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By T. A. Rickard

The dictionary defines 'jargon' as "barbarous or debased language". This description does not suffice. Quiller-Couch has said, it is "a kind of writing which, from a superficial likeness, commonly passes for prose in these days, and by lazy folk is commonly written for prose, yet actually is not prose at all ". The two main vices of jargon, he says, are "that it uses circumlocution rather than short straight speech", like the Babu who reported his mother's death by saying: "Regret to inform you, the hand that rocked the cradle has kicked the bucket ". Its other chief' vice is that "it habitually chooses vague woolly abstract nouns rather than concrete ones", like the newspaper statement; "He was conveyed to his place of residence in an intoxicated condition", instead of saying, "He was carried home drunk ". Jargon is "an infirmity of speech", it is not journalese, but akin to it. "Like respect- ability in Chicago, jargo4 stalks unchecked in our midst" and renders much technical writing ridiculous. It deals in periphrasis instead of going straight to the point, it loves the abstract rather than the concrete, it dabbles in words of sound rather than of meaning. Avoid it, despise it., if you purpose earnestly to write well. "III literature as in life he makes himself felt who not only calls 4 spade a spade but has the pluck to double spades and re-double." * Jargon is rampant in technical publications. Catalogues and other advertisements are conspicuous offenders, but with these the critic is not concerned, except in so far as such 'write-

Jan 1, 1931

By S. D. Warriner

ONE of the most, if not the most, difficult of the problems associated with the mining and distri-bution of anthracite is to get clearly into the minds of the consumers and of the editorial and reporto-rial writers in the public press the relationship between the cost of production, the price at the mine and the price that the consumer pays for his coal, delivered in the cellar. One sees in his morning paper a statement to the .effect that out of the $12 or $13 per ton that his dealer charges him, the miner gets only $2 or even less, and he asks himself or the paper asks for him, "Who gets the difference?" Not infrequently the amount that the miner gets is given for run-of-mine bituminous coal while the price quoted is that of prepared anthra-cite, egg, stove, or chestnut, as the case may be, delivered to the bin of the consumer; and the difference stands out with all the more prominence; and it sticks in his memory with a persistency which no manner of explanation is able to efface. A recently published official report for the year. 1921 of one of the State Bureaus stated the total production of anthracite in net tons of 2000 lb., and included not only the output recovered by washeries from old culm banks and by dredges from creek and river channels, but also the colliery consumption;, i.e., the coal used by the companies in the operation of the collieries. This resulted in a total production of 90,509,075 net tons for which the labor cost was stated at $283,961,300, or $3.13 per net ton, equivalent to $3.50 per gross ton. This figure of $3.50 was immediately seized upon as representing the labor cost per gross ton of fresh-mined commercial coal. It is almost a hopeless task to try to correct such errors of statement in the first place, and, in the second place, to correct the misapprehen-sions that arise from them. As a matter of fact, the report was misleading in regard to the labor cost of the entire production shipped, as the coal used for colliery consumption should be deducted. Correctly stated, the report should have shown, calculated in terms of gross tons of 2240 lb., the legal weight in Pennsylvania, as follows: Gross production 80,607,359 tons Less colliery fuel 8,757,137 tons Commercial production 71,850,222 tons Total labor bill $283,961,300.00 Labor cost per ton...: 8 3.952 The foregoing figures" of tonnage are obtained from the State Department of Mines. Even these include the quantity recovered from calm, banks by washeries, and consequently the $3.95 arrived at as the average labor cost is somewhat less than that actually involved in the mining of fresh-mined coal. Unfortunately, the figures of washery production and the cost of producing it are not available.

Jan 7, 1922

By Joseph N. Morrison

A comprehensive solution is offered to the problem of dust emissions at belt conveyor transfer points. Details of enclosure design are discussed and a straightforward procedure for calculating required dust control exhaust volume is presented. Many design variables are taken into account which heretofore have been commonly ignored or inadequately considered. These include belt widths, belt speeds. enclosure openings, material flow rate, material bulk densities, material lump sizes, height of material fall, material temperature, and ambient air temperature. All of these questions are handled by means of a "fill-in-the-blanks" type of calculation form, permitting quick, reliable solutions by relative "non-experts."

Jan 1, 1972

Jan 1, 1970

By Maureen G. Johnson

At least three million ounces of placer gold has been mined from hundreds of deposits in the Southwest since the 1600's. Nevada, the most productive state, produced about 1,700,000 oz. Most of the placers are in accumulations of unsorted, coarse, angular gravel in gullies, dry washes, and on hill- sides. The gold is mixed with debris from the adjacent bedrock and is typically concentrated at or near bedrock or on clay layers or caliche-cemented gravels above bedrock. The most extensive and productive placers are thick accumulations of debris in well-defined stream or gully channels, in alluvial fans at the edges of the range fronts, or as thick residuum on hillsides. With very few exceptions, the gold has been transported only a very short distance from the source. Numerous small high-grade gold-quartz veinlets, rather than single large lode deposits, are by far the most common source of placer gold. Most placer mining consisted of small-scale one-or two-man operations using rockers, pans, and sluices when water was available and dry-washing machines when it was not. Where gravels were deep the miner would dig shafts to bedrock and drift along the paystreak. Large-scale operations in the major districts utilized floating or stationary dredges or, more rarely, hydraulicking to mine extensive deposits. An adequate supply of water for efficient concentration of gold has always been a major problem in the Southwest. To overcome this problem, difficult and sometimes ingenious techniques were used-pipelines to carry water for miles to the placer area were constructed, or gravel was hauled to central washing plants where water was available; numerous designs of dry-washing machines were invented. In some districts, attempts to mine the gravels by large- scale operations failed because the gravels were too wet for dry concentration methods, and no water was available for wet methods; or, when water was available, the gravels were too porous to retain sufficient water in the dredging pond.

Jan 3, 1974

By J. van Lookeren

In the case of a reservoir where the oil underlies a large gas cap and overlies bottom water, production can be inzproved considerably if wells are perforated below the water-oil contact rather than opposite the oil-bearing section. The theoretical arguments for this improvement, which in some cases may be tenfold, are supported by experimental evidence. INTRODUCTION Reservoirs frequently consist of one sand body containing an oil layer underlying a thick, gas-bearing section and overlying bottom water (Fig. 1). Wells in such reservoirs are customarily opened up opposite the oil-bearing interval or, rather, opposite the lower part of this interval (Fig. 2). More often than not, it is inefficient or prohibited to blow off large quantities of gas with the oil. This im-psses a severe limitation on the drawdown, which results in low oil-production rates. Because of the small difference in specific gravity between oil and water, the latter will easily cone upwards, so that the production of water together with the oil is not prevented by this completion method. In such a situation wells should be opened deeper, in the originally water-bearing zone. The gas can be shut off by not perforating over the upper part of the interval (Fig. 3) or by a tubing hung close to the bottom of the interval (Fig. 4). Initially much water will be produced, but when steady-state conditions have been established (as depicted in Figs. 3 and 4) larger drawdowns are permissible than in a conventionally completed well, and correspondingly higher oil-production rates will result. Water cuts are only slightly higher because of the small effect of gravity on the water-oil flow distribution. CALCULATIONS The ratio of improvement has been estimated by means of approximate calculations. The completion depicted in Fig. 4 is the most convenient basis for these calculations. By postulating that vertical flow gradients can be disregarded, the Appendix shows that the well-known Dupuit formula can be obtained except for some complication due to the presence of two fluids rather than one. The Appendix makes the reasonable assumption that, for suitable boundary conditions, the oil layer occupies a constant fraction of the total fluid height throughout the reservoir. The oil- and water-production rates can thus be related to the liquid levels in the borehole as follows:

Jan 1, 1966

By R. F. Mehl, C. S. Barrett, A. H. Geisler

THE mechanism by which the super-saturated solid solution of 20 per cent silver in aluminum decomposes has been reported in two previous publications. 1,2 The analysis of streaks in Laue photograms showed that thin platelike particles (the so-called Guinier-Preston aggregates) form upon {111} matrix planes in the early state of decomposition.1 The size of these particles is larger, the higher the temperature at which they form in accordance with nucleation theory;3 at all temperatures they increase in size with aging.2 When they have grown thick enough to afford three-dimensional diffraction, powder X-ray photograms show that the structure is not that of the equilibrium precipitate y but that of a transition lattice ?'. Since this is also platelike in shape and also lies upon the {111} matrix planes with the {110} direction in the matrix parallel to the {11.0} direction in ?', it seems likely that the original platelet particles are merely ?' in an early stage of formation, and thus finely dispersed. The atomic spacing and pattern on the {00.0} plane in ?' are identical with those on the {111} matrix plane to which it lies parallel, and since comparable directions in the two planes are parallel, the lattices are thus coherent at the interface; an analogous coherence has been found in aluminum-copper alloys.3 The structures ?' and y are both close-packed hexagonal and are oriented alike; they differ only in interatomic distances. Consequently, ? ' is regarded as y strained from its ordinary dimensions by the lattice coherency between it and the matrix.2 The lattice movements that transform the matrix to the equilibrium precipitate appear to be very simple.2 The mechanism of precipitation in this system is simpler and is more precisely known than that in any other system,2,4 hence the system should be a profitable one for the difficult task of correlating property changes with structural alterations. The present report provides additional studies on powder X-ray diffraction from alloys of 10 per cent, 20 per cent and 30 per cent Ag, and presents the correlation of crystallographic changes with changes in microstructure, Brinell hardness and electrical resistivity of the three alloys. PREPARATION OF SAMPLES AND EXPERIMENTAL PROCEDURE The preparation of the 20.2 per cent Ag alloy has been described.2 Alloys containing 9.9 and 29.7 per cent Ag were prepared from 99.97 per cent Al and 99.99+ per cent Ag using a similar procedure. Rolled

Jan 1, 1943

Suggestions for Directorial representatives should be submitted by the District Committees between November 1 of the year indicated and the following Annual Meeting District 1 New York Section (Each Year) District 2 Boston (1950) Pennsylvania Anthracite (1951) Lehigh Valley (1952) Philadelphia (1953) Connecticut (1954) Adirondack (1955)

Jan 1, 1952

New York Meets first Wednesday after first Tuesday of each month. DAVID H. BROWNE, Chairman. PERCY E. BARBOUR, Vice-Chairman. A. D. BEERS. Secretary, 55 Wall St., New York. N. Y. C. A. BOHN, Treasurer. Boston Meets first Monday of each winter month. C. C. EUSTIS, Chairman. R. L. AGASSIZ, Vice-Chairman. E. E. BUGBEE, Secretary-Treasurer, Mass. Inst. of Technology, Boston, Mass. ALBERT SAUVEUR, H. L. SMYTH. Columbia Holds four sessions during year. Annual meeting in September or October. STANLY A. EASTON, Chairman. FREDERIC KEFFER, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2164, Spokane, Wash. C. LIVINGSTON. FRANK A. ROSS.

Jan 6, 1916

By I. D. Shah

A roasting procedure for synthetic copper sulfide which results in a reproducible transient melting at 450° and 470°C is described in this paper. Possible causes for this melting phenomenon are suggested, and also a procedure to avoid it during the roasting. This melting is believed to be responsible for the occasional occurrence of stickiness in the commercial roasting of copper sulfide concentrate. Many workers have studied the roasting of copper sulfides, but only Lewis et al. have reported that fusion and, in some cases, fusion with "boiling" occurred in the neighborhood of 450°C. The DTA and TGA apparatus, the materials used in this investigation, and the discussion of chemical reactions occurring during the CuS roasting are described in an earlier publication. CuS, in the form of either pellet or powder, was heated at 280° to 330°C in a flowing air or 30% 02: 70% N2 atmosphere. Heating was continued at this temperature until no further weight increase due to sulfates formation was observed on the TGA thermogram. This is believed to be due to the inability of SO, to diffuse out from the sulfate layer on the surface of the pellet, thus halting the sulfate-forming reactions. Hereafter, the sample oxidized in this manner will be referred to as "partially oxidized CuS." X-ray analysis and microscopic examination of a polished cross section of a partially oxidized CuS pellet showed the following order of layers starting from the center of the pellet: Cu2S, Cu2O, CuO • CUSO4, and CuSO4. A bare thermocouple inserted in the center of a partially oxidized CuS pellet (2.5 g) did not indicate any noticeable change in the temperature of the pellet when melted at 450° to 470°C in an inert or oxidizing atmosphere. During the preparation of a partially oxidized pellet, the temperature of a CuS pellet increased by 50°C due to the exothermic formation of sulfates in air at 320°C. The endothermic peak associated with the melting phenomenon at 450°C is shown in [Fig. 1.] A CuS pellet (0.2 g) was oxidized in flowing air (150 cc per min) at 10°C per min up to 320°C and held there for about 2 hr. Then, N2 replaced air and heating was continued up to 500°C. The exothermic peak at 320°C represents an overall formation of sulfates, and an endothermic peak at 450° to 470°C represents the melting phenomenon. To observe the melting visually, a small (50 mg), partially oxidized CuS pellet was heated (in static air) in a hot-stage microscope. The melting phenomenon was observed on an auxiliary TV screen. The sample

Jan 1, 1976

Jan 1, 1913

By Lawrence S. Darken

STAFF: Editor, Gerhord Derge Cornegie Institute of Technology Schenley Pork Pittsburgh 13, Pa. Editorial Assistant, M. A. Redmerski Production Editor, Otto T. Johnson THE METALLURGICAL SOCIETY: J. S. Smart, Jr., President; C. C. Long, Past-President; K. L. Fetters, Vice President; T. D. Jones, Treasurer; R. W. Shearman, Secretary. PUBLICATIONS COMMITTEE OF THE METALLURGICAL SOCIETY: C. L. McCabe, Chairman; H. L. Bishop, K. L. Fetters, J. J. Harwood, W. A. Krivsky, F. C. Longenberg, R. E. Lund, W. 0. Philbrook, L. L. Seigle, R. L. Smith, and F. L. Vogal. Review and selection of manuscripts is under the supervision of the following Publications Committees: Extractive Metallurgy Division: C. L. McCabe, Chairman; R. E. Lund, Vice-chairman; D. H. Baker, Jr., W. A. Krivsky, R. A. Lewis, Paul Qusneau, A. S. Russell, R, E. Shinkoskey, W. W. Stephens, and M. E. Wadsworth. Institute of Metals Division: L. L.Seigle, Chair-man, P. A. Back, J. J. Backer, l.l. Bessen, J. 0. Betterton, Jr., J. 8. Clark, R. S. Davis, A. E. Dwight, R. W. Fountain, R. B. Gordon, C. D. Graham, Jr., R. W. Guard, J. C. Gurland, E. L. Harmon, J. J. Hager, A. A. Hendrickson, M. Harmon, J. N. Hobstatter, H. H. Johnson, Jr., H. 5. Kolish, R. R. Nash, T. N. Rhodin, R. H. Richman, W. Rostokar, P. G. Shawmon, C. W. Spencer, L. Slifkin, J. K. Stanley, C. D. Starr, R. Steinitz, and H. C. Stumpf. Iron and Steel Division: H. L. Bishop, Chairman; 2. E. Boni, F. C. Langenberg, J. B. Wagstaff, and T. V. Wainwright. Published bimonthly by the American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc., 29 West 39th Street, New York 18, N. Y. Telephone: PEnnsylvania 6-9220. Subscription PetroleumEngineers,$30 per year for non-AIME members in United States and North, South, and Central America; 332, foreign; $5 for AlME members. Single copies, $4.00, single copies foreign, $5.00. The AlME is not responsible for any statement mode or opinion expressed in its publications . . . Copyright 1%1 by the American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. . . . Registered cable address; AIME New York ..Indexed in Engineering Index, Industrial Arts Index, and Chemical Abstracts.. .Second class postage paid at New York, N. Y., and Ann Arbor, Mich. Volume 221, Number 4.

Jan 1, 1962

By A. M. Gaudin

THE study that is presented here was undertaken in order to condense information concerning comminution, and covering a great variety of conditions, into one or several rules which would be of use in the development of a systematic theory as well as in many directly practical ways. As the result of this work, the following conclusions appear justified 1. Rocks may be classified, from the point of view of comminution, into two general classes which are (a) structurally homogeneous, and (b) structurally heterogenous. Structurally homogeneous rocks are those in which fracture takes place through grains and grain boundaries alike; heterogeneous rocks are those in which fracture passes in preference through grain boundaries. 2. If a sized product composed of structurally homogeneous rock grains is crushed, a product results in which the relation between the percentage weight of grains of various sizes and these sizes themselves follows a definite law. This is not true of structurally heterogeneous rocks. 3. Ball milling with structurally homogeneous rocks, and under certain conditions, presents exceptions to this rule. 4. In ball milling with structurally homogeneous rocks, there exists a critical ratio of size of feed to size of balls, above which the machine operates essentially by surface wear, and below which it operates essentially by breaking across the body of the particle. 5. In ball milling, with structurally homogeneous rocks, and when the size of feed grains exceeds the critical size, the particles worn off are of a, substantially definite size which depends upon the ball size 6. In the case of a typical heterogeneous rock, such as Manhattan schist, particles are crushed in such a way that there is a greater proportion of grains of the size that is the average grain-size of the rock than there would be in that range of size with a structurally homogeneous rock. This has been found to be true with-all the crushers tested. 7. Different methods of crushing produce grains of different shapes.

Jan 2, 1926

By R. E. Goodman, M. A. Mahtab

The, state of stress around a vertical wellbore in rock following nonlinear stress-strain laws is examined by means of finite element analysis. The wellbore, is considered an axisymmetrier body with axisymmetric loading. The initial vertcal and borizontal stresses are "locked" in the rock elements around the wellbore and a new state of stress is generated by the displacements which occur around the borehole. A point-uise variation of the elastic moduli is made on the basis of the new stress state and the triaxial data. The initial stresses tire now reintroduced along with tile changed moduli and original boundary constraints. This procedure is repeatrd until convergent stresses are reached. The effect of nonlinearity on streases is examined for a 6,000-ft wellbore in a scbistose gnezss and Berea sandstone using results of laborratory triaxial compression tests. The results sbou that the effect is restrited to one well radius from the bottom periphery of the bole. Beyond a distance of one-quarter radius, the elfect of nonlinearity on stresscs IS almost always less than percent for the cases conszdered, The consideration of a static pressure inside the well does not magnify the effect of monlinearity on borehole stresscs. INTRODUCTION The terms " wellbore" and "borehole" here designate cylindrical openings in the ground with vertical axis and a circular cross-section. A knowledge of the stress redistribution that occurs on excavating a wellbore is important in understanding (1) the behavior of the lined or unlined hole, (2) hydraulic fracture response, and (3) the effect of stress redistribution on drillability; also it is important in predicting initial stresses in the virgin ground, and in analyzing the response of measuring instruments placed in the borehole. Our knowledge of the state of stress around a wellbore has been restricted to homogeneous, isotropic, elastic material and derives chiefly from the analysis by Miles and Toppingl and the photoelastic work of Galle and Wilhoit2 and Word and Wilhoit.3 In this investigation the state of stress is examined for a nonlinear elastic material by means of finite element analysis. Many rocks possess stress-strain curves that depart notably from straight lines in their initial or final portions. While the literature contains abundant stress-strain data from triaxial tests (axisymmetric loading) on cylindrical rock specimens, there is little information on rock deformability under nonaxisymmetric loading conditions such as occur at each point around the bottom of a wellbore. Although there is some knowledge of the effect of intermediate principal stress on rock strength, there is virtually nothing known about its effect on rock deformability; therefore, we have assumed here that the effect of intermediate principal stress can be ignored. A schistose gneiss4 and Berea sandstone5 were selected as representative rocks for this analysis. The traditional graphs of deviator stress (ol -o3) vs axial strain were reworked to give the tangent modulus as a function of the deviator stress for varying values of the minor principal stress. The result is a nesting family of skewed, bell-shaped curves for tile gneiss (Fig. 1A) and the sandstone (Fig. 2A). A similar replotting of the lateral strain data defines the variation of Poisson's ratio (v) with the deviator stress and confining pressure. These curves, shown in Fig. 1B for the gneiss and in Fig. 2B for the sandstone, are not so well ordered as the tangent modulus curves. However, all of these display an increase of v with deviator stress application, but the rate of increase diminishes with confinement. The ET and v curves for the two rock types are tabulated in Tables 1A and 1A for use in a digital computer so that material properties corresponding to a given state of stress can be assigned by interpolation. STATEMENT OF THE PROBLEM Given a state of stress in the ground prior to drilling a hole (initial stresses), we assume that

Jan 1, 1969

By L. K. Jetter, C. J. McHargue

DEVELOPMENT of preferred orientation in uranium is of interest because of the strongly anisotropic properties of the orthorhombic crystal structure. Harris&apos; reported inverse pole figures for rolled uranium rods which showed <010> and <410>* to be parallel to the rolling direction after On 0.19-in. spherical X-ray diffraction specimens taken from the center of the middle section of each rod, pole distribution data were obtained by the spectrometric method described previously.4 The specimen was rotated rapidly about the axis coinciding with the rod axis in order that a large number of grains could be scanned and was rotated slowly about an axis perpendicular to the rod axis. The variation in the diffracted X-ray intensity was recorded as a function of the latter motion (angle 4). Fiber-axis distribution charts (inverse pole figures) were prepared by the method described by Setter, McHargue, and Williams." After having been corrected for background radiation, the pole distribution data (I vs ?) were normalized. A normalizing factor for each plane has been shown to be Iranaom = f I sin 4 ? 4 and was obtained by graphical integration from the data for that plane plotted as I sin ? vs ?. The axis-distribution charts deduced from the normalized pole densities are shown in Figs. 1 to 3. On these charts, the contours indicate angular positions of equal normalized axis density,

Jan 1, 1958

0PINION was general that this year&apos;s meeting of the Institute of Metals Division was one of the best in its history. In addition to its full and exceptionally fine program of professional papers, there were several other features of general interest-an in-spiring annual lecture by Dr. Cecil H. Desch which appears in abstract elsewhere in this issue, Mr. Sing-master&apos;s talk on the zinc industry at the annual dinner, and the presentation of the James Douglas Medal to one of the members of the Division, Dr. Zay Jeffries. Four technical sessions of the Division were held, dealing respectively with zinc, copper, aluminum, and general metallography, and in addition there was a joint session with the Non-ferrous Metallurgical Committee of the Institute. All of the papers presented were at-tended with much interest and followed by considerable discussion. The papers on plastic deformation of zinc by Messrs. Mathewson and Phillips, Romig, and Hoyt were of particular interest and awakened an extended discus-sion. They well illustrated the progress which is being -made today in the understanding of the mechanism of flow of metals, and the ingenuity of the authors in their crystallographic method of attack of this difficult problem was quite generally admired. A very old subject was treated in a modern way by Messrs. Corson and Bain in two papers on the harden-ing of copper and copper alloys. There has always existed a myth that the ancient Egyptians were masters of an art not possessed by ourselves; viz., that of hard-ening copper. This myth must have been quite defi-nitely dispelled in the minds of all those who listened to this admirable paper. Mr. Corson has applied the modern art of precipitation hardening to this old prob-lem with substantial success, employing small amounts of chromium, nickel, silicon, and cobalt for this purpose. The commercial application of these very important .developments of Mr. Corson is being actively investi-gated at the present time.

Jan 3, 1927

Jan 1, 1880

By E. A. Slover

THE usual reverberatory system of smelting cop--1- per concentrate or calcine has for its component parts a furnace and one or two waste heat boilers. These parts are operated on a basis of compromise, since the furnace can send gas to the boilers at too high a temperature and the boilers by plugging, due to dust or slag, can place a definite limit on the amount of fuel the furnace can burn. Over the years the copper concentrate smelting furnace has had few advances in design. The simple rules of design such as the flame should wipe the bath and the speed of the gases should be reasonably low for dust carrying purposes seem to cover the main features. In the construction of the individual furnaces some innovations are always being introduced. Among these are charging so that the work of smelting is a complete bath process, the use of suspended brick arches in place of sprung arches, the use of basic brick, not only in the crucible, but also in roof and sidewalls, the use of various means to feed the charge, the use of magnetite or other heavy material to construct the hearth, water cooling of bridgewall and slag skimming bay, the smelting of raw charge instead of calcine, the use of preheated air, and possibly the use of oxygen-enriched air for combustion. But the general outlines of the furnaces have not changed much except as to size. Furnaces at Hurley As shown on Fig. 1, the furnace at Hurley is 126 ft long between the longitudinal buckstays and 32 ft wide at the skewback plates. The foundation is a concrete retaining wall with piers at intervals that go deeper into the earth. Purposely the wall at the burner end of the furnace is not backed-up as tightly as the other parts of the foundation so that movement due to expansion may take place here rather than into the boiler foundations. Within these foundation retaining walls of concrete, the earth has been removed to allow the placement of the crucible brick base inside of which a silica hearth is laid 4 ft 6 in. in depth. No expansion is left in the brick base and crucible where they are in contact with the hearth. The hearth itself is of quartzite crushed to 1 in. size with fines left in the product. An 8 in. layer is laid and tamped with paving tampers to about 6 in. in thickness. Then a layer of silica flour is spread and vibrated into the hearth. This operation is repeated until a depth of 4 ft 6 in. is occupied by the silica mass onion-skinned in layers of approximately 6 in. Before firing the entire hearth is covered with broken slag to a depth of 4 in. so that a seal may be formed on the hearth. The crucible is completely faced with magnesite chemically bonded brick while the outside, against the foundation, is made of silica brick. The side-walls are carried up with silica brick in which expansion joints are left at intervals. Above the crucible the sidewall is corbelled to form a shelf on which the charge may build up along the side-walls, see Fig. 2. The arch of the furnace is sprung 20 in. silica brick, with the longitudinal centerline horizontal the length of the furnace, and some 9 ft in the center above the bath. Both straight and wedge brick are used in the construction and a thin silica mortar is troweled for joints. After the arch under heat has assumed its permanent shape, a silica slurry is spread over the arch to fill any cracks that have formed, thus giving bearing surface to the brick and preventing dust from entering the body of the arch to act as a future fluxing agent. The uptake of the furnace slopes up to the boiler entrance where a brick pilaster divides the gas stream for the two boilers. Over this flared uptake is a suspended flat arch of firebrick. The pilaster and sidewalls are constructed of firebrick but the bottom of the uptake is lined with silica brick and fettled through holes in the roof with siliceous fettling. Close to the entrance of each boiler is a brick covered slot through which water-cooled dampers may be lowered in event of boiler trouble. These water-cooled dampers are hung permanently in position ready to be lowered when needed. Flexible hoses to follow the dampers as they are lowered are connected at all times and individual chain blocks are used to lower the dampers. A pump supplying water is started before the dampers enter the heat. Charging of the furnace along the sidewalls for some 80 ft from the bridgewall is accomplished by electric vibrating conveyors fed by belt from charge storage bins above the furnace. These conveyors

Jan 1, 1954

By Thomas Egleston

All industrial establishments whose operations depend upon chemical reactions use gases. In the simplest case the oxygen of the atmosphere, heated or not, as the case may be, is used, and in other cases, gases which are produced by a special apparatus of more or less complex composition. The manufacturer depends, for the success of his operations, entirely upon having these gases arrive at the right time, in the proper proportions, at the required temperature. It often requires but a slight variation in their composition to make a given process a success or a failure. In most cases the gas used is formed from fuel, and according as variations in its composition are produced by alterations in the manner of charging the grate, not only different, but often directly opposite, results are obtained. The great industrial question of the present time, and one upon which the prosperity of the world depends, is how to get the greatest amount of useful effect from fuel, whether the caloric is used directly or is transformed into horse-power. In almost all industrial pursuits this translates itself into the question of how to construct a fireplace and its adjuncts in such a way that the heat of the flame and of the products of combustion shall be made to produce a maximum effect. Unfortunately, until very recently, except by comparison, there was no means of ascertaining whether the loss of useful effect was 80, 40, or 20 per cent. of the total amount of fuel employed. It seems now strange that there should have been furnaces so constructed as to produce 20 per cent. of carbonic acid in the fireplace, but this has been proved by analysis to have been true. It does seem incredible that, notwithstanding the immense number and variety of furnaces used for different processes, and the great difference in kind, quality, and quantity of fuels consumed, there should formerly have been used for them all, the same stereotyped fireplace, varied only in its dimensions of height, length, and breadth. It is true that, with a good fireman, excellent effects may be, and have been, produced, but the manufacture is here, as in many other cases, dependent on the intelligence of the workman, a very uncertain reliance for capital to rest upon. The workman, unless he receives a prime for fuel saved, or is fined for excessive use of it, may be said

Jan 1, 1915