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H. Van F. Furman, Denver, Colo. (communication to the Secretary): There are some statements in Dr. Carpenter's interesting paper which appear to require explanation, if not modification.

Jan 1, 1901

By W. A. Eardley

FIFTEEN years ago the world's deepest oil well penetrated the earth about 7300 ft. That depth has now been more than doubled. Why has such deep drilling become necessary and how has it become possible? Three factors have had an important bearing: (1) Depletion of shallow zones, making it necessary to search for deeper producing measures. (2) The perfection of prospecting methods, which have been success- fully used to locate favorable buried structures, many at great depth. (3) Improvement in the quality of steels used for drilling.

Jan 1, 1940

By L. Dr. Edeleanu

CRUDE petroleum is a mixture of various groups of hydrocarbons and some bodies containing oxygen or sulphur. These constituents possess properties differing considerably one from another and the proportion in which they are contained in the crude oils is also very different. Owing to this complicated composition the practical use of crude petroleum is much restricted. For example it is sometimes used as a liquid fuel. But its employment in this way is uneconomical because various valuable qualities of the individual constituents are not made use of. The rational utilization of petroleum can only be accomplished if the various groups of hydrocarbons are separated. The mixture of hydro-carbons present in the crude oil must be split up in such a way that the hydrocarbons are divided into various groups having certain predominant characteristics and uses. To accomplish such a separation is the aim of the technical refining of petroleum. ORDINARY REFINING BY DISTILLATION AND CHEMICAL TREATMENT Hitherto this has been accomplished by two processes, namely, fractional distillation and chemical treatment of the distillates obtained. Distillation Process The process of distillation consists in the separation of the constituents of petroleum into various fractions, the boiling points of which lie within certain defined limits. The fractions so separated possess certain special qualities in common, which enable them to be applied for specific purposes in practice. For example, we have the fractions known as benzene, illuminating oils, heavy oils, lubricating oils, etc.

Jan 9, 1914

By H. Evans, L. A. Hunt

In the pellet-producing industry it is sometimes claimed that "The pellets are made in the concentrator," or that "The key to good pellets is in the balling operation." However, one claim is generally agreed on: If you can put in, on, and through the indurating furnace a good green ball of Proper size and adequate strength to withstand the handling, load, dehydration, and thermal shock until it is properly heat-hardened, you will have the pellet product you desire-that is, a "competent" green ball. The strength requirements that enable a competent green ball to withstand the environment of the indurating furnace are usually less restrictive than those for transporting the green ball from its source of production to the furnace. Experience has shown that different types of material may have different balling characteristics which may impose limitations on the quality of the green ball that can easily be produced under normal conditions. Therefore, if a specific material will produce a green ball that meets the physical requirements for competency in the furnace, but not for handling or transportation, various practices must be instituted to overcome this deficiency. In other words, if a normal handling system is too rigorous for the green balls that can be produced under standard conditions, then "handling with care" should be tried.

Jan 5, 1967

By BLAllEY STEVENS

(Canal Zone Meeting, November, 1910.) I. INTRODUCTION. TEH object of this paper is to show how igneous intrusion is governed by definite mechanical laws. A distinction is made between dikes and fissures, and the various characteristics of intrusions are explained on an exact scientific basis. The modification of rock-stresses by intrusion is then considered and extensive isostress regions are recognized. Finally, a complete classification of intrusions is constructed covering all pos-sible cases. The generalizations of observed data, taken from Geikie's Textbook of Geology, conform to the laws of intrusion herein stated, and the deductions based upon these laws. No authority, however, is quoted for the type which I have named a corrugated intrusion. Its existence is a necessary deduction from the laws of intrusion, and even the entire absence of examples in technical publications cannot disprove its reality. In all probability, corrugated fissures would have remained undiscovered, but for the working of mineral veins. As intrusions of tabular form are seldom worked for commercial purposes, it has been left for theory to anticipate the discovery of corrugated dikes. In the light of these laws of intrusion and the corresponding laws of fissures,1 there seems to be a remarkable uniformity of stress-distribution in rocks at moderate depths. This renders .possible the mathematical calculation which should help us to approximate exact science in this and kindred branches of applied geology.

Jan 1, 1911

By Thomas L. Kesler

I all of the 14 million tons of kaolin produced in Georgia through 1949 had been mined from a single deposit 20 ft thick, it would represent a mined-out area of less than 1 sq mile. This measure of depletion is in such strong contrast with the large size of the area shown in Fig. 1, from which most of the output has come, that there has developed an optimistic outlook concerning future supplies of kaolin equal in grade to that already mined. Dozens of mines are widely but not evenly distributed within this area, which consists mostly of parts of Twiggs, Wilkinson, and Washington counties. There are scarcely half a dozen kaolin mines elsewhere in the state that have been appreciably productive, although the areas in which they occur may have good possibilities. Most of the efforts to find new deposits, therefore, will be confined to the area shown in Fig. 1, for it is here that the industry has established its facilities, and prospecting is encouraged by relatively numerous outcrops and opened deposits of kaolin. The Ocmulgee and Oconee rivers drain the area. They and their main tributaries have flat, swampy floodplains covered with alluvium and for the most part thickly wooded. The divides between these streams are intricately dissected by the minor tributaries, which are spring-fed in steep-walled, cirque-like heads. Gullying and under-cutting are active along the streams but are partly controlled by unusually dense vegetation. The mean altitude is about 350 ft above sea level, and locally the relief ranges up to 200 ft. The area is near the inner margin of the Coastal Plain, and is underlain by Cretaceous and Tertiary formations. Its general location is shown in black in Fig. 1. The division between the Coastal Plain and the Piedmont plateau is actually a very sinuous line, the fall line, marking the extent to which erosion has stripped the Coastal Plain sediments from the southeastward-sloping surface of the crystalline rocks of the Piedmont. Cretaceous Host Formation The kaolin deposits, which are described in the succeeding section, occur sporadically in lenslike bodies in a thick series of poorly sorted clayey sands constituting the lowermost of the Upper Cretaceous formations, the Tuscaloosa. The basis for this correlation has been reviewed by Cooke.1 The same formation has been termed the Potomac group by Ladd2 and the Middendorf formation by Smith' in reports on the kaolin deposits. In another report, Veatch4 called the formation the Tuscaloosa but correlated it with the Lower Cretaceous. The Tuscaloosa in this area consists of fine to very coarse sands, commonly cross-bedded, which contain widely different proportions of white, pink, and yellow kaolin and considerable white mica. A few of the coarser beds contain quartz grains up to 3 in. in length, with bodies of pure white kaolin of equal size that appear to have been formed by the weathering of feldspar grains in place. In the kaolin-producing area, gravel and cobbles occur mainly at the base of the formation. Fig. 2 shows the relations of the Tuscaloosa and its kaolin deposits to the adjacent formations. Its base, on the eroded surface of the crystalline rocks, dips southeastward 50 to 60 ft to the mile, according to LaMoreaux.5 The upper surface of the Tuscaloosa is also an unconformity,

Jan 1, 1952

By Russell Webster

In having maintained production for more than 40 years Arizona's Magma mine is unique in a mineral district that includes several major copper mines. Other past and present producers in this area are Miami and Inspiration at Miami, the Old Dominion in Globe, the Ray mine in Ray, and to the south the new San Manuel mine near Tucson. Magma's production of copper, silver, gold, and some zinc has come from nearly parallel east-west striking mineralized faults, one called the Main or Magma vein and the other the Koerner vein, about 1100 ft to the south. This vein system has been prospected and partially mined for some 9000 ft horizontally and 4800 ft vertically. In ascending order from the deepest exploration level, the Main vein cuts Pre-Cambrian schist, Pre-Cambrian Apache Group, Post-Devonian diabase, and Devonian, Mississippian, and Pennsylvania limestones. Until 1950 very little ore was obtained from replacement mineralization.

Jan 10, 1958

By WALTER CARROLL

Between cross currents of economic factors and international expediencies the iron and steel industry in 1948 made an outstanding contribution to the general economic picture. Were it not for an unfortunate episode during the month of April involving a temporary shortage of coal, 1948 would have been an all-time record year in output. Exceeded in no previous peacetime year, the production of iron and steel in 1948 totaled some 88,500,000 tons. That it was a worthwhile effort of no small magnitude is evidenced by the fact that in three and one half years following the war, this nation has produced as much steel as in the five years preceding the war. This figure of 88,500,000 tons is 68 per cent greater than that for 1939.

Jan 1, 1949

By William L. Batt

FROM the time the Japs overran the Far East, the United Nations faced a serious military problem in the critical shortage of many raw materials desperately needed to prose¬cute the war on two fronts. For many months this critical shortage threatened substantially to limit the gigantic effort to get shooting equipment into the hands of the fighting men on the far-flung battle lines. Now this crisis has been met. Solvency in raw materials has been achieved. Simply stated, this job of producing solvency has been done by "cutting cloth to fit the garment." This does not mean that we have all the raw materials we need. Unfortunately, a few raw materials are still short, thereby limiting the total production of certain war goods, or making these goods less effective. Where the supply of raw materials is known to be limited, however, substitutions have been made or production schedules have been geared to the amounts available, and an over-all balance has been achieved between various parts of the war-production program.

Jan 1, 1943

A. Bement, Chicago,Ill. (communication to the Secretary*):— Formerly it was the general practice of engineers to designate coal that is free from moisture and ash as " combustible," notwithstandirig that it contains oxygen and nitrogen. The origin of this practice was more particularly due to the requirements in connection with boiler-testing, which demanded a consideration of that portion of the fuel which took part in the combuition-process because results based on a unit of either moist or dry coal were not comparable, since both moisture and ash were recognized as variable quantities. Thus, a pound of " combustible " became a standard of value, and was treated as a constant before employing measurements of heating-power and calculating therefrom the percentage of efficiency. The recognition of this term " combustible " was an advance to be credited to the engineer rather than to the chemist, because the latter, not having to do with the interpretation of analyses in practice outside the laboratory, usually saw no reason for reporting results in terms other than those of the moist-coal composition. Some years ago I needed a table of fuel-composition in terms of moist, dry, moisture-free and ash-free coal, and of the combustible components. This table required the use of the word combustible in its proper sense, for the purpose of designating carbon, hydrogen, and sulphur, instead of including these three elements with oxygen and nitrogen, to which aggregate the term combustible was formerly applied. To make such a tabulation involved either the use of the inconvenient and cumbersome term, "ash- and moisture-free coal," or of some other representative term, and for this purpose I adopted the expression pure coal, which is short, simple, convenient, and technically correct. It is also harmonious, because it agrees

Jan 1, 1909

By Paul T. Benson

MOST important of the various departments of a custom smelter, so far as the financial welfare of the plant and the confidence of shippers are concerned, is that responsible for correct weights, accurate moisture sampling, and the obtaining of control samples that are strictly representative of the lot of ore from which they come. Treatment rate schedules are based on the metal content of ores received, reduced to dry weight. These rates must be low enough to keep the ship- per from taking his business else- where and still must allow the smelter a profit. Assay results, likewise, must satisfy the shipper, but if they show too high a metal content for the ore they represent, the smelter will actually lose money. It is always considered, and constant checks through umpire assays prove, that laboratory results are closely correct, so the bur- den of the plant profit and loss and the satisfaction of the shipper rest squarely upon the sampling department.

Jan 1, 1936

By Charles A. Lindberg

Mobile cranes on tires are perhaps the most important accessory in truck-haulage pits. They usually are of 20-ton capacity at short radius and with outriggers but have considerable overload capacity. Standard booms are 30 ft but have 10-ft extensions with which they are usually operated. Cranes have two engines, both originally gasoline, but 150-hp Diesel engines have been found more reliable for the propulsion motor, the 100-hp gasoline motors being retained for hoisting. Pro- visions are made for dropping the ballast counter- weight to reduce axle weights to legal limits for highway travel. The weights are carried on a regular truck or are transported on an extra trailer axle behind the crane. Tractors-Probably equalling the cranes in usefulness are the track-laying tractors which are used to prepare roads and other surfaces, to clean up at the shovel, and for dozing on stripping dumps. A new type of tractor mounted on rubber tires has been tried out on the Mesabi Range for the past year and a half. The advantage of this design is its mobility which makes it capable of taking care of the spill at the shovel and then running to the dump to clean up. Alternating between these two jobs, it relieves heavy tractors that can be used to better advantage on heavier work that does not require so much traveling. This tractor can travel at speeds of 12 to 13 mph and is designed to facilitate repair of the expendable parts. Weaknesses have developed in the internal construction which have seriously marred the performance record of this unit, but when used within its capacity it is quite successful.

Jan 1, 1949

By H. B. Kinnear

THE first copper stool used under an ingot mold to receive molten steel has recently been taken out of service after it had received ingots amounting to 6012 gross tons. This stool, weighing 8330 lb. had been in continuous service for 1822 heats since its installation. From this modest beginning the use of copper for ingot-mold stools grew to 425,000 lb. in 1934, with an additional 50,000 lb. of copper used in the form of inserts in cast-iron stools. During 1935 the quantity of copper used for stools increased by about 350,000 lb., making a total of 775,000 lb. now in use for that purpose. Copper used for inserts has increased during this time 180,000 lb., or over 350 per cent, to a total of 230,000 lb. The total of copper, therefore, in use at present under ingot molds is slightly over 1.000,000 lb.

Jan 1, 1936

By T. A. Read, H. K. Birnbaum

Deformation of AuCd alloys having the 8 (orthorhombic) and (3" (tetragonal) structures occurs by the stress induced motion of twin boutdaries. A restoring force acts on displaced twin boutdaries as a result of internal energy increases in the volume through which the boundaries are displaced. The phenomonology of the twin boundary motion is described and a mechanism for twin boundary motion and the restoring force is proposed. A time-dependent stabilization behavior of the twin boundaries, which is observed after the twins are formed by the diffusionless phase transformations, is described. THE AuCd 8 phase (ordered bcc structure) exhibits a transformation to a phase having an orthorhombic structure, 8' (space group D'), for compositions in the vicinity of 47.5 at. pct Cd and to a phase having a tetragonal structure, 8" (point group 4/m, m,m), for compositions in the vicinity 50.0 at. pct Cd. Both transformations are diffusionless, occur on cooling at 60" and 30OC, respectively, and are crystallo-graphically reversible.' They are accompanied by an inhomogeneous deformation which was observed to be twinning in the low-temperature phase. 3'4 The transformations may occur by a "single interface" or by "multiple interfaces."5'6 In the "single interface" transformation, the twinned product phase consisted of two twin orientations as shown in Fig. 1. In the multiple interface transformation the product phase contained "domains" each of which contained two twin orientations, Fig. 2. Deformation of specimens containing transformation twins was achieved by motion of the twin boundaries. Releasing the applied stress resulted in the displaced twin boundaries returning towards their initial positions. This "pseudo-elastic" behavior of the boundaries varied with time after the formation of the twin boundaries by the transformation.

Jan 1, 1961

By FRED T. WILLIANS

INTRODUCTION. THE Park City mining-district is distinctively a camp of few properties, 5,000 acres, or one-third of the entire district, being under the management of but three companies. As a rule, the ore-bodies lie deep, with no outcrop, except where erosion has formed the deeper canyons and gulches. Ontario canyon exposed the famous Ontario ledge, and Woodside gulch showed the first ore of the Silver King Coalition mine. The Quincy ore-bodies were first brought to light in upper Empire canyon, and Thaynes canyon was instrumental in aiding the prospector during the early days of the camp. There are 22 shafts which have reached a depth of at least 500 ft., ten a depth of 1,000 ft., five a depth of 1,300 ft., and two a depth of 2,000 ft. The amount of lateral development has been proportionally extensive, including six long tunnels, four of which are in 3 miles, with a fifth now being driven. The Ontario lower drain-tunnel is now more than 4 miles long. The formations are sedimentary, dipping about 30° NW. and N., and traversed by many fissures, dikes, and faults. The principal ore-bodies are found associated either with the contact of the basal Ontario quartzite and the overlying limes, or on a quartzite stratum within the limes, or in the fissures, or along some of the porphyry dikes. The district covers the intersection of the Uintah and Wasatch ranges, which explains the existence of large folds and faults, and fissures of great length, width, and depth. In a general way, the geology of the district consists of a basal quartzite dome, which has been exposed by erosion at the Ontario property. The Ontario fissure lies entirely within this formation. Flanking this dome on the west, north, and east lie

Jun 1, 1911

By Charles E. Hughes

HERBERT HOOVER had to sit through an hour and a half of eulogy of himself at Carnegie Hall last night, said the Sun and New York Herald of Feb. 19. When his turn to answer came he remarked that, although one of the speakers had referred to him as a modest man, he would never, in view of this experience, be able to prove it. The occasion was the presentation by the Civic Forum to Mr. Hoover of its medal of honor for distinguished service, the only recipients in past years having been General Goethals, Thomas A. Edison, and Alexander Graham Bell. Only by distortion of intent could there be said to be anything political in the affair, which was carefully described by the chairman, Charles E. Hughes, as non-partisan. Nevertheless, the praise bestowed on the former Food Administrator by the former Republican candidate for President, proved specially interesting to a much applauding audience which filled the hall to the uppermost gallery. A piece of real news was supplied by Horace V. Winchell, whom Mr. Hoover succeeded on Tuesday as President of the American Institute of Mining and Metallurgical Engineers. He said that Mr. Hoover, when in Europe after the . armistice, caused to be collected the literature of the war in all Europe.

Jan 1, 1920

By Reichmuth, Donald R.

Most brittle solids are relatively weak in tension and this weakness can be very significant in determining their performance in structures and excavations. Consequently, accurate knowledge of the tensile strength of brittle materials has long been recognized as important. In the past, measurements of the tensile strength of materials such as concrete, ceramics, and particularly rock have been hindered by problems encountered in fabricating test specimens and in accurately loading them. These difficulties have resulted in a scarcity of published tensile strength data. This can be readily seen in tabulations such as Wuerker's "Annotated Tables of Strength and Elastic Properties of Rocks.

Jan 1, 1968

By C. W. Hall

MINE executives, as a rule, have always been willing to adopt new ideas of operation, or to listen to proposals which might increase the effectiveness of their enterprise, more especially so if they could be shown how definite results might be attained by introducing any conception suggested. In these days of high wages, high cost of supplies, and high taxes, operators are even more inclined to accord consideration to innovations or improvements, and many go so far as to employ men to conduct special investigations and make studies for the purpose of advancing production. Where a man is brought into an organization to do work of an efficiency nature, it often creates resentment among the operative heads because of having their work directly scrutinized, or investigated, and there is a tendency, if not actually to obstruct, to fa.il to cooperate; in which case the investigator is handi-

Jan 1, 1925

Jan 1, 1920

By M. J. Coolbaugh

Mining of potash more than 3000 ft beneath the water-bearing sediments in Saskatchewan presented the unique challenge of designing stable mine workings and assuring protection from overhead water in a material that was believed to flow plastically, but whose behavior as a plastic material was not sufficiently known. Under the stress conditions ordinarily encountered in mining most rocks behave as elastic materials; that is, they compress slightly under pressure, and rebound when the pressure is released. Salt and potash, however, are different. Even under the relatively low pressures encountered at shallow depths, these materials become slightly plastic and yield to stress by flowing.* The plastic properties become more pronounced at greater depth and pressure, and the question arises as to whether or not the plastic flow will be rapid enough and exert enough pressure to destroy underground structures or interrupt the mining process.

Jan 5, 1967