bluuebunny/crossref_metadata_2025 huggingface dataset:
X‐RAY INVESTIGATION OF THE EFFECT OF HEAT ON CHINA CLAYS1
Authors: McVay T. N. , Thompson C. L.
Published: June 2006

X‐ray diffraction patterns were obtained from an English china clay and a Georgia sedimentary kaolin, both raw and fired to various temperatures. The chief crystalline constituent of the raw clays was found to be kaolinite. Upon dehydration the kaolinite lattice was destroyed and the clays gave no diffraction pattern. Mullite was formed in both clays at 950°C and the amount increased with increase of firing temperature. In addition to the mullite, free alumina was present in the Georgia clay from 950 to 1100°C and cristobalite at temperatures above 1200°C.
DETERMINATION OF IRON OXIDE AND TITANIA IN CLAY REFRACTORIES1
Authors: Kerr W. Raymond , Read Edgar B.
Published: June 2006

Customary method of determining iron oxide and titania from ignited R2O2 precipitate requires considerable time. Direct titration of fusions with sodium carbonate is impossible because of gelatinous silica. Direct titration of fusions with potassium bisulphate is accurate with clays low in silica and unfired clays. By treating with hydrofluoric and sulphuric acid, and dissolving with dilute hydrochloric and precipitating the R2O2 by ammonium hydroxide and then fusing with potassium bisulphate the iron and titanium oxide can with accuracy be titrated. A detail method of procedure is given.
AN INVESTIGATION OF THE HYDROMETER METHOD FOR DETERMINING COLLOID CONTENT1
Authors: Slegel Paul J.
Published: June 2006

Two clays, bentonite and Florida kaolin, were used in the study of the George Bouyoucos hydrometer method for determining the colloid content in a clay suspension. It was found that the hydrometer method was not an accurate means of measuring percent colloid, and since this method checks the heat of wetting, the latter, therefore, is also unsatisfactory.
VARIATIONS IN PYROMETRIC CONE EQUIVALENTS OF SILICA CEMENTS AND FIRE CLAYS1
Authors: Cole Sandford S.
Published: June 2006

In order to determine what variations might occur due to the method of preparing the sample for the pyrometric cone equivalent test a series of 100 silica cements and five fire clays were tested using the cement “as received,” ground to pass a 65‐mesh Tyler screen, and after calcining a t 1400°C grinding to pass a 65‐mesh Tyler screen. The pyrometric cone equivalent values were obtained by two operators, the cones being made by one operator. It was found that testing of silica cements “as received” gave closer checks than ground samples. The grinding of the sample lowers the pyrometric cone equivalent 11/2to 2 cones in general.
SOME PHYSICAL PROPERTIES OF GLASS TANK BLOCK REFRACTORIES1
Authors: MacGee A. Ernest
Published: June 2006

Porosity, crushing strength, elasticity, specific gravity, transverse strength, thermal expansion, impact strength, and resistance to heat shock were determined on five glass tank block refractory bodies. Ability to resist heat shock was successfully predicted from the elasticity, transverse strength, thermal diffusivity, and thermal expansion values.
SOME EFFECTS OF COAL ASH ON REFRACTORIES1
Authors: McVay T. N. , HURSH R. K.
Published: June 2006

The action of coal ash on the following types of refractories was studied: (1) high diaspore brick, (2) fireclay refractories with very little quartz, (3) fireclay refractories with considerable quartz, (4) refractories containing a mixture of diaspore and fireclay, and (5) andalusite refractories. The tests were carried out in a rotary test furnace at temperatures ranging from 1500 to 1600°C. The phases present in the coal‐ash refractory slag were identified by means of the petrographic microscope and consisted of magnetite, mullite, and glass. The effects of time of slag action and slagging temperature were studied.
DRIVING CLAY‐WORKING MACHINERY1
Authors: Brown Davis
Published: June 2006

Illustrating and describing the application of various power transmitting and speed reducing devices with suggestions for further simplifying the methods of applying motors to machines to be driven.
THE VARIETY OF CLAYS OF WASHINGTON AND THEIR ADAPTABILITY TO CERAMIC INDUSTRY1
Authors: Burkhalter Edward
Published: June 2006

A brief description of clays in the Northwest which have a proven industrial value.
PHOTOMICROGRAPHY IN NATURAL COLOR1
Authors: Curtis Thomas S.
Published: June 2006

An outline of the processes and technique used in the Vitrefrax Laboratory for the preparation of permanent and faithful records of ceramic and refractory body structures.
EFFECT OF REDUCING GASES ON THE TRANSVERSE STRENGTH OF FIRECLAY BRICKS1
Authors: Westman A. E. R.
Published: June 2006

It was reported that fireclay brick, when heated in the presence of carbon monoxide, were disintegrated by the progressive deposition of finely divided carbon at the “iron spots” in the brick. The conditions necessary for the occurrence of this phenomenon were not definitely known, although the known reversibility of the catalytic reaction around 650°C and the outcome of small scale experiments indicated that disintegration would not occur above this temperature. To obtain more definite information on this score, the effect of city gas at 550°C and 1100°C on the transverse strength of three brands of fireclay brick was determined. No significant changes in strength occurred at 1100°C. At 550°C two of the brands suffered very significant decreases in strength, but the other brand was unaffected, although it had the highest iron content.
SPRAY ROOM CONTROL WITH A CAMERA1
Authors: Davis Harry E.
Published: June 2006

The use of the camera for recording spray room applications is described and its advantages over the old method of keeping actual samples of each spray which soon forms a bulky, dusty accumulation, subject to accident and deterioration. The problem of distinguishing between colors, where several applications are made, remains to be solved by the selection of the proper dyes.
THE COMMERCIAL DEVELOPMENT OF A KAOLINIC FIRE BRICK1
Authors: Norton ByF. H.
Published: June 2006

The development of a kaolinic brick from Georgia clay is described. The high and continued shrinkage of this clay makes it necessary to fire the brick a t a very high temperature. A temperature of over 3000°F was required. The development of a kiln for the firing of the grog and brick was a problem that was satisfactorily solved. A light weight brick for use in marine boilers and a dense refractory for use in glass tanks were developed. The following physical properties of these two refractories are given and compared with other high grade bricks: (1) start of deformation under 25 Ibs. per sq. in. load, (2) 10% deformation under 25 Ibs. per sq. in. load, (3) start of permanent volume change without load, (4) mean coefficient of expansion, (5) cycles in 2900°F air‐spalling test, (6) melting point, (7) thermal conductivity a t 1000, 2000 and 2750°F. Various successful applications of this type of brick are described.
MINERAL CONSTITUENTS AND ORIGIN OF A CERTAIN KAOLIN DEPOSIT NEAR SPOKANE, WASHINGTON1
Authors: Goodspeeed ByG. E. , Weyuouth A. A.
Published: June 2006

This paper discusses petrographic and mineralogic features of kaolinite and associated minerals from a certain kaolin deposit near Spokane, Wash. Here the kaolin occurs in dikes, veinlets cutting a sandy material, and has field relations and mineral associations that are not in harmony with the usual conception of residual deposits due to weathering. The evidence points strongly to endomorphic action or perhaps even direct primary origin from highly aqueous magmatic solutions.
STUDY OF CHINA BODIES OF BELLEEK TYPE1
Authors: Collins Paul F.
Published: June 2006

After a preliminary study of Belleek bodies of four compositions, using three different frits and firing to three temperatures, a further study was conducted using the moot promising of the three frits as the basic frit and three new frits containing nome different ingredients. A standard body was used in the later study. Resultsobtained are enumerated and discussed.
EQUATIONS AND TABLES FOR SHRINKAGE, EXPANSION AND DESIGN CALCULATIONS1
Authors: Westman A. E. R.
Published: June 2006

Attention is drawn to an error in the equation for calculating linear shrinkage (per cent of dry length) from volume shrinkage (per cent of dry volume) which was given in the Report of the Committee on Standards, AmericanCeramicSociety, Year Book, 1921–22. In order to avoid errors due to the use of incorrect equations, in future work, the more useful equations for making the ordinary shrinkage, expansion, and design calculations are derived and tabulated. To facilitate numerical computation, four figure tables are given by means of which the labor involved in the more usual ceramic calculations involving shrinkage and expansion can be greatly reduced. The use of the equations and tables is explained and illustrated by means of examples.
SCIENCE VERSUS ENGINEERING IN THE SCHOOLS—A FURTHER CONTRIBUTION TO THE SYMPOSIUM ON CERAMIC EDUCATION1
Authors: Gorton A. F.
Published: June 2006

In discussing ceramic education it is suggested that (1) as it is the function of a technical school to impart as complete a scientific foundation as possible to its graduates, the tendency is to produce technologists rather than engineers; (2) engineering ability does not develop from formal training but from individual traits or inborn qualities; (3) the average‐size plant should endeavor to make better use of the talents and ability of their so‐called practical men by encouraging them to acquire technical knowledge through evening courses and extension work. The benefits of cooperative agreements with local educational institutions by maintaining scholarships are also pointed out.
THE LOSS OF SILICA DURING GLASS MELTING1
Authors: Scholes S. R.
Published: June 2006

Repeated analyses of glass taken from an operating tank at different times show that, when round‐grained and dustless sand is used, the silica found in the glass averages 0.64% lower than the value calculated from the batch. When sharp‐grained dusty sand is used, the loss is greater, amounting to 1.13%. This loss is suggested as the reason for sharp‐grained sand being easier to melt than round‐grained, leaving less silica for fusion. These results are confirmed by the data from other analysts, showing that the percentage of silica found is usually smaller than that calculated for a given glass.
INFLUENCE OF OXIDIZING AND REDUCING AGENTS ON SELENIUM GLASS COLORS1
Authors: Silverman Alexander
Published: June 2006

The effects of oxidizing and reducing agents on the colors produced in selenium glasses are discussed.
THE USE OF FUSED SILICA AS A RAW MATERIAL IN THE MANUFACTURE OF PORCELAIN1
Authors: Wesman A. E. R.
Published: June 2006

The effect of different forms of silica commonly used in porcelain bodies on their properties is compared with that produced by use of fused silica. Sources of fused silica are discussed. Comparative tests were made on two bodies, typical of electrical porcelain commonly manufactured in the United States, the only difference between them being that one contained Ottawa sand flint while the other contained powdered fused silica. The firing behavior and thermal expansions were determined and a microscopic examination of thin sections was made. The fused silica body differed materially from the porcelain and due to its difference the name “fusilain” has been suggested for it. A further investigation of other properties thereof is planned.
A REVIEW OF THE LITERATURE ON LABORATORY SLAG TESTS FOR REFRACTORIES1
Authors: Ferguson Robert F.
Published: June 2006

A critical description is given of the numerous laboratory tests which have been proposed to determine the resistance of refractories to slag action.
NOTES ON A METHOD FOR DETERMINATION OF WORKABILITY OF PLASTIC CLAYS
Authors: McDowell Samuel J.
Published: June 2006

A factory control test is described for determining the point at which workable plasticity is developed.
POSSIBLE FUTURE USES OF CLAYS1
Authors: Koehler W. A.
Published: June 2006

The need for investigation of new uses for clays which may become necessary if brick are substituted for by new materials is stressed. The shortcomings of brick, and possible new methods of clay processing are enumerated.
ACID‐RESISTANT ENAMELS1
Authors: Malinovsky A.
Published: June 2006

The qualities of an acid‐resisting enamel are enumerated. Kerstan's formulas are given and results of tests made on the enamels of these formulas are discussed.
THE DETERMINATION OF IRON IN GLASS SAND1
Authors: Lundell C. E. F. , Knowles H. B.
Published: June 2006

Data are presented in tabular form showing the determination of iron in the Bureau of Standards Sample of Glass Sand, No. 81. The electrometric titration method, the H2S reduction method, and the gravimetric method are described in detail.
EXPERIMENTS WITH STOKER FIRING1
Authors: Theobald E. F.
Published: June 2006

The use of stokers on a downdraft kiln is discussed. Results of several firings are given, changes being made to correct defects observed. Difficulties encountered and advantages noted are listed.
A STUDY OF UNDERGROUND CLAY MINING1
Authors: Nold H. E.
Published: June 2006

The conditions in underground clay mining as noted during a survey of the heavy clay industries of Ohio are discussed. The need for greater study of the subject is stressed, especially the haulage, drainage, timbering, panel development, and pillar drawing phases. The solution suggested is a mine as carefully planned and operated as the manufacturing plant in order to increase the percentage of recovery and reduce the cost per ton.
RECENT PROGRESS IN ELECTRICAL APPLICATION FOR THE HEAVY CLAY INDUSTRY1
Authors: Huestis T. B.
Published: June 2006

The advantages, proved in installations, of electric drives and controls are recited and detailed descriptions are given of the manner and advantages of electric drive and control of the several machines and means of moving the clay and ware in the heavy clay products plants. The paper is illustrated by photographs of installations which have been found successful.
WINNING OF MISSOURI DIASPORE, BURLEY, AND FLINT CLAYS1
Authors: Forbes C. R.
Published: June 2006

The process of mining Missouri diaspore, burley, and flint clays is described in careful detail.
MODERN TREND OF DESIGN FOR POTTERY PLANTS1
Authors: Jacoby H. S.
Published: June 2006

A discussion of the most advantageous type of building to house pottery manufacture is given. The one‐story building is advocated in preference to a multi‐story building. Objections raised to one‐story construction are cited, but overshadowing advantages are enumerated. Details recommended by best modern practice in the construction of one‐story plants are given.
BERYLLIUM GLASS1
Authors: Lai Chi Fang , Silverman Alexander
Published: June 2006

Beryllium glass has been prepared for the first time, and some of its physical and optical properties have been determined. More than eighty different compositions have been melted and studied. Four series were taken from the clear glass area and examined for density, hardness, refractive index, and ultra‐violet light transmission in comparison with magnesium and calcium glasses
CHEMICAL CONTROL OF FELDSPARS1
Authors: Kniget F. P.
Published: June 2006

A definition of feldspar is given. Minerals in feldspars are enumerated. The importance of chemical control, method of analysis, and calculation of mineral composition from chemical analysis are taken up. A discussion of the value of the calculation is presented. In explaining mechanical control procedures, method of sampling, storage and mixing of feldspars, fusion test, block test, reasons for the non‐uniformity in fusions and free quartz determinations are described and discussed.
ADSORPTION AT CRYSTAL‐SOLUTION INTERFACES*
Authors: Benneit G. W. , France W. G.
Published: June 2006

The present work is a continuation of the study of adsorption processes at solution crystal interfaces. It consists of an investigation of the adsorption of dyes, gelatin, and amino acids by the various faces of ammonium alum. The growth ratios of this alum were measured both in the presence and absence of these foreign substances. Adsorption was found to occur only at the cube faces and to be specific in character. The effects obtained are explained on the basis of residual valencies, polar groups in the adsorbed material, and the interionic distances in the crystal lattice. The extension of these ideas to the study of the flocculation of suspensoid sols has been suggested. The growth ratio V100/V111 for pure ammonium alum was found to be 1.53
THE USE OF 8‐HYDROXYQUINOLINE FOR THE CHEMICAL ANALYSIS OF SILICATES1
Authors: Robitschek Josef
Published: June 2006

A method for the gravimetric and titrimetric determination of different metals, devised by Berg, is used for the analysis of silicates. Alumina and magnesia are precipitated with 8‐hydroxyquinoline and the precipitates can be either dried and weighed or dissolved and titrated. Both metals can be determined in the presence of silica and thus much time is saved, if determination of the silica is not required. For different purposes different methods have been devised and very accurate results have been obtained
FIRING OPEN TERRA COTTA KILNS WITH GAS1
Authors: Owen W. O.
Published: June 2006

Experiments conducted with a small kiln in firing terra cotta without the use of a muffle giving satisfactory results, the large kilns at this plant were equipped for gas firing, the muffles being removed. The equipment for gas firing is described and alterations made in the kilns are explained. The general operation of the kilns is discussed. Savings obtained are enumerated. The consideration of gas as a fuel in the ceramic industry is recommended.
SOME INVESTIGATIONS OF A NEBRASKA CLAY1
Authors: Rymes Arthur James
Published: June 2006

A brief review of the literature on the fluxing action of different metallic oxides on clays is given. A series of mixtures of what seemed to be the “dirtiest” clay of four obtained, with varying amounts of pure calcium carbonate which passed a 150‐mesh screen was made up into briquets and physical properties were studied on the unfired and fired specimens. The firing was done at four temperatures, 1800°F, 1900°F, 1950°F, and 2000°F. Properties observed were fusion point, drying and firing shrinkage, crushing strength, and porosities of the fired specimens. The principle of the Armstrong volumeter used for porosity determinations is explained. The results obtained indicate possibilities of materially improving qualities of brick now being produced from so‐called ordinary clays but only after a very considerable amount of further work is done.
SEARCH AND RESEARCH
Authors: Binns Charles F.
Published: June 2006

Individual investigation is discussed and suitable laboratory operations are described and explained in detail. The minimum of equipment is presumed.
PORCELAIN MAKING IN CHINA1
Authors: Leibson J.S.
Published: June 2006

A brief description is given of the history of Chinese porcelain and of the methods and materials used by the Chinese at the present time in their manufacture of art and service porcelains. Reference is made to a factory in Shanghai, China, manufacturing dry‐process electrical porcelain under American methods.
THE MEASUREMENT OF ABSOLUTE VISCOSITY BY THE USE OF CONCENTRIC CYLINDERS1
Authors: Lillie Howard R.
Published: June 2006

A method is described for the measurement of absolute viscosities of liquids, employing the torque exerted upon a stationary inner cylinder or spindle, suspended by means of a torsion member into the center of a fluid, when the cylindrical container is given a uniform angular motion. The “true” viscosity of the castor oil, used as a test fluid, is found by extrapolating values of apparent viscosity, given by spindles of various lengths but equal radii, to that value corresponding to infinite length. For the oil being used, the viscosity at 20°C is given by this method as 9.67 poises. Using this as the true value, the effective length and thereby the end effect in terms of additional length may be found for any spindle in a liquid of given finite boundaries. The end correction to length, so determined for a spindle of 0.5 cm. radius by 10 cm. length in the center of a liquid of boundaries 3.2 cm. radius by 13 cm. height, a system similar to that used in measuring glass viscosities, was found to be 0.44 cm.
VOLATILITY OF SELENIUM AND ITS COMPOUNDS IN THEMANUFACTURE OF RUBY GLASS1
Authors: Krak J. B.
Published: June 2006

The volatility of selenium in making selenium ruby glass has been studied. About 75% of the selenium added to the batch was lost by volatilization. Sodium selenite and barium selenite were stable at 950°C and are probably stable at higher temperatures. Regardless of whether selenium or the compounds studied are used, the resulting glass contains about equal amounts of selenium. Methods of preparing sodium and barium selenites are described. An outline is given of an analytical procedure by which selenium is determined in glass.
EFFECT OF SOLUBLE SALTS ON THE PROPERTIES OF ENAMELS1
Authors: Danielson R. R.
Published: June 2006

Enamels, in common with other types of glasses, are more or less soluble in water, depending on their compositions. The nature and quantity of salts dissolved from the enamel glass during milling have a very definite bearing on the suspension, work ability, and other properties of the enamel, such as pitting and crawling.

Those enamels which produce mill liquors which are excessively alkaline have very poor floating qualities. The ratio of free alkali to boric oxide dissolved from the enamel frit is an important factor in the flotation properties of the enamel.

The poor floating powers of certain enamels can be corrected by the addition of suitable electrolytes. The kind and quantity of salts dissolved from the frit will determine the selection of the proper electrolyte. Enamel compositions having minimum solubility for good suspension and other properties are given.

The value of an enamel clay cannot be determined by floating the clay in water. Tests must be made with the clay in the type of enamel with which it is to be used.

Any studies on the effect of aging of enamels on their working properties must give consideration to the constitution and quantity of the individual salts dissolved from the enamel frit, and to the action of carbon dioxide in neutralizing part of the free alkali.
SCRATCH HARDNESS TESTS OF CERAMIC MATERIALS1
Authors: Navias Louis
Published: June 2006

Three sets of standards were prepared: (1) a set of minerals according to Mohs'Scale, (2) a set of steel samples, and (3) a set of Carboloy (tungsten carbide alloy) samples. The sets of standards were compared with each other according to their scratch hardness. Specimens of ceramic materials were then measured for scratch hardness with each set of standards. The results are compared.
A TUNNEL KILN REFRACTORIES PLANT1
Authors: Whitesell B. E.
Published: June 2006

A description of the Salina Plant of the Kier Fire Brick Company, where all the ware is fired in two hand‐fired, car‐tunnel kilns. Some of the steps taken in changing the old plant to the new, the present plant layout, the method and procedure in the manufacture of the different shapes, capacities of the machines, etc., are described.
A COMPLETELY AUTOMATIC DECORATING TUNNEL KILN1
Authors: Jans John T.
Published: June 2006

A continuous decorating kiln is described which is completely automatic in temperature control and ware movement. This paper deals chiefly with the automatic ware movement, which is achieved by mechanical operation of the two four‐way valves, through which oil is supplied to ten hydraulic cylinders which open and close the doors, move the transfer cars on each end of the kiln, and move the ware cars through the kiln and down the loading track. An electric repeating contact clock determines the schedule upon which the kiln operates.
A STUDY OF THE ABSORPTION OF TWO EARTHENWARE BODIES AND THEIR RESISTANCE TO CRAZING IN THE STEAM TEST1
Authors: Wright E. P.
Published: June 2006

An ivory and a white earthenware body fired in different positions of periodic and tunnel kilns and maturing to various absorptions were subjected to autoclave steam treatments at the pressures of 100 and 150 lbs. per sq. inch. The ivory body resisted the crazing induced by this test for absorptions from 7 to 8% in the 100‐1b. pressure treatment. The white body withstood the destructive effect up to an absorption of 8.5%. Within a narrow range, thorough glost firing had some effect in increasing the resistance. In the 150‐1b. test, the critical resisting absorption was lowered to 6% for each body.
THE SERVICE OF REFRACTORY BLOCKS IN A SMALL EXPERIMENTAL GLASS TANK1
Authors: Pendergast W. L. , Insley Herbert
Published: June 2006

Tests to determine the relative resistance of various types of refractories to the action of flowing molten glass were made in a small laboratory glass‐melting furnace similar in shape and in operation to commercial scale, continuous glass tanks. The results of tests made in nine runs of the furnace, each run continuing for approximately 30 days, are given. The resistance of the refractories to glass attack apparently does not depend entirely upon chemical composition and porosity of the refractories, but is probably related also to (1) the size of pores, (2) the relative composition of grog and bond, and (3) the degree of adherence between particles in the refractory.
DENSITY FACTORS FOR SODA‐LIME GLASSES1
Authors: Scholes S. R.
Published: June 2006

Density factors based on oxides are criticized. A series of glasses are analyzed, compositions calculated in terms of Na2O·2SiO2, CaO·SiO2, MgO·SiO2, SiO2, and Al2O3. Factors for the three assumed compounds are calculated from three of the glasses, factors for SiO2 and Al2O3 as given by other investigators adopted, and the factors applied to the calculation of densities for the series of glasses. The results show close agreement with measured densities for six glasses analyzed and one described in the literature.
THE DETERMINATION OF STRAIN IN GLASS BY A RADIATION METHOD1
Authors: Ingerrsoll L. R.
Published: June 2006

The method of determining the strain in glass by a radiation measuring instrument is given and its adaptability if developed on a commercial basis.
CHEMICAL CHANGES IN CLAY AND CLAY‐LIME MIXTURES ON FIRING1
Authors: Frankforter C. J. , Detrick J. N.
Published: June 2006

The results of the experiments indicate that lime added to a clay, of the type studied here, combined chemically with certain of the various constituents of the clay when the mixture was fired at 1000°C. There is also an indication of reactions between iron oxide and silica. The exact nature and extent of these several possible reactions cannot be determined from the data of this limited experimental work.

It would be of great value for work of this kind if more information was available relative to the chemical action of various reagents upon the several constituents of clay. Obviously it would be necessary to use pure substances representing these constituents rather than any mixture of them.

Work was undertaken to obtain indication of the chemical changes which occur on firing a low lime clay and the same clay with calcium‐carbonate additions.
THE EFFECT OF VARIOUS ADDITION AGENTS AND TREATMENTS ON THE GREEN STRENGTH OF MISSOURI REFRACTORY CLAYS1
Authors: Paul A. J. , Holmbs M. E.
Published: June 2006

Tests were made with the plastic and semiflint fire clays of north central Missouri and the burley diaspore of south central Missouri. Aging plastic fire clay ten days produces about a 38% increase in modulus of rupture. Na2CO3 treatment produces about a 50% increase. Tannic acid which flocculates the colloids improved the modulus a good deal; an acid treatment after an alkali treatment, however, produced no added effect of importance. The effect of developing bacterial growth was marked, especially if aged for a considerable time. The addition of bentonite Collotone R increased the modulus almost 3 times. The maximum is reached with about 8% bentonite. The additive effect of dextrine in combination with bentonite is positive but of negligible consequence. Tennessee ball clay is without important positive effect in amounts up to 8%.

Sodium silicate additions up to 8% gave negative results.

With as little as 4% bentonite the modulus of rupture of flint clay is tripled. Aging of flint clay has an important positive effect. Effect of the bentonite can be obtained in the dry‐press, stiff‐mud, or soft‐mud bodies, but it is greatest in the stiff‐mud.

Burley clay is less self‐bonding than the flint and the effect of the bentonite was more marked even than in the case of flint. Four per cent bentonite increased the modulus of rupture to about 4 1/2 times its original modulus of rupture.

The modulus of rupture of flintclay‐bentonite mixtures might approach that of plastic fireclay‐bentonite mixtures at high contents of bentonite, leading to the indication that in the case of these two clays the total colloidal content is the determining factor.

With 3% bentonite the modulus of rupture of the flint is made equal to that of the plastic and straight, a result applicable to problems where the dissolving out of the bonding material in the refractory is a determining factor in service. The P.C.E. of the plastic fire clay drops 1 cone for 3% and 2 cones for 6% of bentonite addition.
THE SOLUBILITY OF QUARTZ AND CLAY IN FELDSPAR1
Authors: Parmelee C.W. , Amberg C.R.
Published: June 2006

The literature on the subject is completely reviewed. The method used involved the addition of increasing amounts of kaolin to fixed amounts of feldspar and the addition of increasing amounts of quartz to fixed amounts of feldspar. All compositions were examined microscopically and the presence of undissolved kaolin was shown by the appearance of mullite needles, while the presence of undissolved quartz was shown by the presence of cristobalite. Soda feldspar is a better solvent for both quartz and clay than potash feldspar. The solution of quartz in soda feldspar starts at about 1350°C and increases with the temperature until at 1425°C. 32 parts of quartz per 100 of feldspar are dissolved. The solution of quartz in high potash feldspar does not start until 1400°C and only 4 parts are soluble at 1425°C to every 100 parts of feldspar. The solution of clay in soda feldspar starts at 1225°C and increases with the temperature until at 1425°C thirty‐six parts are soluble. The solution of clay in high potash feldspar starts at 1250°C and at 1425°C the solubility is 20.5 parts per 100 of feldspar. The solution of quartz in porcelain bodies starts at the same temperature as it does in the pure feldspar which the body contains. The amount of solution per unit of feldspar is much greater. The general trend of one of the boundary lines in the ternary system K2O‐A12O3‐SiO2 has been found.
COMPARATIVE TESTS OF CHINAWARE USING TWO FORMS OF TESTING MACHINES1
Authors: Wray G. W. , Brand C. M.
Published: June 2006

Two forms of impact testing machines, designed to determine the resistance of chinaware to chipping and impact, and their use in testing chinaware are described. The results of testing 33 brands of domestic and foreign‐made ware with these machines are given. In addition, the weight, dimensions, and percentage of water absorption of the ware are given.
A PORCELAIN AT CONE 31
Authors: Hodgdon Frank B.
Published: June 2006

A body of the composition: clay 60%, frit 30%. and flint 10%. was mixed and ground until it passed a 200‐mesh. It was cast, dried in the open air, biscuited to cone 08, glazed, and finished at cone 3. An excellent translucency and color resulted.
A STUDY OF CHROME AND DIASPORE MIXES1
Authors: Jones Harlow G.
Published: June 2006

The history, development, and properties of chrome and diaspore brick are discussed. The plan for this investigation was the determination of (1) softening points of various mixes, all of which withstood cones 33 to 34, (2) workability of mixtures, wherein it was found that bars of soft mud were workable with difficulty while no trouble was experienced with dry‐press, (3) porosity and shrinkage on reheating; slag action and spalling. Increasing the proportion of diaspore increased the shrinkage while the absorption remained about the same in all cases. Various slags from different sources were used in the investigation, and it was found that a small per cent of finely‐ground chrome ore cut down slag action on diaspore while the addition of diaspore to chrome increased its resistance to spalling action; conversely, the addition of finely‐ground chrome to diaspore increased its resistance to spalling action.
THE TRANSVERSE BREAKING STRENGTH OF REFRACTORIES1
Authors: Vincent‐Daviss Cedric A.
Published: June 2006

A furnace has been designed which has the following characteristics: (1) The possibility of running a4‐hour day testing schedule. (2) The feasibility of measuring the modulus of rupture at temperatures up to 1500°C.
OIL FIRING OF REFRACTORIES1
Authors: Zehm Robert C.
Published: June 2006

Notes on the construction and condition of kilns used for refractories, comments on the results obtained when firing with fuel oil, and data on the equipment and operation of the kilns, are discussed in this paper.
STUDIES OF BAO·Al2O3· SiO2 AND ZNO·Al2O3SiO2 SEPARATELY WITH EUTECTICS, KNaO FELDSPAR EUTECTIC, AND CaO‐MgO. Al2O3SiO2 EUTECTIC1
Authors: Zimmer David C. , Neff John M.
Published: June 2006

Because of the lack of a means for graphically representing more than four variables it was deemed best to study groups of eutectics, the uncertainties of this type of investigation being taken into consideration. The purpose of the study was to determine the deformation of certain eutectics and the effect of variations of alumina and silica on these eutectics when applied to glazes.
THE INFLUENCE OF ALUMINA AND SILICA ON THE (K2O‐Na2O) Al2O3 SiO2 EUTECTIC1
Authors: Butterworth W. N. , Kates Paul
Published: June 2006

A series of eight studies was made on the influence of Al2O3 SiO2 and (K2 Na2O) Al2O3‐SiO2 eutectic. It was concluded that the reduction of silica lowers the deformation temperature of the KNaO‐Al2O3‐SiO2 eutectic. The reduction of Al2O3 makes little change. The problem must be studied as a three‐component series consisting of definite end members.
VITREOUS ENAMEL AND ITS DEFECTS1
Authors: Malinovszky A.
Published: June 2006

Causes for various defects in enameled cast iron ware are traced in the enamel Photographs show the iron defects.
SOME PROPERTIES OF GLAZE SLIPS1
Authors: Schramm Edward , Sherwood Robert F.
Published: June 2006

Data are presented for a fritted glaze and a raw porcelain glaze giving the relation The influence of grinding between viscosity and specific gravity and Ph of glaze slip. The influence of grinding on the properties of the slip and of the fired glaze is also discussed.
COMPARATIVE TESTS ON MONOLITHIC REFRACTORY CEMENTS1
Authors: Clark H. N.
Published: June 2006

Samples of the leading monolithic cements on the market were subjected to laboratory tests. The three best cements as determined by the laboratory tests were then subjected to various tests under practical working conditions. This paper covers all the laboratory and practical working tests up to date.
THE EFFECT OF CORES IN BRICK DIES ON POWER CONSUMPTION1
Authors: Ogden D. P.
Published: June 2006

Recording wattmeter determinations of power, moisture content and production rates were secured on an individually motor driven auger machine for each of two standard brick dies, with and without cores. Variation in these factors was recorded. Use of cores causes a great increase in power consumption per thousand brick. Moisture content variation ranged from 17.7 to 20.1%.
AN INVESTIGATION OF TWENTY‐ONE SASKATCHEWAN BALL CLAYS1
Authors: Worcester W. G.
Published: June 2006

Twenty‐one Saskatchewan ball clays have been investigated; the study covers in a general way their chemical, raw, and fired properties. The information presented will no doubt prove of immediate interest to the ball clay trade and especially to the Saskatchewan shippers and exporters.

In general, the more outstanding properties of the clays studied are raw strength, fired color, craze resistance, and rate of vitrification.

Their raw strength is remarkably high, greater than that of any similar clay on the market at the present time. One clay developed the exceptional raw strength, though diluted with 50% potters’ flint, of over 1000 lbs. per square inch, a second one 938 lbs., while the average of the eleven highest is 812.8 lbs.; clays of such high strength should prove of interest to the trade where it is desirable to reduce losses in the raw and bisque state.

A number of the clays tested are outstanding as ball clays in that they fire white or nearly so up to and including cone 12, the purity of whiteness being equal to that of white firing china clays.

The porosity and fired volume shrinkage of the Saskatchewan clays correspond more nearly to those of the English ball clays than do the Tennessee‐Kentucky clays as studied by Sortwell.
THE RELATION OF A MODULUS OF GRAIN SIZE TO THE MECHANICAL STRENGTH OF SAGGER MIXTURES1
Authors: Birch Raymond E.
Published: June 2006

A series of sagger mixtures is prepared with grain size varied on a calculated fineness modulus. Both dry and fired strength are related to grain size and a striking maximum point is obtained.
PROGRESS REPORT ON INVESTIGATION OF SAGGER CLAYS. V. Preparation of Experimental Sagger Bodies According to Fundamental Properties1
Authors: Heindl R. A. , Mong L. E.
Published: June 2006

This is a Fifth Progress Report giving the results obtained in a preliminary study of sagger bodies, which is a continuation of an extensive investigation of sagger clays for the purpose of determining the properties of clays and bodies best suited for sagger purposes. The report contains data on the modulus of elasticity, transverse breaking strength, plastic flow, thermal expansion, and resistance to failure due to heat shock of 55 sagger mixes representing 39 different bodies fired at either 1230°C or 1270°C. The 16 bodies prepared in duplicate were tested both after firing at 1230°C and 1270°C. All of these bodies were compounded with two clays whose properties are given in earlier progress reports, and a mixture of graded grog. The grog was graded into sizes so as to result in two types of bodies, those having (1) a coarse and open‐grained structure and (2) a dense and fine‐grained structure. The data on the fired bodies show that those containing the fine sizes of grog have the higher modulus of elasticity, transverse strength, and in the majority of cases, thermal expansion. Very little difference in total porosity of the two types of bodies is indicated although the rate of absorption shows large differences. The data obtained in this preliminary study indicate that those bodies having (1) a porosity of less than 25% (2) a low modulus of elasticity, (3) as high transverse strength as is compatible with the low modulus of elasticity, and (4) low thermal expansion below 250°C are the most desirable for sagger purposes.
THE INCRUSTATION OF CERAMIC WARE1
Authors: Lencaner Theodore
Published: June 2006

The history and evolution of the application of gold and other precious metals over acid‐etched designs on glass, china, and enamel ware is discussed. Details involving the preparation of the plate and transferring of the design to the article are briefly outlined and also the acid treatment of the article. The application of the metals, and finally a resume of the incrustation as a decoration is given.
LEPIDOLITE IN CONE 6 TERRA COTTA GLAZES1
Authors: Davis Harry E.
Published: June 2006

The following study was undertaken to discover what possibilities might lie in the introduction of Li2O into the RO of a terra cotta glaze, using lepidolite.
SPECIAL DEPTH GAGE FOR MEASUREMENT AND CONTROL OF CERAMIC COATINGS1
Authors: Bennett A. Lee
Published: June 2006

A depth gage is described whereby the thickness of ceramic coatings on any piece of ware may be determined regardless of its shape or surface.
NOTES ON TERRA COTTA GLAZE CONSISTENCY1
Authors: Spurrier H.
Published: June 2006

Some of the difficulties encountered in applying glaze to terra cotta are discussed. The use of a hydrometer to test glazes is misleading as a hydrometer supplies gravity indication only in true solutions and glazes are not true solutions; furthermore the viscosity of a glaze may obscure the real specific gravity. It is suggested that in order to Control a glaze it should first be made to a desirable specific gravity and then the desired viscosity at that gravity be ascertained by experiment. A viscosimeter and specific gravity bottle are suggested for this purpose. The effect of change of alkalinity and of bacteria together with the control of glaze wastage are also discussed.
THE DEVITRIFICATION OF SODA‐LIME‐SILICA GLASSES1
Authors: Morey George W.
Published: June 2006

The isotherms and boundary curves in that portion of the ternary system Na2O‐SiO2–CaO.SiO2–SiO2 of direct application to glass technology, namely, from 64 to 78% SiO2, 0 to 20% CaO, including the whole of the field of the compound Na2O.3CaO.6SiO2, and portions of the adjoining fields of Na2O.2SiO2, Na2O.2CaO.3SiO2, CaO.SiO2, tridymite, and quartz, have been determined with greater precision than in a previous study2 by greatly increasing the number of mixtures studied, and thereby decreasing the interpolation necessary in the interpretation. An extended discussion is given of the devitrification of glass, in which it is shown that the liquidus temperature is the only datum point which is solely a function of glass composition, and is unaffected by the past history of the glass or by fortuitous circumstances at the time devitrification is taking place. At the liquidus the first trace of crystalline phase is in equilibrium with the glass; above the liquidus the glass will dissolve any such crystals which may have been formed at some previous time, but new crystals cannot form; while only below the liquidus is there a tendency for crystals to separate. The driving force causing this reaction is derived from the difference in free energy between the unstable glass and the stable aggregation of crystalline phases, and this force is opposed by a resistance of the nature of a viscosity. The dissociation in the liquid phase of the compounds which separate on devitrification diminishes the rate at which the devitrification equilibrium is reached, and increasing the complexity of the glass will have a similar effect. The excess in surface energy at the interface glass‐crystal may have an influence at the instant of formation of the first infinitesimal crystal, hut after the crystal has grown to a dimension appreciably greater than the sphere of molecular action the excess energy at this interface ceases to be of importance. The only surface tension measurements which have been made on glass refer to the interface glass‐air, and the excess energy at this interface has no necessary correlation with the devitrification process.
FIRE CLAYS. SOME FUNDAMENTAL PROPERTIES AT SEVERAL TEMPERATURES1
Authors: Heindl R. A. , Pendergast W. L.
Published: June 2006

This report gives the results obtained in the second phase of an extensive investigation of fireclay refractories. It is limited to the twenty‐six representative clays included in that investigation. The geologic formation, chemical analyses, and pyrometric cone equivalents are given together with such properties of the clays fired at two widely different temperatures, as porosity, shrinkage, thermal expansion, moduli of elasticity and rupture, and plastic flow. Data are given to show the conversion of aluminous fire clays into mullite and cristobalite by firing at certain temperatures. At higher temperatures the cristobalite is converted to glass.
INDUSTRIAL USES OF RUBBER1
Authors: Fritz H. E.
Published: June 2006

A discussion of rubber‐lined steel tanks for the purpose of storing and transporting muriatic acid and other corrosives is presented. Rubber‐lined steel pipe, valves, and fittings for the transportation of corrosives, and the rubber cutless bearing are discussed.
VARIOUS METHODS OF TOOLING CONTINUOUS ENAMELING FURNACES1
Authors: Blackburn Paul V.
Published: June 2006

The importance of adequate firing tools for handling the various shapes which are enameled in continuous furnaces is discussed. The maximum efficiency of a continuous furnace can only be realized when the conveyer chain is equipped with tools which permit uniform loading throughout its entire length with enough ware to utilize fully the heating capacity of the furnace.

Materials and principles of design are considered and specific tools and racks suitable for various sheet‐iron and cast‐iron parts are illustrated.
STIFF‐MUD DIE TROUBLES1
Authors: Lovejoy Ellis , Henderson H. B.
Published: June 2006

This paper illustrates faulty and cracked ware in consequence of improperly adjusted dies for stiff‐mud products.
FORMING PRESSURE OF DRY‐PRESSED REFRACTORIES. II. THE EFFECT OF PRESSURE VARIATIONS ON FIRED PROPERTIES1
Authors: Birch Raymond E.
Published: June 2006

Laboratory tests of the dry‐pressed fire brick revealt hat fired porosity varies inversely with the forming pressure. The change, however, is less marked at high pressures. The resistance to thermal spalling is considerably lowered by increased pressure. The course of spalling is traced for brick of various pressure and density. The relative importance of the various factors affecting spalling loss is discussed. In regard to the load test, increased pressure results in marked improvement with the highly plastic mixtures and more indifferent results when much flint clay is present. In general, firing shrinkage is increased by increased forming pressure, the phenomenon being explained as due to improved continuity of the material tending to further the pyrochemical reactions. The comparatively low pressures of mechanical presses are reaffirmed by a study of fired properties. A summary of the data indicates that by utilizing higher pressures, brick of greater density may be obtained which are greatly improved in appearance, in resistance to abrasion, and in load‐carrying capacity, but with diminished resistance to thermal shock. It is indicated that higher forming pressures would partially obviate the necessity of firing ware to the present high temperatures.
AN IMPROVED METHOD FOR DETERMINING THE TENSILE STRENGTH OF UNFIRED CLAYS1
Authors: Phelps Stuart M. , Cartwright Vance
Published: June 2006

It is thought that knowledge of the tensile strengths of unfired clays is valuable and in view of this fact the present unsatisfactory method for its determination has been improved upon. A new apparatus and method for tensile strength determinations is described, in which the cast or pressed cylindrical test piece has a collar of low‐melting alloy cast around each end, thus eliminating gripping difficulties and greatly increasing the accuracy. The apparatus is also adaptable to determinations of bond and transverse strengths of clays.
A UNIT ANALYSIS OF FELDSPAR1
Authors: Pressler E. E.
Published: June 2006

A method of feldspar analysis is described by which all the major oxides are determined on one sample, and a practical routine procedure is developed on the basis of this method.
NOTES ON CASTING SLIP1
Authors: Sample Leslie
Published: June 2006

This is a note showing the unreliability of viscosimeter control for casting slip. A rule is given for control of the “hardness” and thickness of slip.
THE DEVELOPMENT AND USE OF A SIMPLE CONSISTENCY PIPETTE FOR USE IN THE ADJUSTMENT AND CONTROL OF ENAMEL SLIPS1
Authors: Kinzie C. J. , Commons C. H.
Published: June 2006

A metal consistency pipette is described and some details relative to its development and use are given.
ALUMINIUM FLUORIDE IN CAST‐IRON ENAMELS1
Authors: Cormly Alan L.
Published: June 2006

Aluminium fluoride was used in cast‐iron enamels, replacing cryolite. The fluxes were increased, when substituting aluminium fluoride for cryolite, to care for the extra alumina introduced by the fluoride. The costs of an enamel containing cryolite and one containing aluminium fluoride are compared.