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By F. Keller, A. H. Geisler

Some of the important changes that take place in the structure of aluminum alloys are largely submicroscopic in character. This is especially true of the changes that accompany age-hardening and recrystallization. Although improved metallographic practices have been helpful in indicating some of these changes indirectly, results are limited by the resolving power of optical microscope lenses. The electron microscope, however, provides a new and important means for investigating the fine structure of metals in a range not possible heretofore. It is anticipated that this microscope will yield new and useful information to metallurgists when suitable techniques are developed to utilize its very high resolving power. Several unique methods have been devised to permit the examination of the structure of opaque samples by the electron microscope. These are all based on the principle of producing a very thin film that represents the prepared surface of the opaque metal sample, which can be examined in the transmission microscope; however, the available methods fall into three categories, depending on the manner in which the film is obtained. With the oxide-film method developed by Mahl3-17 a very thin surface layer of the metallographic sample is converted into oxide by a thermal, chemical or anodic treatment. After removal from the metal sample by one of the special techniques described by Evans,19 this oxide film is examined in the electron microscope, and is found to portray the structure of the original metal surface. Films formed on aluminum,8,17 nickel,7 iron 3,8,9 and a nickel-beryllium alloy" by heating; films formed on iron 8.9 by chemical action; and films formed on aluminum3-16 by anodic oxidation, have been examined. The other two are more recent methods developed principally in this country; they consist in making the thin film in the form of a mold or replica of the surface contour of an etched sample. With the negative replica method the thin film is made directly on the sample; with the positive replica method it is made on a negative reproduction of the sample. With both methods, variations in the contour of the metal sample, caused mainly by etching, produce variations in the thickness of the surface replica. Because of the direct dependence of the amount of scattering of the illuminating electrons upon the thickness of the film penetrated, only the variations in thickness of the replica are responsible for tones in the electron image. Negative replicas are made by forming a thin film of some suitable material directly on the polished and etched metal sample, and derive their name from the fact that after removal from the sample they have the high and low points in the sample reversed, as shown in Fig. I. Nega-

Jan 1, 1944

By Clinton H. Crane

IN October, 1925, J. R. Finlay delivered an address entitled, "The Future Price of Lead." Lead was then selling at 8.85c. and Mr. Finlay and most of the rest of us were concerned about the shortage. Now, a little more than six years after, lead is selling for 3.55c., and nobody is worrying about the difficulty of getting plenty of it. For 1931 the U. S. G. S. reports United States produc¬tion as 390,000 tons of recoverable lead in ore. Our estimate is slightly higher than this; nearer 400,000 tons. This is the smallest production since 1911 and 1912, but in spite of this, stocks for the year-have increased nearly 50,000 tons. Our estimate for the production outside the United States is 1,120,000 tons, or more than double the production of either 1920 or 1921, and 30 per cent more than in 1913. Stocks abroad probably have not increased more than stocks in the United States. In other words, foreign consumption is double what it was in 1.920-21, whereas domestic consumption is substantially less. It looks as if Mr. Krueger, president of the Swedish match trust, was right when he said that "This country had better stop worrying about Europe and think a little bit more about its own affairs."

Jan 1, 1932

By H. Kenworthy, M. M. Fine

The progress made to date in the mineral dressing of complex Arkansas titanium ores is reported in this paper. Concentrates of rutile, a dioxide of titanium, were produced by treating a submarginal ore from the Magnet Cove Rutile Co., Inc., Magnet, Ark. The rutile recovery at present is 45 to 50 pct of the total TiO2 with the possibility of increased recovery with additional research. The work reported herein is part of a general study which will later include results of investigation of other titanium ore bodies in the Magnet, Ark., area. The fragile character of the rutile minerals, the softness of the gangue, the occurrence of pyrite and leucoxene, and the considerable proportion of extremely small size rutile in the presence of montmorillonite- and illite- type clays in the Magnet Cove open-pit mine are the important factors in the mineral dressing of this submarginal rutile ore.

Jan 1, 1949

By Earl R. McMillan

Though much has been written during the past several years about the Russian success in using hydraulic jets for coal mining, little or none of the published information, in so far as this writer has observed, has been of any use or practical application in this country. It is true, according to their published reports, that the Russians were pioneers in the use of high-pressure water jets in the mining of coal. They report the use of water jets for this purpose as early as 1936. However, according to a survey of foreign literature on the subject made by the U.S. Bureau of Mines1 a few years ago, water jets in the USSR, as well as in other nations including New Zealand, Poland and West Germany, were used principally to sluice the loosened coal after it had been previously drilled and blasted, rather than to cut or break it from the solid face. The interest of the Northern Pacific in the potential application of a high-pressure water jet to the actual extraction of coal, particularly in steeply dipping beds, originated in a visit by this author to the operations of the American Gilsonite Co. at Bonanza, Utah, in March 1958. After seeing the extraction, on a commercial basis, of gilsonite from a 22-ft wide vertical vein of this solid material with a 3/8-in. diam stream of water under approximately 2200 psi, it was felt that, with some modifications, water jets were the solution to the problem of economically mining the steeply dipping (i.e., steeper than 20º) coal beds in the State of Washington.

Jan 6, 1962

By Messrs. von Jonstorff

Continued Discussion of the Paper of Messrs. von Jonstorff, Blair, Dillner and Stead, presented at the New York Meeting of the Iron and Steel Institute, October, 1904.* (Bethlehem Meeting, February, 1906.) CLEMENS C. JONES, Richmond, Va. (communication to the Secretary+) :-In the chapter of this paper entitled "Method for the Determination of Phosphorus," by Andrew A. Blair, a form of the reductor used by Mr. Blair is illustrated. This form was employed by me in my earliest experiments, and abandoned after my adoption of the final apparatus described in my paper on the subject in 1889. The results reported by Mr. Blair are very closely accordant; but my experience was that, in the use of this form, a loss of the solution, amounting to almost a cubic centimeter, was occasioned by minute bubbles of hydrogen rising to the surface, and there exploding. My final reductor was designed to prevent this loss; and the most satisfactory results were obtained with a reductor having the open cup replaced by a bulb-shaped receptacle, provided with a glass stopper, similar to that of a separatory funnel of similar capacity, as suggested in a foot-note in my original paper. In my experience, the use of this later form of reductor repeatedly gave duplicate results which were, coincident to the fourth decimal place. R. W. RAYMOND, New York, N. Y.:-The. remarks of Mr. Jones recall to my mind an interesting part of the history of the Institute, and, of its relation to modern progress in the department covered by this interesting and valuable paper. In

Mar 1, 1906

By J. J. Pelley

NOT being a scientist, an engineer or a metallurgist, I consider it a very great honor indeed to be asked to address the American Institute of Mining and Metallurgical Engineers. Your program indicates that any lack of intricate and technical knowledge on my part in the field of metals will be well taken care of by others. Therefore, I believe any remarks that I have to make might well be devoted to the practical side of metals in railroad service and to the general railroad situation as I view it today. The experiments now being conducted on the railroads with so-called streamlined, light-weight trains and cars would not have been possible had it not been for scientific and engineering research in the past that made these lighter weight metals available. The railroads now have approximately forty units of these new trains in operation. Experi-ence with them will no doubt be a guidepost for future construction in that direction. While the best known experiments are in the passenger service, they are being extended into the freight service. Within the past three years there was constructed for the Association of American Railroads a new standard box car of ordinary carbon steel, in which, by reason of superior design, weight was reduced by 3500 to 4500 lb. under that of existing cars of like capacity. The Association is now testing a box car that weighs approximately six or seven tons less than practically all of the box cars of like capacity in service today. If these tests are successful a very large field for the use of lighter weight metals will immediately be opened, provided the costs of such metals are not too high. The fact that various experiments are being carried on with other classes of equipment constructed with so-called light-weight and non-corrosive metals no doubt will have a considerable effect upon the rebuild-ing of old equipment. The question then will be: How much can we afford to spend on the rebuilding of an old car weighing six to seven tons more than a new car constructed with the latest available materials?

Jan 1, 1936

By Roland Blanchard

Recent discovery at Mount Isa of copper mineralization in commercial amount at a depth of 1000 ft., coinciding with downward termination of ore at about the same depth within the larger silver-lead-zinc lenses that have been the standby of Mount Isa's production to date, has been cited as an example in support of mineral zoning. A previous paper by the author and Graham Hall1 furnished a detailed description of the geology of the ore at Mount Isa as exposed up to that time, but necessarily dealt mainly with the silver-lead-zinc mineralization. Most of the geologic facts that constitute the first half of the present paper were set forth in the previous one in much greater detail, with full supporting evidence for the facts cited. The large amount of underground development (approximately 20 miles) and the extensive exploration carried out by diamond drilling (100,000 ft.) at Mount Isa, added to extensive microscope work conducted over a period of years, both by the company's staff and by others, had made possible the calculation within fairly close limits of mineralogical composition of the principal mineralized block of ground down to 1000-ft. depth, and had established closely the mineral succession, with reasons for deposition of the various minerals in the patterns now occupied by them. The geologic facts as outlined in the previous paper remain as stated; but because substantial development within the new copper ore body and further exploratory diamond drilling within the new silver-lead-zinc area (Racecourse) have taken place since that paper was written, statements and figures relating to those two areas in the present paper supersede those furnished in the previous one. The recent work likewise has established more clearly the paragenetic relationship between the chalco-pyrite and galena. Evidence confirming the relationship is furnished in the present paper. The facts of ore occurrence at Mount Isa show Accepted Zonal Succession Silver sulphantimonides Galena Sphalerite Tetrahedrite Arsenical sulphides Chalcopyrite Pyrrhotite Mount Isa Succession I In the main but prob- Silver sulphantimonides ably not wholly Tetrahedrite I contemporaneous Galena Pyrrhotite Sphalerite Arsenical sulphides They show further: (I) that instead of the silver-lead minerals yielding to increased zinc in depth, the zinc yields to increased silver-lead; (2) no dovetailing of the silver-lead-zinc sulphides into chalcopyrite takes place; (3) despite the large amount of pyrrhotite deposited in the district (estimated at upward of 100,000,000 tons), its deposition took place under moderately low temperature conditions; (4) no evidence has been found for increase in temperature of deposition, with depth, to deepest exploration in ore (1475 ft.). The anomalous condition at Mount Jsa, both as to the unorthodox mineral succession and the largely unorthodox patteru of mineral distribution, is explained in the present paper,

Jan 1, 1949

By Roland Blanchard

Recent discovery at Mount Isa of copper mineralization in commercial amount at a depth of 1000 ft., coinciding with downward termination of ore at about the same depth within the larger silver-lead-zinc lenses that have been the standby of Mount Isa's production to date, has been cited as an example in support of mineral zoning. A previous paper by the author and Graham Hall1 furnished a detailed description of the geology of the ore at Mount Isa as exposed up to that time, but necessarily dealt mainly with the silver-lead-zinc mineralization. Most of the geologic facts that constitute the first half of the present paper were set forth in the previous one in much greater detail, with full supporting evidence for the facts cited. The large amount of underground development (approximately 20 miles) and the extensive exploration carried out by diamond drilling (100,000 ft.) at Mount Isa, added to extensive microscope work conducted over a period of years, both by the company's staff and by others, had made possible the calculation within fairly close limits of mineralogical composition of the principal mineralized block of ground down to 1000-ft. depth, and had established closely the mineral succession, with reasons for deposition of the various minerals in the patterns now occupied by them. The geologic facts as outlined in the previous paper remain as stated; but because substantial development within the new copper ore body and further exploratory diamond drilling within the new silver-lead-zinc area (Racecourse) have taken place since that paper was written, statements and figures relating to those two areas in the present paper supersede those furnished in the previous one. The recent work likewise has established more clearly the paragenetic relationship between the chalco-pyrite and galena. Evidence confirming the relationship is furnished in the present paper. The facts of ore occurrence at Mount Isa show Accepted Zonal Succession Silver sulphantimonides Galena Sphalerite Tetrahedrite Arsenical sulphides Chalcopyrite Pyrrhotite Mount Isa Succession I In the main but prob- Silver sulphantimonides ably not wholly Tetrahedrite I contemporaneous Galena Pyrrhotite Sphalerite Arsenical sulphides They show further: (I) that instead of the silver-lead minerals yielding to increased zinc in depth, the zinc yields to increased silver-lead; (2) no dovetailing of the silver-lead-zinc sulphides into chalcopyrite takes place; (3) despite the large amount of pyrrhotite deposited in the district (estimated at upward of 100,000,000 tons), its deposition took place under moderately low temperature conditions; (4) no evidence has been found for increase in temperature of deposition, with depth, to deepest exploration in ore (1475 ft.). The anomalous condition at Mount Jsa, both as to the unorthodox mineral succession and the largely unorthodox patteru of mineral distribution, is explained in the present paper,

Jan 1, 1949

By A. S. Hewitt

After an interval of fourteen years, saddened for all of us by the death of David Thomas, the father of the anthracite iron-trade, first president of the Institute, and by the untimely loss of his successor, Alexander L. Holley, whose memory we are about to honor by loving services, the members of the American Institute of Mining Engineers have conferred upon me for the second time the office of president, under circumstances similar to those which led to the choice in 1876. Then the whole world was represented at the great exposition of industry which was held in Philadelphia to celebrate the one hundredth anniversary of our declaration of political independence. In 1890 it is our privilege to receive as guests the members of the British Iron and Steel Institute, who, with singular and graceful felicity, have appointed a meeting in the United States in the year when we pass from the second to the first place in the international column of the production of iron, and thus celebrate our industrial independence. For the honor of being chosen to extend to our distinguished guests the right hand of fellowship and a hearty welcome I return to my associates the grateful acknowledgment of one whose chief claim to your favor is to be found in his love for the professional occupation in which we are all engaged, and in his efforts, public and private, to promote its advancement into new fields of usefulness. In order to indicate the full significance of the visit of our foreign guests at this time, it will be proper to explain briefly the origin, aims and work of the Iron and Steel Institute. It unquestionably owes its birth to the International Expositions held in London in 1851 and 1862, and in Paris in 1867. These expositions served to break down the jealousies of nationality and to diffuse a better knowledge of industrial processes. Trade-secrets, which had been carefully guarded, became common property; manufacturers who had previously regarded themselves as rivals formed bonds of union and ties of friendship, as the results of an intercourse which

Jan 1, 1891

By W. H., Bassett

IN January, 1926, the writer began a study of the commercial value of beryllium in its relation to copper. The purpose of the investigation was not to make a mere laboratory study of the characteristics of beryllium-copper alloys, but to determine under mill conditions the behavior of copper when alloyed with beryllium and when other metals were added to such alloys; in other words, it was considered important to know whether the alloy bars could be hot-rolled or cold-worked, and what limits in composition would have to be established for these two methods of working. Consequently, more stress has been placed on the practical application of the alloys in engineering and commercial use than on a discussion of the metallography of the specimens examined, although this part of the matter has not been entirely neglected. Credit should be first given to G. Oesterheld,1 who, in 1916, published the copper-beryllium equilibrium diagram. Fig. 1 has been copied from the original article with the simple substitution of English words. It will be noted from Fig. 1 that alpha solid solutions are formed, up to about 1.5 per cent. Be (10.5 atom.). The freezing-point curve, after falling from 4.2 per cent. Be (23.5 atom.), enters into a very complicated form over the entire beta region. There is a possible compound, Cu2Be, at about 6.5 per cent. Be (32.3 atom.). The pure gamma range extends from 11.2 to 12.2 per cent. Be. (46.5 to 49 atom.), after which the liquidus rises rapidly to 30 per cent. Be. (75 atom.). The delta solution extends from 25 per cent. to an unknown percentage of beryllium. There is a eutectoid point at 575" C., extending from 1.5 to 11.2 per cent. Be., the maximum time interval of which occurs at 6 per cent. Be. Below this line the beta solution is described as breaking up into alpha and gamma. Microscopically, the eutectiferous alloy thus formed closely resembles pearlite, and requires a high magnification for its resolution.

Jan 1, 1927

By AIME AIME

ENGINEERS in the past have been largely associated with private enterprise and there has been a considerable tendency on the part of some members of our profession to depreciate government service for engineers. We engineers must change our mental attitude about employment in government service, particularly in view of the present most friendly attitude of the U. S. Civil Service Commission toward engineers for major posts in our Government. We must also take a much more active interest in public affairs. It must be realized that the national-defense program, which we are now organizing, will require for its effectiveness large numbers of engineers skilled in a wide range of technical and administrative services. In fact, the success of this undertaking will depend largely upon the extent to which our Government can command expert engineering talent to serve during the emergency. There is an acute shortage of technical and supervisory engineering personnel not only in the industries concerned with national defense but also in the Army, Navy, and other defense agencies of the Government. By an Act of Congress, approved on Oct. 9. 1940. $9,000.- 000 was turned over to the U. S. Office of Education, the regular defense agency of the Government which has co-operated with higher education for

Jan 1, 1941

By Culver, Richard S.

In spite of the widespread interest in rock bolt research, relatively little is known about the critical region surrounding the bolt anchor. In analyzing the stress distribution around an opening resulting from rock bolt support, it is commonly assumed that the bolt is fixed at a point far enough from the surface so that the anchor does not influence the performance of the bolt. Furthermore, a bolt anchor is assumed to per- form satisfactorily if it will hold the design load with a minimum amount of load relaxation, commonly called bleedoff. From the standpoint of the design engineer both of these assumptions are reasonable, but they ignore the fact that the extremely high stresses in the region of the anchor are capable of generating fractures in the rock. Lang estimated the bearing stresses for a slot and wedge anchor on a one-inch-diameter bolt to be as high as 125,000 psi. This paper describes a more thorough analysis of the magnitude of the stresses around the anchor and the nature of the potential fractures that might result.

Jan 1, 1968

By G. F. Comstock

The subject of transverse fissures in steel rails has been discussed very thoroughly in recent years from various points of view and the final opinions expressed may be roughly classified into two groups: That these fissures are the result merely of fatigue of the steel and are independent of the quality of the metal. That the quality of the metal and the mill practice must have something to do with them. The first point of view was most ably and logically presented by J. E. Howard,' and in the discussion of this paper, as well as in several other preceding publications, Dr. P. H. Dudley, Consulting Engineer of the New York Central Lines, has strongly defended the other opinion.2 The steel makers of the country have naturally rallied under Mr. Howard's banner, hoping to place the entire blame for these failures upon the railroads with their high wheel-loads, hard steel, heavy traffic, and sometimes inferior road-bed; while the railroad men, on the other hand, have been busy accumulating statistics and records in the effort to find an actual reason in the rails themselves that would account for the seemingly haphazard occurrence of transverse fissures under varying conditions and at widely separated points. The view that these fissures were due merely to normal fatigue under alternating stresses seemed most reasonable to the writer until quite recently, because from work done in this laboratory, as well as the work of other investigators, of the problem, no structural differences, in the vast majority of cases, were found between metal at the nuclei of transverse fissures and metal at similar positions in the same rails or in other rails that had not developed fissures. Within the last year or two, however, since the method of etching polished sections for the microscope with a oupric chloride solution has been tried systematically on lengthwise sections, passing through the nuclei of transverse fissures, evidence

Jan 1, 1920

By Charles M. Romanowitz

The motivation for the art of dredging for placer mining can be compared in a slight degree to the spread of civilization which started in the Near East and spread both east and west. Dredging started with the "bag and spoon" dredge in the lowlands of Europe reportedly about 1565, went southeast to New Zealand where designs were developed for a bucket-line mining dredge known as the New Zealand type, and westward to the eastern United States where a dredge was developed and used exclusively for excavating. Then it moved to Montana, where it was first used for mining in 1895. The New Zealand-type dredge was imported into California in 1898 (Fig. 1) and was followed shortly by the Montana design. As today, these early dredges were equipped with continuous bucket- line chains, a treatment plant, and a means of waste disposal mounted on a wooden hull. Both types of dredges are complete mining units: they dig the formation, transport the dug materials, and concentrate the valuable ore. After sizing, the fines containing the ore are passed by gravity to the treatment unit, while the barren materials are discharged overboard. By digging the materials to be treated at the bow and depositing all the waste, at the stern, the dredges automatically advance to new reserves without presenting any transportation problems. The main differences between the two types are in the method of holding the dredge in the digging position and in the disposal of the tailings to the rear. The New Zealand type (Fig. 2) uses the headline system with a bow anchor for holding the dredge in the digging position and long tailing flumes or short stackers off the stern for disposal of the barren materials. The California type (Fig. 3) uses box girder spuds projecting into the ground in a vertical position at the stern of the

Jan 1, 1969

By Richard F. Link, George S. Koch

Advantages and disadvantages of deflecting (wedging) diamond-drill holes to obtain sampling data are compared with the alternative of drilling additional holes. The discussion is based on a statistical analysis of a large set of deflection data from exploratory boreholes in South African gold mines. Representative cost comparisons show the conditions under which deflections are likely to be desirable.

Jan 1, 1969

By Hugh Steele, Brower Dellinger

U. S. mining trends for 1956 continued steadily U+ S. uphill, technique and equipment advanced with the pull, and exploration and development of once mined districts attracted more attention than new areas. Expansion of the Ambrosia Lake district in New Mexico more than doubled known uranium ore reserves, and production began from several of the large new ore discoveries. In Canada the up trend was more spectacular, especially in exploration and development. To combat increasing problems arising from high labor costs, taxes, low grade orebodies, and dwindling discoveries, manufacturers and mining companies have continued to introduce new techniques and new products-reamer bits for enlarging small holes drilled by jacklegs, whup d'whups for drift mucking, Cryderman machines and over-the-head small crawler-type machines for shaft mucking, the 20-ton TL 220 four-wheeled tractor trailer unit for underground haulage, inertia-type dust collectors, roof bolting in conjunction with chain link fencing for wall support, wooden roof bolting using compression support of ground for wall support, and new one-use carbide bits.

Jan 2, 1957

By G. R. Hodgson, M. P. Lebourg

The introduction in the field of a new type well completion called for the setting of tubing open-ended in the well before perforating the casing. This paper describes a new perforating tool of the shaped charge expendable type, small enough to pass through tubing and powerful enough to perforate the casing. The perforations are produced at an angle and are large enough for optimum production. Performance of this tool in targets and under various well conditions is described. Very often no lifting equipment will be available at the well. In some cases, pressure will exist in the well at the time of the perforating operation (workover wells or multiple trip perforation) ; therefore, new equipment and new technique for the perforating operation were devised. This paper describes this equipment and technique, particularly casing collar recording, sheave support, and cable pull-down device. this last item being necessary for wells under pressure. Results obtained with this tool in the field are given. INTRODUCTION One of the key requirements for the introduction in the field of a new method of permanent well completion was the development of a new perforating method involving the use of a perforating gun small enough to go through tubing and with enough penetrating power to perforate the casing satisfactorily. The equipment described in this paper was basically designed to go through open-ended two-in. tubing and to perforate 5 1/2 in. casing. The equipment is illustrated in accompanying figures. NEW COMPLETION METHOD With the new permanent type well completion, the production string of casing is run and cemented through the potential producing zone. Open-ended tubing is -then run into the well and used to replace the drilling fluid with oil or water. The amount of the oil or water "cushion" can be varied according to the expected bottom hole pressure. Thus, if desired, the hydrostatic head can be greater, equal to, or less than the expected pressure within the zone to be perforated. Mud having been displaced, the tubing is -then positioned so that the end is above the zone to be perforated. The Christmas tree and flow lines are installed and tested. The drilling rig can now be removed from the well since it is not necessary for the perforating operation, thus resulting in a saving in rig tme. The perforating equipment is then moved to the well and the gun lowered through the tubing. After the gun passes out of the open end of the tubing, the depth measurements are correlated with casing collars and the gun placed opposite the zone to be perforated. Upon firing, the gun body is shattered and falls to the bottom of the well. Since the lubricator has been closed before firing, it is possible to withdraw the casing collar locator and head and then open the well immediately to the tanks. DESCRIPTION OF GUN An investigation of two basic types of Perforators, namely a bullet perforator and a shaped charge gun, was undertaken towards the development of a gun to meet the aforementioned requirements. Preliminary tests on various bullet perforator designs within the diameter limitations did not give results encouraging enough to warrant further study. Somewhat better results were obtained by using conventional shaped charges; but, as in the case of the bullet types, the necessarily small overall diameter proved to be a severe limitation and resulted in insufficient penetration. A shaped charge employing a new design was developed which gave excellent penetration. These shaped charges were designed to produce a large hole directed upward at a 45" angle. In order to obtain the maximum space possible for these charges, it was decided to use an expendable carrier made of drillable material, usually aluminum, which would shatter at the time of firing, leaving only harmless fragments at the bottom of the hole. The fixed spacing is five shots per ft. wit11

Jan 1, 1952

By Frank Firmstone

In the summer of 1842 my father, William Firmstone, was engaged by Charles Jackson, Jr., of Boston, to examine the conditions in the Lehigh valley as a site for blast-furnaces using anthracite for fuel. In consequence of his report, he was further engaged by Mr. Jackson to build a furnace for him and his partners on the Lehigh canal, 2 miles above the mouth of the river at Easton. Work was begun in the fall of 1842, and the first furnace blown-in in 1844. The history of the works, therefore, from 1844 to 1887, when my own connection with them ceased, covers only four years less than the whole period of the rise, culmination, and commencement of the decline in the smelting of iron with anthracite in America, the beginning of which, in a commercial sense, may be put in 1839.' Although this paper, as the title indicates, is concerned almost exclusively with the furnaces at Glendon, still what was done there was more or less influenced by current opinion in the district, and even reflects, to some extent, the changes in opinion and practice with mineral fuel the world over. No. 1 Furnace was built of red brick, on four piers, had three tuyeres and fore-hearth and tymp, as was universal with furnaces using mineral fuel until the introduction of Lurmann's cinder-tuyere. The dimensions and profile are shown in Figs. 1 and 2. The first hearth (Fig. 1) was of sandstone; all after were of fire-brick (Fig. 2). The profile was no doubt derived directly from Gibbons's furnace,2 for it appears from W. Firmstone's note-books that in October, 1840, he visited " Gibbons' new furnaces building at Corbyn Hall," and I have an old drawing,

Jan 1, 1910

By Smith, George Otis

ENGINEERING is in essence quantitative, and the engineer must deal with exact figures when he plans and, constructs. Engineering truths are not best expressed by adjectives, yet my wish, today, is not to attempt a quantitative measure of the dominant position of the mineral industry of the United States in the existing scheme of material things, but rather to seek a clualitative appraisal of what mining and metallurgical engineers are doing to promote and make secure our , national progress. Statistics help when we wish to gage material prosperity, but they fail when we desire to determine what share the engineers have in adding to the happiness and welfare of our people

Jan 1, 1928

By ROY BERENTZ

MANUFACTURE is the transformation of material by the application of energy and power. The energy of a man exerted throughout a day is equivalent to about one horsepower-hour of mechanical work an amount which can be purchased for less than 2c. It is evident that manual labor is uneconomical if mechanical energy can be applied effectively, or without disproportionate expense. Since manual energy is relatively so costly, economy demands that mechanical power be employed so as to reduce the human effort connected with mining operations to a minimum. Power, like other commodities, is most efficiently produced in large quantities. Mechanical transmission, once prevailing, is being rapidly superseded by electric drive. There are many reasons for this change; such as increased production, ease and accuracy of control, convenient application, ease of moving, etc.

Jan 1, 1930