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By M. P. Boss

Of the two methods of mechanical reduction—that of percussion and that of abrasion—it is not easy to say which was first employed by primeval man. The stone hammer and the flat or hollowed stone used for grinding are found together in the remains of prehistoric periods. But the use of the maray, or bucking-stone, developed from the hammer, was probably introduced later than that of crude millstones. Diodorus Siculus, the Roman historian of the first century B. c., mentions such millstones as used in the mines of Egypt to pulverize material which had been previously broken in a mortar. The invention of the arrastra for fine grinding is declared by some authorities to have been made by Bartolomeo de Medina, at Pachuca, Mexico, about A. D. 1557—which is quite probable. Being the first to amalgamate silver on anything like a business scale, he must have felt the necessity for oregrinding apparatus of greater capacity than the old primitive millstones; and the arrastra was thus the natural successor of the millstone. It is very unfortunate that the archives of Pachuca, which has made so much history in ore-treatment, were destroyed in some one of the many insurrections for which, also, the place is renowned. The first application of the stamp to the crushing of rock is asserted by some writers to have been the invention of a Saxon nobleman named Von Maltitz, about the year 1505. Better authenticated reference, however, is made to one Paul Gronstetter, a native of Schwarz, and called an ingenious worker, who, in the year 1519, established at Joachimsthal a process of wet stamping and sifting. Two years later, a larger plant was established at the came place. It is said that he had previously introduced the same device at Schneeberg. How much of the invention was due to Gronstetter is not certain;

Jan 1, 1902

ALL the ores of any kind whatsoever, even though they be semiminerals and may be perfect in their qualities, have to be recognized by experienced and good sorters. These men must have a detailed as well as a general experience of the metals so that in this first preparation, which is most important, they may know how to distinguish the good from the bad, and to know what is rock and what is ore. They must use patience in this, breaking and cutting and king the ore from the earth. They must separate the good ore from the bad, avoiding as far as possible every occasion for poisoning it by traces of other ores, evil stones, or other things inimical to its nature. Finally, with the judgment of the eye and with tools, and, in the end, by roasting it with fire and then quenching it with water, or by washing and re-washing it, the ore must be made as pure as possible in order to join it better with the companions that seem to be the most beneficial for its needs. Ores would be useless stones without smelting. Therefore, when it is certain that such ores are of divers elemental mixtures, aid must be given to each one according to the evil ingredients [47v] that harm it. But because such evil qualities are things that are often not apparent to the eye, such as too great a burning, or too much earthiness so that when they are alone the fire burns these ores before it melts them, it is necessary to temper them with other materials. To do this it is necessary to have the ability

Jan 1, 1942

By H. B. Fuqua, B. E. Thompson

For a very brief description of the North Texas area, and the general geological features with which it is associated, the reader is referred to the opening paragraph of last year's summary1. A more complete discussion of the structure of the area, together with other interesting data concerning it, has been published recently by the Bureau of Economic Geology at the University of Texas2. It has been impossible for the authors to isolate the statistics for production for each of the many small pools of this district, as such statistics are not kept by operators except by counties or arbitrary divisions of counties. The total number of wells drilled in Archer, Wichita and Clay counties also has been subject to some estimate, as many of the shallower holes are not reported. While both routine development in proven or semiproven areas and exploratory drilling during 1935 showed an increase over the year 1934, the discovery of new producing areas of importance did not show improvement over that period. Several extremely local productive spots within semiproven areas were found in Archer, Cooke and Wilbarger counties; and extensions to older producing areas were developed in Archer, Baylor, Cooke, Montague, Wichita and Wilbarger counties. In Archer County, the Grace and Woods No. 1 Archer County (Fee), 4 miles northwest of Archer City, in the Thomas Glass survey, encountered a sand from 2836 to 2845 ft. of Pennsylvanian (lower Canyon) age, which showed an initial yield of 75 bbl. daily. While its production is of negligible importance, it is given special mention in this review because of the fact that it is producing from a new and deeper horizon than has been previously exploited in the county. Little deep development occurred in the district during the year. The Walter Gant No. 2 C. M. Worsham in J. M. Swisher survey, about 14 miles east of Henrietta, in Clay County, was abandoned at 5127 ft. in

Jan 1, 1936

By G. Bjorling

The opening oxidation of a hydrometallurgical treatment of natural sulphides must for several reasons be so controlled that a maximum of the sulphide sulphur is transformed into elemental. If the oxidation is performed at low pressure and moderate temperatures and with mild reagents such as diluted nitric acid (or ferric or cupric chloride) the just mentioned condition is realized and it has been found possible to conduct the reaction so that solutions are obtained from which the metals can be recovered and the reagents required for the dissolution are regenerated. Experiments in laboratory scale with nitric-acid promoted oxidation have shown that this method is applicable to several types of raw materials, and in combination with electrodialysis both for partial neutralization and for final regeneration of the circulating acid can the requirements of low consumption of chemical reagents and formation of harmless residues be well fulfilled. The metals can be recovered as cathodic deposits or as hydroxides, and the method should be applicable also for low grade ores and concentrates. Although oxidation of sulphides by ferric or cupric ions has the advantage that it can be performed in open vessels it seems well worth the complication of working with nitric acid promotion in a low-pressure autoclave. Also complex sulphidic, oxidic and metallic materials can be treated.

Jan 1, 1973

The Library of the above-named Societies is open from 9 A.M. to 9 P.M. on all week-clays, except holidays, from September 1 to June 30, and from 9 A.M. to 6 P.M. during July and August. The Library contains about 55,000 volumes, including sets of technical periodicals and the publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library can render valuable service through correspondence; letters requesting information will receive special attention. The Library is prepared to furnish references and copies of articles on mining and metallurgical subjects; to determine the existence of mining-maps, and to furnish general information as to the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape. The members of the Institute can be of service to the Library by forwarding copies of mining-reports, maps privately issued, and similar material, which will be classified, indexed, and made available to other members. Suggestions for additions to the Library, either by purchase or personal solicitation as gifts, will be welcomed. It is hoped that members while in the city will use the Library freely, and assurance is, given that most careful service will be rendered to them.

Jan 9, 1913

By Malcolm C. Bridges

A review of the application of geomechanics to open stope mining in Australia was recently undertaken for the Australian Mineral Industries Research Association (AMIRA). It compiled the current state of geomechanics and its application to open stope mining, and recommended avenues of research which should be supported by the industry. Information was compiled for eleven mines which use the method. This included their geological setting, the performance of the mining and evolution of the method, properties and behaviour of rock and backfill, and techniques for measurement and analysis. Open stoping accounts for about two-thirds of production from underground mines in Australia. In the future this proportion will progressively increase and the method will become more complex. Overall, the method is being sucessfully applied, but its full potential is not being achieved because a range of problems and limitations are evident within the mines. Many of these are common to several or more mines. These include: zones of poor ground conditions that delay access and stope development; crown pillars that are irrecoverable; substantial overbreak from the walls and backs of stopes; and lack of a widely accepted method to design systems of stopes. Generally, geotechnical information and techniques for applying it to mining are well-developed. However, it nee

Jan 1, 1983

By Thomas L. Watson

The occurrence of zircon in pegmatites of acidic composition is recorded by many observers both in this country and abroad, and they form one of the most important geologic modes of occurrence of the minera1. As is well known, commercially the most important American locality for zircon is near Zirconia in Henderson County, North Carolina, where many tons of the mineral have been obtained from a kaolinized pegmatite dike 100 ft. wide and traced for 1 1/2 miles along the direction of strike N. 50" E. Zircon may be developed in pegmatites as inclusions in the principal rock-forming minerals, chiefly quartz and feldspar, and as a separate megascopic constituent in the form of grains and crystals not exceeding, as a rule, 2 in. in size, and usually smaller. In the Henderson County, North Carolina, pegmatite, zircon occurs in prismatic crystals with pyramidal terminations measuring up to 30 mm. in diameter, associated chiefly with the feldspar. In some of the apatite veins of Canada, which are closely allied to pogmatite dikes, zircon is reported in crystals upward of 6 in. in length and 2 in. and more in thickness. Zircon in large masses occurs in Virginia in the well-known pegmatites near Amelia in Amelia County, and near Gouldin in Hanover County. Both localities are in the middle eastern portion of the Piedmont Plateau province, and are separated by a distance of about 40 miles in a northeast-southwest direction. The rocks of both areas, including the pegmatite bodies, are in an advanced stage of decay, and the hard and moderately fresh rocks are concealed beneath a cover of variable thickness of rock decay derived by the normal processes of weathering. Exposures, there-

Jan 1, 1917

By Walter J. Karplus, Otto J. M. Smith

The transient response of earth formations may be tlcter.171ined by means of four electrodes mounted coli-rienrly on n sonde. Exponentially decaying current pules are applied to one pair of electrodes and the re.rrrlting voltage transient at the other pair is recorded. It is shown by theoreticol analysis and verified by laboratory experiments that this arrangement readily yields the direct resistivity of the formation and provides valrrable additional information as well. INTRODUCTION Although electrical transients have been employed with moderate success in geophysical prospecting, their application to well logging has received virtually no attention in technical literature. In the conventional direct resistivity logging methods only the zero frequency impedance of the formation under study is measured, and no information is obtained regarding its reactive characteristics. Since the use of certain transients appears to offer some advantages in this respect, experiments were performed on a laboratory scale to investigate this possibility. This investigation was limited to a study of a four-electrode array where both the receiving and transmitting electrode pairs are mounted on a logging sonde, and decaying exponential pulses are applied to the transmitting electrodes. THEORY Given an electrode configuration as shown in Fig. I, located in a homogenous medium of resistivity p, if each electrode has an effective radius, r, which is small compared to the spacing, s and a, it is easy to show by integrating the volume resistivity that the input resistance, Rrw, of the transmitting electrodes is Rxw=p/2pr If a capacitor of capacity C, charged to a voltage Em, is suddenly connected to these electrodes, the resulting current, I(t), will then be The voltage transient, E(t), at the receiving electrodes may then be found by substracting the resulting potential at electrode Y from that appearing at electrode Z. and by inserting Eqs. 1 and 2 Integrating Eq. 4 with respect to tim

Jan 1, 1957

By AIME AIME

JAMES TERRY DUCE is still on the sunny side of fifty, having been born on Dec. 30, 1892 in Worcester, England. Early in life he came to the United States, however, and graduated from the University of Colorado in 1915 .as a geologist. Thereafter for a few years he was with the Colorado State Geological Survey and Bureau of Mines, also doing a bit of teaching at his alma mater and at Washington University, St. Louis. Towards the end of the World War he was with the chemical warfare section of the U. S. Army. Beginning in 1919, he spent 21 years as geologist in various capacities for The Texas Corporation, for a time

Jan 1, 1941

By B. L. Sackett

IN a general way, the situation in copper smelting is quite similar to that of lead smelting. In other words, the introduction and successful flotation of copper ores has tended to decrease greatly the tonnage to be handled by the smelter and therefore has resulted in curtailed smelter operation. However, copper production has increased rather than decreased. The general effect of flotation has been to decrease the number of furnaces operating, but it has also increased to a considerable extent the difficulties in handling the material, just as was outlined in the case of lead smelting. In copper smelting, the flotation concentrates must be roasted and prepared for the reverberatory furnace. HANDLING FLOTATION CONCENTRATES The handling of copper flotation concentrate, which is more or less wet and mucky, is more difficult than was the handling of the old gravity concentrate. Also, the roasting of the concentrate and the handling of the calcine produced is more difficult. That is mainly because the material is extremely fine and the tendency to higher dust losses is greatly increased. The draft in the roasting furnaces must be kept as low as, possible, and the feeding of the calcine into the reverberatory furnace must be done carefully, so that dust losses may be kept at a minimum. TRANSITION STAGES OF CONCENTRATION AND SMELTING The general process through which the copper smelter has gone as a result of flotation has been somewhat as follows: In the relatively old days, when copper ores of low grade were first treated, a large number of furnaces were required, and naturally comparatively poor recoveries were made. Also, the profits on low-grade ores were small and the handling of those ores was possible only because of the large tonnages. Then came gravity concentration, which was a great improvement but which only incompletely removed the gangue material, the insoluble and the iron, from the copper ore, and made comparatively poor copper recoveries. This still left a considerable amount of insoluble and iron, as well as the copper itself, to be treated at the smelter.

Jan 1, 1928

Clarence M. Haight, Franklin Furnace, N. J. (communication to the Secretary*).—In that part of Mr. Wilson's paper describing the Gilman cut-and-fill system, a few features do not appear to be fully explained. In what way is the waste used for filling obtained? The text mentions that if waste is encountered when driving the filling raises, these raises are stopped until the fill is needed; that seems to suggest mining the capping for fill, which might make the backs of the stopes bad as the stopes approach the top of the ore. If, on the other hand, the fill is brought to the raises in cars, are the crosscuts that are necessary in ore or waste? Is the cost of this fill included in the stoping costs given? The second, or lower, series of stopes will present a different problem to that which the first series (under the capping) gave. Although no mention is made in the text, it would seem that the second series of stopes will have to be worked on center lines which are offset half the stope width, 20 ft., from the centers of the stopes above, in order to take advantage of the "rafter" effect of the stringers so named. How is the fill to be introduced into the lower stopes? There are no crosscuts mentioned to provide for this; or is it intended to tap the filled stopes above for the fill? In the latter case the method of control of this fill will be of interest. Ore that will admit of a stoping width of 40 ft. with the lengths mentioned in the description is stronger than any with which many mining men are familiar. Has the practice of starting to mine a second stope before the preceding one is filly completed been tried to any extent? If

Jan 1, 1917

By Allan J. Clark, W. J. Sharwood

When the cyanide process came into general use, late in the nineteenth century, chlorination was quickly supplanted, but amalgamation yielded place more slowly, being still the major process at many plants, where it is followed by cyanidation of the tailings. The research work of the Denny brothers in South Africa' was probably the most important contribution of its time to the metallurgy of gold. By grading analyses of mill products, they pointed to the necessity of fine grinding to accomplish maximum extraction by cyanide. The work here described is merely an extension of the Dennys' method. Developing the fine-grinding principle, the steps of "crushing in solution" and of "all-sliming" were logical sequels, though both had been attempted early in the history of the cyanide process. Crushing in solution introduced certain complications in amalgamation; when "all-sliming " was adopted it was observed that the omission of amalgamation did not materially affect the total recovery. Thus the field of the older process has become much restricted, being at present confined to ores which, yielding freely to amalgamation, either are too low in grade to show an economic advantage in "all-sliming," or present chemical or other difficulties making the use of cyanide solution unadvisable during the crushing and preparation of the ore. South African ores are typical of the former class; Homestake ores are of both classes, but even in these instances the amalgamation work is being curtailed and greater burdens thrown on the cyanide plants. It is obvious that the time required for the dissolution of gold depends on the size of its particles. In an effort to determine the critical size, the following laboratory method was evolved. A standard amalgamation test2 had already been established, which involves the agitation of about 100 gm. of ore with 20 gm. of pure mercury, the latter then being separated and its gold contents determined. This method was applied directly to certain mill products with interesting results, a few of which may be noted here. The column "Free Gold" gives the value per ton thus amalgamated, as against the " Total Gold " determined by fire assay.

Jan 1, 1923

By George A. Bell

The mine and milling plant of Demonstration Gold Mines, Ltd., is near the city limits of Baguio, Mt. Province, P. I. The mine road connects with the main highway to Manila. The nearest railway point is near sea level, approximately 40 miles distant. The Baguio district is very mountainous and has one of the heaviest rainfalls in the world. It is therefore difficult to maintain roads or to impound tailings and mine dumps. All supplies are trucked into the district direct from Manila or the nearest railway point, which means uncertain deliveries and high freight rates. Installation of equipment is difficult and costly. The average elevation at the mine is 4000 ft. and the climatic conditions are ideal except for a three months rainy season. The company generates its own power for mining and milling operations with three 400-hp. Ruston Diesel engines direct connected to 250-kw. General Electric alternating current generators. Labor conditions have been excellent, although at present social security laws are causing some unrest. Labor receives a higher average wage rate in this district than other labor in the Islands. The company also furnishes free living quarters, hospitalization and workmen's compensation. Taxation has been reasonable up to the present time, but some of the new mining legislation may make it difficult to operate and pay dividends. The future depends largely upon the continuation of $35 gold and the political outcome in the Islands. History The Demonstration ore body was worked by the Igorots for many years, as evidenced by old stopes and fill encountered in present operations. Attention of Americans was first attracted soon after the Spanish-American war. During the building of the Benguet road to Baguio, the engineers and foreman became interested in the geology of the district.

Jan 1, 1939

By Clark Millison

The core recorder, a mechanical instr-ent for determining the exact depth at which core is recovered, drilled up or lost, is described. Examples of charts from the recorder are explained and interpreted. The uses of the core recorder are discussed. INTRODUCTION In the experience of geologists and engineers during coring operations on drilling wells, many will recall the times when a full core was not recovered and particularly when the requirement was urgent that they know exactly what part of the core was lost. To make this determination, the core recorder was designed. Its uses are many, and only the most obvious will be presented here. Although this discussion will be limited to drilling wells for petroleum, the core recorder can be used in any type of coring operation. The principle of the core recorder is the proportional reduction of the motion of core entering or dropping out of the core barrel to a stylus moving in such a manner as to record the reduced motion on a chart. The time element is registered on the same chart by the revolution of a clock which turns the chart drum. Thus the exact amount of core entering or dropping out of the core barrel is charted and the time of such entry or exit from the core barrel is precisely correlated to the depth at which the core is recovered or lost. Lack of movement of the stylus which is revealed by the continued revolution of the chart drum indicates that no core is entering the barrel. The principles are accomplished by an instrument placed inside of the core barrel. A cylinder which contains the clock and mechanical apparatus has a diameter smaller than that of the core barrel. Near the top of the cylinder is an eighteen hour clock which turns the drum that contains the chart. Near the bottom of the instrument is a serrated wheel which by friction against the inside of the core barrel is turned as core enters or drops out of the barrel.

Jan 1, 1949

By E. M. Norris

In the summer of 1917 it was decided to fireproof the main tramway hoisting shaft of the Anaconda Copper Mining Co. at Butte, Mont. The shaft has three hoisting compartments and one pump compartment; it is timbered with 12 by 12-in. (30.5 by 30.5-cm.) fir timber, and is 2475 ft. (754 m.) deep. Subsidence and displacement of the surrounding country rock had produced exceedingly heavy ground, and had carried the shaft out of line, in several places, by as much as 2 ft. (0.6 m.) displacement. Constant repairing and realigning of the timbers had been necessary in order to maintain clearance for the cages. The most feasible method of fireproofing, therefore, seemed to be to cover the timbers with a coat of concrete applied with the cement gun. The cement gun, which is operated by compressed air at ordinary mine pressures, feeds a mixture of sand and cement through a hose to a nozzle having a water connection. The mortar in fluid form is thus sprayed upon the prepared surface in thin layers, which can be built up to any desired thickness. The cement gun can be set up at any convenient point; satisfactory results have been obtained with the nozzle a distance of 500 ft. (152 m.) from the gun. The shaft was thoroughly overhauled and the timbers put in the best possible state of repair. Between the 1000 and the 1400 levels, much loose ground lay against the shaft timbers on the north side; this was breast-boarded back and a 30-in. (76-cm.) reinforced-concrete retaining wall was erected, leaving a space of 12 in. (30.5 cm.) outside the shaft timbers to allow for future movements of the ground. For convenience in handling men and materials; it was arranged to concrete the auxiliary hoisting-cage compartment and the pump compartment first, using the cages of the main hoist to serve the cementing crews. The auxiliary cage was then available while the remainder of the shaft was being concreted.

Jan 3, 1918

By Francis Pyne

THE following notes are presented in an endeavour to point out the disadvantages attending the use of chrome brick in reverberatory furnaces used in the treatment of materials that are too valuable to allow any great amount of metal absorption by the brick. Several years ago one of the large Eastern copper refineries decided to utilize basic material in place of siliceous material in the walls of their reverberatory furnaces for the treatment of very foul blister copper, as the latter rapidly corroded the siliceous linings. It was also expected that there would be less slag formation, with a consequent decrease in the cost of treatment and a reduction in the metal losses. Magnesite brick were first used, but while the corrosive action of the foul material was greatly reduced, and the amount of. slag formed was very much less, the magnesite proved to be unsatisfactory in certain parts of the furnace, because of its tendency to crack and span badly when subjected to the alternate heating and cooling that takes place in a reverberatory refining furnace. This made many repairs necessary, and consequent frequent interruption in the operation of the furnace, which, together with the high price of the magnesite brick, ran up the cost of maintenance to an unreasonable amount. It was, therefore, decided to substitute chronic brick for magnesite brick in the parts of the furnace affected. The results, as far as the reverberatory furnace was concerned, were very satisfactory. The corrosion due to the action of the foul blister was small and the amount of slag formed was no greater than when using magnesite, and the tendency to crack and spill shown by the magnesite was eliminated. Gradually the use of chrome brick was extended to all furnaces; those treating blister copper as well as those melting cathodes, and the results were so satin-, factory that the siliceous roofs were replaced by roofs of chrome brick except in certain places where experience showed a more satisfactory performance on the part of the silica brick.

Jan 12, 1917

By John W. Cobb

The attempts of British investigators to arrive at definite knowledge concerning the nature of the nitrogenous constituents of coal have been mainly made through studies of the behavior of coal on carbonization and gasification. There have been carried out numerous determinitions of the distribution of nitrogen in the products of carbonization under laboratory and large-scale conditions; and by a careful consideration of the extent to which nitrogen is liberated, say as ammonia,. at different temperatures and under different conditions of operation as regards atmosphere, it has been possible to form some general notions as to the nature of the nitrogenous compounds present in the coal; and at the same time to arrive at clearer ideas as to what are the important operative factors in determining the ammonia yield under working conditions. This work has been spread over many years and is summarized below. The difficulties of connecting the results in such a way as to allow of the nitrogenous constituents of the coal being described in terms of specific organic structure are great. They arise, for example, in the carbonization process, because the phenomena of decomposition observed at any one temperature can only refer to compounds decomposing at that temperature, each of them with a previous history of chemical transformations occurring at lower temperatures. To put it in &other way, the compounds occurring in the coke at any stage are not in the least likely to be those present in the original coal. The same difficulty, in a milder form, occurs when the method of differential solution is attempted. There is always the preliminary question, almost impossible to answer, as to how far the separation by the use of the solvent has involved some form of decomposition of the original compounds. In the following summary, an attempt has been made to bring together results obtained by British workers.

Jan 1, 1925

By E. Cortese

PHOSPHATE occurs in many places in Egypt,. in two main zones: one in Upper Egypt, along the Nile Valley, principally on the right side, and one near the Red Sea coast. In the Nile zone, the principal layers of phosphate rock are to be found: in the mountains east of Mahamid (right side of the valley); in the hills near Sibaiya, also called Sebaieh (both sides); in the hills of Agula, Hagaza and Gurn (right side); and further on, along the cancel road leading from Kena to Kosseir, a few miles east of Legheita's Oasis. Following, that track, after, having crossed the watershed, underlain by rocks like granite, serpentine, porphyry and diabase, one comes again to the Cretaceous formation containing considerable quantities of phosphate, at Gebel Duwi, Gebel Nakheil and Gebel Kosseir El Kadim, not far from the coast. More to the north, in the hills near Safaga Bay (Um El Uettat El Wasif) is another rich bed of the same formation. There are reports of phosphate existing near Suez and in the Sinai peninsula, and possibly some other zones can be traced or discovered in the future. The mines are well developed on the right bank of the Nile at Sharawna (near Sebaieh Station) and along the Red Sea coast, at' Safaga and near Kosseir. Prospecting work has been done at Gebel Duwi, Gebel Gurn, Agula, Hagaza, and near Mahamid. The phosphatic formation in Egypt is quite variable, not only from place to place, but even within small areas. The phosphate is all of Cretaceous age, as is proved by the fossils found in it. It is considered to belong to the Campanian or, more appropriately, to the Maestrichtian series. The principal fossils are: Alectryonia Villei Coq. sp.; Roudereia Auressensis Coq. sp.- R. Drui Mun. Chalm.; Trigonoarca multidentata, Newton.; Cardita libyca, Zittel; Libycoceras Ismäely, Zittel; Nautilus sp.; Ancystrodon libycum Dam.; Corax pristodontus Ag.; Lamma biauriculata Zittel sp. Above the Maestrichtian beds, we have the Danian series, unconformably covered by Lower Eocene beds. Under the phosphate is a grayish marly clay, and beneath this, bluish-gray scaly shales resting on the Nubian sandstone (Santonian).

Jan 2, 1918

By N. M. Langdon

ON account of its greater economy and cleanliness, and the extent to which iuferior fuels can be utilized for its generation, there has been of late a rapidly increasing tendency to substitute gaseous for solid fuel for metallurgical and other industrial purposes, which has led to various improvements both in the process and apparatus for its manufacture, notably among which may IN mentioned the Tessie Gas Producer* described by Mr. A. L. Holley. A considerable experience by the author with producers of various kinds using anthracite fuel, in connection with the Taylor ore-roast ing furnace at Chester, N. J., with more or less unsatisfactory resnlts, finally led to the erection of the experimental producer described below, which combines in its construction, simplicity, dorability, and accessibility for cleaning and removing the ash and manipulating the fuel. It is adapted to the use of various kinds of fuel, and is capa ble of generating a steady and uniform supply of gas at a minimum cost. It has been in constant use day and night for about five months, and has given very satisfactory results. The producer, as shown in the accompanying sketch, consists of a cylindrieal furnace, preferably inclosed in an iron jacket or casing, having a bosh or inverted cone-shaped base as in a blast furnace. It is provided with a bell and hopper, the bell being hung to a forked lever, and having guide flanges to prevent it from swing ing, and an opening at its apex through which to insert a bar for manipulating the fuel, which when not in use is closed with a plug or stopper. Cleaning is effected through two small doors placed opposite each other at the hearth level, which in order to facilitate the operation is elevated above the floor. The doors are removable, and when closed are by their own weight and by means of bevelled lugs held tightly against their frames, forming a practically tight joint. A blast of commingled steam and air is injected into the fuel through a series of tuyeres underneath the bosh communicating with steam jet injectors. A small flue also connects the door

Jan 1, 1884

When the suggestion was made by Major General Leonard Wood that the Institute assist in the formation of a National Reserve Corps of - Engineers, Dr. Drinker's name occurred first to the Board of Directors as the man who would be most capable of carrying out the proposed plan. Dr. Drinker has long been associated with work in connection with military training and is at present the Chairman of the Governing Committee on Military Training Camps Association which is having such important results at Plattsburg and other places in this country. As Chairman of the Institute's Committee on National Reserve Corps of Engineers, Dr. Drinker was a member of the Joint Conference Committee of the National Engineering Societies .on. this subject., He was an earnest worker in the movement, which, has finally resulted in definite legislation by Congress; whereby a Reserve Corps of Engineers is authorized in the new Army Bill which became effective July 1, 1916. Notice of the results of the work was sent to all the members of the National Engineering Societies early in July, and the and the Department of the United States has recently issued a circular which has been sent to all the members of the National Engineering: Societies, as well, as to many other engineers, outlining, the line, whereby engineers may enroll themselves in the Officers Reserve Corps. Dr. Drinker has, therefore, fulfilled the mission which he undertook when assuming the Chairmanship of the Institute's Committee. He now asks the permission of the Board of Directors to withdraw as Chairman and has requested that he be replaced in this position by Mr. Arthur S. Dwight, in; the belief that the Chairmanship of the Institute's Committee and, membership on the Joint Committee should be vested in a man ,located in New York City, for the better carrying put of the important work now before the Joint Committee. We are happy to say that Dr. Drinker has consented to remain a member of the Institute's Committee; but the completion of the first phase of his work; as,Chairman, should not be allowed, to pass without an expression of appreciation on behalf of the Institute for his services.

Jan 9, 1916