bluuebunny/crossref_metadata_2025 huggingface dataset:
HANDLING AIR1
Authors: Robinson R. R.
Published: June 2006

The following points are brought out in this paper: (1) composition of air, (2) laws governing flow of air, (3) laws governing expansion of air due to temperature and pressure, (4) methods of proportioning ducts and fans as equipment for moving air (cen‐ trifugal and disk), (6) coijrdination of fan and duct characteristics, (7) selecting proper type of fan, and (8) use of the disk fan.
POWER CONSUMPTION IN CLAY PLANT OPERATION1
Authors: Everhart J. Otts
Published: June 2006

The results of power tests on preparation and forming machinery in plant operation are presented. The effect of such variables as speed of operation, grain size, and mois‐ ture content on power consumption is also discussed.
METHODS USED IN TESTING MASONRY SPECIMENS FOR BENDING, TENSION, AND SHEAR1
Authors: Kelch Norman W.
Published: June 2006

Twenty‐four walls, 41/2 feet wide, 51/2 feet high, some 8 inches and some 12 inches thick, werr tested for bending alter aging sixty days and six months, respactively. It was shown that aging of lime mortar is essential. Failures in shearing stress were also due to immature mortar. Brick masonry withstands earthquake shocks when mortar is matured by aging. An outline of the more extensive tests is given.
STRENGTH TESTS ON ROOFING TILE1
Authors: Kelch Norman W.
Published: June 2006

Conditions and methods of making simulative tests on roofing tile are developed. Rupture of the whole tile on standard edges seems to be the most reliable test and is, therefore, recommended. Specifications are adopted covering (1) absorption (15%), (2) soundness, and (3) strength.
THE INFLUENCE OF TIME ON THE MATURING TEMPERATURE OF WHITEWARE BODIES. I.1
Authors: Norton F. H. , Hodgdon F. B.
Published: June 2006

In this investigation quantitative relations have been established between the time and temperature effects in the maturing of whiteware bodies. Six typical commercial whiteware bodies were used. Similar shrinkage and porosity curves were obtained for different firing times but the longer the time the lower the curve was shifted on the temperature scale. It was found that in all cases the usual logarithmic law relating temperature with the rate of reaction applied. The constant, however, was not the same for all bodies. The microstructure of these bodies will be dealt with in Part II of this paper.
DRIER PROBLEMS WITH CALCULATIONS1
Authors: Carruthers John L.
Published: June 2006

The importance of proper drying of clayware and some of the causes of drier troubles are discussed briefly. The use of a humidity chart in control and design problems is described. The Carrier humidity chart is used in illustrating the solution of several typical problems,vis., air and heat requirements and the control of condensation in waste‐heat and radiated‐heat types of driers.
THE EFFECT OF HYDROGEN‐ION CONCENTRATION UPON THE SEDIMENTATION OF CLAY1
Authors: Beeman Norvil
Published: June 2006

The addition of an acid to a clay suspension usually causes rapid sedimentation, while the addition of a base reverses the process. This is generally explained by saying that clay is a negative colloid and hence flocculated or precipitated by the hydrogen ions of the acid and for the same reason deflocculated by the base. These experiments showed that the effect of hydrogen‐ion concentration upon the rate of sedimentation2 was relatively great and explains why changes in the ph values produce such noticeable changes in plasticity and viscogity They show also that elutriation is an uncertain process without ph control.
DIFFICULTIES IN FIRING WHITE WARE1
Authors: Robson James T.
Published: June 2006

The causes and methods of overcoming various difficulties in the firing of both vitreous and semivitreous white ware are discussed, together with a method of easily observing craze marks produced in crazing tests.
USE OF SMALL QUICK‐ACTING KILNS FOR INSTRUCTION AND RESEARCH1
Authors: Norton F. H.
Published: June 2006

Considerable experience with small, quick‐acting kilns in the laboratory, both for instruction and research, has indicated the distinct advantages of this type of kiln. By the use of an insulating refractory the mass of the kiln can be reduced to less than one‐tenth of that usually employed, which makes rapid heating possible without great expenditure of fuel. Two types of kilns are described which have given good service for a considerable length of time. Temperatures as high as 2600°F can be obtained with atmospheric burners and temperatures up to 3000°F with blast burners.
MISSOURI HARD FLINT CLAY FIRE BRICK1
Authors: Holmes M. E. , Paul A. J.
Published: June 2006

The hard flint clay obtained in the diaspore pits of Missouri, which has exceedingly low bonding properties and high shrinkage, but a P.C.E. value of cone 34, with the use of as low a percentage of flint clay grog as 20%, can be bonded into a strong brick, free of physical defects and of super‐refractory quality. Excessively high forming pressure is not required. A small addition of bentonite adds materially in bonding the clay. The results of spall, hot load, cold compression, porosity, shrinkage, and reheat tests are presented.
SHRINKAGE OBSERVATIONS ON A PORCELAIN BODY1
Authors: Hunt M. H.
Published: June 2006

Data on the shrinkage of large porcelain tubes and rods are given. The shrinkage of the test samples varies considerably not only in different sections of the same pieces, but among samples taken from tubes and rods formed in various ways.
MECHANICS OF ENAMEL ADHERENCE, III
Authors: Carter W. K. , King R. M.
Published: June 2006

A study of the use of sheet‐steel enamels on copper showed that cobalt oxide decreased the adherence of the enamel. Several sheet‐steel enamels were fired on copper and in general the adherence was less than on sheet steel. A white cover coat was found to be most satisfactory for copper. Several color photographs are given showing contact lines between enamel and copper, enamel and gold, and enamel and silver.
THE RELATION OF FINENESS OF FELDSPAR USED IN COMPOUNDING A PORCELAIN ENAMEL TO RESISTANCE TO DEFLECTION1
Authors: Türk Richard H.
Published: June 2006

The effect of changing the fineness OF the feldspar in an enamel was investigated, from which test it was concluded that resistance to deflection is lowered about 9% with a slight increase in fusion temperature when substituting 40‐mesh (glassmakers') feldspar for 120‐mesh feldspar, both of the same chemical composition.
THE ESTIMATION OF THE ALUMINA CONTENT OF DIASPORE AND BURLEY CLAY FROM THE SILICA CONTENT1
Authors: Holmes M. E. , Keller W. D.
Published: June 2006

The formula, % Al2O5= 0.85 ×% SiO2+ 0.85 (100 – 2.15 ×% SiO2) – 5.1, is presented for use in estimating the per cent of All08 of diaspore and burley clays. The silica determination is quick enough and cheap enough to make control testing of carload shipments practicable. The method applies to the lowest‐grade burley as well as the highest‐grade diaspore. The results of 381 actual analyses are presented showing that the method is accurate to 1% in 65% of the tests and to 2%, in 89% of the tests.
THE SPECIFIC HEAT OF MAGNESIUM AND ALUMINUM OXIDES AT HIGH TEMPERATURES1
Authors: Wilkhs Gordon B.
Published: June 2006

The mean specific heat of pure aluminum and magnesium oxides has been determined from room temperature up to 1700°C and 1800°C, respectively. The specimens were heated in a vertical carbon tube furnace with a magnesite tube liner for oxidizing conditions. A special calorimeter was designed and used to prevent the loss of heat by vaporization of the water when the white hot specimens were immersed.
FIRING STRUCTURAL TILE1
Authors: Shook T. W. , Sylvester G. R.
Published: June 2006

The modern railroad‐car tunnel kiln can fire structural tile economically in sufficient quantities for commercial operation. The setting arrangement is important both as to arrangement of flues and also as to the stability of the structure. Various sizes of tile can also be placed on the same car. There are approximately three tons of tile on each car. The kiln used is a Harrop car tunnel kiln, 350 feet long with a cross‐section of 5 feet 8 inches by 5 feet 5 inches. Either oil or powdered coal is used as fuel. The tile are in the kiln a total of 29 hours, giving a total production of 130 tons per twenty‐four hours.
A SIMPLIFIED METHOD FOR THE ACCURATE WET BLENDING OF GLAZES AND SLIPS*
Authors: Kautz Karl M.
Published: June 2006

A method is given for the accurate wet blending of glazes and slips whereby a single characteristic of the suspension called the G value (or grams per cubic centimeter value) is determined and used as the basis for all blends.
EFFECT OF FIRING AT 1500°C ON THE POROSITY AND SPECIFIC GRAVITY OF QUARTZITES1
Authors: Cole Sandford s.
Published: June 2006

Quartzites from the various deposits being commercially utilized for the manufacture of silica brick in the United States, Canada, and Europe were tested for porosity and apparent specific gravity before and after firing at 1500 °C for 2 hours. Petrographic examination was made of several of the raw quartzites, and the differences in crystalline structure are shown by photomicrographs. The rate of conversion of the quartz. was not constant for the quartzite? reported. The porosity after firing varied from 2 to 30% and the apparent specific gravity varied from 230 to 244. A fine‐grained quartzite tends to give lower porosity after firing.
THE PRODUCTION OF PAVING BRICK BY THE DRY‐PRESS PROCESS1
Authors: Everhart J. Otis
Published: June 2006

Comparative tests of stiff‐mud and dry‐pressed ware have been made and data are given showing the effect of pressure, moisture content, and evacuated molds.
NOTES ON CASTING SLIP IN PRODUCTION1
Authors: Wills George A.
Published: June 2006

The conclusions regarding eleven properties of a casting slip as to their influence on the loss record of shop and kiln are given. A description of the test is given with each conclusion when the standard test was not used. A list of properties for a daily record of the character of a casting slip is given.
RESIDUALS IN THE MELTING OF COMMERCIAL GLASSES*
Authors: Eitel W. , Weyl W.
Published: June 2006

By heating alkali silicates under CO2 at high pressures, alkali carbonates are reformed to an extent depending upon temperature, pressure, and chemical affinity. The CO2 thus existing homogeneously dissolved in the glass, and other anions and oxygen similarly dissolved and in chemical equilibrium are termed “melt‐residuals” (Schmelzrelikte).

Their importance in planing, coloring, decolorizing, machine‐working, vacuum bulb, and electric‐lamp manufacture is discussed.
THE “MOISTURE EXPANSION” OF GLASSES1
Authors: Milligan Lowall H. , Armitage David
Published: June 2006

Changes in the overall length of bars, about 4 by 3/4 by 1/8 inches in dimensions, made of plate glass, Pyrex glass, and various glasses such as constitute bonding agents in vitrified grinding wheels, were studied by means of a Zeiss optimeter that could be read to hundred thousandths of an inch. The bars were measured, then heated for one hour in (a) saturated steam at 150 lb. per sq. in., or (b) air oven at 184°C, and then allowed to cool to room temperature and remeasured. No increases in length of any of the bars were found within the experimental accuracy of the results (about 0.0015%).
A NOTE IN THE CONCEPT OF BRITTLENESS1
Authors: Preston F. W.
Published: June 2006

Attempts have been made to define the brittle state, or at least to explain it, in terms of physico‐chemical structure. It is generally assumed, however, that the reader knows just what is meant by brittleness, and the definitions dealing with its mechanical aspect are somewhat perfunctory. In this paper, the mechanical properties are briefly described. Brittleness is a property of the fracture system rather than of the material, and is not connected directly with physico‐chemical constitution, since certain crystalline and amorphous materials share it, while other crystalline and amorphous materials do not show it.
SOME NOTES ON THE NATURE OF CLAY1
Authors: Norton F. H. , Hodgon P. B.
Published: June 2006

The porosity and particle spacing was determined for a number of plastic and non‐plastic materials under various conditions of wetness and pressure. This was done by pressing the material in a cylindrical mold and measuring the resultant density of both the freshly‐molded and the dried specimen. The results show that all of the materials at the lower pressures have a critical water content, beyond which the particles re‐orient themselves into a denser packing. This point corresponds to the pores being one‐half filled. The clays are differentiated from the nonplastic materials by their ability to hold a stable water film onto the surface of the particles. The maximum stable thickness of this film occurs at or beyond the point where the pores are filled, and for the clays tested averages about 3 × 10−6 Cm. in thickness. This film is so stable as not to be influenced by pressures as high as 800 kilograms per square centimeter. A size analysis of the particles of all the materials was made, and their average sue and diameter computed. All of the materials were found to have some elasticity when the pressure was relieved. These data taken as a whole allow the construction of a comparatively accurate picture of the clay structure.
COLOR FORMATION IN VITREOUS BODIES1
Authors: Norton F. H. , Dulplin V. J.
Published: June 2006

A simple vitreous body of the Parian type was made up and the coloring produced by adding varying amounts of cobalt, chromium, iron, uranium, nickel, and copper oxide was determined. The color was measured by the Hardy recording spectrophotometer, and the resulting curves were analyzed for the three attributes of color. The hue, brilliancy, and saturation were all proportional to the logarithm of the coloring oxide. It was found that the color was mainly due to the particles of the practically undissolved oxide, and not to a colored glass. This makes it possible to color a body for use in reflected light, but not for transmitted light. Some excellent magenta red bodies were produced by reducing the copper oxide, but the results could not be consistently reproduced.
FUNCTION AND ACTION OF OPACIFIERS1
Authors: Kirk Leander R.
Published: June 2006

The causes of opacification and the function of opacifiers in white ware glazes are discussed briefly. The relative covering power of tin oxide is shown to be greater than that of zircon oxide under the same conditions. The fluidity of the glaze is affected by the amount of opacifier used and can be controlled in commercial practice by the use of a simple inclined testing block.
EXTRUSION OF REFRACTORY OXIDE INSULATORS FOR VACWM TUBES1
Authors: Navias Lurs
Published: June 2006

A method is described whereby nonplastic materials such as refractory oxides are given a temporary plasticity, sufficient for extrusion. The organic plastic gel used consists of flour or starch paste with ammonia as an electrolyte. A short detailed account is given of the manufacture of twin‐hole insulators made of MgO 98% and talc 2% for radio 227 vacuum tubes, with supplemental experimental results on other materials. The refractory oxides Al2O3, BeO, ZrO2, MgO, and ThO2 are compared from the standpoint of their physical properties and their ability to act as insulators in contact with hot tungsten filaments. Examples are given of the use of such extruded oxide insulators for hot filament supports.
THE PRODUCTION AND CONTROL OF COPPER REDS IN AN OXIDIZING KILN ATMOSPHERE*
Authors: Baggs Arthur E. , Littlefield Edgar
Published: June 2006

Experiments are reported demonstrating the possibility of producing localized, definitely controlled effects of reduction, in oxidizing or neutral kiln atmospheres, through the use of glazes or slips of special composition. This control was obtained by two methods as follows: (1) by incorporating silicon carbide in the glaze batch and (2) by introducing silicon carbide into underglaze slips. In ordinary kiln atmospheres both methods produced satisfactory results in which predetermined areas of copper reds and copper blues or greens were developed on the same piece.
NOTES ON ELECTROMETRIC IRON DETERMINATION* Iron in Feldspar
Authors: Lyle A. R.
Published: June 2006

Results arc presented showing the variable effect of platinum on the determination of iron in feldspar. Most of the platinum is introduced during the pyrosulphate fusion. The use of vitreous silica crucibles for the fusion reduces the platinum contamination so that the results are well within the required limits of accuracy.
THE TEMPERATURE COEFFICIENT OF VISCOSITY AND ITS RELATION TO SOME OTHER PROPERTIES OF LIQUIDS AND GLASSES*
Authors: Preston F. W.
Published: June 2006

A possible connection between the temperature coefficient of viscosity (not the viscosity itself), the latent heat of fusion or some similar work‐function, and the absorption spectrum of liquids and glasses is discussed. The three things seem to be connected in a fairly clear and simple manner.

It is shown, for instance, that from viscosity data alone it is possible to predict the position of the ultra‐violet absorption band in glasses, and the black color of pitch. Also, that at high temperatures the ultra‐violet absorption band invades the visible spectrum and migrates down into the infra‐red, and that at room temperature the viscosity of typical soda‐lime‐silica glasses is of the order 1070 poises. A meaning is attached to the term “viscosity” at temperatures at which it can not be measured mechanically, and a means of tracing it optically down to absolute zero is suggested.
SODIUM ALUMINATE AS AN ELECTROLYTE FOR CASTING‐SLIP CONTROL*
Authors: Carter W. K. , Kino R. M.
Published: June 2006

Sodium aluminate has been used as a water‐softening agent, but not to any great extent in the ceramic industry. The results of this investigation show that sodium aluminate when used as a substitute for sodium carbonate in casting slips eliminates or minimizes some of the troubles usually encountered in the control of slips and in casting ware.
PRECISE MEASUREMENTS OF THE VISCOSITIES OF GLASSES AT TEMPERATURES NEAR THEIR ANNEALING POINTS*
Authors: Lillie H. R.
Published: June 2006

The paper describes a new apparatus for measuring glass viscosities of 1013 poises and higher. It consists of causing the glass flow to take place inside a steel tube by means of air pressure. The amount of flow is observed by means of interference fringes between the top of the glass sample and a stationary plate of fused silica. Preliminary experiments with two glasses, a lime and a light flint, are described and the results given. A comparison is also made between results by this method and by that of fiber elongation. The new results indicate that the apparatus can he successfully used for observing flow‐pressure relations at extremely high viscosities and also that at the temperatures used these two glasses are purely viscous liquids.
APPLICATION OF GARDNER MOBILOMETER TO ENAMEL SLIP CONSISTENCY STUDIES AND CONTROLS*
Authors: McIntyre G. H. , Irwin J. T.
Published: June 2006

A brief review of the type of instrument used by previous investigators is given. The Gardner mobilometer is described and its application to enamel‐slip consistency problems and control is discussed.
NOTES ON TUNNEL KILN CAR LUBRICATION*
Authors: Robson J. T.
Published: June 2006

A discussion of the properties required by oil for kiln‐car lubrication is presented. The results reported on questionnaires answered by forty plants operating tunnel kilns are given, together with comments and conclusions therefrom. The residue, flash, and burning points of ten different oils approved for kiln‐car lubrication are listed with directions for using oil as a lubricant on tunnel kiln cars.
THE EFFECT OF BORIC OXIDE ON THE DEVITRIFICATION OF THE SODA‐LIME‐SILICA GLASSES. THE QUATERNARY SYSTEM, Na2O‐CaO‐B2O3‐SiO21
Authors: Morey George W.
Published: June 2006

Commercial glasses of the soda‐lime‐silica types do not consist solely of these three oxides, but in addition contain significant amounts of other constituents which arc introduced incidentally as impurities or deliberately for some beneficial influence. Such minor additions may have either a favorable or unfavorable influence on the tendency of the glass to devitrify, and an investigation into the effect of such minor components is desirable. Previous results with MgO and with A12O3 have shown that a systematic study of a four‐component system is necessary to the understanding of its devitrification relations, and that arbitrary and fragmentary excursions into such a system give little insight into the general effect of the minor constituent and may be misinterpreted to erroneous conclusions as to the effect of this constituent on glasses of slightly different composition. Accordingly, in taking up the study of the effect of B2O3 on the devitrification of the soda‐lime‐silica glasses, it was added to 21 glasses in and near the field of devitrite, Na2O·3CaO·6SiO2, in the ternary system, Na2O–CaO‐SiO2, in amounts up to about 5%. In all cases the liquidus temperature was lowered, and the tendency toward devitrification reduced. Both of these effects are desirable and add to the thermal stability of the glass. With glasses containing 10% CaO, initially in the field of tridymite or so near to it that a small addition of B203 brings the resulting glass into the tridymite field, this initial lowering is replaced by an increase in the liquidus temperature which passed through a maximum at from 4 to 6% B2O3. With all other glasses the lowering continues, and the rate of decrease is greatest with glasses originally in the field of Na2O·2CaO·3SiO2. An exploration of the quaternary system showed that no new compounds are formed in any mixture that can be obtained by adding B203 in amounts up to 50% to any mixture in or near the devitrite field. It also indicated the probability that a narrow band of immiscible liquids is formed, extending across the ternary system, CaO‐B2O3–SiO2, and including the mineral danburite, CaO·B2O·2SiO2, but probably not extending far into the quaternary system. The fields of wollastonite and of Na2O·2CaO·3SiO2 were found to sweep out regions in the quaternary system extending over the square, Na2O·SiO2‐Na2O·B2O3‐CaO‐B2O3‐CaOSO2, and the field of Na2O·CaO·SiO2 was found to extend over the middle of this square, and is probably adjacent to the fields of wollastonite and of Na2O· 2CaO·3SiO2. A compound is formed between Na2O·B2O3 and CaO·B2O3. There is included a general survey of the literature relative to the effect of B203 on the properties of glass.
MECHANICS OF ENAMEL ADHERENCE, IV‐VII*
Authors: Greaves‐Walker Arthur MCK. , King R. M.
Published: June 2006

Sheet‐steel enamels with varying amounts of cobalt, nickel, and manganese oxides were applied to cast iron. Their impact resistance was determined and a study of contact zones was made.
VI. A Petrographic, Metallographic, and X‐Ray Study of Enamel‐Metal Contact Zones
Authors: Schwartzwalder Karl , King R. M.
Published: June 2006

Pieces of enamel were removed from contact zones and studied microscopically and with the X‐ray and metallographic microscope. A new technique for enamel study is suggested.
VISCOSITY‐TIME‐TEMPERATURE RELATIONS IN GLASS AT ANNEALING TEMPERATURES*
Authors: Lillie Howard R.
Published: June 2006

Viscosity data published by the author in 1931 are discussed with reference to their limitations. New experiments on fiber elongation in a redesigned apparatus are described in which one of the glasses previously used is tested. The results show that the viscosity of a newly drawn fiber increases with time of heat treatment according to a definite law which may be explained on the basis of a change in the state of aggregation in the glass. A finite equilibrium viscosity is indicated at each temperature, this limit being approachable from either side depending on previous heat treatment of the sample. This is taken to indicate an equilibrium average size of aggregate for any temperature, the groups starting to break up again if the temperature is increased after a long treatment. The expression of Sheppard and Houck is used for estimating effective molecular or aggregate weights in equilibrium at various temperatures, an example being 112,000 at about 500°C. The variation of viscosity with time is at least one reason why glasses fail to conform to Adams' and Williamson's annealing equation at low temperatures.
WATER‐TIGHT TERRA COTTA MASONRY*
Authors: Anderegg F. O.
Published: June 2006

In spite of the lessened opportunity for moisture to pass the face of a terra cotta wall as compared with brick masonry, certain precautions should be observed to produce a water‐tight wall, especially where the exposure is severe. The bearing of each of the important properties of masonry cements in regard to their application to terra cotta is pointed out and recommendations are made for suitable cementing materials. Suggestions are offered for the selection of sand and for securing uniformity and intimacy of mix. A joint width of to ¼ inch is recommended where the regularity Of the units permits. The joints should be shoved and given a tool finish at the proper stage of stiffening. The joints subjected to extra severe exposure should be packed with prehydrated mortar and properly tool‐finished. Mortar may be aided to adhere to a glazed surface either by using prehydrated mortars or by first painting the surfaces with cement paint. For back‐up, a hollow tile with webs vertical is recommended.
A SIMPLE DISPERSION TEST FOR CLAYS*
Authors: Wilson Hewitt , Page George A.
Published: June 2006

A test method was devised to indicate the comparative degree of dispersion of dry clay by simple blunging and removal of particles finer than 325‐mesh. Tests of seven kaolins and one ball clay are given.
SOME NOTES ON THE NATURE OF CLAY, II*
Authors: Norton By F. H.
Published: June 2006

The drying shrinkage curves were accurately determined for a number of clays and Other finely divided substances. Some clays show a secondary shrinkage and other do not. The latter are generally the less plastic ones. Other finely divided materials beside clay may show considerable plasticity, e.g., ferric oxide. The shrinkage curves give an insight into the nature of the surface film on the clay particles.
EFFECT OF VARIOUS GASEOUS ATMOSPHERES ON THE VITRIFICATION OF CERAMIC BODIES*
Authors: Badger A. E.
Published: June 2006

Various types of ceramic bodies were fired in atmospheres of O2, N2, CO2, H2, and H2. A marked increase in the rate of vitrification occurred when bodies containing feldspar were fired in an atmosphere of H2O. This effcct was explained on the basis of a feldspar‐water eutectic.
THE BLISTERING OF CAST IRON ENAMEL*
Authors: Poste Emerson P.
Published: June 2006

This Progress Report II is a continuation of the report presented before the Enamel Division in 1932. The subjects discussed are (1) gases from metal, (2) possible reaction between enamel and iron, and (3) gases from the enamel itself. The author concludes in this report that nothing has developed which is inconsistent with the facts summarized in the 1932 report.
THE DIELECTRIC STRENGTH OF PORCELAIN: THE INFLUENCE OF POROSITY*
Authors: Monack A. J. , Smith R. K.
Published: June 2006

This work utilized the samples used by Monack, Shardlow, and Warnsley in previous experiments.1 Between cones 7 and 10, the dielectric strength was found to be inversely proportional to the per cent apparent porosity. Between cones 10 and 15 the dielectric strength increased gradually while the apparent porosity remained essentially zero. No relation existed between dielectric strength and total porosity (open and closed pores). Overfiring does not seem to decrease the dielectric strength unless a definite vesicular structure is developed.
RESULTS OF SOME SHOP TESTS ON REBOILING*
Authors: Porter Frank R.
Published: June 2006

The reboiling problem was studied in the plant from three viewpoints, as follows: (1) ground coat, type of milling conditions and application; (2) processes, metal cleaning and ground‐coat drying and firing; and (3) enameling iron, source and gage.
GASES IN GLASS*
Authors: Dalton R. H.
Published: June 2006

An apparatus is described for extracting the gas from glass at glass‐furnace temperature and determining its composition. Results are given for glasses of various compositions and various melting histories. All ordinary glasses were found to contain appreciable quantities of dissolved (or chemically combined) gas, the amount varying from a few hundredths to a few tenths per cent. Water is frequently the most abundant gas, the content being highest in borosilicate glasses. Carbon dioxide is also usually present, the amount depending on the basicity of the glass. Nitrogen, carbon monoxide, and hydrogen were never found present in appreciable quantities. All oxidized glasses contain some oxygen. Glasses containing arsenic give off a comparatively large volume of oxygen. The effect of this oxygen on fining is discussed. It has been found that remelting a glas has little effect on the gas content. The gas content is greatly influenced by the size of the melt, being the lowest in small experimental melts.
A METHOD FOR THE DETERMINATION OF THE COEFFICIENT OF EXPANSION1
Authors: Kinzie C. J. , Commons C. H.
Published: June 2006

A description is given of a furnace and accessories for the determination of the coefficient of expansion of glasses. Suggestions are presented which may lead to the useful application of the method for the determination of the coefficient of expansion of materials in the hightemperature range.
SOME FACTORS INFLUENCING PROPERTIES OF ACID‐RESISTING ENAMELS *
Authors: Spencer‐Strong G. H.
Published: June 2006

Abstract

The effect of metal gage, firing treatment, drying method, application methods, and base‐coat compositions upon acid resistance and other physical properties, both alone and in combination, was determined upon three acid‐resisting enamels of widely varying types. The firing treatment and application method, especially in combination with the metal gage, were found to affect acid resistance, while all of the other factors affected physical characteristics. The type of enamel and application method controlled the degree of the effect of the factors. Dust coats were found to be more sensitive to variable factors of production than heavier applications.
CHARACTERISTICS OF IRON AND STEEL FOR PORCELAIN ENAMELING *
Authors: Porter F. R. , Nead J. H.
Published: June 2006

Abstract

The chemical and physical requirements of porcelain enameling sheets are presented. It is explained why the most satisfactory base metal for enameling purposes is one low in carbon, manganese, sulfur, phosphorus, and silicon. Thermal expansion curves and pertinent photomicrographs are shown.
STUDY OF METALLOGRAPHIC CHARACTERISTICS AND ENAMELING QUALITIES OF CERTAIN CAST IRONS *
Authors: Schaal R. B.
Published: June 2006

Abstract

The enameling properties of three different irons are described and their analyses are given. Photomicrographs are shown, depicting the structure of each iron near the surface before and after enameling. Structural changes during enameling are described and discussed as to their possible influence on enameling properties. It is shown that one iron anneals perfectly during enameling with no apparent surface alteration, another anneals perfectly but shows surface decarburization; the third sample does not anneal perfectly. Sample No. 1 enamels better than either No. 2 or No. 3.
MEASUREMENT OF SURFACE TENSION OF VISCOUS LIQUIDS *
Authors: Bradley C. A.
Published: June 2006

Abstract

The surface tensions of liquids of widely differing viscosities have been measured by the maximum bubble‐pressure method. With liquids whose viscosities are greater than about five poises, a modification of the customary technique is employed, which consists in observing the maximum pressure at which a bubble is stable. This is the same procedure which Parmelee used. The applicability of this method for viscous liquids has been tested by measuring the surface tensions at 25° C of a series of solutions of rosin in benzyl‐benzoate whose viscosities varied from about 100 to 2500 poises. The values obtained are within 1 % of those observed by the method of capillary rise. The method has been applied to the measurement of the surface tensions of molten glasses whose viscosities varied from 50 to 2500 poises. The precision obtained is about 1%. A technique for the approximate measurement of surface tension of glasses by means of sessile drops is described.
FAILURE OF COKE‐OVEN WALLS BY REACTION WITH COAL ASH *
Authors: Rueckel W. C.
Published: June 2006

Abstract

The failure of coke‐oven walls by slagging is described and data are presented which trace the source of the damaging material to the coal. Mechanism of failure is explained with the help of phase‐rule diagrams for the systems FeO‐SiO2 and Fe and O2.
PYROMETRIC PROPERTIES OF SPODUMENE‐FELDSPAR MIXTURES *
Authors: Boyd J. E.
Published: June 2006

Abstract

An experimental study is reported on pyrometric properties of mixtures of potash feldspar, soda feldspar, and spodumene. Numerical and graphic data show that the addition of spodumene to the feldspars up to 20% lowers the P.C.E. of the mixtures very rapidly. As spodumene is increased above 40%, the P.C.E. of the mixtures increases rapidly. By means of a triaxial diagram a considerable area is shown with P.C.E. values six to seven cones below those of the feldspars.
SPECIAL WEAR‐RESISTING MATERIALS FOR CLAY MACHINERY PARTS *
Authors: Everhart J. O.
Published: June 2006

Abstract

A study of wear‐resisting materials for clay machinery parts was made at the Ohio State University Engineering Experiment Station. More than 50 alloy irons and steels were subjected to actual plant tests, e.g., mill knives, die liners, muller tires, and grinder parts. The best of these are discussed from the standpoint of economy and service. Recommendations as to the proper kind of material for various types of installations are given.
COMPUTATION OF HEAT TREATMENTS FOR WHITEWARE BODIES *
Authors: Meyer W. W.
Published: June 2006

Abstract

The constant in Arrhenius’equation, when applied to the vitrification process of feldspathic whiteware bodies was calculated, using known data. Proceeding from this point, a mathematical expression for the amount of reaction taking place in a normal whiteware mixture, heated according to a given schedule, was obtained. Formulas were also derived for calculating heating schedules of various rates of temperature rise and lengths of soaking period productive of a given amount of reaction. The calculated amounts of reaction necessary to vitrify feldspathic whiteware bodies were correlated with the RO contents of the bodies. Data on the physical properties of variously heat‐treated bodies are given to substantiate the validity of the formulas. A chart is given by means of which many heat‐treatment problems can be solved without using the mathematical formulas.
TEMPERATURE MEASURING CONES *
Authors: Rea Robert F.
Published: June 2006

Abstract

A series of pyrometric cones that measure temperature independent of the rate of heating has been developed. These cones are mixtures of inorganic salts and melt congruently. Melting‐point data are presented for the three binary systems MgSO4‐Li2SO4, K2SO4‐KBr, and Na2SO4‐NaBr.
QUADRANT‐CHART TYPE NOMOGRAPH APPLIED TO CLAY SLIPS *
Authors: Pask J. A.
Published: June 2006

Abstract

An example of the quadrant‐chart type of nomograph for “changing the concentration of a water‐solid mixture to another desired concentration of 100 cubic centimeters volume” and a general summary of the mechanics of construction of this form of graphical solution are presented.
CRITICAL STUDY OF METHODS OF DETERMINING EXCHANGEABLE BASES IN CLAYS *
Authors: Graham Robert P. , Sullivan John D.
Published: June 2006

Abstract

A study was made of analytical methods of determining exchangeable bases in clays and similar ceramic materials. Total exchange capacity can be determined by electrodialysis or by the teaching‐distillation method. The time required for electrodialysis can be materially reduced by agitation of the clay slip during dialysis. Electrodialysis effects decomposition of bentonite and similar materials unless extremely low current densities are applied. Exchangeable cations of clays and similar materials are replaced slowly by percolation methods, but an agitation leaching‐centrifuging procedure was developed which effects a rapid replacement. In ultimate analyses by leaching methods, correction must be made for soluble sulfates. Aqueous 1 N ammonium acetate is a satisfactory leaching solvent for most clay bodies, but for those containing appreciable amounts of calcium carbonate, alcoholic ammonium acetate should be employed. Details of recommended analytical procedures are given.
SURFACE PROPERTIES OF FUSED SALTS AND GLASSES: I SESSILE‐DROP METHOD FOR DETERMINING SURFACE TENSION AND DENSITY OF VISCOUS LIQUIDS AT HIGH TEMPERATURES *
Authors: ELLEFSON Bennett S. , Taylor Nelson W.
Published: June 2006

Abstract

An apparatus is described which allows measurements to be made of the contact angle and the exact dimensions of a sessile drop of liquid resting on an electrode graphite surface in vacua or in nitrogen atmosphere. Temperatures up to 1100°C have been employed. Under these conditions, surface tension and gravity are the only forces acting on the drop, and the exact shape, surface, and volume may be computed from the tables of Bashforth and Adams. The method may be used with liquids having viscosities up to 600 poises, whereas the bubble‐pressure method used by Jaeger is limited to liquids of viscosity less than 70 poises.

On the basis of internal evidence, the surface‐tension values obtained by the sessile‐drop method are considered correct within 5%. They also agree with data by Jaeger, but are, roughly, twice as great as those of Washburn and Libmart, who used a ring method. The probable error in Washburn and Libman's work appears to be in their assumption of zero contact angle.
ELECTRICALLY FUSED MAGNESIA *
Authors: White Harold E.
Published: June 2006

Abstract

Electrically fused magnesia has gradually won a place in the special refractories group, owing to its physical superiority over the ordinary grades of dead‐burned magnesite. The history of its development dates from the world‐war period, when considerable interest was aroused in the sources of supply of magnesite in this country. The economic advantages depend largely on the European situation and the prevailing price for the fused material, but the practical advantages of using a totally shrunk, well‐crystallized material are obvious. The crystalline material obtained from various grades of raw material differs somewhat in its physical characteristics, and there is a decided difference in the physical properties between dead‐burned magnesite and electrically fused magnesia.
THE USE OF TALC AND PYROPHYLLITE IN SEMIVITREOUS DINNERWARE BODIES *
Authors: Lintz Elmo H.
Published: June 2006

Abstract

The use of talc and pyrophyllite in semivitreous dinnerware bodies is discussed. The effect of these materials on shrinkage, absorption, modulus of rupture, and moisture expansion are shown. The advantages obtained are better drying and firing properties, higher mechanical strength, and greater resistance to delayed crazing.
DIELECTRIC LOSS OF GLASS AT HIGH FREQUENCIES*
Authors: Thurnauer H. , Badger A. E
Published: June 2006

Abstract

Power factor measurements at frequencies of 100, 500, 1500, and 5000 kilocycles were made on a series of soda‐lime‐silica glasses and on another series of glasses, starting with a base glass of the composition of 17.4% Na2O, 10.1% CaO, 72.5% SiO2 (or 1.4 Na2O to 0.9 CaO to 6.0 SiO2), to which 0.030 gram‐atom of various elements in the form of their oxides were added. In the first series, the power factor for all glasses measured decreased with increasing frequency and increased markedly with increase in Na2O content. In the second series, the power factor decreased with increasing frequency as in the case of the first series. An increase in power factor was produced by additions of Zr, Na, and Al oxides, and a decrease was produced by additions of the oxides of Si, V, Zn, Mg, B, Ti, Co, Ca, Ce, Ni, Mn, Fe, Ba, Pb, Li, and K.
SURFACE TENSION MEASUREMENTS ON MOLTEN GLASS BY A MODIFIED DIPPING CYLINDER METHOD*
Authors: Babcock C. L.
Published: June 2006

Abstract

Surface tension measurements have been made on a series of both calcite and dolomite lime glasses by using a modified dipping cylinder method. The measurements cover the temperature range from 1100° to 1400°C. and the viscosity range from logarithm viscosity = 1.65 to logarithm viscosity = 3.30 (45 to 2000 poises). Measurements on ordinary liquids, of known surface tensions were made for check purposes.

The results obtained on the glasses agree well with published data obtained by the maximum bubble‐pressure method. The temperature coefficient of surface tension is approximately —0.02 dyne per cm. per degree C. The surface tension of glass at a particular temperature may be represented as a linear function of composition on a mol. fraction basis.
DETERMINATION OF QUARTZ (FREE SILICA) IN REFRACTORY CLAYS*
Authors: Trostbl L. J. , Wynne D. J.
Published: June 2006

Abstract

A rapid procedure is described for determining quartz in refractory clays by fusion in potassium bisulfate and subsequently by dissolving precipitated silica with a hot caustic solution. Data are included on the quartz content of several clays.
EFFECT OF ADSORBED ELECTROLYTES ON PROPERTIES OF MONODISPERSE CLAY‐WATER SYSTEMS*
Authors: Speil S.
Published: June 2006

Abstract

A sample of Florida kaolin was separated by a supercentrif uge into three nearly mono‐disperse systems whose sizes were, respectively, 0.1 to 0.2, 0.2 to 0.4, and 0.4 to 1.0 micron. These samples were electrodialyzed, and to aliquot samples of the H clay thus obtained, varying concentrations of sodium or barium hydroxide were added.

The base‐exchange capacity at pH 7 varied linearly with the surface area. The apparent viscosity was reduced to about 4% of its original value by the addition of 1 milli‐equivalent of sodium hydroxide, after which further additions had a very slight lowering effect. The addition of electrolyte decreased the yield point and increased the maximum strain before rupture at the water content of optimum plasticity. The water of plasticity, pore water, shrinkage water, and film thickness were decreased by adding electrolyte. The dry transverse strength was doubled by the change from H clay to Na clay. Most properties varied linearly with the surface area within the experimental error. The potential concept of plasticity is briefly outlined.
EFFECT OF EXCHANGEABLE BASES ON ABSORPTION AND TRANSVERSE STRENGTH OF CLAY BODIES*
Authors: Graham Robert P. , Sullivan John D.
Published: June 2006

Abstract

The absorption and transverse strength of clay bodies, both in the fired and unfired state, are influenced greatly by the nature of the exchangeable bases present on the surface of the clay particles. Plastic clays with high exchange capacity are more affected than nonplastic clays, such as flint clays. Of the various common base forms studied, sodium‐type clays in general require less water to give the same degree of stiffness, and their fired and unfired transverse strengths are high. Hydrogen clays require higher water content and have greater porosity and lower transverse strength. Data are given on a plastic fire clay, a ball clay, a bentonite, and two flint fire clays. All experiments made were on stiff‐mud bodies.
THE TEARING OF VITREOUS ENAMELS*
Authors: Rosenberg J. E. , Langerman A. F.
Published: June 2006

Abstract

Similar to other enamel shop problems, tearing has not been reproducible under controlled conditions in the laboratory. Experiments show that tearing is caused by a cracking of the bisque before enamel fusion. To produce bisque cracking experimentally in the laboratory, a ground‐coated cross‐bend strip, 2 by 12 inches, was covered on one side with a coating of the test enamel. The enamel was dried, and before firing it was flexed to a predetermined degree in a Danielson‐Lindemann cross‐bending machine. The strip was fired, and the degree of tearing was studied. The effect of various factors, such as grinding fineness, application, clay, and other mill additions, in overcoming tearing difficulties was determined by this method. Certain materials which overcome tearing do not prevent bisque cracking but cause the cracked bisque to heal rather than break away during the firing process. Experimental results are given.
AN INVESTIGATION OF THE VOLATILITY OF GLAZE CONSTITUENTS BY THE USE OF THE SPECTROGRAPH*
Authors: Harrison H. C. , Lawrence W. G. , Tucker† D. J.
Published: June 2006

Abstract

A procedure, developed for the study of volatile glaze constituents, consists of heating the glazes beneath an absorbing medium which is subsequently tested by the spectrograph for the volatilizable constituents evolved. Data are presented showing temperatures at which certain important glaze constituents begin to volatilize, the order in which they leave the parent glaze, the influence of glaze composition on the volatilization temperature of each volatilizable constituent, and the effect of heat treatment on the volatilization temperatures.
ANALYSIS OF SELENIUM IN GLASS*
Authors: Pavlish A. E. , Silverthorn R. W.
Published: June 2006

Abstract

A new method for the determination of selenium in glass is reported. It comprises fusion of the sample with sodium carbonate, dissolution of the melt in sulfuric acid, distillation of the selenium as selenium tetrabromide from a sulfuric‐hydrobromic acid solution, and titration of the distilled selenium by the iodide‐thiosulfate method. The method is rapid, accurate, and precise and recovers all forms of selenium. The recommended procedure is outlined.
STRESSES IN BOTTLES OR JARS FROM DIFFERENCES IN OUTSIDE AND INSIDE TEMPERATURES (STATIC TEMPERATURE GRADIENT)*
Authors: Preston F. W.
Published: June 2006

Abstract

This investigation shows that there is likely to be a severe concentration of stress in bottles or jars on the outside face of the junction of side walls and base when the bottles are subjected to a thermal gradient, that is, hot inside and cold outside. The stress in this area apparently may be two or three times as high as the general average, and its amount depends on the details of design at this point. A general formula, intended as a first approximation to the stress, has been worked out. That this region is a region of weakness is not news, but the reasons for it, as deduced in this study, are different from those generally given. Murgatroyd has shown that scratches on a bottle have a greater influence here than elsewhere and that their vulnerability is greatest if they are horizontal. His results are empirical, and he does not explain them. The explanation is given here.
EXPANSION STRAINS IN THE INITIAL FIRING OF CERAMIC WARE*
Authors: SIEVERT G. E. , Moffat J.
Published: June 2006

Abstract

The initial firing of some ceramic bodies is accompanied by a preliminary expansion before shrinkage takes place. This expansion, which has been determined for several types of ceramic bodies, may set up strains and result in the cracking of large pieces when they are improperly fired. A firing schedule that will lessen the strains and eliminate the cracking has been effected and is described in this paper.