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By John A. Church

Jan 1, 1903

By George Weaton

Two years ago the general features of the St. Joseph Lead Company's zinc-smelting process were described.1 At that time the discussion was limited to a description of the production of high-purity electrothermic zinc oxide. The present paper will describe the commercial production of electrothermic zinc metal. Since a fairly complete description of the plant of the Josephtown smelter was given in the earlier paper, the brief recapitulation given here will be limited to mention of additional equip-ment recently installed and a bare outline of the preparatory process. The raw material is zinc sulphide concentrate received from the com-pany's mines in St. Lawrence County, New York. An average dry-weight analysis of this material is: Zn, 58.28 per cent; Pb, 0.56; insoluble, 1.6; Si02, 1.12; Fe, 6.4; CaO, 0.47; MgO, 0.27; S, 31.9; Cd, 0.1; Cu, 0.06; Mn, 0.24. Moisture content is usually about 3 per cent. Three 21-ft. 6-in. diameter, 12-hearth Nichols-Herreshoff furnaces roast the concen-trate to a calcine of average composition (first 10 months of 1938) : Zn, 67.69 per cent; Pb, 0.06; insoluble, 1.75; Si02, 1.26; Fe, 7.24; CaO, 0.47; MgO, 0.36; S, 1.88; Cd, 0.1; Cu, 0.07; Mn, 0.27. The sulphur dioxide gas, after passing through a waste-heat boiler, proceeds through a recently redesigned low-resistance gas-purification assembly to the contact sul-phuric acid plant, of which the capacity is 200 tons of concentrates per day. The calcine is mixed with a portion of returned furnace residues and sintered on 42-in. by 44-ft. Dwight-Lloyd sintering machines, gas-fired. Wind-box gases pass through air coolers before filtering in a 1440-bag Dracco unit, and thence to stack. The Dracco fume is mixed with Cottrell dust, from roaster gas cleaning, and sent to the leach plant, where it is roasted (SO2 to acid plant) and leached with sulphuric acid to recover, as end products, lead sulphate, zinc sulphate and cadmium.

Jan 1, 1939

R. W. Raymond, New York City: As was announced in the Secretary's note, appended to the pamphlet edition of Dr. Ledoux's paper, I have undertaken to superintend the preparation of the samples required by his plan, and the ollation for publication of the results reported. Promises of cordial co-operation hare been received already from a number of leading assayers;? and it is to he expected that the data thus collected, and the discussion to be based upon them, will shed much light upon the important question raised in this paper. Although a detailed discussion of methods on the present occasion might be deemed premature, I am sure that suggestions on the subject from members engaged in assaying would be timely and valuable as a preliminary to later and more detailed criticism. Herbert G. Torrey (U. S. Assay Office), New York City : I may say in relation to the losses in the furnace that I have made a number of experiments, and on my little blank form years ago I put down a place for the losses in the cupel. It met with a good deal of opposition among the smelters, but I claimed that it was my duty to give the full amount of the gold and silver present, and that it

Jan 1, 1895

By Paul W. Zimmer, Carl E. Dutton

Iron ore in the Menominee district is mined from two iron-formations of middle Precambrian age. The older formation is present in the northeastern part; is composed mainly of hematite, magnetite, quartz, and minor silicates; and contains about 34 per cent iron. The rock has been so coarsened by meta- morphism that concentration of magnetite and hematite is feasib!e, and pellets containing more than 60 per cent iron are being produced. The older formation is also present in the southeastern part where it has 1:een only slightly metamorphosed. Ore containing more than 50 per cent iron was formerly mined from local residual concentrations of iron oxides from which silica had been sufficiently leached, or replaced by iron oxide, or affected by combinations of these processes. The younger iron-formation occurs in the western part of the district and, if unaltered, is interlayered siderite and chert. The ore in this area also contains more than 50 per cent iron and formed as local residual concentrations but in two stages. The siderite was converted to iron oxides (hematite and "limonite"), and silica was contemporaneously or subsequently removed by leaching, or replacement, or combinations of these processes.

Jan 1, 1968

By AIME AIME

APPARENTLY unperturbed by any misgiving as to ill luck connected with the mystic number thirteen -for there were exactly that number of Directors on deck-the Board held two sessions on Tuesday, Feb. 21. , . Between the executive session at 5:15 p. m. and the general session at 8:30 p. m., 28 Section and Division delegates were wests of the Directors at dinner. Committee chair- " men and past officers brought the attendance to 75. Messrs. McAuliffe, Merica, Mudd and Tally had expressed their intention to be at the Directors' meeting, but each was prevented unavoidably at the last minute. At the executive session of the Board, J. V. W. Reynders was unanimously chosen to fill the unexpired term of Dr. Becket as Director: and Eugene McAuliffe in like " manner was selected to become Vice-president to fill the vacancy created hy Dr. Becket's assumption of the Presidency. Upon nomination of President Becket the following Executive Committee was appointed: Frederick M. Becket, chairman; Howard N. Eavenson, H. A. Guess, J. V. W. Reynders and William Wraith; and the Finance Committee was appointed as follows: Henry Krumb, chairman; Paul D. Merica and H. G. Moulton. Karl Eilers was reelected Treasurer and A. B. Parsons was re- elected Secretary to serve for the ensuing year, whereupon the executive session was adjourned.

Jan 1, 1933

By L. P. Durham

DuRing the early mine development period, 1929 and the first part of 1930, a 300-ton pilot-plant concentrator was built at Nkana mine of the Rhokana Corporation, Northern Rhodesia. This plant operated from May 26, 1930 until Oct. 26, 1931, treating 101,080 tons of Nkana ores and producing 4372 tons of concentrate. The plant was built, primarily, as a test unit to determine the grinding characteristics, floatability, etc. of the Nkana ores and other ores of the Rhodesian copper belt and to supply sufficient data on which to base the design of a 5000-ton concentrating plant at Nkana mine. The test unit operated wholly on development ores and no attempt was made to grade or select the ores from any section of the mine. The average assays for the 17 months of operation are given in Table 1. The first ground was broken for the 5000-ton concentrator during June, 1930, and the construction of the plant was completed in November, 1931. The plant started on Dec. 10 and has operated continuously since that date: The whole of the concentrating plant is compact and closely connected, yet with sufficient space for expansion of all sections up to 20,000 to 25,000 tons per day capacity. Mining operations are carried on along a length of about four miles on the easterly limb of the Nkana syncline. This length includes the North orebody, from which all production has thus far originated, and the Mindola orebody, now being developed for production. The ore-bearing measures in the North orebody are leached for some 75 ft. below the surface; the oxidized zone varies in vertical extent from 100 to 150 ft. Practically all the ore below the 200-ft. level is sufficiently

Jan 1, 1935

By C. R. Knopp

Gas-oil relative permeability ratio is an important relationship in oil reservoir predictive calculations. A correlation has been developed from 107 gas-flood k/k tests on Venezuelan core samples. The correlating parameter is based on restored-state water saturation tests and' is applicable to both consolidated and poorly consolidated sandstone reservoirs. Data of the correlation show that there are no distinguishah1e differences between the mass-data groupings for the two c1assifications A procedure is recommended for running .sufficient relative. permeability analyses to compute a geometric mean of the sample group. The geometric mean is more representative of the total core, and probably the entire reservoir. For example, while only one in four of the k,,/k,., test curves agreed closely with the resultant correlation of this report, the geometric mean curves of the 16 suites (three samples or more). showed good agreetment ill three cases out of four. INTRODUCTION The gas-oil relative permeability ratio is an important, fundamental relationship in most oil reservoir predictive calculations. Predictive calculations are made to estimate future reservoir production characteristics and ultimate oil recovery. The k1,/k2, relationship is specifically needed to relate the surface gas-oil ratio to the reservoir oil and gas saturation, and to calculate the relative movement of these phases within the reservoir whenever some of the more complex driving mechanisms are present. Laboratory k1/k2, tests are not generally run as a routine analysis. Consequently, k1/k2 data often are not available when needed because the cost of laboratory work could not be justified or the need for such data had not been properly anticipated. When laboratory k1/k2, data are available, they are often very difficult to interpret. For example, wide divergence is sometimes shown in a family of k1,/k1, tests representative of the producing horizon in a single well. With these considerations in mind, a study was made to determine if a relationship might exist between the k1,/k2, curve and some other simple laboratory test criteria. The most probable k1/k2, curve correlation for Venezuela described in this paper is the result of the investigation. The presented correlation defines the most probable gas-flood k,,/k,, curve through the medium of air-water capillary displacement and centrifuge water saturation tests. The laboratory procedures of these tests are. relatively simple, and inexpensive; test data should be. widely available- from routine analysis. DATA AVAILABLE, LABORATORY METHODS The report correlation utilized 107 gas-Hood k1/k2, tests run on sandstone cores of Venezuelan reservoirs. Table 1 is a general tabulation of data pertinent to the tests, while Table 2 summarizes the data. Thetests include 96 from Western Venezuela and 11 from Eastern Venezuela. Eighty-two- of the 107 test samples were sandstones that varied from poorly consolidated to-unconsolidated; 25 were consolidated. The average sample porosity was 26.7 per cent and the average permeability was 1,121 md; these values typify the better sandstone reservoirs of' Venezuela. The Welge gas-flood technique,' based on fundamental Buckley-Leverett frontal displacement theory, was introduced in about 1952 and is widely accepted in the industry. The laboratory procedure is relatively simple, rapid, and can be performed on small core samples. While there have been some minor variations in sample preparation and laboratory procedure in the tests used for the correlation, these tests can be generally summarized as follows. The core sample was first sol vent-extracted and dried. Connate-water saturation was restored by the oil-flushing or evaporation-blow down methods. At the beginning of gas flood the hydrocarbon pore volume was completeiy saturated with the test oil phase. Unsteady-state gas-oil displacement then began with the injection of nitrogen or helium. while the displaced oil and gas phases were incrementally metered at the out-flow face. From the test data, the k,,/k,, curve was calculated by the Welge method.' The individual oil and gas relative permeabilities were also calculated." CORRELATING PROCEDURES In attempting to establish a basis of correlation, we found that broad mid-range sections of 105 of the 107 k,,/k,, test curves could be closely duplicated by a straight line. Only two curves did not show a degree of linearity in this region. Correlation-curve definition parameters were subsequently developed from this observation of consistent mid-range linearity. Possible correlating variables were limited to the physical properties measured on core samples that (1) were widely available as common test data and (2) could be easily and cheaply obtained through future laboratory work. The more obvious possibilities were porosity, permeability and

Jan 1, 1966

TO THE BOARD OF DIRECTORS AND MEMBERS OF THE AMERICAN INSTITUTE OF MINING AND METALLURGICAL ENGINEERS GENTLEMEN Submitted herewith are the report of the Treasurer for the year 1937 and the reports for the same year of the following standing committees: Admissions, Membership, Papers and Publications, Library, Student .Relations, Speakers for Local. Sections and Student Societies, and Mining and Metallurgy. To these reports members are referred for further details. Finances.-Income for the year was the largest since 1930, the figure being $189,394, an increase of $18,803 compared with income for 1936, exclusive of a special Rocky Mountain Fund appropriation of $2500 in that year for visits to western schools and Local Sections. Major items of increase were: $8,000 from current dues and arrears; $7,700 from advertising in MINING AND METALLURGY and the two periodical "Technologies"; and $4,800 from sales of TECHNICAL PUBLICATIONS (pamphlets) and TRANSACTIONS volumes for both current and former years. Initiation fees and clues from new members declined $2,300, principally because of the larger 'proportion of Junior Members to Members among the new enrollments. Junior Members pay no initiation fee and dues are $10 compared with $15 for Members.

Jan 1, 1938

William M. Courtis, Detroit, Mich. (communication to the Secretary*):—I have a few items to add to the history of the Lake Valley mines. In December, 1879, I was sent to the Bassic mine of Colorado and then to Lone mountain, near Silver City, N. M., and to various copper-camps in Arizona. I staged from Glorietta, N. M., to Tucson, Ariz., stopping at Silver City to see the Cosette mine. This mine led to the opening of the Lake Valley mines, and is a deposit of similar formation. New Year's day, 1880, found me crossing the Rio Grande above the Jornado del Muerto. At Aleman, Victorio's band crossecl four hours ahead of us. We picked up four wounded soldiers to take to Fort Bayard, for during the day the colored troops under General Hatch had been driving the Indians back through the San Andreas mountains. The traveler of to-day little realizes the dangers of these trips, when over very rough roads we made about 100 miles in a day and a night. I subsequently made this trip six times, up to 1882, and each time I missed an Indian attack by from one to four days. The day I arrived at Silver City news had come of the massacre of 75 women and children at the San Francisco ranch. The fighting-men of' Silver City had gone to rescue others. I was the only passenger from Socorro, N. M., until we picked up the soldiers. The next day we came suddenly on 5 of Victorio's band, but we had picked up several miners, so our stage bristled with guns, and we mere let alone. At or near my stone quarry, 6 miles from Socorro, 9 men, were killed by the band that, a day or two after, killed George. Daly, Lieutenant White, and all their men. During this raid, our miners and women at the mine slept in the tunnel. At the Cosette mine I had 35 men at work. These Indian raids had

Jan 1, 1910

By George J. Young

(San Francisco meeting, October, 1911.) THE nature of slimes handled in the treatment of gold- and silver-ores has been discussed in technical literature to a considerable extent. The subject of slime-filtration from the practical worker's stand-point has also received much comment, and scattered through the literature of the subject are descriptions of many slime-filtration installations. Articles of this nature serve a valuable purpose and assist materially in the design of new and the improvement of old plants. The subject of the physics of slime-filtration has been touched upon to only a slight extent. The underlying principles are worthy of more intensive study and experimentation than they have received, and the main purpose of this paper is to present the results of such study and experimental work as will serve to make clear in part at least many of the principles which control the filtration of slime. Nature of Slime. Much has bean written concerning an accurate definition of the term ? slime," but no comprehensive definition seems to be generally accepted. The reason for this is clear. A slime consists of at least three different substances, each, when separated, possessing distinctly different physical and to a certain extent chemical properties. These substances are extremely fine sand, a colloidal material which may be and generally is in a coagulated condition, and a colloidal material which is in a non-coagulated condition. Suspending a slime in a relatively large volume of water by shaking and allowing sedimentation to take place, results in the fine sand settling out with comparative rapidity, followed by the coagulated material, which settles much more slowly and finally a certain portion remains

Nov 1, 1911

By R. M. Howe, J. Spotts McDowell

Preparation and Use.—Magnesite is an important refractory in open-hearth, heating, and electric furnaces for steel-making and in many of those employed in the metallurgy of copper and lead. It is sold in the form of brick, finely ground "furnace magnesite" for bricklaying, and dead-burned grains for making and repairing furnace bottoms. The latter are a mixture of granules varying in size from pieces of about 5/8 in. (1.6 cm.) diameter to very fine but sandy particles. Dead-burned magnesite results from calcining the crude or lightly burned mineral at a temperaturc that will not merely drive off practically all the CO2, but will also cause sintering of the particles. During this process the pieces shrink considerably and become hard, dense, and inert to atmospheric moisture and CO2; under-burned material, on the other hand, will hydrate on exposure to the air. A small percentage of ferric oxide seems to be necessary for the production of a satisfactory sinter; from 4.5 to 8 per cent. in the dead-burned grains is considered the most desirable amount. Dolomite has been little used for brickmaking in the United States, but it is prepared for use in the granular condition calcined or "double-burned" and is the principal ingredient of several materials offered for sale under various trade names for refractory purposes. Dolomitic refractories are almost wholly confined to the open-hearth and electric furnaces, where they are used for fettling and as substitutes for magnesite. Much more magnesite and dolomite are used for basic open-hearth steel-making than for all other refractory purposes. The hearth of the furnace is usually built up of magnesite brick and dead-burned grain magnesite so laid that the brick base is protected by a working bottom of the granular material. The latter is sintered into place in layers 1/2 to 1 in: (1.25 to 2.5 cm.) thick to a total depth of 12 to 18 in. (30 to 45 cm.) at the center of the furnace. After each heat, burned dolomite is thrown against the banks as high as it will stick, and all holes in the bottom are Glled. At most plants such holes, at the end of each week, are also carefully filled with dead-burned grain magnesite. For temporary

Jan 1, 1920

By R. W. Raymond

Edward Cooper was born in New York City, Oct. 26, 1824. His father, Peter Cooper, to say nothing of manifold reasoils for fame as an inventor and philanthropist, deserves to be remembered as a pioneer in the establishment .of public schools ; and it is not surprising that. he sent his son to one of the democratic institutions in which he was himself so ardently interested. From the public school Edward Cooper went to Columbia College, where he made the acquaintance of Abram S. Hewitt, who was first his tutor, afterwards his traveling companion, brother-in-law, business partner and life-long friend.' For twenty years I was the consulting engineer of the firm of Cooper & Hewitt, and also connected with the work of the Cooper Union, in which they were both deeply interested and faithfully active. On the basis of the intimate knowledge thus gained, I venture an estimate of Edward Cooper's character and career which, if not fully comprehensive, may facilitate a juster estimate than would be reached by the student of those data which the modesty of the man permitted to be placed upon public record.

Jan 1, 1907

Eight members of the Board, the Secretary of the Institute, and eleven guests were present. Vice-president Henry S. Drinker presided. The President was authorized to appoint delegates to a meeting, on May 16, of the League to Enforce Peace. The Joint Conference Committee reported that the American Institute of Metals had accepted the invitation to form the Institute of Metals Division of this Institute. The Committee on Publications of the Institute of Metals was added to the Committee on Publications of the A. I. M. E. Exchange of one volume of Transactions of the A. I. M. E. at reduced price to members of the British Institute of Metals was authorized, in return for the reduced price given to our Institute of Metals Division on the annual proceedings of the British Institute.

Jan 6, 1918

By JAMES SCULLY

For the last 4 years political leaders have found a new subject on which they can safely generalize wihout creating opposition. That subject is commodity prices. Since the four-fold increase in OPEC crude oil prices, public attention has focussed as never before on the subject of commodity prices. To advocate stabilizing commodity prices is akin to supporting motherhood or peace or better schooling. Everyone gives lip service to the concept that stable commodity prices are desirable. It is easier to state the principle than to achieve it. Prices that are stable in terms of one currency may be clearly unstable in terms of a different currency. This has become a troublesome matter since 1971, when the world's leading trading currencies were set free to float in relation to each other. To illustrate: consider copper prices in the interval between the end of 1974 and the end of 1977. During those 3 years, the copper price in pounds sterling on the London Metal Exchange rose by 25 per cent. During that period, however, in terms of the USA dollar equivalent, the price was unchanged. And during that period, in terms of the German mark equivalent the price shrank by 13 per cent while the Japanese yen equivalent fell by 20 per cent. Thus a price that appears stable in dollars, rose in terms of pounds sterling and fell in terms of marks and yen. Had this result been achieved as a consequence of an international effort to stabilize prices, an American would have said the effort was successful. An Englishman would have said it had failed to prevent a price rise. And a German or a Japanese consumer would have been happy to have covered his copper needs at a lower cost in terms of his own currency.

Jan 1, 1978

FOLLOWING the presentation of the papers by Messrs. Mahan and Butler, the discussion printed below ensued. A. C. LANE* With particular reference to the New England con-sumer, I entirely agree with Mr. Mahan that intelli-gent marketing methods will do a good deal, but there is more than one way of improving them. For instance, coal can be shipped best to New England about this time of year-after the storms of the winter and before the movement of crops in the summer. For that reason there ought to be seasonal freight rates. This will be agreed to by most coal men if you will ask them, especially those who are connected with large concerns like the Metropolitan Coal Co., and yet they do not get seasonal freight rates partly because the railroads are afraid if they once reduce them they will never have a chance to get them back again. But it would be an improvement to have seasonal freight rates. Another thing: When we are buying in New England we want really a certain amount of heat value in our coal. There is no great advantage in our buying ash, nor is there any particular advantage in the railroad shipping ash and clogging the circulatory system of the body politic any more than clogging the circulatory system of the physical body. It would be desirable if the wholesaler, and to some extent the retailer, could guarantee the amount of ash or sell their coal on heating value. If you are interested in that you will find some interesting charts, in "Anthracite Coal Costs Analyzed," a pamphlet issued by the Anthracite Coal Consumers Association, Inc., New York City, as to rates from various and sundry points for bituminous and anthra-cite coal from the field to New York, Buffalo and Chi-cago. Here in New England they are both up against the competition of oil. About 3 or 3 1/2 bbl. oil will do the work of a ton of coal. One of my millionaire friends who is well posted on the situation is putting oil in his Commonwealth Avenue house because it is the most economical. Moreover, we can get Welsh coal from across the water (and help equalize this matter of exchange with Europe) in close competition with Penn-sylvania coal.

Jan 4, 1928

By M. C. Manderson

The sharp drop in world phosphate demand that took place in 1975 due to temporarily high prices, now seems to be reversing itself. And prices for both phosphate rock and phosphate fertilizers, which declined dramatically from their 1975 highs, now appear to be bottoming out. This recent price weakness has delayed new mining ventures that had been planned for completion by around 1980. While there is ample capacity to supply near-term rock needs, the stage seems to be emerging for a better supply-demand and price environment in the late 1970's and early 1980's.

Jan 1, 1979

By J. A. Fellows, Earnshaw Cook, H. S. Avery

THE increased use of heat-resistant alloys (26 per cent Cr, 12 per cent Ni; 16 per cent Cr, 35 per cent Ni; 12 per cent Cr, 60 per cent Ni; etc.) in recent years has been accompanied by continued demands by the consumer for improvement in properties. The manufacturers of these materials, of necessity, have resorted to more critical studies of the basic causes of variations in fundamental properties. To keep pace with the need for augmented information, previous techniques of investigation have been refined and new test methods and instruments created. It is the purpose of this paper to describe the apparatus, experimental technique and precision of measurement that were employed in the exploration of properties of heat-resistant alloy presented in a companion paper.? The detailed precautions in experimental procedure essential for attainment of accurate and comparable data at elevated temperatures cannot be too highly emphasized. THE CREEP TEST Since the fundamental concepts of creep testing have been recognized for the past 20 years, present interest is restricted to refinements in equipment and experimental procedure. The creep-test laboratory constructed for the American Brake Shoe and Foundry Co. is designed to permit 1000-hr. tests in the temperature range of 1200° to 2200°F. with a choice of applied stress extending from 50 to 50,000 lb. per sq. in. in increments of 50 lb. per sq. in. To simplify the calculation of weight combinations, the loading beams (Fig. I) are provided with counterweights to eliminate the tare. The precision of the knife-edges (10.1 ratio) is such that a 10-gram weight placed on the upper specimen grip will be exactly balanced by a 1-gram weight attached to the loading shackle. Check of the loading weights proved the maximum error to be 0.06 per cent. Axial alignment is provided by crossed knife-edges in the grip seats. The furnaces are similar in design to those of Crane and Company, Battelle Memorial Institute, and the U.S. Steel Corporation. An 80 per cent Pt, 20 per cent Rh No. 19 B. and S. gauge wire is used as the heating element. The details of construction are shown in the radiograph reproduced in Fig. 2. The windings are held in place on an alundum tube with alundum cement; the distribution of turns is adjusted to give a maximum temperature gradient of ± 1°F. over a 4-in. gauge length (Fig. 3). To avoid sharp temperature differentials at the ends of the test section, the length of the furnace is four times the gauge length. Sixteen-inch coupons are used to reduce the temperature of the threaded

Jan 1, 1942

Meeting of Mar. 26, 1915.-The following Committee on Nominations was appointed: Fred W. Bradley, Chairman; James F. Kemp, Past President; Frank M. Smith, Chairman Montana Section; R. C. Gemmell, Chairman Utah Section; Frank A. Ross, Chairman Columbia Section; Louis S. Cates, Arthur Thacher. The Committee on Precious and Base Metals and the Committee on . Coal and Coke were appointed, the personnel of which is shown in another part of this Bulletin. The President was authorized to appoint a Committee on Welfare with J. Parke Channing as Chairman. W. P. Cutter, Librarian of the United Engineering Societies' Library, was appointed a representative of the Institute on-the Committee oh Classification of Engineering Knowledge to co-operate with similar committees of other engineering societies. A vote of thanks was extended-to Edward B. Sturgis for his excellent work in arranging for the Annual Dinner. in February, of this year. The suns of $57.30 was appropriated to the New' York Section. It was resolved that in response to the courteous invitation from 36 members of the Institute in Arizona and the neighborhood, the 1916 summer meeting of the Institute be held in Arizona.

Jan 5, 1915

By C. P. Sandberg

Notwithstanding the growing importance of this subject, no work specially devoted to it has hitherto been published. Having had to inspect during the last twenty years nearly a million tons of iron and steel rails for various countries, I have obtained experience of what rail manufacturers can practically execute, as well as of what railway engineers practically require. Bearing these two points in mind, I have from time to time published observations with a view to unite both interests,—that of the producer and that of the consumer,—and to reduce the specifications and the forms of sections to standards, or types, in order to facilitate the execution of the works and to improve the construction of permanent way. The Swedish government railways, as well as private companies owning railways in Sweden, Norway, and Denmark,.have during the time above mentioned consulted with me and intrusted to me their rail inspection. I therefore owe to these countries much of the opportunity which I have enjoyed of gaining experience and position. Next to Sweden, America is the country which has most liberally favored me with its confidence in placing these matters in my hands. Through circumstances not under my control there has been little exportation to, and less work done by Europe for, America during the last six years; but the recent revival of the rail trade has been the more gratifying to mo, seeing that almost all the importers of American rails are still specifying for the Sandberg rail sections and inspection. It is therefore with feelings of gratitude that I now beg to lay before the American Institute of Mining Engineers, and I hope, through that body, before the American railway world, the results of some experience which I have gained in the execution of work for their country, and which therefore belongs rightfully to

Jan 1, 1881

By C. P. Sandberg

INTRODUCTION. NOTWITHSTANDING the growing importance of this subject, no work specially devoted to it has hitherto been published. Having had to inspect during the last twenty years nearly a million tons of iron and steel rails for various countries, I have obtained experience of what rail manufacturers can practically execute, as well as of what railway engineers practically require. Bearing these two points in mind, I have from time to time published observations with a view to unite both interests, -that of the producer and that of the consumer,-and to reduce the specifications and the forms of sections to standards, or types, in order to facilitate the execution of the works and to improve the construction of permanent way. The Swedish government railways, as well as private companies owning railways in Sweden, Norway, and Denmark, have during the time above mentioned consulted with me and intrusted to me their rail inspection. I therefore owe to these countries much of the opportunity which I have enjoyed of gaining experience and position. Next to Sweden, America is the country which has most liberally favored me with its confidence in placing these matters in my hands. Through circumstances not under my control there has been little exportation to, and less work done by Europe for, America during the last six years ; but the recent revival of the rail trade has been the more gratifying to me, seeing that almost all the importers of American rails are still specifying for the Sandberg rail sections and inspection. It is therefore with .feelings of gratitude that I now beg to lay before the American Institute of Mining Engineers, and I hope, through that body, before the American railway world, the results of some experience which I have gained in the execution of work for their country, and which therefore belongs rightfully to

Jan 1, 1881