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By Samuel S. Wyer

1. The following is an abridgment of a recent report made by the author, covering an investigation of: (A) The necessary use of natural-gas compressors; (B) The effect of gas compressors on natural-gas field operating conditions in Ohio, with special reference to the working pressure relations of gas wells of one company discharging by natural rock-pressure flow without compressors, and adjacent wells of other companies, discharging into intake lines to gas-compressing stations. Tests were made at 107 different places in the counties of fairfield, Licking and Knox, Ohio, which required 7,000 miles of automobile driving, and consumed 6 months' time. 2. A proper conception of the necessary use and effect of natural-gas compressors in natural-gas production necessitates a clear understanding of certain fundamental definitions and judicial doctrines, which are given herein. 3. Gas is a fluid composed of a large number of molecules which are vehicles of energy continually in motion, and havingan inherent tendency to get farther and farther apart. The range of motion of the molecules is limited only by the volume of the closed containing vessel in which they constantly move to and fro. The most distinguishing characteristic of gas is its universal property of completely filling an inclosed space. 4. Gas pressure is the result of the combined efforts of all the moving molecules in the mass trying to get farther and farther apart, that is, a mass of gas inclosed in a vessel expands and fills it, and being restrained from further expansion, it exercises a pressure against the walls of the vessel. This pressure is the same in all directions on equal areas of surface, as shown in Fig. 1. With a given mass of gas, any increase in volume of containing vessel will give the molecules more range of motion, * The public's interest in the age and magnitude of the art of gas compressing and development of the law relating to the use of grs compressors in natural gas production is discussed in the preceding paper. Development of the Law Relating to the use of Gas Compressors in Natural Gas Production; see also Is It Feasible to Make Common Carriers of Natural Gas Transmission Lines, vol. xlviii, 471 to 480 (1914). Consulting Engineer.

Jan 1, 1916

By J. C. Wright

A practical program of education for workers of the mining industries is being formulated by the Federal Board for Vocational Education in cooperation with the states in which this industry is a dominant one. The Federal Government last year passed a law, known as the Federal Vocational Education Act, that provides for the promotion of vocational education and for cooperation with the states in the promotion of such education in agriculture and trades and industries and in the preparation of teachers of vocational subjects. More than 1,000,000 men in the continental United States are employed in mines and quarries. The following table, from the 1910 Census Report, shows the relative importance of mining and manufacturing pursuits: Manfactures Mines and quaRRies Employees.......... 7,405,313 1,109,410 Capital............. $18,428,269,706 53,380,525,841 Value of product..... $20,672,051,870 $1,238,410,322 Of the more than 1,000,000 men employed in mining, almost three-fourths are engaged in the production of bituminous and anthracite coal; one-fifth, in the production of copper, iron, lead, zinc, and other metals; and the remainder in getting out structural and miscellaneous materials from quarries. The meeting of the needs of the coal-mining industry, therefore, is the problem of greatest importance in the point of numbers to be served. Moreover, the dangers in coal mining are greater than in metal mining. Practically all states have set up educational and technical standards for the position of foreman, boss, superintendent, etc., and every applicant for these positions must have a certificate of competency. The qualifications, too, are becoming increasingly difficult in the field of technical information. In some states, every miner must have a certificate, which is issued by the mine examining board only after an oral examination. Did these state laws not call for definite and comprehensive plans for the vocational education of men in the mining regions, the conditions

Jan 1, 1919

By Herbert F. Miller

For a long time I have believed that the gas- and brick-costs of open-hearth furnaces using prodncer-gas could be greatly decreased by a change in the design of the port, which would materially reduce the first-cost of the furnace, the rebuilding-cost, and the repair-cost. The defects of the present type of such furnaces, which has clone duty for so many years, may be studied in Fig. 1, in which A A are the two air-uptakes, B is the gas-uptake, and C the end of the gas-port. In the present type of furnace, C is practically 011 the edge of the bath and therefore combustion begins to take place at that point, but has no effect until the gas passes from 5 to 10 ft. into the hearth. As the furnace grows older, C moves back by reason of the burning or falling down of the arch. The furnace reaches its highest efficiency when C has moved a certain distance, but is still near enough to the bath for the overhead layer of air to hold the gas down on the bath, and far enough back to permit combustion to take place at some distance from the bath. This latter fact means that the temperature is sufficient to melt steel at the edge of the port. From this time on, the furnace decreases in efficiency. What is the reason ? As C moves further hack, the gas is released from the gas-port at a point where there is little or no overhead layer of air. The result is that the gas floats along the roof, with the air mostly underneath it. Why the air does not stay over the gas is readily seen in Fig. 1. The lines of draft naturally run parallel to the length of the furnace. The air-uptakes being on the sides and the gas-port in the middle, most of the air will naturally be drawn along the sides of the furnace and the layer of air will be thinnest over the gas, where it is most needed.

Jan 1, 1914

By Robert S. Archer, Zay Jeffries

It is about fifteen years since the development in Germany, largely by Alfred Wilm, of the aluminum alloy called duralumin. In this alloy, combining as it does the tensile strength of mild steel with the lightness and corrosion resistance of aluminum, a distinctly new material was presented to the engineering world. Despite the evident usefulness of this material, however, its commercial development has been slow, due in part to the difficulties involved in its fabrication. In view of the potentially great utility of strong aluminum alloys, it seemed desirable to find means of producing such alloys with better fabricating properties, and work was undertaken with this object in the laboratories of the Aluminum Company of America several years ago. This work has resulted in the production of two new types of aluminum alloy of the "strong alloy" class, having distinctly improved fabricating qualities. The knowledge gained has also made it possible to produce alloys of the duralumin type with greater strength and hardness than previously obtained. There have thus been made available some new engineering materials which it is the object of this paper to describe. These alloys, induding duralumin, are fundamentally wrought alloys. Castings of the same compositions heat treated in the same manner give inferior physical properties, particularly as to ductility. The statements made subsequently concerning properties and heat treatment apply to material that has received sufficient working to thoroughly break down the cast structure. The material referred to has, in general, undergone a reduction in section of at least 80 per cent, by mechanical working. It may be mentioned in passing that other compositions have been found that are suitable for the production of the maximum physical properties in heat-treated castings.

Jan 1, 1925

By J. Burns Read, Charles H. Fulton

A previous article1 by the authors contained a general description of the new roasting furnace herein described but it did not go into detail as to the metallurgical behavior or the results obtained. Believing that such information would be of great value, they have elaborated on the subject and have given many unpublished details. The furnace described applies the principle of roasting finely divided zinc-sulfide ores, now produced in large quantity by the flotation process, in gaseous suspension; that is, the ore particles are carried, in suspension, in a current of air and gaseous products of the roast. The relatively great fineness of flotation concentrate presents difficulties and problems of roasting in furnaces of the ordinary type; the fine ore is forwarded through the furnace in the form of a shallow bed and its very fineness leads to dense impervious bedding which prevents oxygen from reaching the interior of the bed, thus unduly lengthening the time of roasting and preventing the elimination of the last of the sulfur. The fineness of the concentrate, normally, should lead to a rapid and complete roast, for the speed of roasting is a function of the surface exposed to oxygen, which surface is greatest, per unit of weight, in very fine material. The difficulty in bed roasting is to get the oxygen to the particle. If the fine ore, during the roasting, could be freely suspended in oxidizing gases, full advantage could be taken of the great surface conferred by its fineness. This fundamental idea, of course, is not new, for the Stedtefelt furnace, familiar to the older metallurgists, is an example of it; but the manner in which this is accomplished may be new. The numerous efforts to roast in gaseous suspension show that the idea is attractive; in fact, an analysis would indicate that it is the most reason-

Jan 1, 1925

By H. W. Turner

The axis of the middle portion of the Ural mountains is made up chiefly of highly compressed igneous and sedimentary schists, considered of Devonian age by the Russian geologists, with large areas of serpentine (peridotite originally) gabbro, etc,, intrusive in the schist series. In addition there are large areas of probably older granitic and gneissic rocks. The nickel deposits referred to in this paper are found in the Devonian schists and their associated igneous rocks. The gabbro-peridotite intrusions probably took place in late Devonian or early Permian time, inasmueh as the Permian and Carboniferous beds lie at gentle angles on the Devonian series on the west slope of the Urals. Perhaps the first attempt to work a nickel deposit in the Urals was made about 1866 in the Revdinsk district, which is situated southwest of Ekaterinburg. 3 was informed by a Russian that a wet method of extracting the nickel was tried but was not a commercial success. This deposit has been described by Muller,l Foullon, and Karpinski.3 Beck4 gives an abstract of these papers. ; Lying to the southeast of the Revdinsk district, the Sissert estate intervening, is the Verkhne-Ufalei district, which is traversed by the railroad from Ekaterinburg to Cheliabinsk, as shown on the map, Fig. 1, there being a station on this railroad at the iron-smelting town of Verkhne-Ufalci. About 7 versts (4.6 miles) north of this town is the Nijni-Karka-dinsk iron mine, which is a limonite deposit. In one of the shafts in this mine a serpentine rock showing a green mineral was encountered. A sample of this mineral collected in 1910 was tested by Mr. Wyatt, chief chemist of the Karabash laboratory of the Kyshtim Mining Works, and determined as nickel ore. A thin section of one piece of the serpen-

Jan 1, 1915

By C. Baldwin Sawyer

J. S. Vanick,* Washington, D. C. (written discussion).—To those who have been confronted with the study of the gas-metal reactions, this paper is a most welcome contribution. My personal interest in work bearing upon this general problem, stimulated by an appreciation of the difficulties inherent to problems of this type, prompts a few words of discussion. Table 2 of the paper shows a gradual increase in the nitrogen content with an increase in pressure, and an interpretation follows in which nitrogcn is used as the compressed medium when the conditions admit that cyanogen gas could be active as a contaminating ingredient. Fusions of electrolytic iron made in the induction furnace in an atmosphere of deoxidized nitrogen and out of contact with contaminating materials have shown no microscopic evidence of -a nitrogen increase; using a refractory-lined graphite crucible in the furnace under the same conditions or admitting air often resulted in the occurrence of nitride needles in the solidified melt. These results suggested that a nitrogenous compound served as a vehicle for the introduction of nitrogen and that such compound was not available when the pure gas and carbon-free refractory were used. The fusion of pure iron in pure nitrogen is perhaps a matter of theoretical interest. The author's work serves a more practical purpose when applied to steels rather than iron. Table 2 reports the absence of nitride needles in melts made under pressure of one atmosphere, although the quantity of nitrogen present would seem to exceed microscopically detectable percentages. In some recent work29 on carburized iron, nitride needles have been observed in areas analyzing as low as 0.015 per cent. nitrogen. This low percentage of nitrogen would indicate that the solubility limit is less than 0.030 per cent. for hypoeutectoid steels. There is the possibility that the areas of pearlite which exist in a hypoeutectoid steel restrict the distribution of nitrogen and limit its presence to the ferritie fields. In view of this work and the references quoted by the author, I am led to expect that the value for the solubility of nitrogen in solidified iron may approach

Jan 1, 1924

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 W. M. Weigel

The rapid advance, during recent years, in the manufacture of articles that have been in common use for generations and the development of new materials entering into appliances and devices unheard of fifty years ago have created a demand for some of the more common non-metallic minerals. To supply this demand there has quietly developed a branch of the mining industry of which little is known by most mining engineers —the mineral-filler industry. In this paper, and generally in the trade, the term mineral filler is applied to a mineral used in its natural state after mechanical preparation only (such as grinding, milling and washing), without undergoing any chemical change and without exerting any chemical action on the substance with which it is incorporated. The consumption of mineral fillers is confined chiefly to large manufacturing centers in the Eastern and Northern Statcs. Where available, materials originating near the place of consumption are used, as most fillers bring a comparatively low price and, frequently, the freight may equal the cost of the finished filler at the mine. The Southern States have abundant deposits of non-metallic minerals suitable for fillers, which supply the manufacturing industries in adjacent states. Many of these deposits are equal to, or superior, in quality to those mined in the North, but they can not compete with them because of the freight rates. The mineral-filler industry has felt the present depression, but it has suffered less than most mining industries, for as a rule the mills are simple, the overhead expenses are low, and the labor is entirely local and can revert to farm work when the plant closes down. Many other deposits in the southern district will undoubtedly be developed when business revives and freight rates are adjusted. Most of the non-metallic mines are small and the tonnage handled is low in comparison with the tonnage involved in modern large-scale mining of coal, iron, copper, etc. On the other hand, at nearly all non-metallic

Jan 1, 1923

By W. M. Weigel

The rapid advance, during recent years, in the manufacture of articles that have been in common use for generations and the development of new materials entering into appliances and devices unheard of fifty years ago have created a demand for some of the more common non-metallic minerals. To supply this demand there has quietly developed a branch of the mining industry of which little is known by most mining engineers —the mineral-filler industry. In this paper, and generally in the trade, the term mineral filler is applied to a mineral used in its natural state after mechanical preparation only (such as grinding, milling and washing), without undergoing any chemical change and without exerting any chemical action on the substance with which it is incorporated. The consumption of mineral fillers is confined chiefly to large manufacturing centers in the Eastern and Northern Statcs. Where available, materials originating near the place of consumption are used, as most fillers bring a comparatively low price and, frequently, the freight may equal the cost of the finished filler at the mine. The Southern States have abundant deposits of non-metallic minerals suitable for fillers, which supply the manufacturing industries in adjacent states. Many of these deposits are equal to, or superior, in quality to those mined in the North, but they can not compete with them because of the freight rates. The mineral-filler industry has felt the present depression, but it has suffered less than most mining industries, for as a rule the mills are simple, the overhead expenses are low, and the labor is entirely local and can revert to farm work when the plant closes down. Many other deposits in the southern district will undoubtedly be developed when business revives and freight rates are adjusted. Most of the non-metallic mines are small and the tonnage handled is low in comparison with the tonnage involved in modern large-scale mining of coal, iron, copper, etc. On the other hand, at nearly all non-metallic

Jan 1, 1923

By H. D. Hoskold

DuRing the last few years, various persons have been put forward as originators of some mechanical device for the purpose of finding distances without the use of a chain or other linear measuring-instrument, and among these, the Englishman, Gascoigne, 1639, is prominent as the first in England; while James Watt, 1771, and William Green, 1778, are also included in the list of inventors. It is possible that this useful and important problem occupied the attention of others prior to the date cited, and, consequently, it is difficult to decide what nation first gave birth to the inventor of an instrument for the object under consideration. A very important work appeared, not long since, in Paris, devoted to a history and discussion of some of the older and newest forms of surveying-instruments,* and at page 79 of that work a curious old instrument is exhibited, called Bigonometre, i. e., an instrument for finding distances and solving trigonometrical problems. in surveying. A copy of the diagram of the instrument exhibited in the book referred to is represented in Fig. 1. Having had an occasion to read the French work referred to, I communicated with the author of it, and he was good enough to reply that he found a diagram of this old instrument in a book published in 1597, by Danfrie, existing in the library of the Academy of Sciences, in Paris. Col. Laus-

Jan 1, 1904

By Richard Moldenke

Note.—At the request of the American Society for Testing Materials, this paper wau presented at the New York Meeting, February, 1923, in connection with the "A. S. T. M. Tentative Specifications for Foundry Pig Iron" and The Physics of Cast Iron and Its Bearing on All Cast-iron Products and Specifications for Cast Iron," by William R. Webster. The discussion of this paper was not published by the Institute, having been referred to the American Society for Testing Materials, as these papers were again presented for discussion at the meeting of that Society at Atlantic Cit;, June, 1923. The result of these discussions is shown in the following abstract from the Committee A3 report on cast-iron specifications: During the past year, the adaptability of the tentative specifications for pig iron for the steel and the malleable foundry, in addition to the iron foundry proper, have been studied and suitable changes and rearrangements are being made which appear to cover the situation properly. In spite of the experience of foundrymen to the contrary, there is a persistent call from consumers of castinga for defixute compositions for given lines of castings. To respond to this call for information desired by the consumer—information every modern foundryman should have and guide his procedure with—the committee has requested the Sub-committee on General Cast!rigs to take up this matter with a view of constructing tables of analyses rang? for Important lines of foundry product. These analyses ranges however, are to be given as "recommendgd practice" and not intended for actual spkcification. In this way, the consumer of the foundry product will get the information he wants; the furnace-man will be gulded in the production of his pig irons to prepare for analyses ranges which are more closely standardized and have less of "freak" requirements made by Inexperienced metallurgists; and the foundryman will not be bound by chemical requirements he knows will not work out well with his particular reglonal supphes of melting stock. Doctor Moldenke's paper is published in full as it shows clearly the good results of the Institute's work in 1895 and a comparison of the same with the present knowledge of the metallurgy of cast iron—Bradley Stoughton, Chairman, Iron and Steel Committee. In MaRch, 1895, William R. Webster contributed a carefully prepared scheme for the study of the physics of cast iron to the American Institute of Mining Engineers at its Florida meeting. This summary of the interrelation of the chemical and physical characteristics of cast iron with the operations of daily foundry practice caused a wide discussion of the then little understood though universally used material. Mr. Webster has requested the author to bring the subject up to date and, while glad to comply, he must pay that with all the knowledge that has been gained in the quarter century that has passed since the subject was brought to the attention of the Institute—and we now are pretty familiar with cast iron in all its aspects—there is practically noth-

Jan 1, 1923

By Richard Moldenke

Note.—At the request of the American Society for Testing Materials, this paper wau presented at the New York Meeting, February, 1923, in connection with the "A. S. T. M. Tentative Specifications for Foundry Pig Iron" and The Physics of Cast Iron and Its Bearing on All Cast-iron Products and Specifications for Cast Iron," by William R. Webster. The discussion of this paper was not published by the Institute, having been referred to the American Society for Testing Materials, as these papers were again presented for discussion at the meeting of that Society at Atlantic Cit;, June, 1923. The result of these discussions is shown in the following abstract from the Committee A3 report on cast-iron specifications: During the past year, the adaptability of the tentative specifications for pig iron for the steel and the malleable foundry, in addition to the iron foundry proper, have been studied and suitable changes and rearrangements are being made which appear to cover the situation properly. In spite of the experience of foundrymen to the contrary, there is a persistent call from consumers of castinga for defixute compositions for given lines of castings. To respond to this call for information desired by the consumer—information every modern foundryman should have and guide his procedure with—the committee has requested the Sub-committee on General Cast!rigs to take up this matter with a view of constructing tables of analyses rang? for Important lines of foundry product. These analyses ranges however, are to be given as "recommendgd practice" and not intended for actual spkcification. In this way, the consumer of the foundry product will get the information he wants; the furnace-man will be gulded in the production of his pig irons to prepare for analyses ranges which are more closely standardized and have less of "freak" requirements made by Inexperienced metallurgists; and the foundryman will not be bound by chemical requirements he knows will not work out well with his particular reglonal supphes of melting stock. Doctor Moldenke's paper is published in full as it shows clearly the good results of the Institute's work in 1895 and a comparison of the same with the present knowledge of the metallurgy of cast iron—Bradley Stoughton, Chairman, Iron and Steel Committee. In MaRch, 1895, William R. Webster contributed a carefully prepared scheme for the study of the physics of cast iron to the American Institute of Mining Engineers at its Florida meeting. This summary of the interrelation of the chemical and physical characteristics of cast iron with the operations of daily foundry practice caused a wide discussion of the then little understood though universally used material. Mr. Webster has requested the author to bring the subject up to date and, while glad to comply, he must pay that with all the knowledge that has been gained in the quarter century that has passed since the subject was brought to the attention of the Institute—and we now are pretty familiar with cast iron in all its aspects—there is practically noth-

Jan 1, 1923

By Franklin R. Carpenter, W. P. Headden

TWO notes have already appeared in the Transactions concerning the columbite or tantalite of the Black Hills tin-mines. In vol. xiii., page 232, Prof. Schaeffer speaks of the mineral as tantalite, and concludes by saying that its separation from the tinstone "is a matter which will, I believe, prove puzzling to the wisest metallurgist." He also observes that he is unable to find by analysis in his specimens the least trace of columbic acid. Prof. W. P. Blake, in the same volume, at page 696, says: " Even if it [tantalite or columbite] were present to a considerable amount, it would not injure the tin in smelting. It does not alloy with tin, but carries a small percentage of tin, which would probably be liberated in smelting." He calls the mineral columbite from the fact that a great number of specificgravity tests invariably indicated that it should be so classed. We have made chemical tests as well as specific-gravity tests upon many samples from many different parts of the Hills. Our analyses have always shown the presence of columbic acid, and the specificgravity tests have always indicated columbite, as we have elsewhere shown.* As Prof. Blake has already observed, it is not found in such close association with the tin as to prevent separation by a rough handsorting, but it is usually present with the stream-tin. As Prof. Schaeffer says, it cannot be separated by ordinary concentration; and while, as declared by Prof. Blake, its columbic acid may not unite with the tin in any form, yet its iron and manganese oxides may be reduced, and thus lower the quality of the tin produced, as is also the case when the smelting charge contains wolfram. To determine the effect of columbite in the ordinary potassium cyanide assay, there were assayed at the Dakota School of Mines four samples containing different proportions of columbite. The results, published in the report of the school for 1888, seemed to indi-

Jan 1, 1889

By W. P. Blake

Wm. P. Blake, New Haven, Conn. (Communication to the Secretary, June, 1889): It is gratifying to find that Prof. Carpenter in his paper sustains the accuracy of my original determination of

Jan 1, 1889

By John H. Harden

The Koepe system of winding from shafts is the invention of Mr. Frederick Koepe, Manager of the Hanover Coal Mine, Westphalia, one of the collieries worked by Krupp, the well-known German ironmaster. The first trial of the system was made at the Hanover

Jan 1, 1889

By Fred P. Dewey

Early last March Mr. Jerome Coldren, an old miner add prospector, undertook a prospecting tour through the western part of Kansas, and discovered a very peculiar bed of rock, which yielded a white metal on fusion with soda. Mr. W. D. Church, city chemist at Topeka, examined the metal and found it to contain nickel. This discovery created much excitement, and was at first doubted. Many samples of the material, from a range of twenty miles, were sent to the Smithsonian Institution for examination ; and in every instance a qualitative test showed the presence of nickel, although the amount appeared to vary greatly. The ore is quite different from any other nickel-ore. It consists of a quartzose conglomerate from bean-size down, with much decomposed material between the pebbles, and the whole cemented by a more or less manganiferous limonite. In the qualitative tests, the nickel appeared to vary with the manganese. In all the tests, simple treatment with HCI dissolved a great deal of AI2O3. The principal deposit is near the top of a small hill on the divide between Smoky Hill river and Butte creek. The surface-rock is the conglomerate, and, at varying distances, stains of the limonite appear and gradually increase ; so that the ore is simply the lower portion of a bed of conglomerate which has been heavily charged with the manganiferous limonite. Below the conglomerate is a layer of selenite; below this, a soft sandstone, containing well-preserved fossils, and below the sandstone, a shale. From 2 to 6 per cent. of nickel in selected samples has been reported by different chemists; but the following two analyses on large samples show the average composition of the material:

Jan 1, 1889

By E. C. Potter

FUEL-OIL was first substituted for coal at these works in September, 1888. It was first applied in the converting-department to the battery of boilers, consisting of 14 tubular boilers, 16 feet in length by 5 feet in diameter. To operate these boilers with coal for 24 hours required 14 strikers, 3 ash-wheelers, 6 men unloading coal, and 2 water-tenders, making a total of 25 men. With fuel-oil the same boilers require for the same period 2 water-tenders and 4 men to attend to the burners, making a total of 6 men. This gives a saving of 19 men, which, at an average of $2 per day each, amounts to $38 per day. Comparing the consumption of oil with that of coal, we find that for the week ending January 5, 1889, with an ingot output of 6403 tons, 2731 barrels of fuel-oil were used as against a necessary consumption of coal for the same work of 848 tons, showing 3.22 barrels of fuel-oil to be equivalent to one ton of Indiana block-coal. Figuring oil at 60 cents per barrel, and coal at $2.15 per ton, we have as the cost of oil $1.93, as against $2.15 for its equivalent in coal. In December, 1888, the rail-mill battery of 26 boilers, of the same dimensions as those in the converting-department, was equipped for fuel-oil. For the week ending January 5, 1889, with a rail out-put of 5208 tons, 5987 barrels of oil were consumed, as against a necessary consumption of coal, to do the same work, of 1805 tons, showing 3.31 barrels of fuel-oil to be equivalent to one ton of Indiana block-coal, which at the costs named above would show $1.98 worth of fuel-oil to he equal to $2.15 worth of coal. The labor required to operate the rail-mill boilers for 24 hours, with coal as fuel,is: 26 stokers, 4 water-tenders, 6 ash-wheelers, 12 men unloading coal; total, 48 men. With oil as fuel, the same work requires 4 water-tenders and 6 men to attend to the burners; total, 10 men; a saving over coal of 38 men in 24 hours, which, at an average price of $2 per day, would be $76 per day. In the brief experience we have had with oil as fuel, we find that the efficiency of the boilers is somewhat increased and the repairs are

Jan 1, 1889

By George C. Stone

The stack gases from regenerative furnaces lare very seldom utilized for the production of steam. If the temperature of the gases is not higher than 300" C. (572" F.) there is no economy in their use for this purpose, as the amount of available heat is very small and the temperature is so little above that of the steam that the interchange is too slow. With higher temperatures of the waste gases, however, good results can be obtained. At the plant of the New Jersey Zinc Co. (of Pa.) at Palmerton there are a number of return tubular boilers, each 6 ft. in diameter and 20 ft. long, with 96 3.5-in. tubes, which are heated by the waste gases from the spelter furnaces. These furnaces have continuous regenerators heating the air only and the stack gases reach the boilers at a temperature of about 450". The gas producers for one of these furnaces require 14 tons of anthracite (a mixture of Nos. 2 and 3 buckwheat), and the waste heat from the furnace gives a little more than 42 h.p. in steam. The boilers are not well adapted for the purpose, as they are much too large for the amount of heat going to them and the area of the tubes is not sufficient to take the gas from two furnaces without causing an objectionable amount of back pressure. The plant was built without any idea of using waste-heat boilers, and it was impossible to place the latter as close to the furnaces as they should be. Furnace and boiler are connected by an underground brick flue in which the temperature of the gas drops about 100°, losing 40 per cent. of its available heat. If the boilers were close to the furnaces the horse power of each would be 70 instead of 42. Even under these unfavorable conditions the boilers have been very advantageous, as one boiler easily supplies the steam necessary for two batteries of producers. With such low gas temperatures the heating surface of the boilers is, of course, not as efficient and the flue areas need to be considerably larger than for coal firing.

Jan 1, 1914

By William P. Blake

As the storage of water for agricultural and mining purposes in the arid regions of the West is now receiving much attention by the people and their representatives, some facts coucerning the greatest pioneer enterprise for the purpose should appear on our records. I refer to the dam and reservoir at Walnut Grove, in Yavapai county, Arizona Territory, which was finished in the winter of 1887, and is known as the Walnut Grove Dam, It is not my intention at this time to give a full description of

Jan 1, 1889