Search Documents

The development of coal mining in this state has been well described by Goodyear, and much data are also given in the reports of the U. S. Commissioner of Mining Statistics, and the tonnages in Table 69 are from these sources, only a few of them being estimated. [ ]

Jan 1, 1942

By J. D. Pennock

The different samples of brick examined were Grecian magnesite, American magnesite; silica brick and coke-oven tiling made in Belgium and used in retort coke-ovens. The Grecian magnesite was furnished by a New Pork party. The American magnesite and the silica brick were furnished by a manufacturing company in Pittsburgh. From these brick were made cylindrical cores, '79 inches long and 15/8 inches in diameter. At one end of each was drilled a hole about 1/4-inch in diameter and 11/4 inches long, into which the thermometer was inserted during the experiment. Conductivity.—The apparatus used for determining the conductivity, as shown in Fig. 1, is a sheetriron drum, 18 inches in diameter and 8 inches high. In the center is a little combustion-chamber with walls of split fire-brick, 39 inches square and about 6 inches high. The fire-brick, however, pass through the drum to the table on which the drum stands. The cores are placed horizontally, half-way between the top and bottom of drum and on the line of diameters at right angles. In the four walls of the combustion-chamber are cut holes just large enough to allow the cores to pass through. The cores extend

Jan 1, 1897

[Note.—The paper of Mr. W. H. Hoffman (Glen Summit, October, 1891; Trans. xx., 602), on "Practical Results in the Magnetic Concentration of Iron-ore," together with a paper by the same author (Baltimore, February, 1892; Trans. xxi., 126), on "Granulating Magnetic Iron-Ores with thesturtevant Mill atCroton Magnetic Iron-Mines, N. Y.," and also the papers Presented at this meeting,

Jan 1, 1893

ARTHUR H. STORRS, Scranton, Pa.-I would like to ask whether this same process is applicable to bituminous coal? FELLS A. VOGEL, New York, N. Y.-This Dutch process is applicable to bituminous or any other kind of coal. The Berwind Fuel Co. has had a plant in operation, in Superior, Wis., for about 2 years, using the Dutch process, and it has made a very satisfactory briquette, using Pocahontas coal. There is just one item in Mr. Frey's paper I would like to discuss; that is, the matter of cost. Mr. Frey figures a total cost of $3.35, based on the use of 7 per cent. of oil. Of course, the price of oil has advanced seriously within the last year or two, and any possible reduction in the percentage of oil required in the manufacture of briquettes is very important. I believe that Mr. Frey will agree that very good briquettes can be made with considerably less than 7 per cent. of oil; in fact, actual experience has shown that it can be clone with less than 5 per cent. The only possible effects of a low percentage of oil, particularly in anthracite briquettes, are that the briquette might not burn so freely, and that it might not be quite so hard. Briquettes made by the Lehigh Coal & Navigation Co., using 7 per cent. of binder, are extremely tough. Those briquettes have been handled in one of the local yards in Brooklyn, chuting them from railroad cars into boats and digging them out by grab buckets, and the losses average less than 2 per cent. This compares very favorably with domestic anthracite coal, with which the losses from breakage amount to between 7 and 10 per cent.

Jan 4, 1918

By David J. Mack, Chin Bea Kim

The decomposition of the Ni-Zn eutectoid at 56 wt pct Zn was studied by isothermal transformation. Its progress was followed by metallographic, hardness, and X-ray diffraction methods. Three transformation products were found: lamellar pearlite at high temperatures; an intermediate temperature structure; and martensite at the lower temperaCures. No transition structu,ves were found. THE decomposition of the Ni-Zn eutectoid at 56 wt pct Zn was stuadied as part of a long-range program of study on the eutectoid transformation in alloy systems which do not have one or more components which exhibit allotropy. Available information on the Ni-Zn eutectoid transformation is limited to that presented in connection with the determination of the phase dilagram. No systematic studies of the eutectoid were found in the literature, alkhough the microstructures of the Ni-Zn eutectoid were reported by Tamuru.3 X-ray diffraction data exist for the ß, ß1, y , and y1 phases.' EXPERIMENTAL PROCEDURE The eutectoid alloy was prepared from "A" nickel shot and Bunker Hill super-purity zinc (99.998 pct).

Jan 1, 1962

By F. Cadena

HIWASSEE Dam, now under construction by the Tennessee Valley Authority on the Hiwassee River, a tributary of the Tennessee River, will require aggregate for approximately 800,000 cu. yd. of concrete. Near the damsite deposits of natural sand or gravel are not available and graywacke, a rock that is found in abundance, suggested itself as a likely source of manufactured aggregate. Graywacke is a metamorphosed sandstone composed principally of a mixture of quartz (65 per cent), mica (25 per cent), and feldspar (10 per cent). Other minerals are present in negligible amounts. The rock varies in different parts of the quarry from very fine to a coarse grain containing particles of about 1/4 in. maximum size, although the bulk of the deposit is medium grain. Extensive tests showed that graywacke would be suitable as a source of both coarse and fine aggregates. The aggregate plant available for use at Hiwassee Dam consisted of the coarse-aggregate and sand plant used on the Norris project. The coarse-aggregate plant had also been used at Chickamauga Dam. Although most of this plant equipment is now in use at Hiwassee, the present flowsheet is not only different from that at Norris and Chickamauga but is also unique as compared to the flowsheet of the average crushed-stone aggregate plant. It is hoped that this paper will show the importance of proper arrangement of equipment if the optimum in flexibility and capacity is to be attained. FLOWSHEET Rock is loaded by 3-yd. electric shovels into 12-yd. dump trucks, which carry the rock to the primary crusher, a 42-in. Superior McCully gyratory unit set at 4 ¾ in. (Fig. 1). The primary crusher discharges directly onto a 42-in. inclined belt conveyor, which carries the product to a surge storage pile with a maximum live storage capacity of approximately 3000 tons. A concrete tunnel under this storage pile houses the feed end of a 36-in. belt conveyor (conveyor B) fed by a 36 by 66-in.

Jan 1, 1939

By Paul A. Farrar, Louis P. Stone, Harold Margolin

The Ti-Mo-0 system was investigated in the region 0 to 45 wt pet Mo and 0 to 10 wt pet 0, from 600° to 1400°C. Solidus data are also presented. Isothermal sections at 700°, 900°, 1100°, and 1300°C, and vertical sections at 1 and 28 wt pet Mo, and 1 and 10 wt pet 0 are included. STUDY of the Ti-Mo-0 system has been carried out as part of a general study of titanium phase diagrams. The binary Ti-Mo system has been investigated in whole or in part by several investigators.1-8 It was found that molybdenum and ß-tita-nium form a complete series of solid solutions and that the ß/a + ß transus is depressed to below 600°C at approximately 30 pet Mo.* The Ti-O system has been investigated partially or fully in the range 0 to 30 pet 0 by several investigators." Extensive solubility of oxygen occurs in the field. While a is

Jan 1, 1957

By Milton H. Fies

THE Alabama Power Co. operates its Gorgas mine in Walker County, Ala., immediately adjacent to its steam plant. The coal mine property consists of some 19,000 acres of fee and mineral ownership lands, and all of the production from the mine-approximately 2500 tons per day-is utilized at the company's adjoining steam plant. The company is presently considering the purchase of additional acreage adjoining its present holdings which acquisition will almost double its reserves. The coal is transported from the mine over a short railroad spur in the company's own equipment, either directly to one of the large plants at Gorgas or to a storage pile. The longest haul is about 1 1/4 miles.

Jan 12, 1950

By L. S. Pratt

In 1910 the author was engaged in a qualitative study of the radioactivity of several chemical substances and a few minerals. In the course of the work he studied the mineral allanite (obtained from granite ledges at Topsham, Maine), and found it to be appreciably radio-active. Recently the fact was brought to his attention that the radio-activity of allanite is not well known, although Hon. R. J. Strutt in 1905 published a list of radio-active minerals with their analyses, including allanite from Amherst County, Virginia.' In the work done, a standard type of electroscope was used, and the readings were made with a telescope, fitted with a scale, by means of which the rate of discharge could be readily determined. The natural "leak" of the instrument was carefully determined, and all results corrected accordingly. The method of study was as follows: The material to be tested was finely powdered, and spread over the bottom of a small, inactive pan. The electroscope was then charged, and the pan placed in position. The door of the instrument was closed, and the rate of discharge carefully determined. All results were reduced to common form to permit of comparison. It is to be noted that the materials tested were not used in strictly comparable quantities, such as if 1 g. of each had been used, but about the same quantity of powder was used (in the cases of the solid substances), so that the results are qualitatively accurate. The results obtained were the following, reduced to common form and corrected for the natural "leak" of the instrument used: Mm. in 6 Min. (on Scale) "Leak1'...................................... 1 Radium residue (in pan)....................... 720 Thorianite.................................... 62 Nernst mantle................................ 17 Uranium nitrate............................... 11 Allanite ...................................... 3

Jan 1, 1917

By G. R. Palmer

The occurrence of mercury minerals in precious metal-bearing ores has long been noted. During cyanide leaching of these gold-silver ores, some mercury forms a soluble cyanide complex, which is present in the pregnant leach solution and passes through the process operations of the cyanidation mill. As a result, mercury is found on the electrowinning cell cathodes, on the stripped carbon before It is volatilized during carbon regeneration, or in theme tailings pond. The U.S. Department of the Interior's Bureau of Mines is examining the effectiveness of two ion-exchange resins to adsorb gold and/or mercury from a cyanide leach solution. The resins, Duolite A-7 and Ionac A-305, were contacted with leach solutions containing varying concentrations of mercury, gold, and silver. The resin A-7 reached a maximum mercury loading of 0.0165 lb Hg/ft3, and A-305 reached a maximum mercury capacity of greater than 0.44 lb Hg/ft3. Adsorption of gold by both A-7 and A-305 is influenced by the presence of additional ions in the solution.

Jan 1, 1984

By Fred P. Dewey

Early last March Mr. Jerome Coldren, an old miner add prospector, undertook a prospecting tour through the western part of Kansas, and discovered a very peculiar bed of rock, which yielded a white metal on fusion with soda. Mr. W. D. Church, city chemist at Topeka, examined the metal and found it to contain nickel. This discovery created much excitement, and was at first doubted. Many samples of the material, from a range of twenty miles, were sent to the Smithsonian Institution for examination ; and in every instance a qualitative test showed the presence of nickel, although the amount appeared to vary greatly. The ore is quite different from any other nickel-ore. It consists of a quartzose conglomerate from bean-size down, with much decomposed material between the pebbles, and the whole cemented by a more or less manganiferous limonite. In the qualitative tests, the nickel appeared to vary with the manganese. In all the tests, simple treatment with HCI dissolved a great deal of AI2O3. The principal deposit is near the top of a small hill on the divide between Smoky Hill river and Butte creek. The surface-rock is the conglomerate, and, at varying distances, stains of the limonite appear and gradually increase ; so that the ore is simply the lower portion of a bed of conglomerate which has been heavily charged with the manganiferous limonite. Below the conglomerate is a layer of selenite; below this, a soft sandstone, containing well-preserved fossils, and below the sandstone, a shale. From 2 to 6 per cent. of nickel in selected samples has been reported by different chemists; but the following two analyses on large samples show the average composition of the material:

Jan 1, 1889

By R. E. Lund, D. E. Warnes

SELECTIVE sulfation of individual constituents in ores or metalliferous products has received increased attention in recent years. The fluid-bed reactor with its advantages of close control of both temperature and atmosphere promises to have ap-

Jan 1, 1958

By P. A. Beck

In the course of work on grain growth in high purity aluminum a simple optical method was developed for detecting the presence or absence of preferred orientation in annealed specimens. The specimens were prepared by grinding, polishing and "deep etching." The etching reagent used for high purity aluminum has been described.* The resulting etch pits produced selective

Jan 1, 1949

By John M. Karpinski, David S. Cahn

For many years the green and dry compressive strengths of pellets have been considered as possible criteria of pellet performance during induration. Little attention, however, has been given to standardizing the unfired pellet compressive strength test or to determining the characteristics of this test. The purpose of this study was to compare the constant deformation rate test with constant loading rate tests. In addition, the dependence of these tests on such pellet properties as size and weight was to be investigated.

Jan 7, 1969

By L. W. Casteel

St. Joseph Lead Company's Southeast Missouri mines have been successfully converted to the use of ammonium nitrate and fuel oil as a blasting agent. This is significant to the company because it means a savings of a quarter of a million dollars per year. It is significant to the mining industry because of the unusual conditions involved and the methods and materials used to overcome them. St. Joe has been mining the low grade lead deposits of southeast Missouri since 1864. This ore occurs as disseminated galena in widely scattered pockets within the Bonneterre dolomite. The daily production of 20,000 tons is obtained from several hundred small, room and pillar stopes covering an area 10 miles long and five miles wide. Distribution of explosives and other materials is a real problem. Drilling in the stopes is done with air legs, column- mounted machines or jumbos, depending on the size and location of the stope. Drill hole sizes vary from 1 3/8-in. diam down to 1 1/8-in. Each driller charges his own holes and shoots them at the end of the shift. Numerous shafts provide natural ventilation which is supplemented in isolated areas by churn drill holes equipped with blowers. Water, in most stopes, is not a serious problem, although the mines do produce about 20,000 gpm.

Jan 5, 1962

By S. J. Page

Introduction Dust from cutter machines and face drills is controlled in most mines by water. However, the large quantities of water used in metal and coal mines for dust control and suppression pose serious operational problems in water soluble ores, such as salt, trona, or gypsum. This paper reviews the strategies to suppress and collect dust on cutter machines and face drills where water usage must be restricted to very low flow rates - typically 3.78 L/min (1 gpm) or less.

Jan 1, 1985

By D. L. McDanels, J. W. Weeton, R. W. Jech

An investigation was conducted to determine the stress-strain behavior and tensile properties of metallic composites and to relate them to the properties of the base materials. Tungsten fibers in a copper matrix were chosen as the model sys-tem to investigate these properties. Room-temp-atzcre tensile and dynamic -modulus tests were used To meet the demand for improved structural materials, considerable effort is being directed toward the creation of composite materials. One such material under investigation is the fiber-reinforced composite, in which a ductile, relatively weak matrix is reinforced with high-strength fibers. Some work has been done on the reinforcement of metallic matrices with metallic fibers1"5 as well as with ceramic-whisker reinforcement. Summaries of much of this work have been published by Mach-lin7 and Baske~.' Work done at the Lewis Research Center of NASA-" has involved the making and testing of composites composed of a fiber, tungsten, and a matrix, copper, which were insoluble in each other. An equation was presented that showed the relation between the ultimate tensile strength of the composites and the strengths and relative volume percents of the components. This relation was verified experimentally for composites containing fibers extending the full length of the specimen as well as for composites reinforced with short-length or discontinuous fibers. Since the publication of the preliminary results,9'10 additional data have been obtained. This paper presents these data as well as analyses of the stress-strain behavior and the mechanics of deformation of uni-axially oriented, fiber-reinforced metallic composites, in which both components are mutually insoluble. EXPERIMENTAL PROCEDURE Composites were made with high-purity copper as the matrix and 3-, 5-, and 7-mil-diam tungsten wire as the reinforcing fiber. Some specimens were made in which the reinforcing fiber extended completely through the full length of the composite test section. The fibers were placed in ceramic to determine these properties. The composites were reinforced with either continuous or discontinuos tungsten fibers. The tensile properties and stress-strain behavior of composites reinforced with either type of reinforcement were similar, and in both cases the full strength of the fiber was utilized. tubes to insure axial orientation and infiltrated with copper at 2200°F for 1 hr. Composites were also made with short-length (3/8 in. long) 5-mil-diam tungsten fibers as discontinuous reinforcement and infiltrated under the same conditions. The reinforcing fibers in both cases were longitudinally oriented in the direction parallel to the tensile axis. Room-temperature tensile tests were conducted on the composites, stress-strain curves were obtained, and ultimate tensile strength and elongation were measured. Dynamic modulus of elasticity, based upon the resonant frequency induced in the flexural mode of vibration, was also determined for the composites and the components. A more detailed discussion of the experimental procedure employed in this investigation may be found in Ref. 11. RESULTS Room-temperature tensile tests were conducted on 3-, 5-, and 7-mil-diam tungsten wires which had been annealed for 1 hr at 2200°F and show the tensile strength of the wires to be 331,000, 327,000, and 290,000 psi, respectively. Since all the composites were infiltrated under these conditions, the strengths were considered to represent the strength of the fibers in the composites throughout this study. The average tensile strength of the annealed copper used as the matrix in this investigation was 27,800 psi. Results of room-temperature tensile tests on composites reinforced with 3-, 5-, or 7-mil-diam tungsten fibers are plotted as functions of composition in Fig. 1. These data represent previously reported datag,l0 as well as data more recently obtained. The line shown on each curve represents a prediction of tensile strength as a function of composition; the calculation of this line was explained in Refs. 9 and 10. A similar plot is presented in Fig. l(d) for composites reinforced with short-length, discontinuous 5-mil-diam tungsten fibers. Again, both the previously reported and the recent data are presented, and the line shown is identical to that shown for

Jan 1, 1965

By E. A. Ernst, N. F. Carpenter

The benefits derived from an acidizing treatment are a function of the penetration achieved by the acid before complete spending. Additional penetration may be achieved by (1) controlling acid leak-08 into formation pores in the channel faces, and (2) retarding the reaction rate of the acid. A recently developed chemical additive consists of a synthetic polymeric material which absorbs hydrochloric-acid solutions, when suspended therein, swelling up to 40 times its original volume. These swollen particles have the ability to deform and seal-08 formation pores, providing fluid-loss control. In addition, they provide a diffusion barrier between the fracture face and the acid solution, prolonging the spending time of the acid. Field applications of this new technique have shown promising results. A method of conducting acid fluid-loss tests, using carbonate cores, is believed to provide fluid-loss data that are more representative of formation conditions than the conventional filter-paper determinations. INTRODUCTION The concept of oilwell acidizing has changed since its first commercial application, 30 years ago. Originally, it was visualized that the acid penetrated thousands of tiny pores and flow channels in the matrix rock, enlarging them by dissolving the carbonate walls. The resultant permeability increase was assumed to be the responsible factor in increasing production from the well. Recent laboratory studies,' however, have shown that this does not provide the complete picture. Although this type of individual pore penetration by the acid does take place during acid "soaks", designed to overcome "skin effect" due to mud invasion in the immediate vicinity of the wellbore, many years of experience have shown that considerable pressure is required to attain any appreciable injection rate into the fine capillary pores of the rock. During most acidizing treatments, the bottom-hole pressure build-up due to the restriction of flow into the formation exceeds the "breakdown" pressure of the rock so that a fracture is induced. In most cases, such fractures open up along natural, incipient fissures and zones of weakness in the rock and, therefore, tend to follow the natural stress pattern of the rock—whether it be horizontal, vertical or inclined. Because of the comparatively greater permeability of the channel in relation to that of the matrix, the bulk of the acid volume is diverted into the newly opened fracture. Here it quickly penetrates the formation, opening and ex- tending the fracture in much the same manner as a conventional fracturing fluid. Unlike the fracturing fluid, however, most acidizing solutions contain no propping agent; thus, the open fracture will again close when the injection pressure is relieved. Laboratory studies2 have shown that in many cases the etching of the fracture faces, resulting from the reaction between the acidizing solution and the carbonate rock, is nonuniform due to the heterogeneity of the rock structure. As a result, the two fracture faces no longer match when pressure is released, and support pillars and intermediate voids remain, forming a high-conductivity channel for well fluids. Unfortunately, this is not true over the entire area of the fracture, but only over that portion of the fracture where the rock has been partially dissolved by the acid. The acid solution spends as its travels away from the wellbore; once it has completely spent, even though it may provide additional mechanical fracture extension, no additional benefit due to etching of fracture faces can be expected. Studies of acid reaction rates under formation conditions,3 observing the effect of different variables upon spending time, have shown that the reaction was often so rapid that very little penetration of the formation occurred before the acid was spent. Study was undertaken to devise methods of increasing the penetration of the acid before spending, so as to provide greater benefit from the acidizing treatment by etching a greater portion of the fracture faces. Several techniques were devised to accomplish this purpose. First, chemical additives were developed which were designed to retard the reaction rate of the acid, causing it to penetrate a greater distance from the wellbore before finally becoming spent. Another method was to increase the injection rate of the acid. However, it was found that the resultant increased shear tended to accelerate the reaction rate of the acid, partially offsetting the benefits of the higher injection rate insofar as achieving increased penetration before spending was concerned.' Another approach to the problem of achieving increased penetration was the development of fluid-loss additives for acid solutions, which would minimize the volume of acid lost into formation pores in the fracture faces and provide maximum fracture extension for the volume of acid injected during the treatment. The use of fluid-loss additives is now considered the most effective method of providing maximum fracturing-fluid efficiency.~ Unfortunately, this latter technique does not solve the problem of rapid reaction rate, with consequent limitation of the fracture area benefited by reaction with unspent acid. A newly developed acid additive overcomes many of these limitations by providing the dual benefits of fluid-loss control and mechanical retardation of acid reaction

A bibliography of the use of pulverized coal for the years 1917 and 1918 has been compiled by the Library for the Institute. It comprises three typewritten sheets. Copies may be obtained by those interested at $2 per copy.

Jan 5, 1919

By L. T. Larson, M. L. Picklesimer

The relationship between the apparent angle of rotation of monochromatic plane polarized light and the tilt of the basal pole from the surface normal has been experimentally determined for zirconium over the wavelength range of 500 to 655 mp. This relationship allows the determination of the spatial orientation of the basal pole of an individual grain in a polycvystal-ling zivrconium specimen to within ±3 deg by three simple tneasurements with a polarized-light metallurgical microscope. The method of measurement is discussed in detail. THE optical anisotropy of materials having noncubic crystal structures has long been used to reveal features by polarized-light microscopy. Petrographers have used measurements of certain optical properties to identify and classify transparent or translucent minerals. More recent work (i.e., Cameron1) has extended such measurements to opaque minerals in reflected light. Few attempts have been made to make similar measurements on noncubic metals. Couling and pearsall2 have reported that a sensitive tint plate can be used in a polarized-light metallurgical microscope to determine the position of the basal-plane trace in a grain of polycrystalline magnesium. Reed-Hill3 has reported that the same technique can be used for zirconium. We have found that the precision of measurement can be increased to about ±0.5 deg by using a Nakamura plate4,5 to determine the exact extinction position after the sensitive tint plate has been used to locate approximately the basal-plane trace. This report describes a method for measurement of another optical property, the apparent angle of rotation. This measurement permits determination of the angle between the basal pole of a grain of a hcp metal and the normal to the surface of the specimen. When the two measurements are combined, the orientation of the basal pole in space can be determined from three simple measurements on a single surface. One to two hundred such determinations will permit plotting of a basal-pole figure for the polycrystalline material with reasonable accuracy. When normally incident, monochromatic, plane-polarized light is reflected from the surface of an optically anisotropic material, the light may be converted to elliptically polarized light, the plane of vibration may be rotated, or both may occur. The el- lipticity, the angle of rotation, and the reflectivity can be related to the indices of refraction and the absorption coefficients of the material.6,7 Ellipticity values can be determined with an elliptical compensator, but not with the ease and precision desirable for the present purposes. Measurement of the angle of rotation requires only the determination of the angle from the crossed position (90 deg to the polarizer) that the analyzer must be rotated to obtain extinction when the trace of the optical axis in the surface is at 45 deg to the vibration direction of the polarizer. The angle of rotation of the analyzer is approximately 6/5 that of the true angle of rotation of the light as reflected from the specimen because there is a small amount of additional rotation produced during the passage of the reflected light through the mirror of the microscope. Since we are presently interested only in determining the tilt of the basal pole, the angle of rotation of the analyzer (the apparent angle of rotation of the light, i.e., uncorrected) can be used. Precision of the measurement can be increased substantially by the use of a Nakamura plate4,5 in determining the extinction position. In an optically uniaxial material (hcp or tetragonal crystal structure) the angle of rotation depends only on the optical properties of the material and the orientation of the optical axis of the grain relative to the plane of incidence of the plane-polarized light.7,8 Thus, in a metal such as zirconium, the apparent angle of rotation at the 45-deg position in any given wavelength of light is a direct measure of the tilt of the basal pole from the normal to the surface. If the optical properties vary with wavelength, the apparent angle of rotation for any given tilt of the basal pole will vary. None of the required information exists in the literature for zirconium nor for any other non-cubic metal. MEASUREMENTS ON SINGLE-CRYSTAL ZIRCONIUM A single-crystal sphere of zirconium 9/16 in. in diam was spark-cut from a single-crystal rod grown from iodide bar by an electron-beam zone-melting process.9 The damaged surface was removed by chemical polishing in a 45/45/10 mixture (by vol) of water, concentrated HNO3, and HF (48 pct) and then electropolishing at 50 v in a bath1' of methyl alcohol and perchloric acid (95/5 by vol) at -70-C. The single-crystal sphere was mounted in a five-axis goniometer stage having a removable eucentric X-ray diffraction goniometer head for the two inner orientation axes. The basal pole of the single-crysta sphere was aligned parallel to a third axis of the goniometer stage by using the sensitive tint method to determine the basal-plane trace at several rotational positions of the sphere. The alignment was then checked by removing the sphere and eucentric gonio-

Jan 1, 1967