Search Documents

By Edward L. Clark

The year 1954 witnessed great activity in the field of geology as applied to mining. The search for in nearly all districts is becoming more and more intensified as established reserves are being depleted. Much geologic work has been directed to finding extensions of known orebodies, but prospecting in new areas has constituted a large part of the program of many operators. The acute need for additional reserves has brought into the search all the tools known to the geologic profession. This is reflected directly by frequent references to geophysical and geochemical methods in the regional reviews that follow. The lone prospector of the early days of metal mining has been eliminated almost completely by modern scientific methods involving surface and subsurface geology, exploratory drilling, geophysics, and geochemistry. Nearly all new exploration is based on long-range programs coupled with studies of regional geology to determine the structural environment of areas of mineralization. The success of this approach has encouraged new operators in the field of exploration to adopt similar policies. Only in the search for uranium ores is the individual prospector still active, but the familiar picture of the burro heavily loaded with grubstake, gold pan, and pick and shovel has been replaced by the Geiger counter and the scintillometer carried by hand, by truck, or by airplane.

Jan 3, 1955

Servicing School Opening of a special factory training course in servicing earthmoving equipment is announced by the Euclid Road Machinery Co. Four [ ] beginning and four advanced one week training courses will be offered to representatives of distributors and customers. Circle No. 1 Core Drill The new Acker "Teredo" core drill, is named after the "boringest little animal in the world" to underline its function as a light, compact, portable core drill capable of depths to 600 ft. While light enough to be truck or jeep-mounted, it offers the combination of a three-speed totally enclosed transmission with either hydraulic or screw feed drill heads. Full 24-in. travel gives maximum footage per shift, 360° rotation permits freedom of hole location, a transmission mounted cathead winch is used in pulling rods and casings, and a power take-off is provided for a pump. Circle No. 2 Plastic Pipe Planned production of both flexible and semi-rigid plastic pipe is announced by Triangle Conduit & Cable Co. Rigid and high-impact pipe will be added to the line later. Three types: non-toxic, industrial, and suction, are being made and in sizes from 1/2 to 6 in. Circle No. 3

Jan 1, 1952

By AIME AIME

MILLING called for four sessions and a luncheon and covered broad ranges from speculative theory to basic practice, and from coal to gold. An attractive and profitable feature was the "get-together" of "coal preparers" and "ore dressers" for mutual discussion of their common problems. The first event was the Milling Luncheon in the Engi¬neers' Club on Monday. A concentrated group of high¬grade appeared and many matters were discussed, but only two called for official action: The meeting unanimously recommended the use of the Tyler standard sieve scale as against any new scale, and also the adoption of micron designation for fine particles in place of decimals of an inch or millimeter, or theoretical mesh size. The real sessions began on Monday afternoon with a menu of Mineral Physics for the ore dresser, metallurgist, geologist, physicist, et al. Four papers by the staff of the U. S. Bureau of Mines dealt with the chemical and physical aspects of mineral structure as revealed by the first two years of research to date. A fifth paper by Dr. M. J. Buerger correlated to the foregoing the knowledge of "The Lineage Structure of Crystals" and finally a sixth paper was a progress report of further developments of the last year in explosive shattering of minerals by the U. S. Bureau of Mines.

Jan 1, 1933

By E. E. Schumacher

IN a laboratory devoted to the furtherance of the science of communication, the breadth and variety of the problems encountered are challenging to a metallurgist. In my own long association with the Bell Telephone Laboratories, our metallurgical group has dealt with a vast number of alloys, both ferrous and nonferrous, and with many materials in the border range of metallic properties., The objectives of our design engineers embrace every phase of telephony, and the properties they desire in metals are generally unusual, frequently unique, and often conflicting. Commercial alloys have not always been available with properties to meet a special requirement in the telephone plant, and many alloys have had, therefore, to be custom-made. Anyone who has had the opportunity to observe the results of tests of all types on numerous such alloys, both commercially and specially produced, or who has taken part in the development of an alloy of some necessary, but new or unusual combination of properties, could not fail to be impressed by the frequency with which a desired goal has been reached or adequately approached through the presence of decimal quantities of alloying elements. Nor could One fail to be struck by the occasions when, conversely, of a minute amount Of impurity element has rendered an alloy useful. It is no exaggeration to state that the content be- hind the decimal point often spells success or fail-ure, and the critical content is sometimes far to the right of the decimal point as I shall later illustrate. The great effects of small additions have long been recognized and have, in fact, been described by many investigators. The importance of the minute, however, cannot be overemphasized. Therefore, in this discussion, I propose to illustrate for you some of the startling instances, drawn primarily from our own experiences, wherein small, even vanishingly small, proportions of stranger elements in otherwise common aggregates have com-pletely changed the customary pattern of behavior. No one property has a monopoly as to being dis-proportionately affected by minor elements. Nearly all properties are affected, but there is time here to include only a selected few. I have chosen, there-fore, three of general interest: strength, magnetic, and electrical properties. I shall inquire into both the mechanisms and consequences of these disproportionate effects and try to share with you the fascination and challenge of this field. Strength Properties of Lead and Lead Alloys To illustrate the effect of the minute on strength properties I have selected lead and its alloys, with which we have worked extensively for many years. Lead has the advantages of being available in quantity in a state of high purity and of being fairly easy to melt and fabricate without contamination to any extent detectable by the spectrograph. It has the interesting disadvantages of recovery and recrystallization at room temperature. Whether I

Jan 1, 1951

W. C. MATTESON (communication to the Secretary*).-The criticism and question raised by Arthur Knapp regarding the standardization of nomenclature is most important. Faulty rock classification-is generally the result of carelessness or ignorance on the part of the driller. Two remedies might be suggested. In a field where several large companies are operating on an extensive scale, a geologist from each concern might be assigned to superintend the gathering of well-log data and the classification of samples. The geologists from the several operating companies might then combine their data, which would doubtless give valuable information to all interested parties. At present, coordination is not a big factor, unfortunately, but the time will come when conservation will demand such systematic coordination on the part of competing companies. The second remedy lies in instructing and educating the driller to a thorough understanding of the importance of an accurate log and correct classification of the various formations. The writer does not agree with the statement that "90 per cent. of the logs as taken today are absolutely worthless to any one but the one who has taken the log." While mistakes in nomenclature often occur, the driller is generally able to classify the important water-, oil-, and gas-bearing formations with a fair degree of accuracy. Such information is often sufficient to permit accurate correlation and also constitutes valuable data for projection purposes. It must be borne in mind that to attempt to use well-log data in a strict scientific sense of accuracy is impracticable and impossible. A broad interpretation and a comprehensive knowledge of the practical limits of such' information are essential in applying it successfully. Even experienced geologists do not always agree on rock classification. The question as to what constitutes correct nomenclature should receive the earnest and immediate attention of geologists, operators, and producers. Although standard textbooks on geology give correct definitions and descriptions of the general rock species, such textbooks fail to develop the subject in sufficient detail for the work under consideration. A committee composed of appointed members from the American Institute of Mining Engineers, the Geological Society of America, and the

Jan 6, 1917

DR. PeRsifor Frazer, Philadelphia, Pa. (communication to the Secretary):* Mr. Campbell's very interesting contribution, after complimentary mention, finally decides against the acceptance of the classification proposed by me in a paper bearing the same title and read at the Wilkes-Barre meeting, May, 1877.2 That paper was written primarily for the Second Geological

Jan 1, 1906

By Henry S. Rawdon

The structure of wrought iron as usually described by metallographists and workers in metal in general is that of a fairly pure iron. Impurities, if present, are usually considered as being in solid solution in the crystals of the ferrite matrix or as forming part of the ever present "slag streaks." Attention is herein directed to one type of these dissolved impurities; to the detection of such impurities, particularly in low-grade irons, and to their possible influence on the physical properties of the metal. The attention of the Bureau of Standards was first directed to wrought iron of the peculiar and unusual characteristics to be described later, in material which had failed in service and was submitted for test. The examination was extended to other grades of wrought iron, to see whether such features are of common occurrence in this class of material. MICROSTRUCTURE OF WROUGHT IRON Usual Structure The general microstructure of wrought iron is so well known that a detailed description of it here is needless. There is shown in Fig. 2 the structure of a sample of Swedish iron which illustrates well the matrix of ferrite crystals in which are embedded the slag threads so characteristic of the puddling process and the subsequent working of the material. The usual commercial product contains varying amounts of the impurities commonly associated with iron and steel, i,e,, manganese, phosphorus, silicon, and sulphur together with small amounts of carbon. Of these, the larger part of the phosphorus and some of the silicon present are held in solid solution in the ferrite while most of the remaining impurities, other than carbon, exist in the in closures of slag. Aside from the discontinuities introduced by the slag streaks the ferrite matrix has the microstructure and appearance of a pure metal. No definite orientation of the various crystals or grains is apparent; deep etching of the specimens reveals no intracrystalline features (i.e., within the grains) other than those noted in " pure " metals in general (etching pits).

Jan 1, 1918

By A. E. Nehrenberg

R. A. Schmucker, Jr.—The writer wishes to point out that an acicular growth of austenite, similar to that described in the author's paper, was recently observed in an alloy steel of only 0.06 C content. This steel, which represents an 0.07 max C, 1.35 Cr, 0.55 Ni, 0.20 Mo analysis, combines the characteristics of minimum hardness in the annealed condition with maximum hardenability and is therefore suited primarily for cold-hobbing applications. The acicular austenite formation in this steel was observed accidentally during a determination of its Ac1 temperature. The samples used in this investigation represented as-forged bar stock which had been given a preliminary temper at 1300°F. The critical (Ac1) temperature was finally established at 1400 °F. Fig. 15 represents the microstructure of the sample which had been heated at 1450°F for ½ hr, water quenched, and tempered at 600°F for ½ hr (for the purpose of darkening the martensite). It will be observed from the distribution of the darkened areas of martensite that the parent austenite grains formed at 1450°F had grown in an acicular manner and still occupied only a small percentage of the total area. The remainder of the area contains the original equiaxed ferrite grains in which new austenite had as yet scarcely formed. However, the tiny isolated martensitic patches at several points where three or more ferrite grains intersect indicate that small austenite grains had formed and started to grow in an apparently equiaxed fashion. Fig. 16 represents the prior microstructure of an original sample in the as-forged and tempered condition, before it was heated -above the critical temperature. It is probable that there are two kinds of ferrite in this structure: (1) The equiaxed proeutectoid ferrite grains which separated from the austenite when the steel was cooled from the forging temperature, and (2) the acicular ferrite associated with the aggregate of fine carbide which is represented by the patches of

Jan 1, 1951

By G. R. Rubly, H. J. Steele

The San Manuel property is in town&ips 8S and 9S, range 16E, Gila and salt River Base and Meridan, State of Arizona. This area is in the Old Hat mining district, southern pinal county, and is about 31/25 miles southwest of the town of Mammoth on the San Pedro River And one mile south of the Mammoth mine at Tiger, Arizona, The property consists of over 150 contiguous lode claims. The old Hat district was prospected prior to the civil war, but there was little or no production until 1881.1 The chief producers have been the Mammoth and Mohawk mines, now consolidated and operating as the st. Anthony Mining and Development Co., Ltd. Production to 1936 was $5,200,000, of which 83 pet was gold.2 Since 1940 the production has been chiefly lead and zinc, and some molybdenum and vanadium. There are a few small properties in the vicinity that have produced very minor tonnages of copper ore. In the San Manuel group there are claims which have been held continuously from 1906 to the present time, and at least two churn-drill holes were put down on or near the outcrop in 1917. No logs for these holes are available, but it is assumed that the grade of copper encountered was not sufficient to encourage further exploration. A small amount of ore has been shipped from open cuts on the San Manuel outcrop area, but there is no record of the tonnage Or grade. It is estimated that not more than 50 tons were mined. These cuts, plus a few shallow shafts and some short adits indicate limited and unenthusiastic prospecting at San Manuel. In 1942, through the efforts of James M. Douglas, R. B. Giffin, Victor Erickson, and Henry W. Nichols, owners of the Sari Manuel group, the Reconstruction Finance Corporation and War Production Board authorized the United States Geological Survey to investigate the property, and by their recommendation, the United States Bureau of Mines was authorized to put down a limited number of churn-drill holes. The Bureau of Mines carried On drilling from November 1943 to February 1945 Seventeen holes were drilled, varying from 305 to 1990 ft in depth. The property was brought to the attention of Magma Copper Co. in June 1944, and an option agreement was made with the Owners. Subsequently, a group of claims lying north of the original group and held by the Apex Lead Vanadium Mining Corp, and a group to the east held by the Quarelli family, were optioned. A drilling program was laid out to conform to the Bureau of Mines pattern, and drilling started in December 1944 Sari Manue1 Copper Corp. was incorporated September 1945, and has carried on the exploration program to the present time. Geology General The mineralized outcrop, chief copper mineral of which is chrysocolla, is a tri-

Jan 1, 1949

By G. R. Rubly, H. J. Steele

The San Manuel property is in town&ips 8S and 9S, range 16E, Gila and salt River Base and Meridan, State of Arizona. This area is in the Old Hat mining district, southern pinal county, and is about 31/25 miles southwest of the town of Mammoth on the San Pedro River And one mile south of the Mammoth mine at Tiger, Arizona, The property consists of over 150 contiguous lode claims. The old Hat district was prospected prior to the civil war, but there was little or no production until 1881.1 The chief producers have been the Mammoth and Mohawk mines, now consolidated and operating as the st. Anthony Mining and Development Co., Ltd. Production to 1936 was $5,200,000, of which 83 pet was gold.2 Since 1940 the production has been chiefly lead and zinc, and some molybdenum and vanadium. There are a few small properties in the vicinity that have produced very minor tonnages of copper ore. In the San Manuel group there are claims which have been held continuously from 1906 to the present time, and at least two churn-drill holes were put down on or near the outcrop in 1917. No logs for these holes are available, but it is assumed that the grade of copper encountered was not sufficient to encourage further exploration. A small amount of ore has been shipped from open cuts on the San Manuel outcrop area, but there is no record of the tonnage Or grade. It is estimated that not more than 50 tons were mined. These cuts, plus a few shallow shafts and some short adits indicate limited and unenthusiastic prospecting at San Manuel. In 1942, through the efforts of James M. Douglas, R. B. Giffin, Victor Erickson, and Henry W. Nichols, owners of the Sari Manuel group, the Reconstruction Finance Corporation and War Production Board authorized the United States Geological Survey to investigate the property, and by their recommendation, the United States Bureau of Mines was authorized to put down a limited number of churn-drill holes. The Bureau of Mines carried On drilling from November 1943 to February 1945 Seventeen holes were drilled, varying from 305 to 1990 ft in depth. The property was brought to the attention of Magma Copper Co. in June 1944, and an option agreement was made with the Owners. Subsequently, a group of claims lying north of the original group and held by the Apex Lead Vanadium Mining Corp, and a group to the east held by the Quarelli family, were optioned. A drilling program was laid out to conform to the Bureau of Mines pattern, and drilling started in December 1944 Sari Manue1 Copper Corp. was incorporated September 1945, and has carried on the exploration program to the present time. Geology General The mineralized outcrop, chief copper mineral of which is chrysocolla, is a tri-

Jan 1, 1949

By George Breyer

DURING the past 25 years the steelmaker has experienced some difficulty in producing steel to meet the standards established by the metallurgist. In contrast to the past, when a chemical specification of broad limits was the only requirement, he now has to employ such tests as microscopic, macroscopic, tensile, impact, Magnaflux and even X-ray and supersonic. The development of these tests has more than set the pace for a manufacturing process of which the exactness still hinges to an important degree on the ability of the furnace operator. In our efforts to produce steel, and especially alloy steel, to meet the exactness of modern engineering specification, many factors must be taken into account. It is not sufficient to make a good heat of steel in the furnace and then be satisfied that the job is done, since there are many pitfalls between the furnace and the finished product. The literature abounds with information on melting practices, deoxidation methods and slag control, but the lack of positive information about what happens when the steel is teemed into molds is quite evident. Such questions as what is the proper mold size, shape and thickness; which is the best mold coating; what is the best rate of pour for any given steel, and what is the effect of cooling rates on quality, are still answered by opinions. It is acknowledged that a poor heat of steel cannot be improved in the pouring pit. On the other hand, a good heat can be ruined by improper handling after it leaves the furnace.

Jan 1, 1947

By C. R. Wohrman

A MELT of pure electrolytic iron with about 0.4 per cent. sulfur and 7 per cent. manganese was prepared in connection with a study of inclusions in iron. The alloy darkened rapidly when etched with a 10 per cent. alcoholic solution of nitric acid, and microscopic examination revealed the presence of a semimartensitic, semi-Widmanstättian structure (Figs. 1 and 2) closely resembling the structures found by Benedicks in his artificially prepared "meteoric iron." 1 The structures found by Benedicks were readily explained by the presence in his alloy of the two well known iron-nickel solid solutions, taenite and kamacite, and of their eutectoid (?) aggregate, plessite. By analogy, one would infer the existence of similar phases in the iron-manganese alloy just described, such as inference being strengthened by the similarity displayed in many ways by nickel and manganese in their effects on iron. IRON-MANGANESE ALLOTS ARE REGARDED AS HOMOGENEOUS Heterogeneity of iron-manganese alloys has not been recognized heretofore, judging from the data of standard metallographic books and those of original papers. In fact, iron and manganese are quite generally regarded as completely miscible in the solid state. Dr. Rosenhain,2 for example, writes: Alloys of group (a), of which those of gold-silver, iron-manganese, and copper-nickel are examples, when allowed to crystallize sufficiently slowly to attain their condition of final equilibrium, present a microstructure exactly similar to that of a pure metal-the homogeneous character of the molten solution is in that case so completely maintained that the microscope cannot detect the presence of any second constituent.

Jan 1, 1927

By W. C. Maurer

A drilling-rate formula for roller-cone bits is derived from rock crater-ing mechanisms. This formula holds for "perfect cleaning", which is defined as the condition where all of the rock debris is removed between tooth impacts. Under these conditions, the drilling rate is directly proportional to the rotary speed and to the bit weight squared, and inversely proportional to the bit diameter squared and to the rock strength squared. Under imperfect cleaning conditions, such m those usually present in field drilling, re-grinding of the cuttings occurs under the bit, and the drilling rates fall below those for perfect cleaning. INTRODUCTION Drilling with a roller-cone bit consists of two fundamental operations: the formation of craters under the bit teeth, and the removal of the broken rock from the craters. To delineate the mechanisms of drilling, it is first necessary to understand the mechanisms involved in the formation of individual craters and then to relate these mechanisms to the over-all drilling operation. CRATER FORMATION When a bit tooth impacts a rock, the rock is elastically deformed until the crushing strength of the rock is exceeded, at which time a wedge of crushed rock is formed below the tooth1, 2 as shown in Fig. 1. As additional force is applied to the tooth, the crushed material is compressed and exerts high lateral forces on the solid material surrounding the crushed wedge.- en these forces become sufficiently high, fractures are initiated below the tooth and propagate to the free surface of the rock. The trajectories of these fractures intersect the principal stresses at a constant angle,'s4, as predicted by both Mohr's and Griffith's theories of failure. It has been experimentally 3,1 .6 that the volume of an impact crater, V,, varies as where Ec is the total energy imparted to the rock during the formation of the crater, and E is the threshold energy required before cratering is initiated (Fig. 2). Indexing experiments' have shown that, when there is a second free face to which the crater can fracture, a larger volume of material is removed and that above a transition zone there is a linear relationship between V, and Eo., which has a slope equal to the relationship for the single crater. The beneficial effect of indexing tends to offset the threshold energy requirement to a large extent, as shown in Fig. 2, and the relationship is closely represented by Rate-of-loading effects have been used to explain the nonproportional relationships usually obtained between drilling rate and rotary speed. The data4, in Fig. 3 show that the Ec/Vc parameter remained constant for craters produced with impact velocities ranging from 10 to 8,000 ft/sec. Since no rate-of-loading effects were detected over this wide range of loading rates, it seems improbable that there would be detectable rate-of-loading effects present in the small changes in impact velocities produced by varying the rotary speed. The writer has shown (Fig. 4) that, for craters produced in rock by impacting spheres, where X is the depth of penetration. Simon2 has shown that this relationship also holds for craters produced in rock by penetrating wedge-shaped chisels. The energy used in crater formation is

The Palabora ore consists of two types, a carbonatite containing a low titanium magnetite, and a foskorite containing high titanium magnetite. The latter type also contains substantial quantities of phosphate. These two ore types are separately crushed and are kept separate through copper flotation and magnetic separation, for recovery of magnetite, with the low Ti magnetite being shipped as iron ore. High phosphate tailings are pumped to Foskor, a government-owned phosphate plant nearby. The Palabora plant was originally designed in 1966 for 33, 000 tpd using two 54 in. by 74 in. Allis -Chalmers gyratories; two 7 ft (2. 13 m) standards; four 7 ft shortheads; and six grinding lines, each using one 1,200 hp rod mill and two 1,200 hp ball mills. A fifth short- head and one more grinding line were added later; and with flowsheet improvements, the capacity of the plant was increased to 59, 500 stpd. A further plant expansion involving a third 54 in. primary and two 32 ft by 15 ft (9.75 by 4.6 m) 9,000 hp autogenous mills and another flotation section will bring its capacity to 87,500 stpd in 1977. These two fully autogenous mills are constructed entirely out of doors near the primary crusher, and the ground ore will be pumped a mile to the concentrator by a five-stage pumping system. The Palabora ore is mined with 6, 10, and 12 7d (4.6, 7.6, and 9. 2 cu m) shovels and hauled to the crushers in 110 and 165 st trucks. Sixty-five ton trucks were originally used, but the crusher dump pockets were designed for larger units. Dump pockets, crushers, feeders, and take- away belts are offset in order to keep the two ore types separate. Centerlines of the crushers are only 43 ft (13. 1 m) apart; but, because of their being offset, maintenance room is ample. Initially, more carbonatite ore than foskorite was mined; but as the pit has deepened, this ratio has been reversed. The Palabora ore breaks in the pit with a large amount of oversize boulders; and, with the use of larger trucks, a splitter has been installed on one side of each dump pocket to protect the crusher spider. Smaller trucks dump on the opposite side. To accomodate the splitter, the pocket edge has been raised one meter and moved back one meter. Dust is collected through a special vent shaft between the crushers and the mantle relining area; but even so, two high-pressure water spray headers with nozzles are installed under the edge of the pocket at each dumping position. While only one truck dumps at a time, sprays from all four headers are used to suppress dust. Any leakage of water through the seal around the upper bowl of the crusher is caught by a circular trough under the seal and directed to a sump pump. At this point, there

Jan 1, 1978

AlbioN S. Howe, San Francisco, Cal. (communication to the Secretary*):—In discussing this paper, 'I mould suggest that. the dip for iron pipe be liquid asphaltum, instead of coal-tar and pitch. Asphaltum is superior to coal-tar, and the variety

Jan 1, 1905

By Howard Eavenson

PRIOR to 1907 nearly all coke was made in beehive ovens, and most of the gas produced was made in the old-style gas retorts, and while there were a few coke plants in southern West Virginia, southwest Virginia and Kentucky operating on high-volatile coals the proportion of the total product made by them was small and was usually used locally. The greater part of the coke made, and the coal gas produced, came from the Pittsburgh seam of western Pennsylvania and northern West Virginia-which was then regarded as the standard coking and gas coal of the coun, try, and the best coal available anywhere for these purposes. With the advent of the by-product oven and the building of coke plants at the furnaces, the restriction of the use of one grade of coal for making coke was removed and the use of mixtures of low-volatile and high-volatile coals began. The change in the locations of the coke plants removed the necessity of using Connellsville coal and also made sources of gas available to the public utilities other than of their own manufacture. Most of the first oven plants were built at points distant from the Connellsville region and this afforded an opportunity for the use of coals from the southern Appalachian fields, which were at approximately equal distances from the ovens. Since that time development has been made on a number of seams of coal of great purity in southern West Virginia, southwestern Virginia and eastern Kentucky, which have been largely used for cokemaking, gas and other metallurgical purposes where low amounts of ash, sulfur and phosphorus are determining factors. These coals are much lower in the objectionable elements than the best of the coal from the Pittsburgh seam, or than any northern coal, and in by-product ovens produce coke that is not excelled for any purpose by any coal mined in this country, and is equaled very seldom. Coal from several of these seams is shipped in great quantities without beneficiation and is lower in ash and sulfur than the best washed product from any seam mined in the north.

Jan 1, 1932

By N. LILIENBERGS

DURING the past few years, the requirements for steel have been raised so high that soundness is more important than ever before. The old practice was to mike steel ingots of sufficiently large sections to permit a considerable reduction of area in rolling and hammering to a given size, relying on the fact that by such rolling and hammering all cavities will be squeezed together and practically eliminated. The finished sizes, if found by inspection of the surface to be faultless, were therefore pronounced to be sound. But when such steel is ?worked up,? the manufacturer is surprised and disappointed to find that it splits, or that streaks and seams make the product unmarketable. Large sections, such as rails, beams or heavy forgings, may, within certain limits, be sufficiently strong, even if the sides of the cavities are only squeezed, and not welded together. But it is well known that, in the interior of heavy articles, under certain conditions, forging may develop small streaks into large cavities. Small sections, steel for ordnance and tubes, and numberless articles in the tool-trade, always show up the defects. It may be doubted whether cavities in steel ingots can ever be completely welded. The old theory, is, that the silver-clear blow-holes, without the blue oxide, can be welded by sufficient working. They are, however, not empty, but are filled with carbonic oxide. It is admitted that the "blue" cavities, resulting from air mechanically drawn down into the mold during the casting, can never be welded, because the oxide does not melt, and there would be no escape for it if it did. The only way in which steel can be made satisfactory for the above-named particular purposes is by having it ?dead molten." But then the trouble of piping is encountered. As is well known, a pipe is the result of the contraction of

May 1, 1906

By J. H. Frye, S. G. Holder, E. E. Stansbury

Internal friction studies on annealed and cold-worked pure silver and alloys of silver with 4.5 atomic pct each of Cd, Sn, and Sb are reported. Small amounts of cold work, introduced by stretching pure silver, decrease the internal friction; large amounts of cold work, by wire drawing, cause this decreased internal friction to rise. Results of severol anneoling histories on the room-temperature in-ternal friction indicate a rather complex recovery and recrystallization behavior. A rather system-atic alloy effect is observed for the elements of Period V-B in silver in both the annealed and cold-worked states. DURING recent years internal friction measurements at very small stress levels have been interpreted in terms of structural models and mechanisms occurring within the metal or alloy.These measurements have been made over wide ranges of frequency of vibration and of temperature. While the effects of impurities, alloying, and plastic deformation have been studied by numerous investigators, no investigations of the effect of a series of solutes related by their position in the Periodic Table on a given solvent seem to have been reported. The present paper reports internal friction measurements on silver and on certain silver-base solid solutions to determine the values of room-temperature internal friction associated with varying amounts of plastic deformation and after different annealing

Jan 1, 1957

By C. H. Mathewson

EXCEPTING the joint sessions on gases in metals held during the day on Tuesday, the Institute of .Metals opened its activities with a division dinner at the Commodore on Tuesday evening, with Sam Tour, retiring chairman, presiding. W. M. Corse, secretary-treasurer, outlined the financial status of the division and stated the investment fund is becoming large enough so that in the near future it will be possible to pay all expenses of a foreign lecturer once in two years and not rely on an extended speaking tour to cover expenses. W. B. Price reported on his attendance at the Zurich, Switzerland, meeting of the International Society of Testing Materials and gave a graphic account of his visit to the Grand Salon, his meeting with Mussolini, and his audience with the Pope. Buffalo was announced as the place of the fall meeting, to be held during the week of Oct. 3.

Jan 1, 1932

By F. B. Plummer

GEOLOGICAL engineering as applied to oil fields, or production geology as some prefer to designate the profession, is designed to fill in the border line between pure geology and pure petroleum engineering. Therefore the production geologist may, and frequently does, reach out to grasp much in both professions. Where once the oil geologist was content to pick samples out of a mud ditch and try to identify oil formations from the color or appearance of flakes of rock bailed out of a well, now he has to deal with graphic electrical logs obtained by intricate and highly technical electrical apparatus and to make exact determinations to the fraction of an inch of the depth and thickness of an oil sand 2 miles below the surface.

Jan 1, 1944