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By Cyril Smith

A STUDY of the mechanical properties of the alloys of copper and silver led to the discovery that the solubility of silver in copper was greatly different from that generally supposed, therefore some work was done to determine the solubility with greater accuracy than had previously been achieved. After the work had been completed, two papers were published1 giving solubility figures which agreed closely with one another and with the work described herein. A detailed comparison of that work with the present will be given later. PREPARATION OF ALLOYS The copper used in making the alloys was electrolytic ingot of high purity. The silver was prepared by precipitation as chloride from nitric acid solution, followed by fusion of the washed precipitate with sodium carbonate and potassium nitrate. This method gives metal containing at least 99.99 per cent silver. The copper was first melted under charcoal in a small electric resistance furnace and the silver added as pure silver, it being unnecessary to make any intermediate alloys. After thorough stirring the metal was poured into a mold of suitable form. The alloys contained between 0.008 and 0.015 percent of oxygen. Small amounts of oxide were visible under the microscope, but it is not believed this would have much effect on the results. Copper-silver alloys are notorious for segregation, consequently a few experiments were carried out to find a form of casting with as little segregation as possible. A mold 6 in. long and 1/2-in. dia. was first used, and an alloy nominally containing 5 per cent silver was cast in it, while some of the same alloy was poured directly into water to obtain the maximum rate of cooling possible. Analyses were made both on this sample and on turnings from the top and bottom of the 1/2-in. dia. casting, the turnings being separated into three parts according to the position

Jan 1, 1931

By Alicia O&apos, Overbeck, Reardon

DIFFIDENTLY, because don'ts are rarely greeted with cheers; humbly, because I, myself, have never lined up with the irreproachables, I venture on the subject of manners for the mining camp matron. Mining camps can be divided roughly into two types-the large, opulent settlement that blooms like the rose about a strong mine in full operation; and the puny group of adobe huts, or calamina shacks, or even canvas tents flung down in the wilderness to shelter the gay pioneers of a shining prospect or the shattered survivors of a lost hope. Of the first, I know nothing; but in the second, I have spent some of my best years, and from its curious code of morals and manners, its comic hates and its unreasoning loves, its high impatience and its engulfing kindness, I have charted the narrow .and pitted path which must be trod by the woman who would success¬fully live therein.

Jan 1, 1936

By Leo D. Jones

The use of the centrifuge for dewaxing lubricating oils grew out of the effort to secure better results than had been attained by the common "cold settling" process. This process was the only known method for dewaxing steam refined cylinder stock (600" F. fire test), the product known as "bright stock" being commonlyused for building up "pressed," i.e., dewaxed neutrals of, say, 200-sec. viscosity [to a higher value. The process consisted of mixing the cylinder stock with approximately one and one-half times its volume of naphtha, heating, to dissolve completely all the oil and wax and then slowly chilling to about 15" F. in large insulated tanks. This caused the wax to precipitate. It was allowed to settle out by gravity. The supernatant liquid was then drawn off and the naphtha distilled off, leaving a still residue of bright stock. The sediment from the settling, of a slushy nature, was withdrawn. After removing the naphtha by distillation the residue was petrolatum. At some point in the process, preferably after the dilution but before chilling, the mixture was decolored by percolation through fuller's earth. The finished bright stock produced by this process had a cold test of about 50" F. Efforts to improve this by chilling to a lower temperature resulted in a considerable reduction in yield, and increased uncertainty of settling. Even when chilling to 15" F. it was not uncommon to find that after a week's waiting a tank had not settled. It was then necessary to heat and rechill. This uncertainty was a serious problem; in one case a refinery superintendent had men riveters hold pneumatic hammers against the tank for hours, hoping thus to cause agglomeration and settling of the wax. Yields of bright stock above 70 per cent, were uncommon. History of Centrifugal Application It is not surprising, therefore, that many attempts were made to improve upon the results obtained by cold settling. George H. Taber, vice-president of the Gulf Refining Co., Pittsburgh, Pa., made a number

Jan 1, 1924

By H. G. Turner

The coals mined in the area known as the anthracite fields of Pennsylvania have always been recognized commercially as anthracites. In the literature, however, some of these anthracites have been called semi-anthracites by various writers. The coals mined in Sullivan County, especially those from the Bernice field, have been recognized commercially both as anthracites and semi-anthracites. In the literature they have almost always been referred to as typical semianthracites, although Franklin Platt,1 in his report to the Pennsylvania Geological Survey, uses the terms semibituminous, semianthracite, and anthracite in describing them. The purpose of this paper is to endeavor to dispel the confusion of names used to describe these coals and to supply further information that will permit a logical and definite classification. Most of the confusion of the past has been due to the impossibility of securing enough fresh face samples from which to draw sound conclusions; some of it was due, no doubt, to lack of standard methods of analysis, and of course, to the ever-present lack of definition of boundaries from the standpoint of classification. Map Showing Lines of Equal Volatile Matter and Lines of Equal Specific Gravity As a foundation for this work the writer constructed a map showing lines of equal volatile matter and lines of equal specific gravity throughout the anthracite and semianthracite regions. The points on these lines were determined from a study of analyses of 214 face samples from 28 mines and composite analyses from 18 different breakers. These samples were collected through the joint efforts of the U. S. Bureau of Mines and the Anthracite Institute. The Bureau of Mines standard method of sampling was used in all cases. All analyses were made by the Bureau of Mines and are used here with its permission. The

Jan 1, 1934

By P. H. Scott, Walter Rose

Recent papers by S. T. Yuster have called attention to the largely ignored concept that there will be a transfer of viscous forces across fluid-fluid interfaces during the flow of immiscible fluid phases through porous media. This leads to the implication that the relative permeability us saturation function, as applied to each of the fluid phases of the system, will in some way be dependent on the viscosities of all the other fluid phases which are contiguous to the flowing fluid of interest. In fact, Yuster has selected and analyzed the properties of a capillary-tube model of the reservoir-prototype flow systems and concludes from his studies that relative permeability values will be very markedly influenced by the viscosity ratio in two-phase systems. On the other hand, relative permeability data have been reported in the literature for more than 20 years; and where these data are consistent at all, they consistently how no dependence on viscosity ratio (cf. chapter 7 of Muskat3 for a resume of past experiniental work). This paradoxical situation has prompted us to re-evaluate Yuster's work. The major flaw we find has to do with the properties of the model Yuster employed to give qualitative support to his predictions. This model is defective in that important surface area parameters characteristic of the prototype-reservoir flow system have not been propertly scaled. Fig. 1 shows how we believe Yuster's model should be modified to circumvent this difficulty. It depicts the capillary tube of radius R and length L, comprised of two elements in series. The first part of length, L has the nonwetting phase flowing centrally out to a radius distance r, where an interfacial boundary exists with the wetting phase which flows in the concentric annular pace of the tube. The second part of length, L-L,. has the

Jan 1, 1953

By Eugene Guccione

Upholding individual rights-and abhorring power politics-a newly formed group of young professionals is developing private nongovernmental solutions to environmental problems.

Jan 4, 1976

By Frederick M. Becket

DoctoR Albert Sauveur, distinguished scientist and Honorary Member of this Institute, predicted in the first Howe Memorial Lecture that the privilege of delivering' this annual address would be considered a highly significant honor. The intervening years have well borne out Sauveur's prophecy. I wish to assure the American Institute of Mining and Metallurgical Engineers that I also deeply appreciate this honor, recognizing at the same time the present and even more the future responsibilities with which it is accompanicd. Several of the previous lecturers had the good fortune to attend the classes of Professor Howc and to work in his laboratories. I was similarly favored, although in my instance and to my great regret the period was all too short. However, Howe's book, published in 1903, "Iron, Steel and Other Alloys," afforded me abundant opportunity to continue these studies. How well I remember the inspiration I derived from this famous book by Howe, the metallurgical master, pioneer, and educator! Remembering that Professor Howe contributed numerous papers to The Metallographist, a magazine supported from a technical point of view by the world's pioneers in metallography, I was curious a few days ago to learn the nature of Howe's early contributions to this magazine. The first paper by Howe in the first year of The Metallographist (1898) dealt with the allotropic theory; the second also treated of allotropy, and I quote the first sentence of that paper: The allotropic theory of the hardening of steel may, like so many other important theories, have to be accepted or rejected not on direct proof or disproof, but on the accumulation of circumstantial evidence for or against it. Howe's ability to stimulate others by his deep understanding and clarity of expression was truly remarkable; but just as striking was his intuitive judgment concerning the implications of metallurgical data in the arts and scienees. It therefore seems fitting that this lecture comprise a broad treatment of the subject chosen, rather than a closely documented thesis on any one phase of the problem; that in it attention be focused

Jan 1, 1938

By Frederick M. Becket

DoctoR Albert Sauveur, distinguished scientist and Honorary Member of this Institute, predicted in the first Howe Memorial Lecture that the privilege of delivering' this annual address would be considered a highly significant honor. The intervening years have well borne out Sauveur's prophecy. I wish to assure the American Institute of Mining and Metallurgical Engineers that I also deeply appreciate this honor, recognizing at the same time the present and even more the future responsibilities with which it is accompanicd. Several of the previous lecturers had the good fortune to attend the classes of Professor Howc and to work in his laboratories. I was similarly favored, although in my instance and to my great regret the period was all too short. However, Howe's book, published in 1903, "Iron, Steel and Other Alloys," afforded me abundant opportunity to continue these studies. How well I remember the inspiration I derived from this famous book by Howe, the metallurgical master, pioneer, and educator! Remembering that Professor Howe contributed numerous papers to The Metallographist, a magazine supported from a technical point of view by the world's pioneers in metallography, I was curious a few days ago to learn the nature of Howe's early contributions to this magazine. The first paper by Howe in the first year of The Metallographist (1898) dealt with the allotropic theory; the second also treated of allotropy, and I quote the first sentence of that paper: The allotropic theory of the hardening of steel may, like so many other important theories, have to be accepted or rejected not on direct proof or disproof, but on the accumulation of circumstantial evidence for or against it. Howe's ability to stimulate others by his deep understanding and clarity of expression was truly remarkable; but just as striking was his intuitive judgment concerning the implications of metallurgical data in the arts and scienees. It therefore seems fitting that this lecture comprise a broad treatment of the subject chosen, rather than a closely documented thesis on any one phase of the problem; that in it attention be focused

Jan 1, 1938

By N. O. Taylor

THE failure, by swelling, of several cast aluminum-zinc, spiral, pump rods, used to circulate water in a constant-temperature bath, brought up the question as to whether the presence of tin in varying quantities would have any appreciable influence in controlling this action. Previous workers had found the same difficulty with aluminum-zinc alloys, due to their swelling in water or solutions of electrolyte^.^ It was known that pure aluminum was practically insoluble in concentrated sulfuric and nitric acids, presumably due to the formation of an oxidized film on the surface. Concentrated sulfuric acid had little or no effect on pure zinc and tin and concentrated hydrochloric acid would attack all three metals. These facts aroused curiosity as to the probable reaction of the ternary alloys of these metals, and tests were made to determine their resistivity to the action of common laboratory reagents. Samples, covering the entire range of the ternary series of aluminum, zinc and tin alloys, were made up from good grades of the commercial metals.2 The materials were melted, at as low temperatures as possible, in graphite crucibles in a gas-fired crucible furnace. Graphite crucibles were used in preference to clay, to prevent the absorption of silicon by the aluminum, as found by previous workers. The melted materials were stirred thoroughly with pine sticks in order to ensure complete mixing and the greatest possible freedom from oxidation, and were cast in sectional, iron molds giving bars % in. in diameter and 5 in. long.

Jan 1, 1927

By Eric S. Cheney

Sulfur isotopes are best used in conjunction with other geological studies to determine the origin of known deposits; concept-oriented exploration programs can then be developed to find similar deposits. Geochemical processes are capable of causing different S '41S" ratios in the minerals and fluids participating in natural reactions. Because the magnitude of the resultant isotopic difference is inversely proportional to temperature, sulfur isotopic studies can be used to determine the source of the sulfur in high temperature deposits. The narrow spread of sulfur isotopic values from ores related to cupolas of felsic intrusions suggests that the sulfur in the ore-forming fluids was derived from a fairly uniform source (such as the intrusions) rather than by heated ground water from the adjacent country rocks. However, geologic and isotopic evidence suggest that the sulfur of many nickel sulfide ores may have been derived from the country rocks rather than the associated mafic igneous rocks. This sulfurization hypothesis implies that mafic intrusions in sulfur-rich country rocks should be prime exploration targets. Sulfur isotopic analyses of sulfides in the mafic rocks may indicate whether sulfurization has occurred. In equilibrium geochemical reactions S" is concentrated in the minerals with the greater bonding strengths. Thus the isotopic compositions of coprecipitated sulfides that have not undergone exsolution may be used as geothermometers and to distinguish multiple periods of mineralization, post-ore metamorphism, etc. The sulfur isotopic compositions of coexisting sulfides at Butte, Mont., indicate that the copper minerals did not originate by simple replacement of pyrite. Geologic and isotopic evidence suggest that the mineralogical and isotopic zoning at Butte formed almost isothermally during the geochemical evolution of the ore-forming fluids upward and outward from the Central zone. Unidirectional reactions cause enrichment of S" in the products. At low temperatures the isotopic effects of bacterial and inorganic reactions are difficult to distinguish. Anaerobic sulfate-reducing bacteria apparently were responsible for the sulfur of Gulf Coast salt domes and for diagenetic pyrite in sandstone-type uranium deposits. Sulfur (and carbon) isotopic data suggest that the roll ore bodies of sandstone-type uranium deposits originated by limited inorganic oxidation of diagenetic pyrite rather than by bacterial activity. Accordingly roll ore bodies should be most numerous and thickest against those portions of the sandstone aquifer that contain pre-ore pyrite.

Jan 1, 1975

By Clifford Frondel

THE aluminum oxide known as corundum has several varieties that have been used as gem materials since ancient times. These include the red variety called ruby, the blue variety sapphire, and the asteriated types of ruby and sapphire. Asteriated sapphire was known to the ancients under the name of astrios, and descriptions of this gem were given by Pliny and other early writers. The relation of these gem materials to each other as varieties of a single species, corundum, was first clearly established by Haüy in 1805 and J. M. Güthe' in 1809. Natural gem corundum is obtained principally in Ceylon, Siam, Burma, India, and Australia. Star sapphires and rubies always have been highly prized and in recent years have become particu- larly popular in the United States. Natural star rubies of large size and fine quality are extremely rare and rank with large and fine emeralds and diamonds as the most valuable of gem stones. Interest thus attaches to the recent success in commercially synthesizing star sapphires and rubies of a size and perfection unmatched by nature. Corundum was first synthesized as crystals in 1837 by A. Gaudin, who fused alum and aluminum oxide with potassium sulphate. Numerous other syntheses have been reported in more recent years. Summaries of this work are given in Doelter's Hand-buch der Mineralchemie, Mellor's Compreheizsive Treatise of Inorganic Chemistry, and other reference works. The methods employed include the reaction in the gaseous state at high temperatures of halogen compounds of aluminum with water vapor or boric oxide; the crystallization of aluminum oxide from fusion in potassium molybdate, potassium dichrom-ate or borax; and crystallization from highly aluminous silicate melts. Red, blue, or green colored varieties can be obtained by the addition of small

Jan 1, 1955

By Frank Firmstone

The furnace from which the brick here referred to were taken, was lined under my supervision and blown-in in May, 1902. It was 75 ft. high and 18 ft. in greatest diameter, and used coke to smelt a lean magnetic iron-ore. The lining was put in as follows:—First, blocks 14 in. long by 6 in. thick; second, 2 in. of loam; third, 13.5 in. of 9-in. fire-brick (one-and-ahalf brick wall) laid in English bond; fourth, red brick to within 2 in. of the iron shell; and fifth, 2 in. of slag-wool between the red brick and the shell. The brand of brick used has been known to me for over 20 years, and in my observation had always proved very durable, notably when used in a small furnace 50 k. high which treated the same magnetic. ore. On revisiting and examining the furnace in March, 1903, it was found that the whole of the lining of 14in. blocks at the top, and for an unknown distance (more than 20 ft.) below, had completely disappeared; and a few weeks later the 13.5-in. lining and the red brick at the top likewise vanished, and the furnace was blown out. N~twithstanding the complete failure of the lining higher up, measurements taken after blowing-out showed no unusual wear in the lower part of the furnace. The exact position in the furnace of the piece of brick-work used in the analysis, given below, is not known; but it came from between 30 and 40 ft. above the bottom. It had formed part of the 13.5-in. wall (no 14-in. brick remaining at that level) and consisted of parts of several bricks so firmly sintered together that fracture occurred indifferently through the joints and through the body of the brick. The joints could, however, be traced by a close examination. The surface which had been in contact with the material in the furnace was covered with a yellowish, translucent glaze, somewhat vesicular, and from

Jan 1, 1904

By Leonard Larson

DURING several years immediately preceding the adoption of wet-charge smelting at McGill, various necessary conditions affecting this procedure, such as plant rearrangement and the metallurgical nature of the concentrate produced at the concentrator, were fully considered. Wet-charge smelting is not altogether novel to the recently recon-structed smelter at McGill. A number of years prior to this improve-ment, when flotation methods were initiated at the concentrator, large tonnages of wet and (at that time) sticky flotation concentrate were charged directly into the reverberatory furnaces, because of the difficulty in handling the entire tonnage in the roasters. The plant had excess reverberatory units and this surplus furnace capacity was utilized to smelt raw flotation concentrate. During the years 1927 and 1928, a number of actual operating furnace test runs were made to determine in principle the feasibility of wet-smelt-ing operation. Results were encouraging, and in November 1932 the roasting plant was shut clown. For some time thereafter the wet feed was delivered directly to the reverberatory side-charging calcine hoppers already in place. Feeding the wet material through the old calcine hoppers and charge holes into the furnace involved considerable labor, but under the conditions existing at that time it was desirable to continue wet smelting even under the handicap of this laborious procedure. The smelting plant during this period was on a curtailed production basis, operating only about 15 days per month. The alternate starting up and shutting clown of the roasting plant presented a difficult problem and charging the wet material directly to the furnace entirely eliminated this difficulty. The roasting plant was never operated thereafter.

Jan 1, 1938

By T. B. Counselman

AFTER several years study, the Universal Atlas Cement Co. decided to rebuild its plant at Leeds, Alabama. The entire old plant, which was to operate during the new construction, was then to be scrapped with the exception of two kilns. The quarry was to be mechanized, new and larger kilns installed, with the most modern type of equipment all through the plant. Raw grinding operations at all of the Universal Atlas plants were dry. However, the dust hazard of this operation and the growing emphasis on occupational diseases made wet grinding attractive. Coal at Leeds is cheap, so that a slightly higher coal practice was unimportant. Power was cheap, so that waste-heat boilers were not desirable. Since new kilns were to be installed, these could be made long enough to make filters unnecessary. Wet raw grinding could be either the old practice of open-circuit compartment mills or closed-circuit grinding in accordance with metal-lurgical practice. The latter saved power and steel wear and saved initial investment. This had been demonstrated in cement plants. Also, the elimination of tramp oversize was a most important advantage. Ease of chemical control was another factor. Blending in the thickener, with elimination of slurry mixers had been found practicable. Therefore, if wet raw grinding were used at all, the advantages were clearly in favor of closed-circuit grinding. Detailed layouts of the most modern possible closed-circuit dry-grinding plant and of a closed-circuit wet-grinding plant were prepared, and careful estimates were made of initial invest-ment and operating costs. Full consideration of all the factors involved resulted in a decision to install wet closed-circuit grinding.

Jan 1, 1939

By T. B. Counselman

AFTER several years study, the Universal Atlas Cement Co. decided to rebuild its plant at Leeds, Alabama. The entire old plant, which was to operate during the new construction, was then to be scrapped with the exception of two kilns. The quarry was to be mechanized, new and larger kilns installed, with the most modern type of equipment all through the plant. Raw grinding operations at all of the Universal Atlas plants were dry. However, the dust hazard of this operation and the growing emphasis on occupational diseases made wet grinding attractive. Coal at Leeds is cheap, so that a slightly higher coal practice was unimportant. Power was cheap, so that waste-heat boilers were not desirable. Since new kilns were to be installed, these could be made long enough to make filters unnecessary. Wet raw grinding could be either the old practice of open-circuit compartment mills or closed-circuit grinding in accordance with metal-lurgical practice. The latter saved power and steel wear and saved initial investment. This had been demonstrated in cement plants. Also, the elimination of tramp oversize was a most important advantage. Ease of chemical control was another factor. Blending in the thickener, with elimination of slurry mixers had been found practicable. Therefore, if wet raw grinding were used at all, the advantages were clearly in favor of closed-circuit grinding. Detailed layouts of the most modern possible closed-circuit dry-grinding plant and of a closed-circuit wet-grinding plant were prepared, and careful estimates were made of initial invest-ment and operating costs. Full consideration of all the factors involved resulted in a decision to install wet closed-circuit grinding.

Jan 1, 1939

By N. J. Olson, G. W. Toop

A regular solution is characterized by a finite molar heat of mixing and entropy due only to ideal or random mixing. The thermodynamic properties of binary regular solutions which exhibit constant atomic coordination number and constant atom-atom intefac-

Jan 1, 1967

By Barry D. Lichter, Pierre Sommelet

High-temperature heat contents of InAs and GaAs were measured over the temperature range 400°K to temperatures above the melting points using a di-phenyl ether drop calorimeter. Smoothed values of the thermal properties have been derived and tabulated at even temperature interuals . The heats of fusion of InAs and GaAs were determined as, respectively, 8790 ± 200 and 12,590 ± 300 cal per g-atom at the respective melting points of 1210º ± and 1513º ± 1°K, yielding entropies of fusion of 7.26 * 0.16 and 8.32 ± 0.20 cal perºK per g-atom, respectively. A general discussion of the thermal properties of III-V com-pounds is given. THE low-temperature heat capacities of InAs and GaAs have been determined by Piesbergen.1Using a dynamic temperature modulation technique, Miller2 has determined the heat capacities of the compounds as well as GaSb and Ge between room temperature and 650°K; however, it has been observed that values determined by drop calorimetry for GaSb3 and for germanium4 are consistently about 5 pct lower than Miller's results. Cox and Pool10 report values for the heat content of InAs and GaAs and the heat of fusion of InAs. No value for the heat of fusion of GaAs appears to have been previously reported. This paper reports results of high-temperature heat content investigations of InAs and GaAs measured in the range 400" to above 1500°K employing a diphenyl ether drop calorimeter. These results, together with our previous results on III-Sb compounds3 as well as heat-content measurements5 of solid InP and Gap, are used in a general discussion of these compounds. EXPERIMENTAL PROCEDURES High-purity samples of the compounds, stoichio-metric to ±0.1 at. pct, were supplied in the form of crushed crystal fragments by Dr. Carl Thurmond of the Bell Telephone Laboratories. The sample preparation, description of the calorimeter, and details of the heat content measurement have been previously described.3 Samples were sealed in evacuated silica capsules and suspended by a Pt-Rh wire in a Pt-wound vertical tube furnace, heated to temperature

Jan 1, 1970

By W. L. Chu

It was observed that chromized coatings on low carbon steel could be embrittled by cooling slowly through the 475°C range. A higher chromium coating was more susceptible to embrittlement than a lower chromium coating. Coating structure and composition could be correlated with the chromizing process and prior carbon content of the steel. IT was recently observed that during the fabrication of rectangular tubings made with chromized thin gage 1010 steel, a high percentage of these parts were fractured readily in a brittle manner under the light impact-forming load employed. Ensuing investigation indicated the cause for such brittle failures to be the so-called 475°C embrittlement of the chromized coatings. The experimental work and results are briefly reported. Rectangular tube sections of normalized AISI C1010 steel, which had a cross-section of 0.5x1.5 in. and a wall thickness of 0.030 in., were chromized to yield coatings having several ranges of thickness, varying from 0.0005 to 0.002 in. Essentially, the chromizing process is similar to that described by Samuel and Lockington,' which consists of heating the parts in a sealed container at about 955°C for 4 hr in intimate contact with a chromizing mixture* samples in a hydraulic press, and the other employed a simple beam bending test of the flat sides of the tubing walls. Neither, however, was able to differentiate the relative brittleness of samples known to include both the brittle and tough types, since the impact-brittle samples were found to deform readily in a manner similar to the tough ones. Both the tough and brittle samples were studied by reflection microscopy. Observation showed that the microstructures of the steel cores were similar in content and distribution of inclusions as well as in the ferritic grain size. Results of Filar micrometer measurements showed that coating thicknesses+ of the brittle samples averaged 0.0007 in., whereas those of the tough samples averaged 0.0016 in. The micrographs of Fig. 2 illustrate the structural differences between coatings of both types of samples. By dissolving the steel cores in nitric acid, coatings of both the brittle and tough samples were isolated. Simple bending tests showed that coatings of the brittle samples cracked readily at about 90" bend, whereas those of the tough samples could be bent nearly 180° without cracking. The coatings as well as the steel cores were analyzed for carbon and

Jan 1, 1956

By Harold C. Price

Prior to Sept. 1, 1928, there had never been constructed what might be termed a long pipe line with electric-welded field joints. A year later more than 2500 miles of electric-welded lines had been completed which varied in diameter from 6 to 20 in., and in length from 50 to 700 miles. This paper discusses methods used on five lines with a total length of about 750 miles. The welding equipment used for the firing line or rolling welds, was 300-amp. generators driven with six-cylinder gasoline engines, and for the bell-hole or tie-in welds, 200-amp. generators driven by four-cylinder gasoline engines. A welding gang consisted of a foreman, 6 to 12 firing-line welders and 2 to 4 bell-hole welders, a mechanic and a tractor driver. Coupons about 1/4 in. thick were frequently cut from completed welds, which showed a cross-section of the weld and an indication of its size and penetration. For tests of tensile strength complete welds were cut out. The tensile strength of 52 welds cut from 420 miles of 12-in. line averaged 50,870 Ib. per square inch. The following results give a fair average of the number of welds made per man per day: on 157 miles of 8-in. line both firing-line and hell-hole welds averaged 15.3—the firing-line average was 21; on 39 miles of 10-in. line the firing-line average was 19.9; on 50 miles of 6-in. line, with unfavorable weather, the average was 17.7; on 424 miles of 12-in. line most of which was welded during the spring, 10.3, and with good weather the average rose to 13 welds per day. The average time for making a complete weld on 12-in. pipe 0.313 in. thick was found to be 30 min. for the rolling weld and 45 min. for tie-in welds. A comparison of costs between electric and gas welding shows that the cost of labor for electric welding is 25 per cent. more than gas, generating cost 61 per cent. less than gas, welding wire 40 per cent. less than gas, and supervision and overhead the same. Estimating 50 per cent, annual depreciation on electric welding equipment, and no depreciation

Jan 1, 1930

Iowa Geological Survey, Des Momes, Ia. George F. Kay, State Geologist A list of publications will be sent upon request Most of the papers of the Survey have been published in the Annual Reports, issued since 1892. Separates of the many papers in the Reports may be had for postage, except where they are out of print, and except for vol 1 (1892), 2 (1894) and 14 (1903), where no separates are to be had. Thirty-five Annual Reports have been issued up to and including vol 35 (1929). A charge, plus postage, is made for vols, 4, 5, 7, 8, 9, 10, 28 and 33, others will be sent free upon request, plus postage on from 2 to 6 pounds Space prohibits giving more than a general picture of some of the contents; vols 4, 5, 7, 8, 9, 10, 11, 12, 13, 15, 16, 20, 27, 32, contain, among others, papers on the geology of Iowa, by counties Vol. 19 (1908), 6 lb , contains a number of papers dealing with the peats and coals of Iowa, and has bibliographies of those subjects Vol 22 (1912), 6 lb , contains an annotated bibliography of Iowa geology Vol-24 (1913), 6 lb , contains the analyses of 16 Iowa coals Vol 28 (1917, 1918), price $1 50, 4 lb , completely covers the subject of gypsum in Iowa, and has a bibliography of the sub¬ject. Each volume carries an administrative report and a review of mineral production for the period covered In addition, Technical Paper 2 (1930), Studies of Iowa coals, will be sent free upon request Also a geological map of Iowa, and maps of Iowa showing the distribution of the glacial drift sheets throughout the state, have been issued and are available

Jan 1, 1933