present site of the city of Gland Rapids, Mich., were known to fur traders early in the nineteenth century. However, the deposits seemed without value and were not worked for some time. So far as cat1 be learned, Michigan gyp- sum was first used by a plasterer who settled in Grand Rapids in 1834 as a member of its fourteenth white family. In building a house for one of the early traders, be used some otnamental stucco mouldings manufactured from the local gypsum deposits for decorations in the gables and around some circular windows. The gypsum was broken out with a hammer, ground in an Indian corn mill, and burlled in a caulclron kettle,. After two attempts, the ornaments were successfully set, and remained on the house until it was destroyed by fire in 1850.

Jan 1, 1936

Jan 1, 1966

Jan 1, 1969

Jan 1, 1970

Jan 1, 1967