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By James F. Lewis

The death of Josephus Flavius Holloway, for twenty-one years an active and beloved member, and twice a Vice-President, of the Institute, cannot be allowed to pass without some expression on the part of his brethren of mingled grief and gratitude—grief that we have lost his genial and inspiring presence ; gratitude that we have been privileged to know one who lived " To make the world within his reach Somewhat the better for his being, And gladder for his human speech." The present sketch of his career and character is offered as a sincere, though inadequate, expression of these feelings. Mr. Holloway's father, Joseph T. Holloway, born, in 1796, in Sunbury, Pa., and yielding in his youthful prime to the prevailing impulse of his generation, started alone, with knapsack

Jan 1, 1897

W. G. MATTESON, Houston, Tex.-I think that Mr. Powers has given us some very valuable information on the Healdton field, which is of material interest in view of the fact that the Healdton field has passed Cushing in the point of production, and if not leading, stands second only to the new El Dorado field in the point of production of the oil-in this country. Mr. Powers says that the deepest producing sand at Healdton is 1860 ft. Within the last 3 or. 4 months they have drilled to 2700 ft. there and found a sand which is producing very high-grade oil, if I remember correctly, about 42 gravity. Another very important point brought out by Mr. Powers is the fact that the Pennsylvanian beds and the Permian beds are conformable according to his interpretation. He seems to have based his interpretation upon the gathering of a number of well logs and a very careful study of them, but it seems to me the information furnished by the, well logs is really insufficient to justify such an important conclusion. In the first place, the difficulty of interpreting the line of demarcation between the Permian "Red Beds" of Oklahoma and the top of the Pennsylvanian is apparent, for the reason that sometimes the uppermost Pennsylvanian formation has a reddish phase and the line of demarcation is not very sharp.

Jan 4, 1918

By T. Sterry Hunt

THE essential principle of this new process, now in operation in Chili and in North Carolina, for the extraction of copper from its ores, is the dissolving of the oxides of copper by a hot solution of protochloride of iron and common salt. In the action which takes place, the protochloride of iron is converted into peroxide, while the oxides of copper are changed into protochloride and dichloride, the latter of which, though insoluble in water, is readily soluble in a hot strong brine. From the solution thus obtained, metallic iron throws down the copper in a metallic state, regenerating the protochloride of iron; which is then ready for the treatment of a fresh portion of oxidized copper ore. In the case of slimy ores, the contact of the bath with the ore is effected by agitation in tubs; but when the ores are granular, lixiviation in large vats is equally efficient and simpler. The hot solutions, charged with chlorides of copper, are digested in tanks with scrap-iron, or better, are made to flow through covered channels containing the scrap-iron, and in their passage lose the whole of their copper; the reaction at the same time evolving so much heat as to keep up the temperature of the liquid. In order to prevent a certain loss of chlorine, which otherwise takes place from the production of some basic ferric chloride in the reaction between the ferrous chloride and the oxides of copper (both protoxide and dinoxide being generally present in calcined ores), a portion of sulphurous fumes from the roasting is made to pass through the regenerated bath before adding it to fresh ore. This has hitherto been effected by injection, with the aid of a jet of steam.

By J. Wayne Erickson

One of the major problems facing today's mining industry is how to manage people and control costs in the underground mine. It is a problem with a solution. Because of the concerted effort to find and mine minerals near the surface, open-pit mine opportunities for certain minerals are becoming more limited; the mining industry will eventually be forced to produce more and more from underground mines in order to obtain those resources necessary to sustain our civilization. Although much technical progress has been made towards solving problems associated with the underground mine, such as - mine design, ventilation, rock support, equipment, and blasting techniques, little has been written on managing mining personnel. Much of what is being taught and practiced today about human relations, motivation, incentives, etc., applies to the underground miner, but the uniqueness of his group dictates a different treatment from that associated with the typical construction worker or factory employee. The difference lies with the kind of man attracted to underground mining and his working environment. Anyone who has had the responsibility of managing an underground mine would agree it is a unique problem.

Jan 9, 1976

By Paul M. Tyler

YEAR after year, the kaolin industry of the United States has been setting new production records and making better products. High-grade paper, pottery, and rubber clays are produced in this country mostly in the South. Georgia alone contributes over 70 pct and South Carolina almost 20 pct of the total domestic output. Residual kaolin is mined in North Carolina, highly plastic but naturally sandy Tertiary (Eocene) potting clays are worked in north central Florida, and good white clays are produced in several other states, but the main sources of kaolin or china clay have been numerous deposits in the Tuscaloosa (Upper Cretaceous) formation. This formation of generally sandy sediments is called the Middendorf member in older geologic reports and corresponds in age with some of the New Jersey clays. As shown in fig. 1, it crops out almost continuously in a generally southwesterly direction across South Carolina and Georgia and into Alabama. Clay is mined from this formation in all three states but the principal producing centers lie within about 10 miles of a straight line drawn between Aiken, S. C., and a point about 10 miles south of Macon, Ga. The white kaolins of the South were recognized and used prior to the Civil War but suitable treatment processes were not introduced until World War I when imports, chiefly from England, were curtailed. Although imports of high-grade clays were resumed after 1918, the domestic industry managed to treble its prewar production record during the early 1920's and has continued to grow. Whereas the 1909 to 1913 average total production in the United States was only 132,104 short tons valued at $705,352 f.o.b. mines, the output in 1948 was 1,568,848 tons worth $19,756,738.

Jan 6, 1950

Jan 1, 1934

By H. M. Chance

By courtesy of the officials of the Chicago, Burlington and Quincy railroad, I am permitted to publish the results of an examination made in 1887 and 1888 of' the country west of the Black Hills, and lying between the Black Hills and the foot-hills of the Big Horn Mountains in the northeastern part of Wyoming. With the exception of the country constituting the foot-hills, or the encircling ridge or rim of the Black Hills proper, all of this area is occupied by rocks of Cretaceous age. In the central part of the Black Hills are found the tin-bearing granites, the mica-schists, and gold-bearing slates, already so well known. Surrounding this central area of older rocks (which should be considered as the "Hills" proper) are the attenuated representatives of the Palzeozoic, dipping gently away from the Hills in every direction, overlaid by the gypsum-bearing Mesozoic, which here forms a bold high ridge or rim, completely encircling the Black Hills, and known as the inner ridge. Overlying, and apparently conformable to this, we find the Dakota sandstone, which likewise forms a prominent ridge or rim, known as the first or outer ridge. This is the formation which contains the coal now worked at the mines near Newcastle. It is also the formation in which the best oil-wells have been obtained in the "Stoakdale," or "Beaver," and the " Belle Fourche " oil-districts. Overlying it are the Colorado shales, forming the great plains drained by Beaver creek and the south fork of the Cheyenne river, and extending west to the Belle Fourche, near Donkey creek, where the overlying Fox Hill formation (thin) and the Laramie group, the great lignite-formation, are first seen. The Laramie group occupies the surface from the Belle Fourche at Donkey creek west to the foothills of the Big Horn mountains at Buffalo, an air-line distance of some seventy or eighty miles.

Jan 1, 1891

By J. T. Norton, A. L. Mowry

The monocarbides of the A subgroup elements in the fourth and fifth group of the periodic table in addition to being hard and refractory are of special interest in that they are isomorphous in crystalline structure. They are cubic with a sodium chloride type structure in which the metal atoms are essentially close packed in a face-centered cubic arrangement with the carbon atoms placed in the interstices between. Interstitial structures of this close packed type were first investigated systematically by Egg1 and he gave the rule for their formation, stating that the radius ratio of the nonmetal to the metal atom should not exceed the value of 0.59. The carbides of interest are those of titanium and zirconium of the fourth group and vanadium, columbium and tantalum of the fifth group. Table 1 shows the radius ratio using the Goldschmidt radii for 12 coordination for the metal atoms and the diamond radius for the carbon atom. It will be noted that while there is considerable variation in the size of the metal atom, in all cases the ratio is smaller than the limit of 0.59 placed by Hägg. It has been known for some time that these cubic carbides are soluble in one another, at least to some extent or, in other words, the metal atoms can be replaced, one by another without destroying the stability of the structure. Since the stability of these close packed interstitial substances appears to depend more upon geometry than upon the exact chemical nature of the atoms involved, it is of interest to examine the possibilities of replacement in these carbides in some detail. Hume-Rothery2 has pointed out the importance of the difference in size of solute and solvent atom as a factor in limiting the solubility in simple binary solid solutions. Largely on an empirical basis, he states that if the difference in size between solvent and solute atom is more than 14-15 pct of the solvent atom, the range of solubility is very restricted. The atom size was based on the distance of closest approach in the elements involved. While there is some question as to how one should calculate the size of the metal atom in the carbide structures, reference to Table 1 will show that zirconium is the largest and vanadium the smallest of the group and that the difference is about 15 pct. The Ti-Zr difference is about 9 pct and the others are smaller. Thus one would predict that if the size factor controls the solubility, all of the pairs except VC-ZrC would have wide or complete solubility whereas this latter pair is on the border line and might have restricted solubility. The purpose of the present investi- gation was to examine the solubility of the several pairs of carbides by heating them together until equilibrium was established and then examining the product by X rays. Previous Work Agte3 and his associates prepared various transition metal carbides and determined the melting points of binary mixtures. He concluded from the shapes of the melting point curves that there was extensive solubility in the case of the cubic carbides. Umanskii and his colleagues made an investigation of a number of pairs of the cubic carbides, using X rays and plotted lattice parameter vs. composition curves for the systems TaC-Tic, CbC-Tic, TaC-ZrC and CbC-ZrC. All pairs showed a continuous series of solid solutions. The first two pairs gave a linear relation while the latter two showed a negative deviation from Vegard's law. Kiefer and Nowotny, in a paper which became available after the present work was well advanced, investigated the binary pairs of the five cubic carbides by means of X rays. Relatively few points were obtained and results indicated that in some cases, at least, equilibrium was not reached at the temperatures used. The results indicated that solubility in the VC-ZrC system was not complete. All of the results of previous investigations indicated the desirability of a more detailed study. Materials The raw materials used were mono-carbides of titanium, zirconium, vanadium, columbium and tantalum and were the purest which could readily be obtained commercially. Spectrographic qualitative analysis showed that the CbC and TaC contained less than 1 pct

Jan 1, 1950

By K. F. G. Hosking

I read Professor Gaudin's paper with great interest and pleasure because for some time I have held that the chemical aspect of comminution is a subject of considerable importance to the mineral dresser and deserves to be thoroughly investigated. It does seem appropriate, however, to emphasize the fact that "fresh" edges and corners produced by the grinding of solids display enhanced reactivity has been recognized and utilized in the development of certain mineral identification techniques. Some of these techniques are worth noting, not only because they might facilitate research in the aspect of mineral dressing under discussion, but also because they emphasize the fact that many mineral species commonly regarded as being very inert can display a surprising reactivity when in the freshly ground state. In 1951 Isakov published a number of tests for the components of certain mineral species which depend essentially on grinding in a mortar a mixture of the material under investigation with a solid reagent. Thus when stibnite, 4(Sb2S,), is ground with sodium or potassium hydroxide, the antimony is revealed by a momentary development of a yellow color which changes in air to orange-red. Other antimony minerals need a preliminary treatment before the test can be carried out. This consists of grinding with aluminium sulfate, ferric sulfate or potassium bisulfate, and breathing upon the resultant mixture.

Aug 1, 1956

By W. G. Cornwell, R. J. Hisshion

The development of a process for the treatment of telluride concentrates at Emperor Gold Mining Co. Vatukoula, is discussed. The concentrate is produced by flotation in cyanide solution immediately after milling. Two stages of cleaning are employed and a high-grade concentrate is produced usually containing more than 50% of the precious metal. The process developed in the first instance involved batch roasting followed by batch leaching in strong cyanide solution, recovering gold and silver only. The procedure currently employed is chemical oxidation of the tellurides using hypochlorite as the oxidant in a basic solution of a caustic soda and sodium carbonate. After oxidation the gold and silver are recovered by cyanidation. The residue is then leached with sodium sulfide and elemental tellurium precipitated with sodium sulfite.

Jan 1, 1977

By Henry M. Howe

1. The purpose of the National Research Council as organized for war purposes is twofold, to stimulate those outside its own personnel to conduct researches of importance for winning the war and to carry on such researches through its personnel to a limited extent. How this is done is explained in Section 10. "Research" is used here in a very broad sense, including, for instance, inventing and developing mechanical and physical devices. The need of this work arises from the inevitable concentration of most of the governmental war agencies on the production and transportation of war materials of the types now adopted, as distinguished from devising new kinds of instrumentalities, such as armor, guns, aircraft, and apparatus for detecting, locating, observing, signaling, transporting, and many other military purposes. But it is important that we should devise new agencies. The war came near being won by an invention, the submarine, and its course has been affected greatly by two other inventions, tanks and aircraft. In spite of our numerical superiority victory may well be snatched from us by an invention, if we allow Germany to outstrip us in inventing. Hence the importance of the Council's work in mobilizing and organizing the services of the patriotic civilian experts throughout the country, so as to bring their powers to bear on important war problems and on inventing war devices, as an adjunct to the development work of the regular governmental bodies. 2. Status of the Council.—Though President Wilson's request caused the Council to be created in 1916 by the National Academy of Sciences under its congressional charter; though his executive order of May 11, 1918, directs the heads of "Governmental departments immediately concerned" to "continue to co-operate with it in every way that may be required;" and though the Government has contributed largely to its financial support; it is not a department of the Government but an independent research body, aiming to evolve the necessary mechanism for the novel work of systematic stimulation and guidance of research. Thus the Government, which instigated the creation of the Council, recognizes and collaborates with it, and in part supports it. The Council acts moreover as the Department of Science and Research of the Council of National Defense.

Jan 1, 1919

By C. N. Schuette

THE producers of this liquid metal call it quicksilver, while the consumer generally refers to it as mercury. It is one of he seven metals that were known to the ancients. These seven were gold, silver, iron, copper, quicksilver, lead, and tin. Other metals were sometimes accidentally alloyed with some of these, but it was not until 1490 that antimony, for example, was discovered and identified as a separate metal. It is not surprising that quicksilver should have been known in ancient or even in prehistoric times, as globules of the native metal often occur in the outcrops of the ore. Furthermore, the first man to build a fire on an outcropping of quicksilver ore would probably have found globules of quicksilver in the cold ashes of his fire after it burned out. The inability to pick up the globules with the fingers would excite interest and an attempt to gather it in shells or gourds to be exhibited and traded. The ore of quicksilver is the red sulfide, cinnabar, which has been mined and used as the pigment vermilion since before the beginning of written history. In recorded history, quicksilver is first mentioned in documents by Aristotle, 384-322 B.C. Theophrastus, in 315 B.C., credited the Athenian, Callias, with the invention of methods to beneficiate cinnabar in 415 B.C. In China also there are records antedating Christ which mention both vermilion paint and the fluid metal. From these early records, it seems certain that not only was cinnabar used as a pigment in those days but also that the metal was reduced from the ore and was used for amalgamation, for gilding, and for medicinal purposes. Quicksilver mining and metal-

Jan 1, 1953

By Will Mitchell

There are in this country some 20 or 30 societies for engineers and engineering scientists. Most of these organizations are autonomous, and there is little or no cooperation among them. Many do not touch the lives of our Institute members. However, during the course of the years several societies closely associated with the AIME have banded together to handle specific situations where cooperation was necessary. It is believed by many engineers that the functions of these cooperative societies should be analyzed and a plan set up to unify the engineering profession into an organization similar to the American Medical Association and the American Bar Association. The preliminary study of the AIME Committee for Inter-Engineering Society Cooperation has indicated that the following organizations bear upon the professional lives of our members. Some of these are federated groups, such as EJC and ECPD; others are individual-member participation groups, such as the Founder Societies and NSPE.

Jan 10, 1960

By M. A. Hunter

THIS paper gives the results of an investigation of the specific resistance and temperature coefficient of the electrical resistance of nickel and its important alloy, monel metal. For most of the pure metals, the temperature coefficient of resistance is approximately 0.0004 per degree centigrade at 2.0° C. Nickel and iron, however, are exceptions. This property is important as it gives us good material for the construction of thermometers and other instruments involving electrical control. A summary of information on this subject has been published by the Bureau of Standards.1 The present experiments antedate this publication by several years and as the information obtained is not contained in it, the results of the experiments are published as additional information. ELECTRICAL PROPERTIES OF PURE NICKEL It is generally conceded that the lowest values for electrical resistance are obtained in the purest metal. In the case of nickel, the best material obtainable is electrolytic nickel, which contains approximately. 99.80 per cent. nickel, 0.15 per cent. iron, and 0.05 per cent. copper. Any cobalt that may be present is included in the nickel figure. If the electrolytic sheet has been deposited without intermission, it is possible to cut a section from the sheet and roll it into wire without melting. By this means a nickel wire may be obtained that is uncontaminated by any of the impurities always taken up by nickel during melting.

Jan 5, 1922

By R. B. Ladoo, C. A. Stokes, R. N. Secord, A. L. Hall

INDUSTRIAL mineral history shows that the entrance of new, nonmetallic minerals into commercial production can be expected to occur from time to time. Latest entrant into the field is wollastonite. Except for one short-lived period in Kern County, Calif., starting in 1933, wollastonite has never before been produced on a commercial scale. But the signs are up for its entrance as an economic factor in the mineral market. Small scale experimental production from a deposit near Willsboro, N. Y., started about 1943. A pilot plant was built in 1949-50 and irregular, small scale, production has continued. In early 1951 Godfrey L. Cabot, Inc. of Boston, world's largest producer of carbon black, took an operational lease on the property to study the deposits and make market surveys. This became Cabot's first venture in the mineral field, when they took over operations and began design of a new mill, expected in production in 1953. Properties The properties and major uses of wollastonite are comparable to New York fibrous talc. It has about the same specific gravity and index of refraction as talc, but is somewhat whiter and softer. The two most important fields of use, paint and ceramics, are the same as for talc. Ground wollastonite has a fiber length as much as 13 to 15 times the diameter. This particular property makes it applicable in the paint field and others. In addition, the length-diameter ratio may be controlled to rather narrow limits by choice of grinding method. Another important commercial property is brightness or whiteness. Wollastonite reads from 92 to 96 pct of MgO on the G.E. brightness meter for a 99 pct -325 mesh grind. Purity and uniformity of product are important. Chemically, the wollastonite now being mined analyzes SiO2 51.76, CaO 47.56, FeO 0.46, MnO 0.04, and H2O 0.09 pct. Theoretically pure wollastonite analyzes SiO2 51.75 and CaO 48.25 pct. This analysis indicates over 98 pct calcium silicate, with only small amounts of contaminating ingredients. That these ingredients are not detrimental to color or brightness is shown by the high brightness value of the fine ground material. [ ] By-product calcium silicate from electric furnace production of phosphoric acid has little physical re-semblance. to this wollastonite, being an off color white, and lacking in fibrous crystalline character. Minerology Wollastonite is a calcium metasilicate, CaSiO3, a white, medium hard, fibrous mineral. In this deposit wollastonite occurs as well crystallized aggregates of bladed crystals intergrown with garnet, and with a few percent of green diopside. The beneficiated product is about 75 pct wollastonite, 15 pct garnet, and 10 pct waste, largely middling. Wollastonite-garnet ore occurs in at least two beds. The main bed, varying in true thickness from 30 to 70 ft, dips into the hill at an average 30° and is enclosed in gneisses. Diamond drilling has proven the orebody to an average depth of 200 ft along 2000 ft of outcrop with adequate tonnage for many years of quarry operation. The wollastonite-garnet ratio varies locally, but average composition is uniform over long distances. A friable ore, it is easy to drill, shoot, and crush. Beneficiation Unlike talc this ore has to be beneficiated. Successful treatment depends upon the fact that it contains virtually nothing but wollastonite, garnet and a minor percentage of diopside. A very pure wollastonite product can be made by high intensity magnetic and/or gravity separation methods.

Jan 1, 1952

By R. W. Vander Laan

Conneaut has a long and illustrious history as a major Great Lakes port for coal and iron ore. The first dock was built in 1892 for unloading iron ore from the Mesabi Range for shipment to the Pittsburgh steel mills via the Shenango & Lake Erie Railroad, later to become the Bessemer & Lake Erie Railroad. The Pittsburgh & Conneaut Dock Company was incorporated in 1893. The world's first Hulett automatic ore unloader was constructed at Conneaut in 1899. Steam operated, it was the model for the giant electric Huletts used today, named after its inventor, George Hulett, who was a Conneaut resident.

Jan 3, 1974

CHARLES F. WILLIS,* Bisbee, Ariz. (written discussion ?).-There are few mine officials who will not say that there is, great need of vocational schools in mining communities, but the absence of success of so many of these ventures makes them wary about establishing such schools. They have neither the time nor the facilities to study the systems and to analyze the factors that have made certain schools a success and others a failure. In the first place, it is difficult to secure the proper instructors. Educators cannot make the appeal to the workmen, because of their lack of experience, and experienced men who are capable of the appeal are not usually educators, knowing nothing about the presentation of the subject. Then, too, there is ordinarily no objective in a mine school. The workman is not reached by a school that makes him merely a more valuable man to his employer, unless he can participate in the gain. An objective, as promotion or financial gain, would appeal to the man and would make for regular attendance. Usually vocational schools are run like all others-a number of subjects at a time, continued from one day to another. This is impractical for the workman, whose mind cannot work like the mind of a school boy. The school boy is spending most of his time in school work, while the man is doing it as a side issue, and he cannot be expected to pick up tonight's lesson where last night's left off. The workman is accustomed to the idea of completing a job and doing one thing at a time; his mind is trained that way, and for this reason a school that works on the principal that each lesson is a complete job, with no reference to the previous or following lesson, will go a long way toward removing one of the things that has caused many failures. The usual vocational schools .in mining communities are either very elementary, or are run by the engineering staff and, consequently, are too advanced. There is no plan between. It is believed that there is a possibility of a halfway type, but this is a subject that is large enough for a paper by itself and is entirely, too broad to be presented as a discussion.

Jan 6, 1919

By HILLARY W.

THAT colleges and technical schools constitute a vital factor in our industrial system is being realized more and more of late years. Consequently it is desirable that there should be a constant interchange of ideas between the 'school and the industries and that there should be a more intimate contact between the student and his future employer. Business and industry demand certain proficiencies and qualifications of the student and he, in turn, sees certain rewards and advantages in the industry. . In a meeting of this kind, whose primary purpose is to promote a greater intimacy between the students and those men who are active in the mining profession, it is quite fitting that each state his demnds upon the other in order to establish a common understanding. It is probable that a student, not being conversant with actual conditions in the industry, may be unfair in what he asks of his employer. Therefore criticism, constructive or other- wise, is not only accepted, but is invited.

Jan 1, 1930

During the latter part of the Civil War an income tax was placed upon coal and the production of coal in the various collection districts during the life of this tax is shown in the tabulation that follows. The counties that include coal deposits are shown for each district. No record exists now of the production by counties, but it is calculated here on the basis of tax collected. The table, of course, does not include any territory not under the control of the northern armies, and not all of that in some cases.

Jan 1, 1942

By G. F. Huff, G. R. Bailey, J. H. Richards

An improved bomb-sampling technique for obtaining samples for oxygen analysis from liquid steel is described. Analyses of samples taken from open-hearth furnaces by the improved method show sufficient agreement with laboratory data to indicate the accuracy of the method is better than that of other existing sampling methods. THE bomb-sampling method of determining the oxygen content of a liquid-steel bath was studied by obtaining and analyzing more than 200 samples from normal open-hearth heats. Of these samples, about 60 were obtained with a bomb of conventional design;' the remainder were taken with a somewhat modified bomb designed to give greater protection against slag contamination. In the new device, the contacting faces of the cast-iron mold halves are machined so that they fit closely; the opening at the top of the bomb is covered with a thin steel cap; and the top of the bomb is further covered with a wood block held in place by heavy steel wire. After the bomb has passed through the slag layer and has entered the steel bath, the wire melts and the wood block floats to the surface. Thereafter, the steel melts through the thin cap and flows into the bomb cavity where it is deoxidized with aluminum wire. An assembled bomb, ready for sampling, is shown in Fig. 1. To standardize sampling procedure, the samples were usually taken through the center door and at the bottom of the furnace; that is, the bomb was on the bottom when the metal cap melted. After each addition to the furnace, at least 20 min elapsed before a sample was taken. The oxygen contents of all the samples were determined by using the vacuum-fusion method, two or more specimens from each sample being analyzed. The specimens were cubes of metal cut from a region in the interior of the bomb sample, as shown in Fig. 2. Drillings for carbon analysis were obtained immediately above the oxygen-analysis region. Reproducibility of Results In determining the reproducibility of the results obtained with the modified bomb, the following four factors were studied: 1—variation in the oxygen concentration of duplicate specimens taken from a single sample; 2—variation in the oxygen concentration of duplicate samples taken in quick succession: 3—effect of the amount of aluminum wire

Jan 1, 1953