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By A. A. Mathews

During the past year (1967-68), there have been many instances of either partial or complete failure of a tunnel-support system. It looks like the art is in a pretty sad state, but as long as we permit the field of tunnel design to remain basically an art, that's about what we can expect. The application of scientific principles to tunnel design involves much more than assigning values to a series of factors in an equation. I am reminded of the case where the engineer calculated that steel ribs with struts were required to support a horseshoe-shaped tunnel in firm ground. The contractor had driven several hundred feet without installing the struts when the engineer visited the job. When he was informed that the struts had been left out, he fled the tunnel in alarm. As one authority has so aptly put it, "There is far too much calculating and too little observing." Initially, one might think of a tunnel support as a structural member, such as a strut or arch which is installed in order to support some definite load. Similarly, a tunnel lining might be considered as a treatment of the interior surface of the tunnel in order to produce desired aesthetic, hydraulic, or architectural results, or to serve a protective function. Actually, many linings, such as a concrete lining, serve a dual purpose and support a load as well as satisfy other requirements. Not too many years ago a tunnel, during the driving or excavating stage, was considered to be either supported or unsupported. In recent years, however, several techniques have been developed, which by helping the tunnel to support itself, permit the elimination of separate structural support. Since these techniques in many cases actually become a substitute for the conventional types of supports and linings, a state-of-the-art review would hardly be complete without including them for consideration. Thus, for the purpose of this discussion, we shall define tunnel supports as any system or technique which effectively maintains the integrity of the tunnel opening. In their chapters, both Jacobs (No. 6) and Lippold (No. 7) pointed out how support systems have advanced from timber supports to steel supports

Jan 1, 1970

William B. Phillips, Birmingham, Ala.: The questions raised by Messrs. Wilkens and Nitze are in the highest degree interesting to owners of low-grade iron-ores, aizd no less so to blast-furnace managers. If it can be shown that ores heretofore considered worthless can be brought within the limit of economic use, many large and readily accessible deposits may come into market on the one hand, while on the other the possible increase in the output of the furnace per ton of ore used will prove of advantage to the iron-maker. It cannot, of course, be claimed that this process has been employed on a working-scale with respect to iron-ores, and in so far as concerns results on a large scale no one is any wiser than his fellow. Granting that the results obtained in an experimental way (and certainly the experiments were conducted with a great deal of care) can be attained in practice, we would still be facing the question, what it would cost to get them. In the absence of any specific data, we have to fall back on general principles, helped along, as far as possible, by indications afforded by the experiments. I must confess that as regards the Clinton ores, which I have studied to some extent, I am not sanguine of making a ton of 53 to 54 per cent. concentrates from less than 1.75 tons of 40 per cent. raw ore. It may be possible to get the iron in the heads to 56 to 57 per cent., but the lesser richness of the middlings will probably reduce this to 53 to 54 per cent. in the salable stuff. As the authors remark, it is not worth while to discuss the concentration of the better grades of " soft" Clinton ore; for the price at which they are now delivered at the furnaces, and the comparatively limited amount now remaining, render their concentration unadvisable. If it is to succeed in the Birmingham district, the process must be applied to the low-grade soft and hard ores now con-

Jan 1, 1897

By D. B. Myers

The consistent upward trend in crude oil production prevailing in California throughout the greater part of 1929, was effectively checked in November by a curtailment program instituted by mutual agreement between operators in four of the major fields. This program artificially reduced daily production to approximately the same daily figure as prevailed in December, 1928. The large amount of deep drilling during the later part of 1928 and during 1929 has established a potential, however, which is far in excess of refinery needs in the state. Low prices for crude oil which prevailed in California during 1928 continued during 1929. General curtailment continued in the older fields in San Joaquin Valley. The number of wildcat and exploratory wells drilled throughout California was materially increased, but no major field was discovered unless the recent bringing in of the Ohio Oil Co.'s Recreation Gun Club No. 1 well, near Venice in Los Angeles Basin, during the closing days of 1929 results in such a field. Significant developments during 1929 were: (1) The discovery of three deeper zones in the Santa Fe Springs field known as the O'Connell, Clarke, and Hathaway; (2) Kettleman Hills development and unanimous agreement to restrict production; (3) developments along the Santa Barbara Coast and the drilling of tideland permits; (4) extensions of some of the older producing areas in the San Joaquin Valley; (5) the Lawndale and Santa Barbara Mesa structures, the former discovered in Los Angeles Basin in 1928, the latter in Santa Barbara County in 1929, proved to be failures; (6) intensive exploration throughout the state and the drilling of a large number of deep wildcat wells; (7) discovery of oil by the Ohio Oil Co. in the Los Angeles Basin at Venice; (8) Long Beach and Ventura Avenue fields maintained steady production throughout the year. As a natural sequence to the discovery of high-gravity oil fields in Kettleman Hills and at Elwood in 1928, a tremendous amount of exploratory work was done in 1929 in areas underlain by rocks of lower Miocene age, particularly along the Santa Barbara Coast area, the San Joaquin Valley, and the Salinas Valley, where the Vaqueros and Temblor sands were considered to hold possibilities for production.

Jan 1, 1930

By J. M. Morris

THE point to be made most clear in this paper is the economic value of flotation in the Benguet mill flow sheet. It is rather a statement of effect with no attempt at a technical explanation of the cause. Certain well-known, easily understood reagents, mechanisms and principles have been adapted to the conditions at Benguet, and have proved to be more successful than was demonstrated in the laboratory. The mechanical and metallurgical development of this particular operation was arrived at by trial and error, with fortunately very little error. Changes were slow, of necessity, which in the end proved a blessing in that time was afforded for observation and analysis of the disturbing factors; and as a result each change was a definite step towards higher efficiency. Many of these steps were unpredictable from labora-tory work because of the varied and differing characteristics of ores met with in daily operation of the mill, which were practically impossible to reproduce on a laboratory scale. The Benguet mill receives daily ores that differ as much as if they were delivered from three different properties. There is first the surface and upper-level zone, which produces an oxidized secondary ore contain-ing considerable iron oxide, manganese oxide and some organic matter. Formerly, most of this ore consisted of very soft fill with some hard rock mixed in. It also contained an unusual amount of iron and aluminum sulfate, which formed hydrates upon entering the alkaline cyanide solu-tion and caused excessive frothing. When flotation was introduced in the Benguet mill the general char-acteristics of this upper-level ore had changed considerably, in that it was practically all newly mined, fairly hard ore. It still contained many of the same disturbing elements, but was somewhat simpler to treat than formerly. The small proportion of fines is still troublesome in flotation, and plant practice probably does not show more than 80 per cent extraction on this small portion of the ore. No definite figure on this is available, as this particular ore is delivered at irregular intervals

Jan 1, 1936

By Dorsey Hager

The possibilities of finding new oil pools in Oklahoma and Kansas are far from promising. In 1916, the only new pools of importance were the Franchot pool near Bixby, the Garber, and the Billings pools in Oklahoma, and the Virgil and Utopia fields in Greenwood County, Kansas. In the first 8 months of 1917, a small pool of unknown extent was opened south of the Stone Bluff pool in Oklahoma, and a pool near Casey, Paunee County, Oklahoma. In Eastern Kansas, interest has been caused by the sinking of new wells near the old Iola pool, but nothing of magnitude has yet been found. The outlook for new pools is far from encouraging, especially as geological surveys have covered all of Oklahoma and Kansas. There are a few areas where geological surveys throw little or no light on the subject, as exposures are poor, but the chances of finding new pools in such areas are slight indeed, if one can judge from the past history of such areas. So far the geologists have based their opinions largely upon the presence or the absence of geologic structure, such as anticlines, domes, and terraces, but some pools will most certainly be found where no surface structure exists, but where local changes in the sand body favor oil accumulations. However, the possibilities of new pools off structure are small, as fully 90 per cent. of the oil pools are on definite structure. In the past, it is estimated that one test in 150 "wild cats" or new tests has brought in a new field. The writer feels safe in asserting that the proportion will decrease still further, so that but one out of 500 new tests may bring in a pay well in a new area. Prom now on the principal field of work in Oklahoma and in Kansas will consist in developing the present pools. The years 1915, 1916 and 1917 saw the high peak of Oklahoma and Kansas oil production. The Eldorado and the Augusta oil fields present the largest possibilities for continued production in Kansas. These two pools have been scarcely more than one-third developed, and have greater potentialities than any of the present Oklahoma pools. In Oklahoma, pools of magnitude should

Jan 1, 1918

By A. H. Lee

Discussion of the paper of H. P. HOWLAND, printed in Bulletin No. 111, March, 1916, pp. 627 to 650. A. H. LEE, Buffalo, N. Y. (communication to the Secretary*). The statements and results recorded in Mr. Howland's paper can be accounted for by the use of coke with a low sulphur content (0.60 and under). This allows the furnaces to be run on a small volume of acid slag, which it is presumed was done in Mr. Howland's practice. H. A. Brassert has admitted that this was the largest factor in low fuel consumption in his practice. Where the coke contains from 1.00 to 1.25 per cent. of sulphur the situation is quite different and I doubt whether the results mentioned by Mr. Howland could be obtained under such circumstances. ` N. M. LANGDON, Mancelona, Mich. (communication to the Secretary + ).-Gruner's ideal working (which is but a statement of the law first enunciated by Bell) as given in Gordon's Translation of Studies of Blast Furnace Phenomena, "supposes that the reduction of the oxide of iron is effected by the CO only, without intervention of solid carbon." This ideal, if reached, would mean theoretically perfect or 100 per cent. efficiency of reduction. The workings of the large number of furnaces as given in Bell's and Gruner's great works do not show that this standard of perfection ever was reached. This problem has been worked out by the writer for a number of furnaces, and his results, as well as those given by others, all show a failure to reach perfection. Some furnaces, however, approach nearer to perfection than others. The "ideal" as given by Gruner was not stated as a solved problem in blast-furnace practice, but as an ideal to the attainment of which furnace managers should strive. A study of the factors involved from every angle is interesting and instructive and the paper on this subject contributed by H. P. Howland is no exception to the rule. This article is fairly open to criticism, not because of the unique method of presenting the subject, but for the reason that, as the writer conceives, erroneous assumptions are taken which lead naturally to incorrect conclusions.

Jan 7, 1916

By L. W. Kemph, K. R. VanHorn

During the recent development of aluminum alloys for free-cutting screw-machine rod, it became desirable to know something of the solubility of lead and bismuth in liquid aluminum and in some aluminum alloys. The literature is not particularly helpful in supplying this information. These portions, therefore, of the constitutional relationships of aluminum-bismuth and aluminum-lead alloys were investigated by thermal analysis and by chemical analysis of samples taken from aluminum-rich melts in equilibrium with precipitated lead or bismuth. The solubility of lead and bismuth in some liquid aluminum-copper alloys was also investigated. Some consideration was also given to the solubility of these elements in solid aluminum. Among the earliest investigators of the aluminum-lead and alunlinum-bismuth systems was Wright,' who reported that melts of aluminum and lead formed two layers indicating limited liquid solubility. Under his conditions, the aluminum-rich layer was reported to contain 1.91 per cent Pb and the lead-rich layer, 0.07 per cent Al. Subsequently, Pecheau2 found that in aluminum-rich alloy melts with more than 10 per cent Pb three layers were distinguishable. He reported that the middle layer contained from 3 to 10 per cent Pb. He also found that the melting point of aluminum appeared to be lowered slightly by the addition of lead. Gwyer3 investigated these alloys and found evidence of a slight lowering of the freezing point of aluminum by the addition of either lead or bismuth. He found no evidence of solid solubility in either case and made no attempt to determine the liquidus curves. Hansen and Blumen-tha14 reported that the addition of lead distinctly lowered the solidification point of aluminum. They also found that bismuth lowered the melting point of aluminum. Guillet5 reported almost complete mutual immiscibility for the aluminum-bismuth alloys in the liquid state. Bohner6 examined the effect of various concentrations of lead and bismuth on the electrical conductivity of aluminum. He found decreases in conductivity on annealing at 500' C. as compared with the conductivity of the same alloys on annealing at 300' C.

Jan 1, 1939

By Herbert Clark Hoover, Lou Henry Hoover

MOST illustrious Princes, often have I considered the metallic arts as a whole, as Moderatus Columella2 considered the agricultural arts, just as if I had been considering the whole of the human body ; and when I had perceived the various parts of the subject, like so many members of the body, I became afraid that I might die before I should understand its full extent, much less before I could immortalise it in writing. This book itself indicates the length and breadth of the subject, and the number and importance of the sciences of which at least some little knowledge is necessary to miners. Indeed, the subject of mining is a very extensive one, and one very difficult to explain ; no part of it is fully dealt with by the Greek and Latin authors whose works survive ; and since the art is one of the most ancient, the most necessary and the most profitable to mankind, I considered that I ought not to neglect it. Without doubt, none of the arts is older than agriculture, but that of the metals is not , less ancient ; in fact they are at least equal and coeval, for no mortal man ever tilled a field without implements. In truth, in all the works of agricul- ture, as in the other arts, implements are used which are made from metals, or which could not be made without the use of metals ; for this reason the metals are of the greatest necessity to man. When an art is so poor that it lacks metals, it is not of much importance, for nothing is made without tools. Besides, of all ways whereby great wealth is acquired by good and honest means, none is more advantageous than mining ; for although from fields which are well tilled (not to mention other things) we derive rich yields, yet we obtain richer products from mines ; in fact, one mine is often much more beneficial to us than many fields. For this reason we learn from the history of nearly all ages that very many men have been made rich by the

Jan 1, 1950

By L. W. Kempf, K. R. Van Horn

DURING the recent development of aluminum alloys for free-cutting screw-machine rod, it became desirable to know something of the solubility of lead and bismuth in liquid aluminum and in some aluminum alloys. The literature is not particularly helpful in supplying this information. These portions, therefore, of the constitutional relationships of aluminum-bismuth and aluminum-lead alloys were investigated by thermal analysis and by chemical analysis of samples taken from aluminum-rich melts in equilibrium with precipitated lead or bismuth. The solubility of lead and bismuth in some liquid aluminum-copper alloys was also investigated. Some consideration was also given to the solubility of these elements in solid aluminum. Among the earliest investigators of the aluminum-lead and aluminum-bismuth systems was Wright,1 who reported that melts of aluminum and lead formed two layers indicating limited liquid solubility. Under his conditions, the aluminum-rich layer was reported to contain 1.91 per cent Pb and the lead-rich layer, 0.07 per. cent Al. Subsequently, Pecheau2 found that in aluminum-rich alloy melts with more than 10 per cent Pb three layers were distinguishable. He reported that the middle layer contained from 3 to 10 per cent Pb. He also found that the melting point of aluminum appeared to be lowered slightly by the addition of lead. Gwyer3 investigated these alloys and found evidence of a slight lowering of the freezing point of aluminum by the addition of either lead or bismuth. He found no evidence of solid solubility in either case and made no attempt to determine the liquidus curves. Hansen and Blumenthal4 reported that the addition of lead distinctly lowered the solidification point of aluminum. They also found that bismuth lowered the melting point of aluminum. Guillet5 reported almost complete mutual immiscibility for the aluminum-bismuth alloys in the liquid state. Bohner6 examined the effect of various concentrations of lead and bismuth on the electrical conductivity of aluminum. He found decreases in conductivity on annealing at 500° C. as compared with the conductivity of the same alloys on annealing at 300° C.

Jan 1, 1938

By Henry E. Armitage

The object of this paper is to give a few useful hints on the concentration of low-grade ores. The machines that I shall speak of are, Cornish rolls, revolving screens, Hartz jigs, spitz-lutte, and the Linkenbach buddle (or Roberts's patent buddle, as it is called in Colorado). I think the reason why some of them have been discarded in favor of more recent inventions is that they have not been given a fair chance to do their work in a satisfactory manner. Cornish rolls are usually looked upon as a machine designed simply to crush the ore as a preliminary to sending it to the sizingscreens, beyond which they have nothing to do with dressing the ore. On the contrary, the rolls give the key-note to the whole process. It is well known that one class of rock will crush differently from another, and from the result obtained by passing the ore through the rolls the size of the first revolving screen and the surface required on the jig-screens must be determined. If it is found that the mineral crushes clear from the quartz, a large mesh can be used on the first sizing-screen, and the tailings will not require recrushing ; but if it is found that some of the tailings from the first jig are ragged (that is, are carrying off particles of mineral sticking on the quartz), it will be necessary to recrush them. Again, if a large percentage of the tailings carry off mineral, it will be more economical to commence with a finer mesh screen than to recrush the tailings. Having determined the best mesh to use on the first sizing-screen, the different sizes on the other screens can be determined from it. I have found for practical purposes that, commencing with a 6-mesh, the next should be 8, then 12, and finally 18. The holes in the jig-screens should be a trifle larger than in the revolving screens. For instance, if the revolving screen is made of No. 14 wire, the corresponding jig-screeus should be of No. 16 wire. The jig-screen surface required for each size made depends on the may

Jan 1, 1890

By David B. Reger

The year 1936 in West Virginia was characterized by increased activity in natural gas. The number of actual completions was only slightly increased but many more wells were drilling than at the end of 1935 and there was almost feverish activity in taking new leases. This pronounced revival is partly due to the fact that the extremely cold winter of 1935-1936 showed that additional supplies of gas would be desirable and partly to the hope of finding new pools in the deeper sands. No new pools have actually been found, but the Oriskany sand (L. Dev.) development of Kanawha County, which was already assured by the end of 1935, was greatly extended into wider and richer territory. The Middle Devonian shale (Childres sand), reached incidentally by Oriskany exploration as well as by direct design, has been productive of gas in much wider areas of Boone, Lincoln, Putnam and Kanawha Counties than heretofore known. Routine drilling to the upper sands in dehed territory, also, was greatly increased, although not yet much reflected in completions. Thc supply of marketable gas, however, has been substantially enlarged. In preparation for further exploration there has been an extensive leasing campaign throughout the entire territory where gas seems at all probable, or ever possible. Exact figures are lacking, but new leases have certainly been taken on more than 1,000,000 arres. One operator estimates that 500,000 acres have been leased in the Appalachian geosyncline alone between Parkersburg and Charleston. Exploration, both for shallow and deep-sand gas, on some of these new leases is now under way. There was little activity in oil. No special search for new pools was made and none was found, but the usual routine drilling in old pools occurred. One major gas pipe-line enterprise was undertaken and completed. Operating technology was much the same as usual. In certain localities repressuring for oil has become a matter of routine, and in others the use of acid in treating small wells in calcareous beds has been continued. Financially, the year has been eventless. Some attempts to buy and

Jan 1, 1937

By C. K. Leith

ManGanese is one of the minerals which is principally consumed in countries other than origin. Nearly 85 per cent. of the world's production is used by the United States, England, Germany and France, and roughly a third of the total is used by the United States alone. On the other hand, over 85 per cent. of the world production comes from Brazil, Russia, India, the Gold Coast of Africa and the Sinai Peninsula. It follows from this fact that practically all manganese moves across international boundaries in raw or alloy form, and much the larger part of this inovement is for considerable distances and is occan bornc. There is no indication that any one of the principal consuming countries can develop even approximately adequate supplies of its own. Under abnormal war conditions, with high prices and changes in metallurgical methods, only 35 per cent. of the needs of the United States was met from local sources, and under our recent tariff only 11 per cent. There are thousands of manganese deposits scattered about the world, but only a very few which can figure largely in supplying requirements on a modern scale. The known reserves, together with highly probable extensions and explorations now under way, indicate no shortage from a world standpoint for many deeades to come. The production and marketing of manganese is going steadily into fewer and stronger hands. The steel industry uses over 90 per cent. of all the manganese mined and is acquiring control of a considerable part of the production in all of the principal fields—the Germans in Nikopol, the English in India and Gold Coast, the Americans in Georgia, India, Gold Coast and Brazil. Some of the controlling companies arc of international scope. Concentration of commercial control is a notable tendency. A natural consequence is the growing uneasiness of smaller consumers the world over about their ultimate supplies and desire to know more definitely how and where manganese supplies will be controlled in the future. The sources of supply are few cnough to warrant the belief that more or less monopolistic elements of control arc not impossible.

Jan 1, 1927

By W. A. Backofen, N. E. Paton

DEFORMATION twinning contributes to the plasticity of titanium and has been reported on {10i2}, {1121},{11221}, {1123}, and {1124} planes.' Twinning on {1011} has also been reported in commercially pure titanium as a result of quenching from 1000', but no reports of such twins occurring as a result of deformation alone are known to the authors. In this study single crystals grown from iodide titanium were compressed parallel to the c axis over the temperature range 25 to 800°C. From it has come evidence that (10il) deformation twins are the most common type between 400" and 800°C. Crystals about 6 mm high with a rectangular cross section measuring about 3 by 4 mm were used in the tests. Chemical analyses showed them to contain 220 to 250 ppm 0 arid 10 to 15 ppm N. The long axes of the crystals were made parallel to the c axis while the sides were parallel to (i100) and (1120), as shown in Fig. 1. The crystals were compressed between polished alumina platens with no lubrication, in a vacuum of 2 x lom5 torr. Between 25' and 300°C the predominant twinning mode was (11221, which is to be expected for this stress state. There was an abrupt change at 400°C, however, and from that temperature up to 800°C twinning took place almost entirely on (10i1 ). Twin planes were determined by the two-surface rnethd. Measurement of the crystal orientation within several (10i1) twins by means of polarized-light4 and transmission electron microscopy showed that the lattice reorientations were the same as those previously reported for the (10i l ) twinning in magnesium.' This reorientation is consistent with The calculated (10il ) twinning shear for titanium is 0.10, while that measured from surface offsets on a (1150) face, which is parallel to the shear direction, was about 0.15. Slip within the twins, or in the matrix adjacent to the twins, probably accounts for the larger measurement. Slip in both locations was judged to have occurred from observations on foils in the electron microscope.

Jan 1, 1970

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 R. E. H. Pomeroy

THE statistical data given in this paper are taken from the actual performance of the No. 2 reverberatory furnace of the Nevada Consolidated Copper Co., Me Gill, Nev., for a period of four months, from April to July, 1914. The principal furnace dimensions are: Length, 132 ft. ½ in. at the skim-line level; average width, 18 ft., 10 in. at the skim-line level. The roof is 7 ft. above the skim-line level at the firing end. The average area in the uptake flue is 36 sq. ft., and the area above the skim line under the vulcatory arch is 24.3 sq. ft. Fig. 1 shows a diagrammatic plan and sectional elevation of this furnace. The furnace is equipped with two 400-b.h.p. Stirling waste-heat boilers set in parallel. California crude petroleum is used for fuel and has a specific gravity of 16.5° B., flashing in open test at 199° F. The oil is heated to about 200° F. in a steam heater before going to the burners, requiring about 9 b.h.p. per furnace day to heat it from the line temperature to the burning temperature. Measurement is made by oil meter, checked daily by reservoir readings. The oil is fed by gravity (34 lb. static pressure) to seven low-pressure blast burners of the Steptoe type (Fig. 2). The blast for these burners is supplied at about 40-oz. pressure by a motor-driven Connersville blower of 42 cu. ft. capacity per revolution. The air supplied by the blower through the burners for atomizing the oil amounts to about 10 per cent. of the theoretical air necessary for complete combustion of the oil. The remainder of the necessary air enters the furnace through the burner openings in the firing wall. No checker holes are provided, and the charge holes in the roof are equipped with slide gates and "dog houses? to minimize air leakages. The combustion of the fuel, as shown by gas analysis at the front of the furnace, is practically complete, the carbon monoxide in the gases being less than 0.5 per cent.

Jan 2, 1915

By Eugene McAuliffe

IT is not possible to include in this paper, limited as it is in scope, the many diverse steps toward the reduction of mine accidents that are taken in the mines that produce the nation's coal. Every coal-producing state has enacted laws covering proper mining practices, and the major portion of these are directly related to the safety of the mine employees. The United States Bureau of Mines, the American Institute of Mining and Metallurgical Engineers, The American Mining Congress, a number of national, regional and state organizations, as well as the coal technical press, have covered time and time again all of the "do" and "don't" phases of mine operation that bear on the important question of mine and employee safety. Within the past 15 years The Union Pacific Coal Co. has attempted to put into practice in its mines in southern Wyoming these many good recommendations, finding some value in all, and yet, to secure substantial results, the management found it necessary to resort in the end to what might be referred to as "extra-territorial" methods. It is the writer's purpose to show in this paper that marked and even extraordinary betterment can be brought about when employer and employee work together with due sincerity. In presenting our own experience, one that has been duplicated in so far as results are concerned on numerous other properties, no theory of perfection of management exists; on the other hand, our organization feels that as long as our record of accidents remains as shown by even our latest and best performance we still have far to go. It is the writer's purpose to show in this paper that marked and even extraordinary betterment can be brought about when employer and employee work together with due sincerity. In presenting our own experience, one that has been duplicated in so far as results are concerned on numerous other properties, no theory of perfection of management exists; on the other hand, our organization feels that as long as our record of accidents remains as shown by even our latest and best performance we still have far to go.

Jan 1, 1938

By L. W. Kemph, K. R. VanHorn

During the recent development of aluminum alloys for free-cutting screw-machine rod, it became desirable to know something of the solubility of lead and bismuth in liquid aluminum and in some aluminum alloys. The literature is not particularly helpful in supplying this information. These portions, therefore, of the constitutional relationships of aluminum-bismuth and aluminum-lead alloys were investigated by thermal analysis and by chemical analysis of samples taken from aluminum-rich melts in equilibrium with precipitated lead or bismuth. The solubility of lead and bismuth in some liquid aluminum-copper alloys was also investigated. Some consideration was also given to the solubility of these elements in solid aluminum. Among the earliest investigators of the aluminum-lead and alunlinum-bismuth systems was Wright,' who reported that melts of aluminum and lead formed two layers indicating limited liquid solubility. Under his conditions, the aluminum-rich layer was reported to contain 1.91 per cent Pb and the lead-rich layer, 0.07 per cent Al. Subsequently, Pecheau2 found that in aluminum-rich alloy melts with more than 10 per cent Pb three layers were distinguishable. He reported that the middle layer contained from 3 to 10 per cent Pb. He also found that the melting point of aluminum appeared to be lowered slightly by the addition of lead. Gwyer3 investigated these alloys and found evidence of a slight lowering of the freezing point of aluminum by the addition of either lead or bismuth. He found no evidence of solid solubility in either case and made no attempt to determine the liquidus curves. Hansen and Blumen-tha14 reported that the addition of lead distinctly lowered the solidification point of aluminum. They also found that bismuth lowered the melting point of aluminum. Guillet5 reported almost complete mutual immiscibility for the aluminum-bismuth alloys in the liquid state. Bohner6 examined the effect of various concentrations of lead and bismuth on the electrical conductivity of aluminum. He found decreases in conductivity on annealing at 500' C. as compared with the conductivity of the same alloys on annealing at 300' C.

Jan 1, 1939

By E. Gilpin

The following notes may serve to bring before your Institute an idea of the iron-ore resources of Pictou County. Enough work has been done to permit an estimate to be formed of their quality and probable extent. As yet the systematic mining and smelting of ironore in Nora Scotia is confined to the operations of the Steel Company of Canada, in Colchester County. Although the locality I am about to describe appears, in many respects, well adapted to iron smelting, etc., no attempts have yet been made to begin work. Nora Scotian capital is more readily turned to lumbering, fishing, and shipping ventures; and such an investment appears equally foreign to the rest of the Dominion. I need not, however, go further into this part of the subject, and can only hope that my notes may prove serviceable as indicating a probable field for future development. The accompanying map shows the position of the harbor of Pictou relative to the coal and iron-ore fields, and to the railways which intersect them. The branch of the Intercolonial Railway, running from Truro to Pictou, forms the western boundary of the iron-ore district, which extends beyond the point where the New Glasgow and Cape Breton Railway crosses the French River. The iron-ore district may be roughly described as a triangle formed by the ore-outcrops and the two railways, the former making the base, and the latter the sides of the triangle, the apex resting on the coal-field at New Glasgow. The drainage of the country is toward the Gulf of St. Lawrence, through the Middle, East, Sutherland's, and French rivers; and the surface is undulatory, seldom exceeding two hundred feet above the sea-level, except in the district lying between Glengarry and the upper waters of the French and Sutherland's rivers, where a maximum height of about five hundred feet is reached at several points. Geologically speaking, the district embraces two divisions, the Carboniferous and the Silurian, the latter resting on strata provisionally considered to be of pre-Cambrian age. As no geological

Jan 1, 1886

By W. R. Ingalls

WHEN I was a boy, political economy was taught in the old fashioned New England high school that I attended. I still possess my text-book, an abridgment of one of the old classics, and, I referred to it a few days ago. It began with the definition that "political economy is the science which investigates the' nature of wealth, and the laws which govern its production, exchange and distribution." That definition of 50 years ago strikes me still as being a good one. In college I sat under Francis A. Walker, the greatest of American economists. I still have his old text-book, which begins with substantially the same definition as Fawcett, but adds that "political economy has to do with no other subject, whatever, than wealth." As so developed economics was a dry study which captivated but few. It was characterized as the dismal science. It seemed to lead nowhither. . This was perhaps due to the inadequacy of the data available to economists. Consequently, their discussions and deduc-tions were founded largely on conjecture and assump-tions. Naturally this resulted in differences in the formulation of doctrines. There were controversies respecting the nature and influences of money, over the derivation of wages, over the principles of laissez faire (letting things take their own course) over the Malthusian doctrine, and so forth. Amid all this there was one great fundamental law universally recognized, namely the law of supply and demand, which ranks with the law of gravitation and the law of the conservation of energy among the great fundamen-tal laws of nature. The law of supply and demand is the one thing in economics upon which we may fix our eyes as upon the lode star. In the course of time we have fallen out of agreement with Walker's doctrine that political economy has to do with no other subject than wealth. Although it is indeed the science of the production and distribution of wealth we can see that many things pertain to that subject and that economics links hands closely with engineering, biology, and psychology. It is probably the recognition of this that caused the study and exposi-tion of economics to acquire such a strong sociological

Jan 6, 1923

Discussion of the paper of W. R. SHIMER, presented at the New York meeting, February, 1915, and printed in Bulletin No. 99, March, 1915, pp. 557 to. 585. WILLIAM R. WEBSTER, Philadelphia, Pa.-I would like to ask Mr. Shimer how the finishing temperature of the H-beams and other beams rolled on the Gray mill at Bethlehem compare with the rolling temperatures of the rails referred to in this paper. Also, how the reductions in the rolling of the beams compare with the reductions in the rolling of the rails. I would also like to know if any drop tests were' made on the rails referred to as having been allowed to cool and then annealed; in other words, what results, if any, were obtained from tests on rails after the internal strains of rolling had been removed; and in the matter of the rail blooms, I would like to ask if they are not often heated to a higher temperature than is desirable on account of the thin flanges in order to carry the heat through to the finishing pass. The tensile strength of the steel in these rails is given as 125,000 lb. per square inch, which is almost as high as tire steel. If some of these blooms were rolled into rounds of about the same section as the head of the rail, would you not get better results from tension tests than those from the head of the rail? In other words, in rolling rounds, whether you would not be able to control the rolling and finishing temperatures better than is possible in the rail, owing to thin section of the rail flanges. Some years ago I had experience with the rolling temperatures of tire steel, running from about 127,000 to 133,000 tensile strength. These tires had the tensile strength and the deflection specified. One of the manufacturers had no trouble whatever, after a little experimenting, in meeting the conditions of the specification. Another manufacturer who made some of these tires came to the office and stated that he had tried tires from three heats of steel and could not meet the specifications and

Jan 5, 1915