bluuebunny/crossref_metadata_2025 huggingface dataset:
BERYL AS A CONSTITUENT IN HIGH TENSION INSULATOR PORCELAIN
Authors: Twells Robert
Published: June 2006

Two series, one of 9 bodies and one of 6, were prepared, in which flint and feldspar were partially replaced, weight for weight, by beryl. Bars and discs were fired to cone 8 3/4, to 10, or to 10 3/4 and tested for shrinkage, transverse strength, impact strength, heat resistance, absorption of moisture, and dye penetration. The results show that introduced in proper proportions beryl increases the transverse strength, impact strength, heat resistance and dielectric strength. The best results are obtained with the following limits of composition:
AN EXPERIMENT IN ELECTRIC SMELTING GLASS ENAMEL1
Authors: Geisinger E. E.
Published: June 2006

Operating economies will require smelting of enamel frits in electric furnaces. A refractory enamel containing high content of metallic oxides was smelted in a combination are and carbon resistor furnace, obtaining complete fusion without reduction of the oxides or change in character of the enamel.
THE HARROP TUNNEL KILN
Authors: Cramer W. E.
Published: June 2006

The successful application of the car tunnel kiln to the firing of electrical porcelains is described. This kiln is 321 feet long, 54 1/2 inches wide inside, and has a placing height of approximately 60 inches. The ware is placed in saggers as formerly. Ware has been fired through this kiln in 48 hours‐total time for heating up, soaking, and cooling. The kiln operates at cones 10, 11, and 12, depending upon the ware being fired. Natural gas is used as fuel and is supplied to the kiln through Maxon Premix burners. Auxiliary fuel oil equipment is also installed.
POROSITY: VII. THE DETERMINATION OF THE POROSITY OF HIGHLY VITRIFIED BODIES43
Authors: Washburn Edward W. , Bunting Elmer N.
Published: June 2006

Design and Accuracy.—The accuracy limitations of the general laboratory research type of porosimeter are discussed and the principles of design indicated.

McLeod‐Gauge Type of Porosimeter.—A new type of porosimeter is described with which the pore volume of any test piece may be directly determined within 0.01–0.02 cc.

Results with Electrical Porcelain.—Tests of eight pieces of electrical porcelain indicated a porosity of 0±0.01 per cent. This result was confirmed by dye penetration tests.

An Apparatus for Measuring the Porosity of Full Size Brick.—A simple and rapid apparatus for measuring the porosity of full size brick by the “General Method”(Jour. Amer. Ceram. Soc., 5, 113–16 (1922)) is figured and described.
NEED FOR MORE REFRACTORY HEAT INSULATORS Proposed Conductometers for Measuring Thermal Conductivity1
Authors: Pike Robt. D.
Published: June 2006

The commercial value of high temperature thermal insulators is discussed, and a numerical example of a problem in designing a flue for conducting hot gases is given. A suggestion is offered for carrying out research in the manufacture of more highly refractory thermal insulators than are at present available, and tentative specifications for refractory and insulating properties are given. It is further suggested that refractory manufacturers should interest themselves in such research. The need of a simple apparatus, called for convenience a conductometer, for carrying out routine investigations of thermal conductivity, is pointed out, and, after describing some of the more important apparatus formerly used, a design of an improved new type is suggested and the method of working up the results is described.
AN IMPROVED MAGNET BOX1
Authors: Spurrier H.
Published: June 2006

The plates are made of wrought iron carrying vertical projections, thereby carrying the magnetic poles clear up into the flowing slip.

The slip is broken up into several streams which, on passing the narrow spaces between the fingers, more readily yield their metallic iron.

Settlings in the box do not impair the magnetic efficiency.
A LOW FIRE PORCELAIN1
Authors: Binns Charles F. , Burdick Tina
Published: June 2006

Pieces of the following composition were cast and then fired at about cone 02, or lower, and then glazed and fired at cone 4. The result was a pleasing porcelain.

Frit Batch: Whiting, 0.32 × 100 = 32; Niter, 0.28 × 202 = 56.5: Borax, 0.12 × 328 = 45.8; Soda Ash, 0.18 × 106 = 19; Magnesite, 0.10 × 84 = 8.4; Calcined Clay, 0.24 × 222 = 53.3; Flint, 1.8 × 60 = 108; Total = 322. Georgia Clay 0.07 or 18 parts was added to the fritted batch
WET PROCESS ENAMELS FOR CAST IRON1
Authors: Danielson R. R. , REINECKER H. P.
Published: June 2006

Wet process enameling of cast iron is becoming of importance because of its application to the enameling of stove parts, sanitary fittings and hardware. This paper is a report of an extended investigation of wet process enamels for cast iron, in connection with the use of a ground coat.

Compositions used in dry process enameling have served as a basis for the work, which includes a study of ground coats and white cover enamels. The effect of varying methods of preparing the frits, mill additions, and the relation of composition of the enamels to such properties as adherence, texture and opacity have been carefully studied.

Ground Coats.—Sintering of most ground coat frits has been found desirable in order to develop best adherence on the castings. Clay gave best results as a mill addition for the groundvt and feldspar were found to be less satisfactory. Excessive additions of clay or flint produced flaking of the ground coat while feldspar tended to develop blistering. About 15 per cent of clay or 10 per cent each of clay and flint are recommended as mill additions for the ground coats.

Excessive additions of any one flux were not desirable, and best results were obtained when sodium, lead and boric oxides were combined in more or less definite pro‐portions. Sodium oxide in excess of about 10 per cent gave rise to blistering. Boric oxide increased the firing range of the ground coats and was preferable to lead oxide on this account, although it tended to promote crawling of ground coats high in boric oxide if they were applied somewhat heavily.

The best ground coats developed are Rg‐26, 17, 1, 25 and 18.

Cover Enamels.—Cover enamels were smelted in the usual manner. The mill additions consisted of 5 per cent of clay, 8 per cent of tin oxide, and 45 per cent of water, all based on the weight of the dry frit.

For best results, the cover enamel must he adapted to the ground coat in refractoriness. Boric acid increased the firing range of the enamels but tended to promote crawling, although this was less pronounced in the case of the more fusible compositions. Boric oxide improved the opacity when suhsituted for such fluxes as sodium and lead oxides. Cryolite increased opacity but additions above 10 per cent, based on the melted weight, tended to promote crawling. Considering all factors, cover enamels R‐14 11, 28, 1 and 18 gave best results.
THE ORGANIZATION OF A DECORATIVE CERAMIC RESEARCH DEPARTMENT1
Authors: Rhead Frederick H.
Published: June 2006

Artistic development has been slow in the clay industries and has not yet arrived at that stage where it can be legitimately considered a functioning organization activity.

A research organization is a business activity and not a purely scientific venture. Therefore, it is incomplete if it concentrates on any one essential branch of the industry to the exclusion of the others. Future business possibilities are obviously the main activities.

A budget should be arranged to cover a definite period and a program to provide for a definite result since research work involves considerable expenditure in labor and equipment.

The typical art pottery organization is described, giving the qualifications of the various plant executives and directing heads. The research program in relation to losses is discussed. The types of losses are classified. The investment required in connection with a typical organization of a stated size is outlined. The development program with the results for the first twelve months and the year's results against the expenditures are summarized. The position occupied by the clay working industries in comparison to other national industries is discussed.
THE RELATIVE MERIT OF HEAT RESISTING ALLOYS FOR ENAMEL BURNING RACKS
Authors: Poste E. P.
Published: June 2006

Enamel burning racks fail by oxidation and warpage. Several metals have been studied with regard to oxidation and warpage at a temperature from 1700° to 1800°F. These metals are listed in the order of increasing warpage and increasing oxidation. Actual data is given and comparisons are made by means of a chart. Conclusions are drawn in terms of the choice of rack material for burning heavy and light ware.
THE CAUSTIC CALCINATION OF DOLOMITE AND ITS USE IN SORREL CEMENTS1
Authors: Bole G. A. , Shaw J. B.
Published: June 2006

A method for calcining dolomite in which the pressure of carbon dioxide is controlled is described. Less than ½ of one per cent of lime is liberated. Material was calcined in ton lots using external heating. Two types of retort were used: wrought iron and fire clay. Floors were laid from the material so calcined and physical tests made on the calcine to determine its availability as a stucco material.

The effect of time, temperature, and pressure of carbon dioxide upon three types of dolomite is brought out.

Dolomites are either double salts or solid solutions or mixtures of the two.

The effect of lime and silica is pointed out.

Dissociation, tensile strength, volume change, time of set, and weather test data are given.
I. THE USE OF PULSICHROME FROM A MANUFACTURER'S STANDPOINT
Authors: Clark Ernest
Published: June 2006

I. Two papers setting forth the advantages of the pulsichrometer for applying glazes, followed by discussions. In the pressing room the use of the pulsichrometer gives a uniform appearance; rapid application and pleasing effect in one operation in slipping department; eliminates the necessity for re‐burns in the kiln department; handled with greater speed in the fitting department.

II. The advantages of the pulsichrometer versus the old method of applying glazes are the better production of colors and elimination of the “human element.” Closer coöperation is expected between the terra cotta manufacturer and the architect.
THE EFFECT OF SOME FLUXES ON THE ABSORPTION AND TRANSVERSE STRENGTH OF A TERRA COTTA BODY1
Authors: Hill E. C.
Published: June 2006

The results show the effect on the absorption and transverse strength of a terra cotta body by the addition of various material used as possible fluxes.
MOULDS FOR MAGNESITE, CHROME AND SILICA BRICK1
Authors: Ayars Erling E.
Published: June 2006

Shrinkage.—Determination of allowance for shrinkage in mould manufacture is of prime importance. Design comes next.

Types of Moulds.—Slip moulds including the open slip and vent bottom types, steel slip liner moulds, and the wooden knock‐down screw mould.

Materials Used.—Soft steel, cold rolled steel, galvanized iron and hard woods.

Moulding Tools.—The slicker, short scoop, smacker, putty knife, rammer and hammer.

Manufacture of Moulds.—Relation to the manufacture of all kinds of brick made from these special refractory materials. The treatment of each type of mould includes materials and method of manufacture, the materials and kinds of brick, the manufacture of which it is best suited, together with the manipulation best suited to turning out a uniformly good product. Correction of mould faults and suggestions for overcoming difficulties encountered in moulding brick find their place wherever the discussion of the various moulds and operations suggests any of the common troubles of the moulder.
PHYSICAL DEFECTS IN TANK BLOCKS1
Authors: Loomis Geo. A.
Published: June 2006

An investigation of some of the leading makes of tank blocks of flux grade tends to show that these blocks as a class, are not as free of physical defects, such as fissures and lamination, as could be desired. Photographs are shown of representative sections of the blocks examined.
POROSITY: VI. DETERMINATION OF POROSITY BY THE METHOD OF GAS EXPANSION*
Authors: Washburn Edward W. , Bunting Elmer N.
Published: June 2006

Theory of the method.—The pore volume is measured by allowing the gas which fills the pores to expand into a measured volume and measuring the accompanying fall in pressure.

Applicability.—The method is in general applicable to pieces of any size and shape and to all classes of porous bodies or materials.

A new porosimeter.—For rapid work with shaped test pieces a new porosimeter is described. The new instrument measures accurately both pore volume and bulk volume. A complete porosity determination can be made in 5 minutes. No weighing is required. The results on ceramic bodies arc reproducible to one unit in the first decimal place of the per cent porosity. Considerably higher accuracy than this can be secured if desired.

Results.—The results obtained with the new method are in all cases higher, in a number of cases very much higher, than those obtained by the methods of liquid absorption in current use. For fired bodies the same results are obtained with dry air, hydrogen or helium as the pore filling gas. The results show conclusively that complete filling of all the pores in a reasonable time can not be secured by any of the current methods using a liquid as the pore filling agent.
THE DEVELOPMENT OF CERAMIC WORK AT THE UNIVERSITY OF NORTH DAKOTA1
Authors: Cable Margaret Kelly
Published: June 2006

The development of the Ceramics Department of the University of North Dakota; correlation of research in chemical and experimental laboratories and cultural value of the work; inexhaustible supplies of the state being utilized.
THE HANDLING, STORING AND SETTING OF GLASS POTS1
Authors: Clark Wm. M. , Forsyth J. H.
Published: June 2006

“A glass pot is a wonderful piece of engineering:” It is an expensive article and deserves the most careful treatment. The precautions indicated are; careful packing for shipment in ruin proof box cars, well padded pot carriages equipped with the spring suspensions, storage in a warm, dry room, careful preparation of furnace bench to insure an even distribution of load on the bottom of the pot and to make certain that the pot is level, or tilted slightly forward. Unnecessary jolts often result in damage which only becomes apparent when the pot is heated up.
SUGGESTED NEW METHODS IN THE PREPARATION OF DUST‐PRESSED BODIES1
Authors: Spurrier H.
Published: June 2006

Milling.—A continuous pebble mill of the self‐feeding type is recommended. Segregation due to difference in density is not to be feared.

Drying.—Instead of drying completely, wetting down, tempering, aging and grinding the author recommends drying the press cake only down to a water content of 16%, followed immediately by disintegrating and pressing. The pressed ware produced by this shortened procedure is very satisfactory.

A Combined Disintegrator and Dryer.—The author suggests the application of a hot blast to the clay as it leaves the mill for the disintegrator thus drying and disintegrating it in one operation. This suggestion has not, however, been tried out.
THE WEATHERING OF GLASS CONTAINERS1
Authors: Ford. K. L.
Published: June 2006

Stability in storage is a requisite of commercial glass. A white film or surface spotted with white patches is frequently observed on glass that has been in storage for some time. These weathering effects can be produced artificially by several methods which are given. Several factors, including humidity, have been found to influence the rate at which weathering takes place. Dipping in hydrochloric acid before packing retards weathering and paper properly used in packing is effective in decreasing the tendency to weather.

Three classes of weathering effects are given and illustrated with microphotographs. Experiments show that continued boiling removes the weathered surface.

The products of weathering consist of crystals of soluble salt or salts, principally sodium carbonate, and an insoluble film.

The lime, soda, and silica are found to have the same relative values in the weathered material as in the original glass, with the addition of certain amounts of carbonate, moisture, and dirt and organic material.

Weathering is largely dependent on solubility. Glass showing the greatest resistance to weathering proves equally resistant to action of water at temperatures and pressures above normal.

Condition of surface appears to influence the solubility. Alumina increases the resistance of glass to weathering. Sodium carbonate may exist in glass after manufacture and assist in weathering.
CHROME REFRACTORIES1
Authors: McDowell J. Spotts , Robertson H. S.
Published: June 2006

A compilation from the available literature is presented, giving the more important data on chromite and chrome refractories. A bibliography is included.
THE INFLUENCE OF GRIND AND BURN ON THE CHARACTERISTICS OF SILICA BRICK1
Authors: Howe R. M. , Kerr W. R.
Published: June 2006

Finer grinding improves the appearance of the brick and increases their strength somewhat but not in any marked degree, within the commercial limits of grinding. A grinding of from 15 to 20 minutes seems most desirable. The time of grinding does not affect the porosity appreciably. The firing temperature is the principal factor governing the final strength and also the permanent residual expansion. The maximum temperature cone 19, yielded the highest strength and the lowest expansion.
RESISTANCE TESTS ON FIRE BRICKS UNDER LOADS AT HIGH TEMPERATURES1
Authors: Sieurin E. , Carlsson Fredr , Kjellgren B.
Published: June 2006

Method. —Mixtures of fine ground china clay and ball clay with grog (called by the author “chamotte”) of the same materials were made into 3 cm. cubes and subjected to a pressure of 2 kg. per sq. cm. at temperatures which sufficed to bring about a linear contraction of 0.3 per cent in 2 hours. Definite quantities of silica, alumina, ferric oxide, lime and magnesia were added and both the deformation and the usual softening points determined.

Results. —Even very small amounts of the oxides of iron, calcium and magnesium brought about a considerable reduction in the resistance to pressure. A minimum in the resistance was observed with silica contents between 60‐70 per cent, which does not correspond to the minimum softening point or melting point of clay‐silica mixtures. Additions of alumina increased the temperature required to deform the specimens but with high alumina content mechanical failure due to lack of bonding material occurred. For many purposes clay fire brick will have to be replaced by more resistant materials, such as brick made from silica, aluminous mixtures and silicon carbide.
AN ELECTRIC FURNACE FOR VITREOUS ENAMELING1
Authors: Schwier Carl
Published: June 2006

An electric furnace for vitreous enameling built with round wire coils placed in top, bottom and both sides. The furnace is equipped with a double loading fork and some cost data are given.
COLD END COMPENSATION ON A PYROMETER SYSTEM1
Authors: Thwing Charles B.
Published: June 2006

Attention is called to the fact that every measurement involves two quantities and that failure to correctly determine either leads to erroneous results.

The large cold end variation present in the usual method of mounting thermocouples in brick kilns is pointed out and an improved method shown.

Various plans for converting the cold end error are described.
THE TRANSFER OF HEAT THROUGH REFRACTORIES AND ITS DETERMINATION
Authors: Watts A. S. , King R. M.
Published: June 2006

This paper gives a review and bibliography of the literature on heat conductivity of refractories, as well as a description of a proposed method for the determination of the heat transmitting abilities of refractory materials. In the development of this method, standard apparatus, standard conditions, and standard operations were held as desirable and to a practical extent were obtained. It is believed that this method may be profitably used in testing and control laboratories for securing heat transfer data for refractory materials. The heat transfer values of several refractories, as determined by this method, are given and it is pointed out that this value closely approaches the resultant of all the forces which are acting to produce heat transmission.
PROGRESS REPORT ON SPECIFICATIONS FOR REFRACTORIES1
Authors: Geller R. F.
Published: June 2006

Following a conference with producers and consumers of refractories, a series of proposed laboratory tests were conducted on forty‐one commercial brands of brick. The work included reheating at 1450° and 1400°C, quenching, load test, fusion point determination, chemical analyses and petrographic examination. Results of tests are presented, They will be more fully discussed when correlated with service tests now under way.
METALLURGICAL REQUIREMENTS FOR REFRACTORIES IN THE ELECTROTHERMIC METALLURGY OF ZINC1
Authors: O'Harra B. M.
Published: June 2006

Refractory brick for lining electrothermic dry distillation furnaces must have a melting point of not less than 1600°C, must retain their strength at temperatures of 1400–1500°C, must be non‐porous, and of uniform size. For lining electrothermic smelting furnaces, in which a liquid slag is produced, they must in addition to having these qualities be resistant to the corrosive action of highly heated slags which may be either strongly acid or strongly basic. The condensers are similar for both types of furnace. The brick for lining them need not have a high melting point but must be dense and of uniform size and must be very low in free iron oxide to withstand the disintegrating effect of carbon monoxide in the cooler portion of the condenser.
OUTLINE OF REFRACTORY REQUIREMENTS FOR THE IRON AND STEEL INDUSTRY1
Authors: Davis F. W.
Published: June 2006

One of the greatest obstacles to the development of better refractories for the iron and steel industry has been the failure of the iron and steel men to give refractory manufacturers accurate detailed analysis of chemical, physical and thermal conditions to which the refractories are to be subjected. This paper summarizes briefly some of the conditions to be encountered in the major processes.

Blast furnace refractories may be divided according to requirements as follows: Hearth and Bosh brick should withstand the scouring action of molten iron and acid slag at temperatures around 1800°C. Inwall brick should be impervious to hot, reducing gases, should resist the sand blast action of the from particles of ore carried by the gas, should have a low coefficient of thermal expansion and should possess sufficient compressive strength to support the weight of the upper part of the furnace. Top brick should be as dense and resistant to abrasion as possible. Downcomer, Dustcatcher and Gas Line brick should be dense and resist sand blast action of gas heavily laden by particles of charge. Hot Blast Main and Bustle Pipe brick should be of low heat conductivity. Hot Blast Stove brick should not vitrify at 900°C, should have maximum capacity for absorbing and giving off heat, and be of high compressive strength.

The by‐product coke oven is becoming a big factor in the refractory fields and has major requirements as follows: Canals and Ovens require brick of high thermal conductivity which will resist sudden changes in temperature and will not be affected by reducing gases at high temperatures. Checker brick should have great capacity for absorbing heat.

Bessemer converters require brick resistant to slag at temperatures from 1600° to 1700°C, the nature of the slag being determined by whether the process is acid or basic.

Requirements for open hearth furnaces are as follows: Roof brick (both acid and basic furnaces) must not only be capable of maintaining an arch but should withstand as much as possible the action of iron oxides at temperatures of 1800°C. Checker brick (both acid and basic furnaces) should possess a maximum capacity for absorbing and giving off heat, and a minimum chemical affinity for oxides from charge. Ports (both acid and basic) must withstand the action of slag splashes, also direct action of flame. The hearth of the furnace consists of several courses of brick (acid or basic depending on the process) upon which is built the hearth proper by means of many layers of crushed refractory of the same nature. This crushed material must frit together at high temperatures without excessive softening.
REFRACTORIES FOR FLAT ARCHES1
Authors: Harlow Justin E.
Published: June 2006

Arch construction is discussed, describing present method of placing fire clay tile. Tile are suspended on cast iron hangers by means of a tee‐shaped slot molded in the top end of each tile, giving room for expansion in every direction. Larger quantities of heat units are released, more intense chemical reactions and there is ample shearing strength and small loss from weight or pressure.
A PROPOSED METHOD FOR STUDYING THE ATTACK OF MOLTEN SLAGS AND GLASSES UPON REFRACTORY MATERIALS1
Authors: Rose Charles I.
Published: June 2006

A new method of studying the attack of molten glasses and glasses upon refractory materials, whereby the refractory tested is rotated in a glass or slag melt under arbitrary conditions, is described. The solution and penetration of the refractory are measured separately by means of a micrometer and simple microscope, and some of the advantages of this procedure are enumerated.
THE ORIGIN, DISTRIBUTION AND COMPOSITION OF LATERITE
Authors: Swanson C. O.
Published: June 2006

The term laterite means a red rock or red earth deposit. Laterites are formed by the decomposition of different kind of rocks, under conditions yielding aluminum and iron hydroxides. The different theories of origin are discussed, as well as the chemical process of laterization, and the geographic distribution of this peculiar type of clay.
PRELIMINARY REPORT1 ON THE RESIDUAL KAOLIN AND FELDSPAR IN THE PACIFIC NORTHWEST
Authors: WILSON EEWITT , LEE BENNETT A. , Heath Fred T.
Published: June 2006

Large quantities of residual crystalline kaolin are found in the Inland Empire district of eastern Washington and northwestern Idaho. Preliminary investigation has shown that the properties of these clays, when properly selected and purified, will compare favorably with those of the English china clay upon which the eastern potters and paper manufacturers are largely dependent. With the low cost of the English clay laid down on the Atlantic Coast, it is not believed that the Pacific Northwest clay will be used as a substitute for the English in the eastern markets, but the domestic source will provide the bulk of the raw material for the future whiteware industry in the Pacific Northwest. Commercial quantities of feldspar, quartz, and fire clay are also found in the Pacific Northwest.

The work described here was conducted at Seattle under a cooperative arrangement between the College of Mines, University of Washington, and the Northwest Experiment Station of the U. S. Bureau of Mines.
AN AUTOMATIC DIRECT READING LABORATORY SCALE FOR WEIGHING BRIQUETTES
Authors: Schurecht H. G.
Published: June 2006

An automatic direct‐reading laboratory scale has been designed in the Ceramic Laboratory of the Bureau of Mines, with which it is possible to weigh briquettes in about one‐third the time required with balances. It is capable of weighing up to 150 grams in 50–gram intervals with an average accuracy of 0.05 gram. Although this particular scale was made for the above limits in accuracy and capacity, similar scales may be made in which this range may be modified as desired.
THE FIRE BRICK MATERIALS OF PENNSYLVANIA1
Authors: Ashley George H.
Published: June 2006

Pennsylvania produces over 40% of all clay fire brick and over 70% of all silica fire brick made in the United States. In 1920 Pennsylvania produced and sold fire clay worth nearly two million, fire clay brick worth nearly twenty‐two million, and silica brick worth over ten and one‐half million, a total of thirty‐four and one‐half million dollars worth of brick and clay.

Three kinds of material are used for the manufacture of this fire brick. (1) Soft fire clay from one horizon northwest of Pittsburgh and from the “main clay” of the Pittsburgh bed south of Pittsburgh. (2) Hard or flint clay which occurs in many counties of the State. The hard clays are described as occurring at a limited number of horizons in the Allegheny formation or “Lower Productive Coal Measures,” as being irregular in thickness and distribution, ranging from a feather‐edge to fifteen or twenty feet in thickness and being of two types, “block” clay in which the structure is homogeneous, and “nodular” clay in which the structure is gnarly or knotty. Brief reference is made to the principal flint clay deposits of the State. (3) The third source of material for fire brick is ganister rock, a pure white quartzite occurring as a massive bedded sandstone at the base of the Silurian series and exposed abundantly in the zig‐zag ridges across the central part of the State and as a similar white quartzite at the base of the Cambrian in the southeastern part of the State. A series of tests of flint clays and of soft clays used to mix with the flint clays is appended. These are derived mainly from Clearfield County which is the leading flint clay county.
USE OF SEDIMENTARY KAOLINS OF GEORGIA IN WHITE‐WARES1
Authors: Bole G. A. , Stull R. T.
Published: June 2006

Introduction.—From twenty‐six different clays tested the eleven best suited to the white ware industries were washed and, after preliminary tests were run, were tried out in the different white ware industries.

Laboratory Tests on Crude Clays.—Tables containing data on the physical properties of the green and burned clays are given.

Laboratory Tests on Washed Clays.—Test bars and color pats were made from a typical white ware body. The usual physical tests on unburned and burned bodies are reported. Results obtained on the rate of casting and strength of the clays as compared to English and Florida clays are included in the data.

Industrial Application.—Plant practice tests carried out at two floor tile and one wall tile plant are reported. Bodies containing eleven Georgia clays were tried out. Better results were obtained in the vitrified bodies than in the porous bodies. The smaller shapes gave better results than the larger. Tests on general ware and electrical porcelain art: in progress. The conclusion is reached that the Georgia sedimentary clays can be used to displace all the china clay in a vitrified tile body but less than half the china clay in plastic bodies. The color of a body is greatly improved by using washed clay: and can be further improved by the addition of cobalt stain.
A NEW RAW MATERIAL FOR CERAMIC USES
Authors: Cox Paul E. , Moulton D. A.
Published: June 2006

A mineral, not heretofore reported, similar to feldspar in analysis but partially colloidal like bentonite, is described and some uses suggested for it. Analyses are shown and the properties are described. It should make a very useful material in bodies, glazes and enamels, as it has the properties of a feldspar and the plasticity of a fairly plastic clay.
NOTES ON BURNING REFRACTORIES WITH SPECIAL REFERENCE TO THE CONTROL OF LABOR COSTS1
Authors: HEWITT L. C.
Published: June 2006

The tunnel kiln represents up‐to‐date practice. It is often possible, however, to greatly increase the efficiency of present equipment by keeping in mind the importance of such factors as the setting of dry ware, regular inspection of underground flues, provision for ample grate and flue area, use of burning records, study of vitrification curve, etc.

While the above factors are treated rather generally, more specific reference is made to the control of labor costs through the bonus system. A theoretical problem is worked out to show how the bonus system is applied and in what manner it benefits the employer and employee.
CAPPING FOR COMPRESSION SPECIMENS1
Authors: Foster Harry D.
Published: June 2006

Compressive strength tests have been made on tile capped with unretarded gypsum with neat Portland cement, with a mixture of three parts by volume of Portland cement to one part of unretarded gypsum and on tile whose bearings were ground. The tile whose bearings were ground gave the highest strengths. The interpretation of the results was based on the workability and yielding of the cap and on the influence of the bearing block. As it is impossible to grind the bearings of all types of tile, a cap of three parts of Portland cement to one part of unretarded gypsum is advocated as giving the highest and most consistent results.
COLORS IN A ZINC SILICATE GLAZE1
Authors: Kranbr Hobart M.
Published: June 2006

This represents a study of the effects of the seven common coloring oxides when introduced in a typical zinc silicate or willemite crystalline glaze. All the possible two‐and three‐color combinations for each colorant with a moderate color concentration and another similar series for strong color concentrations were investigated.

A new method by which fritting the glaze is obviated through the use of sodium silicate is described. The soluble sodium content is introduced by sodium silicate rather than by a frit.

Color absorption by the crystal was found to be most pronounced in the case of cobalt, decreasing in order with copper, manganese, iron, nickel, uranium and little, if any, absorption of chromium.

Description of color effects of most of these would be inadequate.
COMPARATIVE SERVICE TESTS OF GROSS ALMERODE AND DOMESTIC CLAY POTS1
Authors: WILLIAMS WARREN S.
Published: June 2006

Glass‐drawing pots made from Gross Almerode clay proved to be superior in a service test to pots made from a synthetic siliceous domestic clay mixture. When removed from service the faces of the Gross Almerode pots are pitted. The faces of domestic clay pots are surface cracked. The blistering of the glass caused by this cracking is eliminated by substituting silica brick grog for fire clay grog.
COLLOIDS IN GLASS1
Authors: Silverman Alexander
Published: June 2006

A discussion of the various elements and compounds found in a colloidal state in glass. Attention is called to the similarity of colloidal behavior in vitreous and aqueous media. Theories and experimental evidence are furnished to account for the formation and destruction of the colloidal state.
THE DIRECT FIRED CAR TUNNEL KILN ON ROOFING TILE1
Authors: Minton C. R.
Published: June 2006

The pioneer car tunnel kiln for the firing of roofing tile is described. The kiln is 324 feet, 11 1/2 inches long and holds 52 cars each of which carries 2.3 tons of fired ware. Ten furnaces equipped with Maxon Premix combination oil and gas burners arc used. A schedule of one car every 65 minutes is in operation, 56 hours and 20 minutes being required for a trip through the kiln. The ware reaches a maximum temperature of 1820°F and is drawn from the kiln at 400°F. Additional cooling is accomplished with a portable fan. The kiln has a capacity equal to ten 30‐foot round down‐draft kilns and shows a fuel saving over the latter of 64.2%. A total of 15 h. p. is required. A saving in setting and drawing labor of 29.2% and 45.8% respectively is effected.
THE EFFECT OF FURNACE ATMOSPHERE ON THE FIRING OF ENAMEL1
Authors: Cooke R. D.
Published: June 2006

It is shown that in firing ground coat and other one coat enamels, the atmosphere of the furnace plays an important part. Oxygen in the muffle penetrates the enamel during the early stages of the firing forming a film of iron oxide on the surface of the steel. This film, whether applied before enameling or formed incidentally to firing, partially dissolves in the fused enamel giving the intimate bond between metal and enamel.

Ground coat enamel fired in an atmosphere of nitrogen was found not to adhere to the steel.

Approximate values are given for the proportion of furnace space to enameled surface to insure sufficient oxidation when residual air is depended upon to supply the oxygen.
A GRAPHICAL CHART FOR DETERMINING EXCESS AIR IN THE COMBUSTION OF PRODUCER GAS1
Authors: Peltz Gordon M.
Published: June 2006

This paper presents a mathematical analysis of the combustion of the principal components of producer gas. Formulae are obtained for determining the theoretically right proportions of air to gas for any analysis of producer gas and the theoretical volume of waste gases which should result from this combustion. In addition, a formula is determined by which the percentage of excess air can be obtained when the analysis of the gas and the percentage of CO2 in the products of combustion are known. These formulae are presented in a chart form which eliminates the necessity for mathematical calculations.
THE DETERMINATION OF POROSITY OF CHINA BY THE WATER SOAKING METHOD1
Authors: Schramm Edward
Published: June 2006

Comparative tests show that prolonged soaking is more effective than boiling in attaining saturation of nearly vitrified ware, and a period of 4 days' immersion in cold water is recommended.
NOTES ON A COMPARATIVE TEST OF QUICKLIMES FOR SILICA BRICK MANUFACTURE1
Authors: Trostel L. J.
Published: June 2006

In attempting to evaluate lime for control purposes in the manufacture of silica brick, it was found that the most consistent results are obtained by using a figure based on the total calcium oxide as compared with the A.S.T.M. available calcium oxide content. In addition, the particular test used serves as a practical basis for the comparison of the numerous quicklimes offered the silica brick manufacturer by lime dealers.
THE USE OF GELATINE IN GLAZE APPLICATION1
Authors: Gerber Albert C.
Published: June 2006

Painting with gelatinized glaze offers distinct advantages. A high grade hide gelatine should be used, and careful regulation maintained in all steps of the process. High clay mixtures gelatinize with greater difficulty than those whose contents of ground material are large. Loss from rubbing or chipping of glaze becomes a minimum.
CERAMIC RAW MATERIALS, DRIERS AND DRYING1
Authors: Metz G. F.
Published: June 2006

A description of certain types of rotary driers used for the drying of such ceramic materials as kaolin, chalk, china clay, whiting, fullers'earth, enamel frit, glass sand, feldspar and various chemicals.
CLAY PREPARATION1
Authors: Klinefelter T. A.
Published: June 2006

A brief description of clay preparation by washing, which practically eliminates defects due to pop outs and bad stains which are a constant source of annoyance under the usual methods of terra cotta clay preparation.
DISTRIBUTION OF KAOLIN AND BAUXITE OF THE COASTAL PLAIN OF GEORGIA1
Authors: Stull R. T.
Published: June 2006

The commercial deposits of sedimentary kaolins and bauxites occur in the Lower Cretaceous of the Coastal Plain. The kaolins vary from “hard clay” to flint clay on one hand to “soft clay” on the other. The hardness of the clays apparently depends on the free silicic acid content. They are difficult to slake and filter‐press. The soft clays are washed for the filler and ceramic trades. Evidently the clays were originally hard clays, the soft clays originating from the hard clays by leaching out of the free silicic acid. The bauxites were evidently derived from soft kaolin through decomposition and removal of the silica. The bauxites occur as lenses embedded in larger lenses of kaolin. These bauxites were probably derived from soft clay by laterization. A proposed classification of the sedimentary kaolins and bauxites is given.
THE OXIDATION OF CERAMIC WARES DURING FIRING.1 IV.—THE ABSORPTION OF SULPHUR GASES BY FERRIC OXIDE IN CLAY
Authors: Jackson Frederick G.
Published: June 2006

The nature and amount of absorption of sulphur gases by an almost pure clay to which seven per cent of ferric oxide had been added is studied at various temperatures. Ferrous salts and sulphites were found as traces or not at all. The amount of ferric sulphate increased with increasing temperature on a smooth curve to a maximum at about 450 °C, then decreased sharply to almost nothing at 630 °C. At its maximum, nearly half of the iron present was in this form. Most of the remaining iron was in an insoluble form called “ferrous sulpho‐silicate.” On the basis of this work, recommendations are made in regard to kiln fuels.
COMPARATIVE CRAZING AND CHIPPING OF WET AND DRY PROCESS CAST IRON ENAMELS1
Authors: Robson J. T.
Published: June 2006

Heat shock tests are run on commercial samples of cast iron stove parts enameled by both the wet and dry process. These enamels applied by the wet process are much more resistant to temperature change than those enamels applied by the dry process.
FIRE‐CLAY BRICK FOR THE OPEN HEARTH1
Authors: Booze M. C.
Published: June 2006

Fire‐clay brick in the open hearth are normally subjected to medium temperatures and to the action of slag containing high percentages of iron and lime. Temperatures near the maximum of the open hearth itself may exist due to failure to reverse the draft and for that reason brick of high refractoriness are used. Resistance to spalling action is not of primary importance because the temperature change is small. The indications obtained from a laboratory test were that brick having a high alumina content would resist the slag action better than ones higher in silica.
THE ELECTRICAL CONDUCTIVITY OF SODIUM CHLORIDE IN MOLTEN GLASS1
Authors: Sutton Willard J. , Silverman Alexander
Published: June 2006

Precipitation of collodial suspensions in glass by dissolved salts leads to the assumption that they ionize. In this investigation the Conductivity of glass alone and with dissolved salts confirms the theory. A special cell has been devised for conductivity work in glass at high temperatures. This is the first study of the electrical conductivity of salts in vitreous media.
A STUDY OF PLASTICITY BY PRACTICAL POTTER'S METHODS1
Authors: Cox Paul E.
Published: June 2006

By the use of the potter's wheel it is shown that bentonite added to non‐plastic and lean ceramic materials will produce plasticity of the same quality as that found in high grade ball clays. Curves show the results obtained. The colloid theory of plasticity is sustained and it is demonstrated that mineral colloids of the type of the bentonites are of great value in ceramic work where plasticity is highly important.
NOTES ON THE BEHAVIOR OF REFRACTORIES IN GLASS MELTING FURNACES1
Authors: Insley Herbert
Published: June 2006

Microscopic examination of used glass house refractories gives evidence about the transformations that have taken place during use, and the relative solubilities of constituents of the refractories in the glass. On this evidence it is concluded that high alumina refractories would resist the solvent action of the glass and the fluxing action of the soda in the furnace atmosphere better than fire clay refractories. Investigations are needed to find a new refractory mortar for use between silica and clay refractories in glass tanks.
A QUANTITATIVE LABORATORY SLAG TEST
Authors: Norton F. H.
Published: June 2006

A laboratory slag test is described capable of giving quantitatively the resistance of refractories to slags. The method consists in continuously spraying powdered slag onto the hot specimens and allowing it to run off. The advantage of this test is the rapidity and small expense with which relatively accurate results can be obtained.
SOME COMBUSTION PROBLEMS IN GLASS MAKING1
Authors: Smith C. D.
Published: June 2006

For a plant operating on producer gas and with possibilities for results that approach present best practice care must be exercised to see that not only producer gas equipment of recognized merit is installed but that gas mains are of ample size with adequate facilities for cleaning or burning out, that valves are large enough to take care of requirements and with minimum resistance to exit gases and that facilities be provided for gas checker temperature regulation as well as air regulation.
THE DEVELOPMENT OF DECORATIVE PROCESSES AT NEWCOMB
Authors: Sheerer Mary G.
Published: June 2006

The decorative processes at Newcomb are described and the following points emphasized: incising design on wet clay, sponging of surface, biscuit painting and modeling the form by hand.
A GENERAL THEORY OF SPALLING
Authors: Norton F. H.
Published: June 2006

A theory is proposed whereby certain physical properties of a material are combined such a way as to give a measure of its resistance to rapid temperature changes. The important physical properties are the coefficient of expansion, the flexibility in shear and diffusivity. These quantities have been measured for a number of types of refractories and the theory checked by actual spalling results on these same refractories. The theory applies mainly to a single brick free from external stresses.
ADAPTATION OF TUNNEL AND CAR KILNS TO FIRING REFRACTORIES1
Authors: Dressler Philip
Published: June 2006

The success of tunnel kilns in a given industry is largely determined by the choice of the type best suited to the requirements of that industry. This paper discusses the adaptation of the various types of tunnel kilns to firing glass house refractories, clay, fire brick and silica brick.
EUROPEAN SILICA REFRACTORIES
Authors: Cole Sandford S.
Published: June 2006

This investigation was on the silica brick and shapes made in Europe and the ganister supplied for the same. Analyses of rock and brick produced according to American practice and in Europe from the same rock are given. The results of tests on the best grades of brick are given. A general conclusion is that silica brick manufactured in Europe is not satisfactory for use in coke oven construction with a few exceptions.
SOME DATA ON THE PULSICHROMETER1
Authors: Galbraith Robert
Published: June 2006

A table has been worked out of the plate openings necessary to use with enamel and slips of different weights reducing the skill required to obtain a smooth coating on a piece. The apparatus is described and tests were run on varying materials, viz., raw materials; fritted enamels and slips. The theory is advanced that the large orifice fails to develop enough back pressure to give the enamel sufficient velocity through the tube. Other features of the pulsichrometer are discussed.
SYNTHETIC SILLIMANITE IN CERAMIC BODIES1
Authors: Curtis T. S.
Published: June 2006

The manufacture, characteristics, and use of a new ceramic product in which the stable form of sillimanite, having a composition of 3A12O3–2SiO2, is the chief constituent. An interesting feature of the product is the fusible matrix of definite composition, in which sillimanite needles are held, and which permits of recrystallization at commercial temperatures when the product is added to porcelain or whiteware body mixes. Introduction of sillimanite apparently greatly toughens and strengthens the body in which it is introduced.
METHOD FOR THE ANALYSIS OF ALUMINOUS SILICATE REFRACTORIES1
Authors: Barrette Edward P. , Schroeder Frederick W.
Published: June 2006

A method is given in which the solution of difficultly fusible refractory material is obtained by subjecting the finely pulverized material to two fusions, the first in sodium carbonate, followed by one in potassium bisulphate. The melts are dissolved in water and after adding sulphuric acid are evaporated to dense fumes. Care is taken to remove any calcium sulphate that may be formed. The final residue is treated with hydrofluoric and sulphuric acids. The alumina is determined according to the method described by Blum as given by Hillebrand especial care being used in heating the final precipitate to constant weight. A temperature of about 1150°C is necessary. Two precipitations are required in the determination of lime. The excess of ammonium salts are removed prior to the precipitation of the magnesia, by adding an excess of nitric acid, evaporating to dryness and heating, which expels the ammonium chloride according to the reaction NH4Cl + HNO3= HCI + 2H2O + N2O.