Search Documents

By H. M. Boylston

METALLIC manganese was first produced in 1773, by Sven Rinmann, a Swedish mineralogist. In 1799 William Reynolds, of Ketley, England, obtained a patent on the use of manganese dioxide in the manufacture of steel, and in 1808 an English patent was granted to John Wilkinson covering the use of manganese ore, or manganiferous ore, as an addition to iron ore in the blast furnace for the production of a superior grade of pig iron. Karsten showed in 1816 that manganese increased the hardness of iron without decreasing its malleability or toughness, while it caused pig iron to be more white in fracture and more fusible. The first practical application of manganese to steel-making, however, is attributed to Josiah Heath who discovered in 1839 (less than 90 years ago) that manganese conferred upon steel the properties of being more easily worked and welded under the hammer. When Bessemer invented the pneumatic process of steel-making which now bears his name he was at first successful because, as it afterward developed, he was using. a Swedish pig iron high in manganese. When his supply of this material ran out, he used a low-manganese pig from English sources and failed signally to produce a steel which could be rolled, while his Swedish licensees were continuing their successful application of his method. And it was not until Robert Mushet, in 1856, suggested the addition of manganese in the form of spiegeleisen to the molten product of the converter that success again came to Bessemer. In 1866, William Siemens patented the use of ferro-manganese as an addition to molten steel to counteract the bad effects of sulfur. It was in 1888, that Robert Hadfield published at some length his account of the effect of manganese as an alloying element in steel and described the unique properties of the now famous Hadfield manganese steel containing about 12 to 14. per cent. manganese and 1.25 per cent. carbon.

Jan 5, 1927

By M. L. Requa

In the fall of 1910, the Nevada Petroleum Co., operating in the Coal-inga field in California, determined to drill a number of wells with rotary tools, in order to prove conclusively the relative value of the rotary as compared with the standard rig. At that time, the rotary was but little known in California and its proposed introduction met with considerable criticism on the part of the operators and quiet opposition among the standard drilling crews. There were few men available who were competent to handle a rotary outfit, and these few had had but little experience in California fields. Machines as then built were much inferior to those now used, being lighter in construction and of a poorer quality of material. The shells encountered at depths between 1,700 and 2,000 ft. seemed to be too hard to permit of successful drilling, and at these depths the rig was changed over to standard tools and by them completed. Because of the heavy depreciation, the time lost in converting from rotary to standard, and the comparatively small profit, it was concluded that unless in the future there was some material improvement in rotary rigs, nothing would be gained by drilling with rotary tools upon this property. Little or no drilling has been done upon the property since that time, but in the meantime a large number of men have been trained in the use of the rotary; in fact, many standard-tool men have abandoned standard drilling and, starting in as roustabouts, have become thoroughly competent rotary operators. The improvements in the machinery have been such as to remove many of the objections and the rotary drilling of to-day is in every way superior to that of 1910. In contrast, a well drilled recently by the Kern Trading & Oil Co., in the east side Coalinga field may be cited. The first 2,500 ft. was drilled in 24 days and it is confidently expected that the water string will be set with a rotary at 3,400 ft.—a record obviously far beyond that made in 1910 by the Nevada Petroleum Co. The records herewith are published with the hope that some one having more recent data will publish them so that comparison may be

Jan 1, 1915

By Robert H. Dickson

Limestone replacement and contact metamorphic orebodies are 80 irregular that sampling and estimating are far less. exact than in more regular types of deposits; both the mineralized masses and the lenses of ore within them are extremely irregular. So much development work is required to find the ore that the expense of blocking out great tonnages is prohibitive; furthermore, the rock near these orebodies is so heavy that drifts or raises cannot be kept open for many years without excessive repairs. As a result, few mines in limestone have more than three years supply of ore in sight. As most of the ore, is developed by stoping— not by drifting, raising, or drilling—estimates of ore developed do not indicate the total amount of ore that may be expected; they simply indicate the relative condition of the mines. But even if they are to do this, they must be made according to a fixed plan, intelligently carried out. The estimates of ore in the Calumet & Arizona Copper mines, Warren District, Ariz., have been of much value to those who plan the mining and development work. This paper describes the methods of sampling and estimating used in these mines. Sampling Samples are taken in various ways and depend on the condition of the working and the purpose for which the sample is to be used. Drifts, crosscuts, and raises are sampled by channels or by taking a grab off each mine car as it is filled. Stopes are usually sampled by drill holes or by taking a representative sample off each mine car; the latter, or chute, sample is by far the best sample. All workings are studied periodically by an engineer, who makes graphic and detail notes of the geologic structure, as shown in Fig. 1. The daily car tally and assay of each particular working is added to the same sheet opposite the material it represents. These sheets make a permanent record, showing the exact boundaries as well as the grade of ore in all workings.

Jan 1, 1925

By Joseph Richards

THERE are two essentially different types of case-hardening processes; that using a dry mixture in which the object to be case-hardened is packed and kept for the necessary time at the necessary temperature, and the "liquid" process, employing a bath of fused, salts into which the object- is immersed and which by immediate contact case-hardens the surface of the article. The Shimer process belongs to the second class, and was a war emergency invention. Of the liquid melts used as baths, the most effective and most fre¬quently used are melted potassium cyanide and melted sodium cyanide. These may be used either pure, or mixed with salts that reduce the melting point and the percentage of cyanide present. The use of these baths since 1914 has met many commercial difficulties because of the high price and frequent commercial scarcity of the cyanide salts; at present sodium cyanide has practically entirely displaced potassium cyanide. Another trouble is the danger to the workmen handling the cyanide salts, which are extremely poisonous, and the annoying and poisonous vapors or gases given off in the workshop, unless an effective system of hoods and ventilation is provided, so as to prevent the gases from the baths mixing with the air of the room. Porter W. Shimer, of Easton, Pa., has invented a substitute for the bath of melted cyanides which case-hardens with equal or greater facility and effectiveness, gives off no poisonous vapors, and costs for chemicals materially less than the cyanide costs in the previously used baths. The process has been in use over a year in a large American works and the following statement embodies the results of practical experience in the use and operation of the process. The Shinier liquid or melted bath consists of a mixture of easily fusible salts that do not possess case-hardening properties, into which is immersed fresh calcium cyanamide, which imparts to the bath case-hardening properties. The composition of the non-case-hardening-,salts appears rather immaterial. Good results have been obtained by using a mixture of sodium chloride, calcium chloride, and barium chloride in

Jan 2, 1919

By H. W. Bell

There was considerable prospecting for new supplies of oil in Arkansas during the past year, regardless of the overproduction affecting the industry throughout the country. Justification for this new work was not lacking, as the local markets more than threatened to absorb a declining production. There were, however, no important new discoveries in the state during 1929. The McDonald area in sec. 2515, S.-18 W., threatened to expand into a major producing area. Oil showings had been encountered here in wells drilled by the McDonald Oil Corpn. as early as the fall of 1928. In July, 1929, an initial production of 1000 bbl. of 32" oil was obtained in McDonald Bros. B-3 Wilson, from a sand at 2780 to 2786 ft., which is about 80 ft. higher than the sand previously tested in the neighboring wells. This production declined rapidly. At the end of the year there were six producers making about 200 bbl. per day total. Seven dry holes have temporarily stopped development in that area. The showing of B-3 was sufficient to cause considerable leasing activity. The area lies several miles west of the Louann portion of the Smackover field. The discovery well went to 2873 ft. and found Glen Rose lime in bottom. The age of the producing sand is in doubt; it seems closely related to the Tokio sand. During 1929, several paying wells were brought in, as a northeastern extension to the Smackover Heavy area, in sec. 34 and 35-15-15, from the Nacatoch sand. Over 20 new wells were drilled and resulted in at least 1500 bbl. production. The down-dip or off-structure territory contiguous to the Smackover uplift was further tested at various locations with the usual results; that is, a showing of "salt water gas," which soon blew off and in some cases a slight showing of oil. These gas showings, found further down the dip than oil, are the results of the ability of water to take gas into solution at the rate of about 3 per cent. by volume at atmospheric pressure and proportionally larger quantities, if available, at higher pressures (measured on the absolute scale). During the year no off-structure wrinkles sufficient to trap conlmercial quantities of oil have been found outside of the other known fields of

Jan 1, 1930

By T. F. Witherbee

Success in this operation is much promoted by adhering to a definite plan. Random work is of little account. In general, anything done that will enable the blast to pass through the obstruction, providing the melted products can be got away from the tuyeres, is all that is necessary. Hence the utility of high explosives in breaking up the chilled mass in the hearth. (This, by the way, should be done with the wind on, so as to prevent the filling of the tuyeres with the usual rush of cinder following the explosion.) If from any cause it is not expedient to use explosives, the simple but very effective instrument known as the kerosene or hydro-carbon blow-pipe can be depended upon to perforate the contents of a blastfurnace hearth to any extent required. It consists, as used in the Champlain district (first by Mr. Charles H. Foote), of several pieces of gas-pipe, liberally supplied with elbows (five in number) so as to be flexible; one end being connected to a tuyere-stock and the other brought to bear upon the place to be melted out. A 1/4-inch pipe leads from the last length, or blow-pipe proper, to a reservoir of kerosene or crude oil, set high enough to overcome the blast-pressure, This 1/4-inch pipe should have a valve conveniently located to regulate the flow of oil, and also another next to the reservoir. With a good hot blast and a surprisingly small quantity of oil, this apparatus will melt, burn or mechanically dislodge anything around a blast-furnace hearth excepting firebrick and water-cooled castings or plates. It may be helped by vigorous prodding with a suitable steel bar, to detach the fused but sometimes sticky material. A very good way to operate on a chilled hearth with it, is to open up a hole from a cinder- or iron-notch to the nose of the most convenient tuyere and then make a blow-pipe of the tuyere by turning

Jan 1, 1885

Butte Meeting. It is expected that the technical program of the Butte meeting will be a sufficient attraction to draw to that point every member who can possibly get away long enough to attend. Attention is particularly called to the papers already sent in by the Committee on Precious and Base Metals, and the papers which they are undertaking to secure for the meeting, as published on pp. ix and x. In addition to these papers, and in addition to those published in this Bulletin, the office of the Institute already has in hand several papers, which will be published at an early date, and presented in abstract and discussed at the meeting. Of the discussion of these papers a special feature is being made. Therefore, let every member come to Butte who can do so. A meeting of the Board of Directors of the Institute will also be held at Butte. In the May Bulletin, we stated for the information of members the railway excursion rates for two suggested tours in connection with the meeting, which included Glacier Park before the meeting and Yellowstone after it. The itineraries there given and rates quoted were planned and offered by the railway agent bureaus in New York. Circulars have been sent to the members of the Institute by A. E. Vaughan & Co., a tourist trip agency of New York City, containing details of tours nearly identical with those outlined in the Bulletin, and quoting rates covering, the expenses of the whole trip. Members can easily compare these rates with the rates offered by the railroads, and published in the last Bulletin. In order that no misapprehension may exist, the statement is here made that the Institute and its officers have no connection whatever with Vaughan & Co.'s proposals and that any such tours will be strictly personal matters between said company and the members of the Institute who take them. Nevertheless, the Board of Directors calls to the attention of members the circumstance that tours such as these will afford an opportunity for members to travel together to the meeting.

Jan 6, 1913

By Bernard MacDonald

THE writing of this paper was prompted by the discussion by H. M. Chance, in the April Bulletin, of the paper written by Thomas M. Chance which appeared in the February Bulletin., and by the remarks of the Editor in which lie stated that while the matter contained in discussion did not refer to the original paper it "was presented as of interest to the operators of cyanide and other lixiviation processes dealing with fluid mixtures of varying specific gravity." For some years past the principle enunciated in the discussion referred to has been known to the writer and demonstrated by him to be an efficient and economical way of separating water or solution from solids in the cyanidation, lixiviation or acid leaching of ore pulps: In utilizing this principle in commercial practice he has invented a method whereby not only the separation of solution from solids may be effected in any given tank, but also the counter migration of the solids and solution may be effected continuously through a series of tanks in which the hydro-metallurgical treatment of ore pulps is being carried on. In effect this method is analogous to the counter-current system, but is different physically in that it is carried on throughout a series of tanks on practically the sane level, continuously and automatically, by hydrostatic pressure and gravity-flow, without the aid of intervening pumps or elevators, at the same time that agitation is being carried on in the same tanks. In the Parral system, agitation is effected in tanks by a number of air lifts of comparatively small diameter through which the pulp is continuously transferred from the bottom of the tank and spouted horizontally on top of the charge. The spouting force of the several streams thus discharged maintains a rotary flow in the pulp charge which extends from top to bottom of the tank. This continuous transfer of pulp and the spiral flow from top to bottom of the tank maintains the pulp constituents in uniform proportions and meets the requirements of efficient treatment in a most economical manner. The quantity of. compressed air required is very small, as the pulp is not lifted but simply trans-

Jan 7, 1918

By Junius D. Edwards, Cyril S. Taylor

Magnesium is the lightest metal used for structural purposes, for which reason perhaps more than usual interest is attached to measurements of its density. Although the density of solid magnesium has been det,ermined frequently, no measurements of the density of the liquid metal are available. Because of unusual experimental difficulties in measuring the density of the liquid, only a limited number of measurements of good precision were secured. The results, especially the value for the crystallization shrinkage, are of great interest in connection with the casting of the metal. A number of samples for these measurements were made available through the courtesy of the American Magnesium Corp. They were in the form of extruded bars 3/8 in- in diameter and several were of exceptional purity, as indicated by careful analyses. Table 1 gives the density values (at 20" C.) for magnesium of varying degrees of purity. The density was measured at room temperature by comparison of the weight in air, and when immersed in distilled water. The necessary buoyancy corrections were applied, so that the density could be expressed in absolute measure—grams per milliliter. The effect of the buoyancy of the immersed suspension and the surface-tension pull of the water upon the suspension were eliminated from the results by a preliminary weighing of the suspension immersed to the working depth. Great care was necessary to prevent the introduction of a significant error by the formation of gas bubbles upon the clean magnesium surfaces; these are sometimes very minute and easily escape observation. They may be detached by raising the specimen from the water and again immersing; this should be done just prior to completing the weighing. Their formation may be almost entirely prevented during a measurement by previously immersing the specimen in a solution of paraffin in petroleum ether. The thin film of paraffin remaining after the evaporation of the solvent prevents wetting of the magnesium surface by the water. In one such determination, the paraffin coating on a 22-gm. Specimen

Jan 1, 1923

By H. Ries

In the marketing of mineral products, it is always highly desirable for both the producer and the consumer to be able to discuss things in a common language, and this can only be done if there are standard methods for expressing the properties of the raw materials. Having developed such a form of expression, the next step would be the making of specifications, which may serve as a basis for selecting raw materials. Considering the large number of non-metallic minerals that are used, there are not a few for which there are no standard laboratory tests to be used in determining their properties, or even standard specifications on which grades or market price may be based. Indeed in many cases the consumer simply requests the producer to submit samples, and rejects or accepts them without any explanation. Could the producer know in advance just what the consumer needed, time and money might often be saved. It appears to the writer that it is of the highest importance to devise standard laboratory tests wherever possible, as this enables the consumer to state definitely what he needs, and is of great assistance to the producer. It should also work to reduce misunderstandings and disputes. In the case of sands, we find that they show a wide variation in their character, ranging from those that are so coarse as to be of gravelly nature to those that are so fine that they might be classed as silt; and from very clayey ones to those that are practically free from clay. For this wide range of sands, we have a corresponding variety of uses, which are based mainly on the physical properties of the sand, although these are not always very definitely stated. The chemical composition need rarely be considered, if the sand is of siliceous nature. To determine and express these properties there should be standard tests, which are to be followed in all cases where the material is tested in the laboratory. The use of sands for foundry work (making molds or cores) is old, and it has been recognized for some time that the important properties to be

Jan 1, 1926

By Olin G. Bell

At the beginning of the year 1935 the older fields in Southwest Texas, and particularly those discovered during 1934, had been practically delimited and only normal development continued. As a result, operations in this area were somewhat slowed down. Shortly after the first of the year, however, activity in the area was greatly accelerated, due largely to the fact that the Loma Novio field, discovered during the last few days of 1934, indicated the presence of a new productive trend east of and parallel to the Government Wells field and also indicated the presence of a new productive horizon, the Loma Novio sand, approximately 100 ft. lower than the Government Wells sand zone. Other discoveries during the year greatly augmented the activity in the district. During the year there were 651 oil wells, 53 gas wells and 275 dry holes drilled in this area during the year. Most of the operations were in the Government Wells, Cole, Loma Novio, Seven Sisters and Lopez fields. New Fields Four new fields were discovered during 1935 as follows: Seven Sisters and Piedra de Lumbre in Duval County; Loma Alto in McMullen County; and Lopez in Webb County. Seven Sisters Field.—The Seven Sisters field, opened in May, was the direct result of a systematic search for new productive areas northeast of the Loma Novio field. The first producer, Harvey & Henderson NO. 1 Chernosky, survey 226, was completed in the Labbe (Chernosky) sand at 2220 ft. However, the second producer, Santa Clara Oil Co. No. 1 Welder in survey 385, drilled about one mile south of the discovery well, failed to find production in the Labbé sand and was carried on down and completed in the Government Wells sand at 2473 ft. with an initial production of 20 bbl. of oil per hour. These two discoveries, in the Labbé and Government Wells sand, started an active leasing and drilling campaign in this part of Duval County and drilling operations continued especially active throughout the remainder of the year.

Jan 1, 1936

The year 1934 saw a very thorough and intensive search for oil in Italy, both by the Government-subsidized company, the A.G.I.P., and by the few smaller operating companies. Approximately two-thirds of the exploration work, however, has been done in the Province of Emilia (northern Italy). The A.G.I.P. has been particularly active in the Emilia district and has sunk several rotary holes between Voghera and Ferrara on structures located by geophysical means in the Po Valley. Only insignificant amounts of oil have shown up in these tests to date but gas has been found in fair quantities, and apparently the company is not yet prepared to abandon its search in this part of the country without further effort. In Central Italy, the same company has put down four tests with cable tools and of these two were "dry holes" and the other two found only traces of oil. The A:G.I.P. also sank two wells in southern Italy and it is believed that in these the indications were sufficiently encouraging for the exploration work to be continued. No serious drilling has yet been done in Sicily by the A.G.I.P. or any other company. The annual subsidy granted to the A.G.I.P. by the Government for the duration of its five-year plan has been considerably reduced for 1935 and this may interfere with the completion of the coming year's program in all its details. The Società Petrolifera Italians, which is the chief producing company in the country, has continued the development of its two fields, Salsomaggiore and Vallezza, and at the same time has intensified its program of exploration. Rotary machinery has been introduced and is undergoing a thorough trial, and prospects of finding new pools at greater depths are considered good. The charcoal adsorption plant at Vallezza has operated satisfactorily throughout the year and has produced nearly 3000 bbl. of high-grade gasoline. Besides the exploration well at Rile dell'Olio, which is still drilling, another wildcat test has been started at Torre-di-Traversetolo. All operations of this company are confined to the district of Emilia. The Società Petroli d'Italia has continued to operate the old fields of Montechino, Gratera and Velleja, and has a well now exploring at greater depths in that general area. Of the two exploration wells in the Torino

Jan 1, 1935

By Leo D. Jones

The use of the centrifuge for dewaxing lubricating oils grew out of the effort to secure better results than had been attained by the common "cold settling" process. This process was the only known method for dewaxing steam refined cylinder stock (600" F. fire test), the product known as "bright stock" being commonlyused for building up "pressed," i.e., dewaxed neutrals of, say, 200-sec. viscosity [to a higher value. The process consisted of mixing the cylinder stock with approximately one and one-half times its volume of naphtha, heating, to dissolve completely all the oil and wax and then slowly chilling to about 15" F. in large insulated tanks. This caused the wax to precipitate. It was allowed to settle out by gravity. The supernatant liquid was then drawn off and the naphtha distilled off, leaving a still residue of bright stock. The sediment from the settling, of a slushy nature, was withdrawn. After removing the naphtha by distillation the residue was petrolatum. At some point in the process, preferably after the dilution but before chilling, the mixture was decolored by percolation through fuller's earth. The finished bright stock produced by this process had a cold test of about 50" F. Efforts to improve this by chilling to a lower temperature resulted in a considerable reduction in yield, and increased uncertainty of settling. Even when chilling to 15" F. it was not uncommon to find that after a week's waiting a tank had not settled. It was then necessary to heat and rechill. This uncertainty was a serious problem; in one case a refinery superintendent had men riveters hold pneumatic hammers against the tank for hours, hoping thus to cause agglomeration and settling of the wax. Yields of bright stock above 70 per cent, were uncommon. History of Centrifugal Application It is not surprising, therefore, that many attempts were made to improve upon the results obtained by cold settling. George H. Taber, vice-president of the Gulf Refining Co., Pittsburgh, Pa., made a number

Jan 1, 1924

By H. P. Leighly

WORNER1 briefly studied the embrittlement of titanium by mercury. He found that mercury will wet the titanium surface at 400°C in vacuo, if the specimen had been heated previously to 700°C to dissolve the oxide coating. Subsequent exposure to the atmosphere causes the mercury film to recede rapidly. Bending of the titanium specimen even after the mercury film has receded results in a brittle fracture. For the study of the embrittling effect of mercury on titanium, specimens 2 by 12 by 0.051 in. were cut from RC-130-A sheet, an alloy having a nominal 8 pct Mn content and a mixed a-ß structure. The specimens were stressed horizontally at a predetermined value after which a plastic ring having a cavity 1/2 in. diam by 1/2 in. deep was placed on the specimen. The cavity was filled with mercury and a hole was drilled in the specimen through the pool of mercury. If the stress level was high enough, fracture occurred instantaneously with the drilling. By repeating the test at different stress levels, the threshold stress can be determined. Mercury embrittlement causes a drastic reduction in the ultimate tensile strength of this alloy from 132,000 psi to about 15,700 psi. The drilling of the hole, in the absence of mercury, does not change the tensile properties. Fig. 1 shows the typical fractures observed as a result of the embrittlement of this alloy by mercury. The central portion of the fracture was brittle represented by the jagged region which appears to have occurred on the shear planes at about 45 deg to the stress axis. Ductile fracture, which is perpendicular to the stress axis, occurred near the specimen edges accompanied by a reduction of the specimen thickness. Examination of the fracture reveals that only in the brittle region does mercury wet the

Jan 1, 1962

By Theron Wasson

Discoveries in Michigan, which at the beginning of the year 1934 indicated possible new areas, did not develop into fields of market-breaking proportions. Hart, Oceana County, developed small production from the Traverse lime. Edmore, Montcalm County, proved a small area for oil from the Traverse. West Branch, Ogemaw County, previously reported as Ogemaw, had quite a drilling campaign but was somewhat disappointing because wells were small and erratic. During the year, 30 wells were completed at West Branch, and at the end of the year 15 others in and around this field were under way. At West Branch the Traverse lime, found at 1800 ft., has thin porous streaks near the top, which make small wells; the Dundee lime at 2800 ft. produces from a porous zone of varying thickness. Over the entire field the Dundee wells average 10 to 20 bbl. per day. Acid treatment has materially increased production from some Dundee wells in this field. About 3000 acres have been proved productive from the Traverse and Dundee. At the close of the year the well in Beaverton township, Gladwin County, is probably the most discussed of any in Michigan and may be opening a new field of some proportions. It had an initial production of 70 bbl. daily from the Dundee lime at 3830, which has decreased to 25 bbl. per day. Deeper drilling into the lime may increase production. During 1935 the area around this test will probably be the most active in the state. Structural conditions in Gladwin County, as in other parts of Central Michigan, are obscured by a thick mantle of glacial drift and it will take considerable drilling to outline subsurface conditions accurately. The most important new shallow gas area of the year is around Edmore in Mecosta and Montcalm counties. Eight wells have been drilled to the Michigan stray and the upper Marshall sand, having a combined initial production of 30 million cubic feet. These gas wells are scattered over so wide an area that an estimate of proven territory cannot be made until more drilling is done. At the present time no gas is being sold from Edmore.

Jan 1, 1935

By W. E. Wickerham

THE Magnetic Storm Monitor is an instrument that continuously records variations in the earth's total magnetic field at a fixed location. It is intended for use in conjunction with airborne magnetometer surveys. There are stormy periods when changes in the earth's magnetic field are so violent that data obtained with airborne equipment would be of little value. The Monitor provides this information so that flights may be cancelled or terminated, thus eliminating useless flying. Moreover, when some unpredictable change in the earth's field occurs during an airborne survey, the Monitor record, showing a similar event, may serve to salvage the data. The utility of a base instrument is determined largely by its physical dimensions, power requirements, stability, and reliability. This instrument is small enough to be transported in any powered vehicle. It will operate from either a 110 v, 60 cycle power line or from an inverter powered by an automobile battery. The development of an electronic feedback circuit that measures the magnetic field strength and a fabricated buckout magnet having essentially zero temperature has contributed to instrument stability and reliability. A tripod supporting the magnetometer head, a chassis housing all electronic components, and an Esterline Angus Recorder comprise the equipment, shown in Fig. 1. The vibrator-type inverter shown is used when a 110 v, 60 cycle power line is inaccessible. Approxi- mately 60 w are required to operate the instrument and the circuit is insensitive to reasonable power line voltage changes or transients. The head unit contains a fluxgate-type magnetometer element and a special magnet mounted on a ceramic structure. Since this magnet is used to buck out most of the earth's field, adjustments are provided for properly positioning the magnet with respect to the element. This assembly is mounted in such a way that the element can be oriented into the total field. Fluxgate Element: The heart of the Storm Monitor is a fluxgate-type magnetometer element. The ability of this unit to detect changes in magnetic fields has been covered at length in the literature.1, 2 For this discussion it will suffice to say that the Gulf

Jan 1, 1956

By Carl H. Beal

DURING the latter part of 1915 and the first half of 1916, the writer held the position of geologist in connection with the conservation work instituted by the U. S. Bureau of Mines, on oil and gas land belonging to the Indians of the Five Civilized Tribes in Oklahoma. The duty of the geologist was to correlate formations containing oil, gas, and water, and to determine the relations of these substances in the different formations so that the conservation agents might carry on their work most intelligently. On account of the rapid development of the Cushing field, which lies in the western part of the Creek Nation, much work was done there by the inspection force. In the course of the geologic studies a large amount of information was collected, which, on analysis, has disclosed some interesting facts worthy of publication. The report, of which the following remarks are an abstract, has been prepared and submitted to the U. S. Geological Survey for publication. This report is now (June, 1917) in the press and will doubtless be issued in a few weeks. Methods Used In addition to the structure maps showing the folding of the Pawhuska limestone, which crops out in several places in the Cushing field, separate structure maps of the three most important productive sands—the Lay-ton (Fig. 2)) Wheeler, and Bartlesville—have been prepared. These structure maps were prepared by obtaining the logs of nearly all the wells

Jan 1, 1918

By Lawrence A. Garfield

From the bottom of a shallow fissure the near-naked man-animal hacked out a hand-sized chunk of the red rock-like material which, when beaten between other rocks, could be drawn out to the thinness of a flint edge. Unlike flint, however, it did not shatter when, as the point for a spear or arrow, it went wide of its mark and fell amongst the rocks or tree branches. For this reason and others, the red rock- like material was specially sought and much time was spent in trying to break it from the real-rock in which it grew. Only infrequently was a chunk broken free and in this area many hours had been spent to win but a few fragments. What luck then, to remove so large a piece where before nothing but real-rock dust formed whenever the stone hammer hit. Why did this happen? Did yesterday's food-fire, burning on top the red rock, loosen its hold on the real-rock and cause it to break free when struck with the stone hammer? It is not a matter of recorded history that the first heat assisted extraction of native copper from country rock occurred under the circumstances or in the manner related but it is known that crude mining operations using these techniques were conducted by primitive man. In this way the first mineral production may have been achieved and the original example of rapid excavation unknowingly given to the world. Rapid excavation is not a method of removing rock or ore from an insitu condition nor does the term refer to a type of equipment which is specifically employed in mining and underground construction. It is, rather, the nomenclature currently popular in industry-primarily in underground construction- relating to a comparative rate of performance.

Jan 1, 1971

By Allen Rogers

IT IS universal practice for corporations, at the end of the fiscal period, to call in a firm of chartered accountants to audit the books. The effect of this is to put an independent organization's seal of approval on the accounting of the business done by the management. Their report lets the stockholders know that the accounts rendered truly present the results of the year's business. This is as it should be; the average stockholder has no personal contact or even acquaintance with the managers of his enterprise and the approval of their stewardship by an indepen-dent agent is very desirable for maintaining confidence in their honesty and ability. But such an examination deals only with what may be called the arithmetic of the business; even the most elaborate audit, as the practice is at present, goes no further than to verify the items of the inventory. In other words, while checking up the entries showing the transaction's of the year and certifying to the correct-ness of the items of the balance sheet, such a report gives the stockholder no idea of the ability with which his affairs have been managed. If the profit and loss balance is satisfactory, as certified by the public accountants, he assumes that the management has been able; where it is not, he turns to the president's report and usually finds an explanation. Such an explanation never takes the form of admission of mis-takes in business judgment or of bad technical manage-ment. It could hardly be expected that it would. The stockholder is generally furnished, therefore, with a certificate of the honesty of his management, but never one of its ability. He does not worry about the latter as long as dividends come in; when they cease, his action generally finds expression in replacing the management. In other words, so long as profits are realized, he assumes the management to be good, even though its success is a matter beyond its control and better management would make larger profits. When there is no profit, the stockholders have no means of knowing whether it is due to conditions beyond the control of the management, as the annual report is sure to allege, or whether, by better management, profit is possible. Here is where the technical audit comes in.

Jan 6, 1922

By J. Campbell

The hydrostatic tensions in pure metals and long freezing range alloys are evaluated theoretically considering the viscous flow of residual liquid and the general plastic collapse of the casting. The former mechanism operates until the radii of the remaining liquid channels are of the order of 10-3 cm radius, after which the second process limits the attainable negative pressures which range from —1500 to -4200 atm for nickel, aluminum, copper, and iron. In previous reports1'2 the maximum possible hydrostatic tensions developed during solidification have been evaluated employing spherical symmetry. This inevitably involves the concept of totally confined liquid regions, the reality of which has recently been brought into serious doubt3 following observations of the freezing of various transparent materials. Regions of interdendritic liquid which are apparently about to be isolated by the growth of dendrite arms are observed not to be cut off because the advance of the dendrite tips is arrested until the region has completely solidified. Although this may be the result of the very low melting point liquid available at this late stage in freezing, or the result of a higher rate of heat transfer to the dendrite tips because of the acceleration in liquid flow rate near the completion of solidification, this point need not concern us. In this paper an attempt is made to approximate more closely to real conditions; thus the assumption of confined liquid regions is abandoned and cylindrical symmetry adopted. It has also been necessary, therefore, to consider the viscous flow of residual liquid through the remaining channels in the pasty zone. Furthermore, the rather special conditions of spherically symmetric solidification led to extremely high solidification rates and hence unusually high tensile stresses as solidification neared completion; the cylindrical Symmetry appears to yield solidification rates and stresses which are more typical of real castings. The rate of solidification is first considered since this critically affects both the flow of the liquid and the creep of the solid.

Jan 1, 1969