bluuebunny/crossref_metadata_2025 huggingface dataset:
E‐90‐P COMPARATIVE TEST OF HAMMER MILL PULVERIZER AND DRY PAN FOR CRUSHING STREATOR SHALE1
Authors: Ogden D. P.
Published: June 2006

In the machines as described below the following points are discussed: (1) the grinding action, (2) energy consumption per ton ground, (3) capacity to produce fines six‐mesh and under, (4) to determine the operating characteristics of the hammer mill. The conclusions given are: (1) The dry pan will not grind shale chunks larger than 15 inches maximum diameter, nor chert nodules of any size. The hammer mill grinds easily in one operation all chunks small enough to go through the 20 × 42‐inch hopper opening and all chert nodules. (2) The energy consumption of the dry pan as compared to the hammer mill in kw. hrs. per ton of fines through six‐mesh is approximately as 1.40 to 1.25. (3) The maximum capacity of the Frost %foot dry pan with 1/4‐inch screen plate openings was known to be approximately 25 tons through six‐mesh per hour. The maximum capacity of the 30 × 42‐inch Williams hammer mill as reached in these tests with hand feeding was found to be 56 tons total feed and 42 tons through six‐mesh per hour. This figure could have been greatly exceeded if the material could have been fed more rapidly. The dry pan tailings coarser than six‐mesh compared to the hammer mill tailings of the same coarseness are as 40 to 25%. (4) The hammer mill is more efficient than the dry pan in practically all respects if properly set up and operated, but it is easily possible to secure less efficient results from the hammer mill, particularly if the feeding is not properly regulated.
COMPARATIVE TESTS OF SOME AMERICAN AND GERMAN FIRECLAY BRICK1
Authors: Geller R. F. , Pendergast W. L.
Published: June 2006

The Bureau of Standards has recently completed a short investigation comprising comparative tests of five brands of German‐made brick and six brands of American‐made brick. The results indicate that the Ge man‐made brick are practically the equal of the American brick.
NOTES ON GREEN SCUMMING1
Authors: Curry Earl R.
Published: June 2006

A description of a green scum formed on brick made from a California clay. Analysis showed vanadium oxide as the principal colorant. Tests of scum prevention were made by adding various compounds to the green body or by dipping the finished piece into solutions of various salts. Several promising methods of scum prevention are indicated.
SOME FACTORS INFLUENCING THE RATE OF PICKLING OF SHEET IRON1
Authors: Hansen J. E. , Lindsey G. S.
Published: June 2006

Experiments with regard to various factors entering into pickling of sheet iron show that: (1) a freshly made sulphuric acid pickling bath pickles faster than a bath in which there is any concentration of ferrous sulphate and that (2) there is no evident advantage in adding a portion of old pickling solution to a new pickling solution “to get it to work right,” although prictical experience indicates otherwise; (3) increased ferrous chloride concentration in a muriatic acid pickling bath increases the rate of pickling; (4) ferric sulphate in a sulphuric acid bath will accelerate the rate of pickling, but will soon change to ferrous sulphate and then retard the rate; (5) decrease in acidity from usual strength decreases rate of pickling; (6) increase of temperature of bath accelerates rate of pickling; (7) iron annealed just previous to pickling loses 250–4000 more in pickling than unannealed iron; (8) use of monel metal basket accelerates the rate of pickling due to electrochemical reactions; and (9) use of muriatic acid or sodium chloride in mixtures with sulphuric acid retards the rate of pickling.
METHODS OF TESTING and THE PHYSICAL PROPERTIES OF WET‐PROCESS ELECTRICAL PORCELAIN1
Authors: Navias Louis
Published: June 2006

Data are given for the compressive, transverse, and tensile strengths of wet‐process electrical porcelain.

Compressive Strength
The height of the sample is an important variable. Initial failure and ultimate failure are discussed and it is suggested that as the latter is the more definite and constant of the two, the, ultimate failure be always determined and recorded as the “compressive crushing strength.” The cylindrical specimen 1 sq. in. in area (11/8 in. diameter) and 11/8 in. high is recommended.

Transverse Strength
The load applied to cause rupture is directly proportional to the cube of the diameter of the cylinder over a wide range of diameters. A cylinder with an area of 1sq. in is suggested. Cylindrical specimens give constant and high values.

Tensile Strength
As the area of minimum cross‐section increases the tensile strength decreases rapidly. The diameter should be given with determined values. An apparatus for making tensile strength determinations on a specimen with conically shaped ends and minimum area of 1sq. in is described.

Relationship of specimen size and effective dimensions to the average general dimensions of the wale and their methods of manufacture is discussed.
HYDROGEN‐ION MEASUREMENTS ON CLAY SLIPS1
Authors: Randolph D. W. , Donnenwirth A. L.
Published: June 2006

A simple electrometric apparatus is described for determining the hydrogen‐ion concentration of clay slips. Some measurements are given to show the relation between hydrogen‐ion concentration and the properties of a clay and water mixture.
FIRING TERRA COTTA IN AN OPEN KILN1
Authors: Mathiasen O. E.
Published: June 2006

Tests on firing terra cotta in an open oil fired kiln are described. A full description is given of the special flue and combustion chamber design used in the kilns. Results of the tests were entirely satisfactory and justify further experiments along this line.
FUSION POINTS OF FIREBRICK‐COAL‐ASH MIXTURES1
Authors: Hewitt L. C.
Published: June 2006

Six types of refractory brick were tested with five types of coal ash, the cone fusion points of the brick‐ash mixtures being determined over a range of 10% brick, 90% ash, to 40 % brick, 60% ash. A departure was made from previous methods in that high ash mixtures were studied rather than high brick mixtures, in the belief that boiler slags contain a relatively low proportion of the refractory. Sintered mixtures of refractory and ash tend to give higher fusion points than the raw mixtures do. Any determinations made in an uncontrolled atmosphere are exceedingly unreliable. The results obtained in this investigation indicate that the “cone‐slag test” is of very limited value as a means of selecting refractories for boiler service.
SOME SOURCES OF AIR IN CLAY COLUMNS1
Authors: Galpin S. L.
Published: June 2006

Absorbed gases are of considerable importance as sources of air in clay column. A few measurements are reported, and inferences drawn thereon.
THE THEORY OF CLEANING OF SHEET IRON AND STEEL FOR ENAMELING PURPOSES1
Authors: Staley Homer F.
Published: June 2006

Cleaning may be done by sand blasting heating, use of solvents, or use of alkaline solutions. Of these methods, heating and use of alkaline solutions are important at present. In cleaning by heating the best results are obtained when the articles are first dipped in a solution of acid, heated uniformly to the lowest temperature that will cause the oils and greases to be burned off, and cooled slowly, both heating and cooling being done with the admission of as little air as possible.

In cleaning by the use of alkaline solutions, saponifiable oils are removed by the formation of soaps and the subsequent solution of these; non‐saponifiable oils are removed by emulsification. Efficient cleaning depends primarily on the choice of cutting and drawing oils so as to have present a proper ratio of saponifiable and non‐saponifiable oils. The cleaning solution must vary in composition according to the kinds and amounts of oils to be removed.
A SIMPLE “SEALED‐IN MERCURY ELECTRODE” APPARATUS FOR TESTING THE BREAKDOWN VOLTAGE OF HEAVY INSULATING MATERIALS1
Authors: Navias Louts
Published: June 2006

A method has been developed whereby thick plates of insulating materials (of small area) may be electrically punctured under oil. The specimen is cemented between two hollow electrode holders by means of red sealing wax, as illustrated. One electrode holder, the elbow, may be made of ordinary cast‐iron piping or glass. Mercury poured into both tubes gives the necessary contact. It is possible by these means to puncture a porcelain cylinder of diameter 1 ⅛ inches and 1 ⅛ inches thick at 142 kv., and with a porcelain cylinder 2 inches in diameter and 2 inches thick to reach 176 kv. without arcing. The “sealed‐in mercury electrode” method has been compared with two other methods employing spheres and disks as electrodes, by puncturing cast polished plate glass specimens. The new method gives consistent results, the values being on the average 15 % higher than values obtained by the other two methods.
SOME SUCCESSFUL CONE 10 SAGGER BODIES1
Authors: Fritz E. H.
Published: June 2006

The various steps taken in the improvement of a cone 10 sagger body are described, which resulted in the development of several successful bodies giving a life as high as eighteen firings. Based on these results, a theory is advanced specifying limits for dry modulus, cone 10 absorption, and total shrinkage of the body, which if met regardless of clays used, will produce results such as were here obtained. Verification of this theory by others is requested.
THE THEORY OF PICKLING OF SHEET IRON AND STEEL FOR ENAMELING PURPOSES1
Authors: Staley Homer F.
Published: June 2006

The fundamental principal of efficient pickling is that efficient pickling does not depend on the solution of a large amount of metal but on the solution of a very thin layer of metal directly beneath the scale, rapidly and with copious evolution of hydrogen. The activity of an acid solution depends on the amount of acid present, the fraction of the acid that is ionized, and on the speed with which the ions move. Since the electrical conductivity of an acid solution is a measure of both the hydrogen‐ion concentration and the speed at which the ions move, the electrical conductivities of a series of acid solutions indicate the relative activities of the various solutions. The most effective concentrations of acid lie between 15 and 20%. Heating acid solutions reduces their viscosity and renders the particles more mobile, thus increasing the activity of the solutions. Sulphuric acid is cheaper in first coat than hydrochloric acid, but the latter acts more rapidly and the pickling is completed with less solution of iron. Additions of small amounts of common salt (sodium chloride) have a marked effect on increasing the rate of pickling of sulphuric acid baths. This is due to the formation of a corresponding amount of hydrochloric acid. The chief action of addition agents is to reduce the amount of acid vapor in the fumes from pickling vats and thus permit the use of highly efficient concentrations of acid (between 15 and 20%). Hydrogen absorbed by metals during pickling may be largely removed by immersing the metal in boiling hot water for a few minutes.
GAS‐FIRED ENAMELING FURNACES FOR CAST‐IRON1
Authors: Read Henry L.
Published: June 2006

A comparison is made of gas fired and electrically heated glass, enamel ovens. Description of equipment, data on output fuel costs, and upkeep are given.
DEFECTS IN ENAMEL DUE TO CAST IRON
Authors: Malinovszky A.
Published: June 2006

Microphotographic examination of iron on which enamel has pinholed, blistered, and come perfect are cited as evidence that carbon is practically the only agent in cast iron causing blistering and pinholing and that it is the condition and not the presence of carbon that causes these defects.
SEVERAL GAS EXPANSION POROSIMETERS1
Authors: MacGre A. Ernest
Published: June 2006

A relatively inexpensive and simple brick porosimeter and its operation is described. A convenient indirect and a direct reading porosimeter for small test pieces is described. The direct reading porosimeter reduces calculations to the minimum.
ON THE DETERMINATION OF THE CONSTITUTION OF GLASSES1
Authors: Tadata Kozo
Published: June 2006

This method of determination of the constituents of glasses is entirely new in its way. It is derived from the author's experiments on the causes of the surface devitrify‐cation of glasses.

It is quite natural to produce crystals in glasses when heated several times at high temperatures. The glasses are super cooled liquids and are very viscous at low temperatures. But, when they are heated at higher temperatures, they attain low viscosities to produce crystals in them. In general, the chemical composition of the crystals produced (primary phase) in ordinary glasses without B2O2 is SiO2. And for production of an elementary body of crystals of silica, there should be at least three neighboring molecules of silica moving within some ranges of speed. The motion of such molecules in glasses is set by two causes: the one is that quantity of energy given to the molecules by heating, and the other is that lowering of viscosity of the medium by heating. Heating glasses to certain temperatures is the exclusive cause of the crystal production of glasses.

This has been already explained by many persons and no ambiguity has been left unsolved.

The author has given another important cause for crystal production on glass surfaces and has described the interpretation.3

From these views, the author has arbitrarily defined devitrify‐cation in five degrees. They are seen in accompanying photographs. It has been determined that these degrees of devitrify‐cation were entirely coincident with the quantities of dissolved silica in glasses.

The experiments have been conducted for a series of glasses of alkali silicates and alkali lead silicates.

From the results of these experiments, the author has determined the constitutions of those silicates in glasses to be meta‐disilicates and the double compounds to consist of those meta‐disilicates.

As the result of the determination of the constituents of alkali silicates and of alkali lead silicate glasses, it is pointed out that the compositions of crucibles to melt glasses of different silica content, should be either rich Al2O3: or rich SiO2 according to the dissolving power of glasses for silica.
SOURCES OF ERROR IN GLASS VOLUMETRIC APPARATUS1
Authors: Renn H. V. E. M.
Published: June 2006

The most serious source of error is the original calibrating operation. Errors introduced are due principally to following causes: (a) volumetric inaccuracy, (b) variation of bore, (c) delivery time, (d) incorrect marking of the meniscus, (e) after‐working of the glass. Elimination of errors due to these causes is discussed. An apparatus for the calibration of volumetric apparatus is described. A source of error that is not usually recognized is the occurence of after‐changes in the glass during a period immediately following manufacture. The length of this period varies with the composition of the glass. Experiments by the writer upon glass volumetric apparatus show that a period of seven months is usually sufficient in order to avoid excessive error from this source.
MONOGRAPH AND BIBLIOGRAPHY ON TERRA COTTA1
Authors: Wilson By Hewitt
Published: June 2006

Abstract

Introduction

Beginnings and progress.

Advantages.

Location of plants.

Development of terra cotta surfaces.

Classification.

Terra Cotta Body

Body requisites.

Body mixture.

Terra cotta clays.

Grog and non‐plastics.

Soluble salts and the addition of barium compounds.

Methods of mining, handling and mixing clays.

Green spots.

Tempering methods.

Aging.

Drafting and Plaster Work

Drafting

Modeling and mold making.

Ashlars.

Profiles.

Old molds.

Checking the warethrough the shop.

Pressing and Finishing

Pressing.

Powermethods.

Hand pressing.

Absorption of water by mold.

Finishing.

With steel.

With water brush.

Drying

Preliminary drying.

Final drying.

Humidity drying.

Slips, Glazes and Spraying

Storage, mixing and identification of raw materials.

Preparation of slips and glazes.

Specific gravity control.

Viscosity control.

Spraying.

Handling ware during spraying.

Spraying technique.

Underslips.

V. Glazes.

High temperature. Gloss and mats.

Low temperature.

Glaze fit and defects. Staley's coefficient of expansion factors.

Vitrifiedslips.

Color Work

Common colors.

White.

Cream.

Gray.

Tan and brown.

Polychrome colors.

Blue.

Green.

Pink.

Black.

Low heat overglaze.

Granite Finishes.

Pulsichrome applications.

Polychrome decoration.

Painting.

Spraying with masks.

High temperature overglaze.

Painting soluble metallic salts.

Kilns and Firing.

Kiln construction.

Flue arrangement.

Fire boxes.

Setting.

Firing.

Cooling and dunting.

Composition and dunting.

Pacific Northwest Clayworkers' Kiln Data.

Fitting Department

Terra Cotta in the Wall

Elasticity.

Thermal coefficient of expansion.

Thermal conductivity.

Porosity and absorption.

Crystallization of water and salts.

Strength of body.

Variations of strength when wet and dry.

Concentration of loads.

Jointing.

Concrete.
INFLUENCE OF Fe2O3 AND ON PURE CLAYS1
Authors: Kuechler Adloph Harmon
Published: June 2006

Abstract

In this thesis, the effect of small additions of TiO2 and Fe2O3on the fusion temperature of kaolin and fire clay is investigated.
PRACTICAL CONSIDERATIONS REGARDING ENAMELING FURNACES1
Authors: Darrah By W. A.
Published: June 2006

Abstract

This paper discusses certain practical requirements which appear essential to securing best commercial results from enameling furnaces. An attempt is made to point out the means by which enameling may be developed into an industry in contrast to an art Various types of enameling furnaces are described and their advantages and limitations pointed out. The action of enamels in the furnace is discussed. The relative advantages of various commercial fuels arc considered.
DYNAMIC SYMMETRY2
Authors: Gucle Marie
Published: June 2006

Abstract

A discussion with examples of the ratios in dynamic designing of ceramic ware.
MODERN CERAMICS OF ART1
Authors: Bergmans Carl
Published: June 2006

Abstract

A brief survey of American ceramic art and a plea for ceramic art training complementing courses in ceramic engineering.
THE USE OF OVERGLAZES FOR POLYCHROME TERRA COTTA1
Authors: Bennett A. Lee
Published: June 2006

The flexibility and economy of single‐fire overglazes as compared with other polychrome methods are emphasized. Insoluble materials are preferable. A base white overglaze formula and its preparation and application are given. These single‐fire overglazes have been used commercially with excellent results.
DE‐AIRING AS CORRECTIVE IN DRYING1
Authors: Brand Fred
Published: June 2006

The physics of mechanical removal of water from clay involves character of pores, adsorption capillarity and it also involves air filled cavities. Theory of clay particle system when plastic is set forth and argument is made for the effect of air on water removal and on drying shrinkage.
A METHOD FOR THE DETERMINATION OF THE RELATIVE SURFACE AREAS OF POWDERED MATERIALS1
Authors: Koealer W. A.
Published: June 2006

The ratios of the surfaces of powders of different degrees of fineness are obtained by determining the relative amounts of a radioactive substance, ThB, adsorbed on the surfaces of the powders. The ThB is dissolved in an ammonical solution of water or alcohol, and equal‐weight samples of the various powders are placed in equal volumes of this radioactive solution. After adsorption equilibrium is complete, 10 cc. of the clear supernatant liquid of each sample are evaporated to dryness on watch glasses, and the relative radioactivities of the deposits are measured in an electroscope. Since, for a given concentration of radio‐active solution, the degree of adsorption is not a straight‐line function of the surface exposed, an adsorption curve must be determined for each material studied.
THE USE OF GEORGIA AND NORTH CAROLINA KAOLINS IN A SEMIPORCELAIN BODY
Authors: Hemsteger S. E. , Stief W. C.
Published: June 2006

Tables are given, comparing properties and analyses of Georgia and North Carolina kaolins and two English china clays. These two domestic clays are found to be very adaptable to this type of body. North Carolina kaolin reduced warping of ware in the glost kiln, but made the body less plastic. Georgia kaolin enabled a higher flint content to be used, also imparted greater dry strength to the body. Since using these domestic kaolins, crazing has been reduced.
REQUIREMENTS OF REFRACTORIES FOR MANUFACTURED GAS PLANTS1
Authors: Cole Sandford S.
Published: June 2006

The requirements of the refractories used in gas producers, water gas sets, horizontal retorts, vertical retorts, and gas and coke ovens are discussed with respect to the specifications which the material must necessarily meet to prevent failure of the installations. Illustrations show various types of installations and details of certain refractory shapes employed. The temperatures encountered in various portions of the carbonizing chambers, flues, and regenerators give a fair idea as to the duty which the fire brick must meet in operation.
A CHROMIUM RED GLAZE1
Authors: Binns Charles F. , Craig Eleanor
Published: June 2006

An attempt to make use of the red color of basic lead chromate in a glaze maturing about cone 08.
A PRELIMINARY STUDY OF THE RESISTANCE TO ABRASION OF CERAMIC GLAZES, ITS CONTROL AND METHODS OF DETERMINATION1
Authors: Harrison A. C.
Published: June 2006

Two test methods, one using an Ingersoll glarimeter to obtain results of a high degree of accuracy, and the other simpler “alternate method” for plant control, are described in detail. Tests on commercial hotel chinaware showed the average resistance of foreign ware was higher than that of the domestic and the variation from the average was, in general, less. Experimental glazes were prepared to study the effect on resistance, of: (1) varying SiO2 and Al2O3 content, (2) glaze thickness, and (3) firing treatment. Data obtained are insufficient to justify definite conclusions regarding the effect of varying SiO2 and Al2O3, but do show the resistance of well‐matured glazes to be inversely proportional to thickness, a decrease in resistance as the tendency to matt increases, a markedly increased resistance by the higher glost fire. That type of body affects resistance less than do glaze composition and temperature of glost fire.
A LABORATORY APPARATUS FOR THE REFINING OF PACIFIC NORTHWEST KAOLIN1
Authors: Clark Roland Joseph
Published: June 2006

A review of the clay purification methods which are used at the present time is given, together with a description of a simple laboratory continuous clay‐washing plant composed of a screw feed, a rotary blunger, sand separator, cone‐bowl classifier, and settling tanks. The methods of operation with a sample of Pacific Northwest kaolin and the results obtained are described.
THE PROPERTIES OF REFRACTORIES IN THE METALLURGY OF ZINC1
Authors: Wheelers E. S. , Kuechler A. H.
Published: June 2006

A study has been made of some of the properties of clays, grogs, and body mixtures used by various zinc smelters for the manufacture of zinc retorts. Only minor differences were observed in the properties of the clays. No attempt has been made to offer any of the results as conclusions. The investigation tends to confirm the following points; that the use of reclaimed retort material in the grog for new retorts is of doubtful economy; that, if old bricks or shapes are used as grog, care should be taken that they were originally made of good quality clay and that they are free from slag; that some flint clay of good quality and properly calcined is advisable for at least a part of the grog; and that zinc in a clay or body mixture markedly affects the refractoriness by lowering the deformation value.
THE BEHAVIOR OF FELDSPAR AND FLINT WITH ACIDS AND BASES1
Authors: Screture E. W.
Published: June 2006

On addition of acids and bases to fine‐ground feldspar or flint, the same phenomena are observed as with clays, Le., flocculation, deflocculation, and absorption. The effects are less sharp than with clays, the zone of deflocculation covering a wider range of PH and flocculation occurring at lower pH (greater acidity). The sensitiveness of flint and feldspar to reagents increases with fineness of grinding.
A METHOD FOR MEASURING THE SOFTENING TEMPERATURE OF GLASSES1
Authors: Littlcton J. T.
Published: June 2006

For the purpose of measurement the softening point of glasses is defined as that temperature at which a uniform thread of glass .65 mm to 1 mm in diameter suspended in a vertical position in an electric furnace of specified characteristic will elongate at the rate of 1 mm per minute. The measurements on a given glass are reproducible to within 1 to 2°C. This method has been found useful as control of glass composition in melting units as well as a point of reference to distinguish between different glasses. Data are given showing the variation in softening point of a tank glass and a pot glass over an interval of time.
LOW FIRE GLAZES USING RUTILE1
Authors: French Myrtle M. , Harder Chas. M.
Published: June 2006

A very fusible glaze containing rutile was fired at cones varying from 010 to 03. The fusibility was adjusted by introducing feldspar, and various colorants were added to control the color. The results were very interesting and varied—especially for a modeled or incised pattern.
THE ECONOMIC LIFE OF MOLDS1
Authors: Sample W. L.
Published: June 2006

The economy of long service from solid cast molds is gradually offset by the loss due to excess thickness of the cast piece. An example of this is discussed, substantiated with figures.
STANDARDIZATION AND PLANT CONTROL AS APPLIED TO BODY MAKING1
Authors: Riddle Frank H. , Twells Robert
Published: June 2006

The variable nature of the raw materials and the intricate methods involved in manufacture make it difficult to secure uniformity in ceramic ware. The elimination of variable factors is helped by adherence to the following rules: (1) Careful analysis of each operation. (2) Development of written standards for each operation, describing the methods and conditions found best. (3) Enforcement of the standards by careful inspection, using accurate tests after each operation to measure the results just obtained. (4) Division of the body as it is made, into homogeneous units or batches, which remain separate through the rest of the production operations. (5) Complete records readily available covering each step through which a batch passes in production. (6) Strict adherence to standard procedure even though tempted by expediency to somewhat let down the bars. The application of the above principles to body‐making at the Champion Porcelain Company is described.
THE EFFECT OF STEAM ON THE TRANSVERSE STRENGTH OF FIRECLAY BRICKS1
Authors: Parmelee C. W. , Westmans A. E. R.
Published: June 2006

In connection with an investigation of checker brick for carbureters of water‐gas machines, it was considered desirable to find out whether or not fireclay brick suffered an appreciable decrease in transverse strength when exposed to the action of steam at a high temperature. Except for occasional references to the “destructive action” of steam, no information on this score was found in the literature. This paper describes experiments in which standard straight bricks at 11,00°C were subjected to the action of steam at the same temperature and the resulting change in transverse strength measured. No significant decrease in strength due to the action of steam alone was found.
THE USE OF SUPER‐REFRACTORIES AS CHECKER BRICK IN GAS MANUFACTURE1
Authors: Knollman H. J.
Published: June 2006

During the past year, Carbofrax and Diamel brick, each having distinctly different but superior, heat‐transfer properties as compared with fire brick, were tried out as part of the regular checker brick in a full‐sized standard single‐shell oil‐gas generator, which was operated under normal conditions. It was hoped that increased gas‐generating capacity would be obtained by their use, but such was not the case, chiefly because of the influence of other factors having as much bearing on generator capacity as the checker brick.

The chief limiting factors were (1) the remoteness of a large portion of the checker brick from the combustion chamber and therefore from the source of heat supply; (2) uneven heat distribution in the generator; and (3) the formation of heavy cokelike carbon deposits on a portion of the checker brick. With the development of improvements in the generators and the correction of some of these difficulties, there appear to be excellent possibilities in the use of brick of superior heat‐transfer properties in promoting operating efficiencies and in increasing gas production.
SOLUTION OF FUSED ALUMINOUS MATERIALS1
Authors: Ellison R. W.
Published: June 2006

A modification and combination of two fusion methods used in the decomposition and dissolving of fused aluminous materials preliminary to analysis is presented as giving none of the troubles encountered with either of the separate fusions.
HYDROGEN‐ION CONCENTRATION AND ELECTRICAL CONDUCTIVITY OF CLAY SLIPS1
Authors: Fessler A. H. , Kraner Hobart M.
Published: June 2006

The apparatus and method of determining the H‐ion concentration and electrical conductivity of clay slips are described. Measurements were obtained on daily samples of tap water, casting and plastic slips, car shipments of clays, and individual blungers of slips in an endeavor to find whether any variations that might occur in the plant processes could be traced to variations in the slips indicated by these measurements. In a following paper values will be given showing the effect of temperature, time and vigor of stirring, specific gravity and concentration of various salts such as NaCI, Na2SO3, MgSO4 and AlCl3 on the H‐ion concentration, viscosity, and electrical conductivity of slips.
THE EFFECT OF MILL PRACTICE ON THE WORKING PROPERTIES AND FINISH OF VITREOUS ENAMELS
Authors: Hansen J. E.
Published: June 2006

Variations in mill or grinding practice are shown to affect the working properties and finish of vitreous enamels. Uniform mill practice from day to day is necessary for exact color matches from day to day in some shades of enamels. TOO small a mill charge contaminates the enamel with abraded pebble and mill lining material, and may therefore decrease the gloss and alter the color. Attention is called to the possibility of obtaining too much “set‐up” in an enamel charge ground in a new or newly relined pebble mill. The particle fineness of the enamel may be tested by the usual screen test, or in a cone screen, which is described.
FORM AND COLOR IN AMERICAN INDIAN POTTERY NORTH OF MEXICO1
Authors: Harrington M. R.
Published: June 2006

Common features in American Indian pottery are the facts that it was strictly hand made without use of any form of the potter's wheel and that it was never really glazed. Due to development of the art in different ways, it is possible to distinguish seven different districts in America. A consideration of the pottery of each district is presented.
SOME OBSERVATIONS ON HEAT TRANSFER IN FURNACES1
Authors: McSwiney D. J.
Published: June 2006

Some of the phenomena of heat transfer in glass furnaces are reviewed; it is suggested that circulation of the hot non‐luminous products of combustion may be an important factor in heat transfer in furnaces, and evidence is given as to the existence and the rapidity of this circulation.
ON THE CAUSES OF THE SURFACE DEVITRIFICATION OF GLASSES1
Authors: Taeata Kozo
Published: June 2006

The explanation on the causes of the surface devitrification of glasses upon heating, as heretofore considered, is imperfect. The modes of surface devitrification are greatly influenced by the surface conditions of the glasses. The author gives an interpretation on the causes of this phenomenon of surface devitrification, i.e., the surface contraction which is caused by the surface tension at the glass surface acts most seriously toward the surface devitrification.
A STUDY OF THE EFFECT OF THE SUBSTITUTION OF CALCINED BALL CLAY FOR NONPLASTIC IN PORCELAIN AND TALC BODIES
Authors: Watts A. S. , King R. M. , Fisk H. G.
Published: June 2006

It has been the purpose of this study to determine the effect of the substitution of calcined ball clay for flint in certain type bodies. Complete data on the physical properties of these bodies has been obtained, including electrical resistivity up to 980°C. A substitution of calcined ball clay for a portion of the talc in a type talc body has also been made.
SOME OBSERVATIONS ON THE DEHYDRATION AND FIRING BEHAVIOR OF CLAYS1
Authors: Geller R. F. , Wadleige W. H.
Published: June 2006

The results of laboratory studies of the drying and water‐smoking behavior of twelve clays, typical of those used in the manufacture of clay structural units, are given and correlated with data obtained at plants during the firing of ware made from these same clays. There is evidently considerable difference in the time required to dry the materials investigated and it is indicated that the fire clays as a group are considerably more difficult to dry than are shales and surface clays. The results also indicate that the removal of hygroscopic and chemically combined water, as initially contained in the clay, are not important factors in regard to the time required to watersmoke and fire clay ware under plant conditions. With proper equipment it would appear to be possible to fire clay ware, approximating brick and paving block in size and shape, to 1832°F in 20 hours, but that the following conditions in practice may necessitate a longer firing time than that shown to be satisfactory in the laboratory: (1) the heating of ware which is not “bone dry” and which necessitates completion of the drying operation in the kiln; (2) the time required to complete oxidation; (3) the limitations necessitated by the kiln construction, the brick work of which may be destroyed by too rapid heating and cooling; (4) limitations of kiln design because of which enormous differences in temperature would develop throughout the setting by too rapid heating; and (5) insufficient movement of furnace gases to promptly remove all water vapor.
IV. PROGRESS REPORT ON INVESTIGATION OF SAGGER CLAYS. THEIR ELASTICITY, TRANSVERSE STRENGTH, AND PLASTIC FLOW AT 1000°C1
Authors: Heindl R. A.
Published: June 2006

This is a Fourth Progress Report outlining results and data which are supplementary to results published in the Third Report. This Report contains values of modulus of elasticity, transverse breaking strength, and maximum fiber elongation of seventeen representative sagger clays as determined by tests at 1000°C and includes (for comparative purposes) the values of these same properties previously determined at several lower temperatures. At 1000°C the rigidity of the clays has greatly decreased and the cross‐breaking strength has greatly increased when compared with values obtained at room temperatures. The pyrometric cone equivalent (P. C. E.) value of the clays appears to give the best indication of the relative plastic deflection exhibited at 1000°C.
THE USE OF SILICON‐CARBIDE REFRACTORIES IN BOILER FURNACES1
Authors: Johnson B. M , King J. A.
Published: June 2006

The chief causes of failure of refractories in boiler furnaces are slag adhesion, erosion, and failure of structure, dependent on the type of coals and feeds used. Some of the physical and chemical properties of different types of refractories are given. The development of bonded silicon carbide brick is mentioned. Clinker trouble is eliminated by use of these brick in furnaces using all kinds of present day stoker equipment. Failures due to chemical reaction between iron and silicon carbide, and torch action on a wall produced by a blast of flame under pressure together with medium amounts of iron in the ash are discussed. Air cooling of walls is taken up. Installations of air‐cooled silicon‐carbide blocks are listed and discussed. Water cooling, the use of preheated air, and conditions of use of the water wall are taken up.
THE QUANTITATIVE MICROSCOPIC ANALYSIS OF COMMERCIAL FELDSPAR1
Authors: Insley Herbert
Published: June 2006

This investigation was undertaken to develop microscopic methods for determining quantitatively the mineral constituents in feldspars used in the ceramic and allied industries. After several methods had been tried, a method of counting the grains and of using liquids of different indices of refraction for distinguishing the constituents was finally adopted. Nineteen commercial feldspars were analyzed by this method and the results compared with the results obtained by computing the chemical analyses to mineral constituents. Another method in which a partially fused sample was examined microscopically was also found suitable. It is concluded that, while neither the counting method nor the fusion method is as accurate as chemical analysis, the counting method gives satisfactory results for plant control in terms of potash feldspar, plagioclase feldspar, and quartz when used by a skilled microscopist, and the fusion method gives satisfactory results in the hands of the plant technologist for estimating quartz.
THE ORIGIN OF BEDDED PENNSYLVANIAN FIRE CLAYS IN THE UNITED STATES1
Authors: Hodson Floyd
Published: June 2006

The bedded Pennsylvanian fire clays are practically all formed in the Pottsville and Allegheny series, and are associated more or less closely with coal beds, although all underclays are not refractory.

Various theories have been advanced to explain the origin of these fire clays, but there seem to be serious objections to most of them.

The author believes that the clays here discussed were mostly deposited in swamps and owe their purity to the leaching action of waters containing carbonic and organic acids, which leached out the iron, alkalis, etc. Such leaching would occur chiefly in those portions of the swamp where the water was circulating along channels. Differential leaching would therefore explain variable composition in the underclays.
THE MICROSTRUCTURE OF EARTHENWARE1
Authors: Insley Herbert
Published: June 2006

Nineteen samples of glazed earthenware bodies were examined with the petrographic microscope to study the development of mullite (3A12O3. 2SiO2) within the body and at the glaze‐body contact of the different samples. A correspondence of the development of mullite within the body and at the contact of glaze and body was observed and there seemed to be relation between the firing temperature of the body and the size of mullite needles formed. Seventeen photomicrographs are shown.
NOTE ON THE SOLUBILITY OF ENAMEL FRIT IN MILL WATER1
Authors: Cook H. L.
Published: June 2006

Methods of determining the solubility of enamel frit in mill water are outlined. Various tests tried show that (1) solution increases as fineness increases, (2) mixing has little or no effect upon solubility, (3) variation of smelter treatment has little or no effect upon solubility, and (4) Na2O and B2O3 will dissolve from dry ground frit proportionately to the fineness thereof.
OBSERVATIONS UPON THE EFFECT OF VARIOUS ELECTROLYTES WHEN ADDED TO ENAMEL SUSPENSIONS MADE WITH AND WITHOUT CLAY1
Authors: Cook H. L.
Published: June 2006

The literature is reviewed. The effects of various electrolytes on clay slip, an enamel slip, finely ground clay‐sand‐water suspension, and finely ground sand‐water suspension were observed. “Setting up” of water suspensions of finely divided insoluble materials seems more dependent on fineness of grinding and degree of solution of the suspended material than upon the presence of clay.
DISCUSSION ON “SPECIFIC HEATS AND THERMAL REACTIONS OF CLAYS, ETC.”1
Authors: Cohn Willi M.
Published: June 2006

Due to variation in specific heats obtained by Cohn and MacGee, criticism and comparison of the results is set forth by Cohn. Methods of determination of specific heat, accuracy claimed for the methods, erroneous assumptions, and several other items are taken up in detail in the fourteen sections of the discussion. The reply by MacGee takes up in detail each of the points raised.
PRACTICAL AIDS TO WET‐PROCESS CAST‐IRON ENAMELING1
Authors: Hansen J. E.
Published: June 2006

The importance of design of castings and proper foundry practice is discussed, to‐ gether with the advantages of the proper type of “filler” for holes in porous castings. The functions and advantages of a ground‐coat enamel are discussed, and the effect of the time‐temperature comeback of the enameling furnace is shown to be important toward getting best results. Multiple‐deck firing aids in obtaining a slower comeback and increases production.
METHODS FOR TESTING CRAZING OF GLAZES CAUSED BY INCREASES IN SIZE OF CERAMIC BODIES1
Authors: Schurecht H. G.
Published: June 2006

Investigations to determine the causes of a type of crazing which develops on certain glazed ceramic wares, some time after firing, revealed the fact that in many cases such crazing is caused by an expansion of the body. This is probably due to the combination of water with the body, while the glaze remains practically constant in size. A body may be tested for this type of crazing by placing the glazed specimens in an autoclave and subjecting them to a steam pressure of 150 to 175 pounds per square inch for one hour. Bodies showing the least tendency to develop this type of crazing are those which have a low porosity, are not very soluble in sulphuric acid, and have a low ignition loss above 110°C.
THE PREVENTION OF DISINTEGRATION OF BLAST FURNACE LININGS1
Authors: Mitra Himansu Kumar , Silverman Alexander
Published: June 2006

Theories and observations on the causes of disintegration of fireclay refractories in blast furnaces are given and a process is developed for improving high iron clays for this use. The disintegration of refractories in blast furnace linings is initiated by alteration in the iron spots. Ferric oxide is reduced to ferrous oxide at 500°C and hastens the cracking of 2CO to CO2+C1 the carbon being retained by the lining. When Fe2O2 is converted to Fe3O4 the brick will not disintegrate.
SOME FACTORS INFLUENCING THE THERMAL PROPERTIES OF MINERALS AND PRODUCTS OF THE CERAMIC INDUSTRY1
Authors: Cohn Willi M.
Published: June 2006

A survey is given of a number of factors which exert an influence upon the following thermal properties of several minerals and ceramic bodies: specific heat, thermal reaction, thermal conductivity, thermal expansion, thermal radiation, etc. The influences in the Case of fired and unfired substances are differentiated. A bibliography is presented, which summarizes the work of recent years bearing on the thermal properties of minerals and ceramic bodies.
ACID‐RESISTING OVERGLAZE COLORS1
Authors: Tailby R. V.
Published: June 2006

There is great demand for overglaze colors which are resistant to the action of acids and alkalis. Difficulties encountered in the production of such colors are mentioned. Requirements to be met are enumerated. Experimental evidence of acid‐resistance is discussed, and a provisional test known as the “immersion test” is described.
A STUDY OF THE CALCIUM‐SODIUM RATIO OF CERTAIN WATERS1
Authors: Hart R. A.
Published: June 2006

As soluble materials are leached from alkaline soils they may become compact and refractory. This phenomenon is hindered by the presence of calcium or magnesium. Data on calcium‐sodium ratios of river waters in different localities are given. It is believed that an unfavorable ratio from the agricultural standpoint would be a favorable ratio with respect to ceramics. The possibilities of use of waters of low calcium‐sodium ratio in tempering clays to produce greater density are to be investigated.
BRICK MACHINE, BUCKET ELEVATOR, AND HAMMER MILL POWER DETERMINATIONS1
Authors: Ogden D. P.
Published: June 2006

Power measurements on brick machinery are determined and compared.
USE OF THE SIMULATIVE TEST FURNACE AS A MEANS OF MAKING COMPARATIVE TESTS OF FIRE BRICK1
Authors: Rogers G. L.
Published: June 2006

The Navy Simulative Service Test for refractories is described, specifications for the test and the furnace used being given. The simulative service furnace has found application in making comparative tests of different brands of refractories, development of and improvement of standard fire brick, and as a control test for maintaining quality of the product.
VACUUM TREATMENT OF CLAY SLIPS AND BODIES1
Authors: Kraner Hobart M. , Fessler A. H.
Published: June 2006

The work contained in this paper was conducted to determine the value of the treatment of clay slips to reduced pressures. Theoretical information obtained in references, however, indicate little possibility of there being much gas adsorbed by the solid particles of a porcelain slip. No improvement of dielectric strength or mechanical strength could be noted as a result of experimental work conducted.
NOTES ON FIRING TERRA COTTA1
Authors: McDowell Samuel J. , Murphy Remington M.
Published: June 2006

Some notes are given on the firing behavior of a 14‐foot diameter muffle type terra cotta kiln, using coal as a fuel. The need of more data on periodic fired kilns in all branches of the ceramic field is stressed.
CONTINUOUS AND PERIODIC ELECTRIC DEC 0 RATING KILNS1
Authors: Eves J. R.
Published: June 2006

Detailed descriptions are given of electric decorating kilns, one of a continuous type installed at the Buffalo Pottery Co., of Buffalo, N. Y., and two of the periodic type installed at the Smith Ceramic Studios of Rochester, N. Y. Construction, equipment, and operation details are given. Advantages of these kilns over other kinds more commonly used are discussed.
FIRING CERAMIC WARE WITH GAS1
Authors: Read Henry L.
Published: June 2006

The significance of the terms oxidizing and reducing kiln atmospheres to the ceramists and the gas engineer is discussed. The applications, advantages, and comparative costs of various fuels used in the ceramic field are considered.
TERTIARY CLAYS OF SOUTHERN CALIFORNIA1
Authors: Linton Robert
Published: June 2006

A discussion is given of the occurrence, geology, use, mining, and physical properties of some California pottery clays. The term “pottery clay” is used to designate all clays employed in manufacturing clay products other than common red building brick and articles of similar grade. Chemical analyses are given for the principal clays.
A TEST FOR THE ADHESIVENESS OF VITREOUS ENAMELS TO METAL1
Authors: Harrison W. N. , Thaler G. T.
Published: June 2006

A method of testing the adhesiveness of vitreous enamels to metal is developed. The test specimens are prepared by clamping together two strips of enameled metal while they are still in the furnace and allowing them to cool slowly in another furnace from a temperature of 500°C. The test consists of determining the force necessary to pull the two metal pieces apart when treated as a continuous strip of metal under tensile stress. As a source of additional data in analyzing results, an estimate is made of the percentage of contact area on each specimen within which failure occurred in the bond. The adhesiveness of an enamel containing cobalt, manganese, and nickel oxides is compared with the enamel minus these oxides. The cobalt enamel gave a much stronger bond than the cobaltless enamel, a result which ie in agreement with industrial experience. The degree of reproducibility is sufficient to permit positive distinction between conditions of adhesiveness which differ considerably.
THE PETROGRAPHIC MICROSCOPE AS AN INSTRUMENT FOR THE GLASS TECHNOLOGIST1
Authors: Insley By Herbert
Published: June 2006

The value of the petrographic microscope to the glass technologist in identifying crystalline defects in glass and impurities in raw materials is pointed out. The behavior of light in passing through crystalline materials and methods of manipulation of the petrographic microscope in the identification of crystalline compounds in glass and glassmaking materials are described briefly.