Document zQKQ9X9mQLEy0qvQzbvr3xm0

FILE NAME: Orton (ORT) DATE: 1940 DOC#: ORT017 DOCUMENT DESCRIPTION: Bulletin - American Ceramic Society 94 Bulletin of The American Ceramic Society--Kriegcl Experiments indicate that 950 to 1000C. is the mini mum safe operating temperature of the graphite resistor in the present silicon-carbide protection tube assembly. (3) Seif-Cooled Silicon-Carbide Resistors in a Continuous Tunnel Kiln Provisions were made for operating the continuous kiln using silicon-carbide resistors (the only commercial nonmetallic heating element on the market a t present) equipped with self-cooled terminals to give a compari son with behavior and operating characteristics of the graphite resistor. A check at cone 13 down on a 60-hour schedule showed 11.2% less power input with the silicon-carbide than with the graphite resistors, a condition that probably was due to the smaller cross section of the graphite terminals, which allowed a relatively low heat transfer and radiation loss through the terminals. At 1170 hours, the silicon-carbide resistors showed an average resistance increase of 46.9%. This study is being continued. E lectrotecubical L aboratory B ur ea u op M inus N orris, T ennessee SUMMARY OF OCCURRENCE, PROPERTIES, AN D USES O F VERMICULITE AT LIBBY, M O N TA N A * B y W . W urth K r ieg el A bstract Vermiculite is the name of a group of micaceous, hydrated silicates which are the alteration products of micas. The Libby mineral resembles jefferisite. Chemical analy ses are given, and the history of the deposits is briefly reviewed. The mineral, which occurs in a stock intruding the Algonkian Belt scries of the valley, is used principally in thermal insulation and also for acoustical and dehydration purposes. The coefficient of thermal conductivity varies between 0.26 and 0.35, the P.C.E. value is 11, and the coefficient of sound absorption varies from 0.34 to 0.58. I. Introduction Vermiculite is neither a rare nor a newly discovered mineral group, but until recent years it has remained a mineralogical curiosity without any particular value or use. W ith increasing public and industrial in terest in thermal insulation in the last few years, ver miculite has become an important insulating material. II. Mineralogy Vermiculite is the group name of a number of mica ceous minerals, all of them hydrated silicates. The chemical composition is indefinite, varying with the composition of the original mineral and the degree of alteration. When the dried material is heated to red ness, it exhibits the characteristic property of all vermiculites, i. e., great expansion. Dana1 lists fourteen varieties from various sources. The Libby vermiculite appears to resemble most closely the physical properties of jefferisite which Dana de scribes as follows: "In broad crystals or crystalline plates. Surface of plates often triangularly marked by crossing lines GO and 120 degrees. Cleavage: basal, eminent. Flexible, almost brittle. H =1.5. G = 2.30. Luster pearly on cleavage surface. Color dark yel * Presented a t the Golden Gate Meeting, American Ceramic Society, San Francisco, Calif., August 11, 1939. Received August 15, 1939. Published by permission of the Director, Montana Bur eau of Mines and Geology. 1E. S. Dana, System of Mineralogy, Descriptive Miner alogy, 6th ed., pp. 664-68. John Wiley & Sons, Inc., New York. N. Y., 1892. lowish-brown and brownish-yellow; light yellow by transmitted light; also greenish-yellow." Chemical analyses of the Libby vermiculite are shown in Table I. T able I Chemical Analyses Column (1) analysis by J. C. M eyer, chief chem ist, G reat Northern R ailw ay C o.; (2) analysis by N atio n al B ureau of S ta a d a id s; and (3) analysis by Universal Insulation Co. (1) (2) (3) Silica Alumina 42.8 41.0 42.6 18.0 19.0 Iron oxide Calcium oxide 26.2 7.0 7.2 1.9 1.0 1.9 Magnesium oxide Sodium and potassium oxides Moisture 24.G 3.6 0.7 21.0 24.6 1.0 3.8 11.0 Total 99.8 100.0 99.1 III. History Though many deposits of vermiculite have been found throughout the United States, including North Carolina, South Carolina, Colorado, New Mexico, Cali fornia, Idaho, Wyoming, the New England States, and other parts of Montana, the history and development of the industry are closely allied with that of the Libby deposits and companies. The Libby deposits are re puted to have been discovered by the late E. N. Alley while he was prospecting for vanadium minerals during the World War. I t is said that the heat of his candle caused the coarse, micalike mineral to swell and assume a golden color. He called the material "feather gold." Vol. 19, No. 3 * 1 Mr. Alley and a j Company to cxplo began to market The mine and plan research laborator and contracts, the panding plants th: the Universal Inst of the Vermicuiit Mont., and operat Zonolite Company had a similar distr tory at Chicago, I were combined in Zonolite Insulation trade names of "Z being manufacture cities; the mineral and Australia; anc Africa and France, in many other coun (1) Topography The deposits ar east of Libby in 1 Valley, two miles a from the main high valley widens near of several small br feet or more above (2) General Gee According to Pa Valley "is underlai that apparently are along the Kootenai are described in det say further th at th in general exhibit ir that trend northwi belong to the Algon A stock compost and one-third syeni trudes the Belt ser miles of this area, quent alteration has (3) Occurrence a Generally, vennit altered igneous rock rock. It occurs in i the Rainy Creek dis The deposits exten The east end (workei contains a high cor. 2J. T. Pardee and Ute and Other Mine Libby, M ont./' V . S. 29 (1928); see pp. 18 s F. C. Calkins, " Gi Idaho and Northwcstc(1009); p. 76. (1940) S C -C E R -3959 T i 60-hour schedule 1 1 the silicon-carbide a condition that iross section of the relatively low heat the terminals, ie resistors showed .9%. This study is * I RM ICU LITE the nalyidiich pally cient i the t\ light yellow by liow." ermiculite are shown ; 3ES chem ist. G reat Northern ireau of S ta n d a id s; and (2) (3) .8 41.0 42.6 18.0 19.0 .2 7.0 7.2 .9 1.0 1.9 .6 21.0 24.6 .6 1.0 3.8 .7 11.0 .8 100.0 99.1 miculite have been tes, including North ;>, New Mexico, CaliEngland States, and j try and development ith that of the Libby bby deposits are rethe late E. N. Alley i Hum minerals during he heat of his candle J 1to swell and assume `.rial "feather gold." Vol. 19, No. 3 ! Mr. Alley and a group of associates formed the Zonolite Company to exploit these deposits. In 1925, the Company began to market the expanded material in a small way. The mine and plant were operated at Libby and a plant and research laboratory at Detroit, Mich. Through licenses and contracts, the unheated material was supplied to ex panding plants throughout the United States. In 1934, the Universal Insulation Company acquired the holdings of the Vermicnlite and Asbestos Company of Libby, Mont., and operated properties adjacent to thdse of the Zonolite Company. The Universal Insulation Company had a similar distribution system with offices and labora tory at Chicago, 111. In May, 1939, the two companies were combined in a new company called the UniversalZonolitc Insulation Company. The products, under the trade names of "Zonolite," "Unifil," and " Porosil," are being manufactured in nineteen American and Canadian cities; the mineral is being exported to England, Brazil, and Australia; and there are projected plants in South Africa and France. The expanded products are being sold in many other countries. (1) Topography The deposits are approximately seven miles north east of Libby in the lower part of the Rainy Creek Valley, two miles above its mouth. A service road leads from the main highway along the Kootenai River. The valley widens near the deposits owing to the junction of several small branch valleys. Mountains rise 1000 feet or more above the drainage level. (2) General G eology According to Pardee and Larsen,2 the Rainy Creek Valley "is underlain chiefly by argillite and quartzite that apparently are the equivalents of the rocks exposed along the Kootenai River west of Libby." These rocks are described in detail by Calkins.3 Pardee and Larson say further th at the rocks in the Rainy Creek Valley in general exhibit moderately steep dips and open folds that trend northwestward and that they "doubtless belong to the Algonkian Belt series." A stock composed of about two-thirds pyroxenite and one-third syenite and their alteration products in trudes the Belt series and underlies about six square miles of this area. Pardee and Larsen say that subse quent alteration has taken place over wide areas. (3) Occurrence and Development Generally, vermiculite is an alteration product in altered igneous rocks and is distributed throughout the rock. It occurs in certain places in large bodies as in the Rainy Creek district. The deposits extend in a generally east-west direction. The east end (worked by the former Zonolite Company) contains a high concentration of vermiculite. Large 1J. T. Pardee and E. S. Larsen, " Deposits of Vermicu lite and Other Minerals in Rainy Creek District, near Libby, Mont.," U. S. Geol. Surv. Bull., No. 805-B, pp. 1729 (1928); see pp. 18-24. 3F. C. Calkins, " Geological Reconnaissance in Northern Idahoand Northwestern Montana," ibid., No. 384, 112 pp. (1909); p. 76. (1940) bodies run as high as 95% vermiculite. In these areas of high concentration, however, cores of partially altered biotite which expand poorly arc encountered. This por tion of the deposit has been developed by numerous pits, ranging from 25 to 40 feet deep and 100 to 250 feet long (Fig. 1). The property has been developed further by a 400-foot adit, which is 400 feet under the surface at the face and is reputed to be in good-quality material. The west end of the deposits (operated by the former Universal Insulation Company) shows few accumula tions of biotite. A series of syenite dikes, ten to fifty feet apart and roughly conformable in strike with the ore zone, block off the ore. The concentration of Ver miculite varies from 30 to 60% with pockets of higher concentration. These dikes are thought to have been the source of solutions that altered the pyroxenite in whole or in part into vermiculite in this end of the zone.4 A second series of dikes intersecting the ore body consists of material high in ainphibolc asbestos with less altered pyroxenite. Where the concentration of asbestos is sufficiently high, it is mined and marketed. The vermiculite is a minor constituent of this zone. Fig. 1.--Portion of a pit in the Zonolite workings showing syenite dikes, S, cutting through the vermiculite, V. IV . Mining and Concentrating The Zonolite Company mined the ore by hand shoveling, selecting only the very high-grade rock; the Universal Company mined the deposits by power shovel on 30-foot benches between the syenite dikes. The dikes were toppled over periodically and trucked to a waste dump. The consolidation of the two companies, which has placed the entire deposit consisting of a mountain approximately 1000 feet high and a square mile in area under a single management, makes possible a more efficient plan of mining. At present, a lW y ard , Northwest gasoline shovel is leveling off the top of the 4P. M. Tyler, "Minor Nonmetals: Graphite, Greensand, Kyanite, Mineral Wool, Monazite, Strontium Minerals, Vermiculite, and WoIIastonite," U. S. Bur. Mines Minerals Yearbook, p. 1072 (1936). 96 Bulletin of The American Ceramic Society--Kriegel mountain, preparatory to cutting the mountain down in 25-foot horizontal cuts; the ore is trucked down the mountain to the mill on the west slope; waste rock is discarded on barren ground. During the summer and fall months, approximately 250 tons of ore are being mined in an 8-hour day which supplies the mill for 24 hours. The concentrator used was built by the former Uni versal Insulation Company. The ore from the mine is dumped on a grizzly, 28 by 3 feet in size with 4-inch openings. The oversize rolls out to the waste pile and the --4-inch material falls into a 1000-ton steel bin. An apron feeder feeds to a 24-inch inclined belt con veyer, which carries the material to the top of the mill building, discharging into a trommel, 4 by 8 feet with Vi-inch openings. The oversize goes to waste and the undersize to a jigger screen with Vs-inch openings; the oversize of the screen passes through one of two ham mer mills. The two products pass through a baffled, conical-shaped, oil-fired, flash drier, operating at 300F., which removes the surface moisture of the vermiculite. The dried material is much easier to screen. From the drier, the material passes through a battery of two Hummer screens. The products are raised by two bucket elevators and are passed through a battery of four Hummer screens which size the material for the separators. Thirty-two specially built air-separators, making a concentrates, a middlings, and a tailings product, re move the greater bulk of the waste rock. The middlings product, which consists mainly of small, thick books of vermiculite, is returned to the hammer mills for further grinding. The concentrates product passes directly into a 5- by 16-foot, oil-fired, Link-Belt rotary drier. All excess moisture th at is not needed for the subsequent expansion of the vermiculite is removed. The moisture content of the vermiculite is periodically checked in the laboratory. The material passes from the drier through a triple-deck, jigger screen, which delivers the vermicu lite into the four commercial sizes, designated as 1A, 1, 2, and 3, which are --W inch to +3-mesh, --3 to +14, --10 to +20, and --16 to +24-mesh, respectively. The 1, 2, and 3 sizes pass through separate air-separa tors and then to storage bins. All waste rock is trans ported to a waste dump by a belt conveyer. Two counter-balanced, 1'/ 2-ton cars lower the sized concentrates along a 2800-foot incline to receiving bins a t the foot of the mountain, and they are trucked about 8 miles to Libby where they are shipped in box cars or placed in storage. The present storage capacity is 2500 tons, but additional bins are being constructed. The concentrator operates most economically on ore containing from 50 to 60% of vermiculite, produces 125 to 160 tons of concentrates per 24-hour day, and makes an 80% recovery. The principal loss is in the fine sizes for which a t present no adequate market has been developed. The electric power for the mill is generated by two direct-connected, Superior, 215-h.p. Diesel en gines. One of these engines also drives a Seroco fan, which delivers 8000 cu. ft. of air per minute to the air separators. Repairs on the equipment are made on Sundays when the mill is closed. The estimated pro duction of the company for 1939 is 20,000 tons of concentrates. Constant checks on the quality of feed and product are made in a small field laboratory. The expansibility of the ore, the percentage of waste rock, and the total water content of the vermiculite are determined. V . Exfoliation When vermiculite is heated to redness, it expands to j corklike pieces of material, increasing up to sixteen times the original volume. Tyler6states that "experi- j ence seems to indicate that no vermiculite product after ] exfoliation, weighing more than 6 lb. per cu. ft., can f be marketed successfully, and although there are many deposits of material that will show a considerable ex- ' pansion on heating, few yield material that expands { sufficiently to meet this requirement. Many vermieu- . lites, moreover, decrepitate when expanded and fail to yield a blocky, corklike product, such as the trade de mands for many purposes." The reason for the phenomenal expansion of vermieu- I lites has been assigned to the sudden expulsion by : the application of heat of the chemically combined j water and the water held between the folia of the I mineral. The total water left in the mineral must not t be reduced to less than 5 or 6% to obtain maximum ex- ! pansibility. the two walls < burners using pr directly into prin tain a temperatu panded vermicul veyer and is del' discharges via a i move any rock o: forces air upward in the bottom of 1 below the slot a chute, there is a panded vermiculi current. The roc stream down pipe The unit is cap feet in size and w ft. The tops of 1 unit are connected dust. The dust lc loss 7% in the opc V I. As usual with i suggested and are success. The prin sulation for dwellii furnaces. Size No II gives the therma T h e r m a l Condu Teat N o. 1 is " Unifil neer, A rm our In s titu te (3) rep re se n t " U n ifil," d v e n tila tin g , P u r d u e Density (lb./cu. ft.) Mean temperature o Thermal conductivit (B.t.u./hr./F./sq F ig . 2 .--Expanding plant of the Unifil Division, Asbes tos Supply Co., at Spokane, Wash. Size No. 2 is bei plasters, in insulatii furnaces, and in the being used with suit alumina cements, ei A typical expanding unit is shown in Fig. 2. The 1 vermiculite is loaded into the hopper, A , by wheelbar- | row. An 8-inch, variable-speed, electric-vibrator feeder drops'the vermiculite into the boot of elevator B, which I discharges it by means of a 3-inch flight conveyer into I the preheating chamber, C, of the expanding unit The preheating chamber is a double-walled cylinde and the inner cylinder contains conical baffles which | impede the fall of the vermiculite. The products of P combustion from the burners pass up through the fall- 1 ing vermiculite. The air for the gas burners is pre heated as it passes through the annular space between 6P. M. Tyler, loc. cit., pp. 1069-70. Vol. 19, No. 3 (1940) Summary of Occurrence, Properties, and Uses of Vermiculite 97 is 20,000 tons of if feed and product . The expansibility rock, and the total : determined. I dness, it expands to sing up to sixteen states that "experiiculite product after lb. per cu. ft., can >ugh there are many r a considerable exterial that expands it. Many vermicuxpanded and fail to ich as the trade de:pansion of vermiculdden expulsion by remically combined an the folia of the re mineral must not abtain maximum ex- nifil Division, Asbesme, Wash. the two walls of the preheating chamber. The six burners using preheated air and artificial gas discharge directly into primary expanding chamber, D, and main tain a temperature of approximately 2000F. The ex panded vermiculite is removed by a 6-inch flight con veyer and is delivered to the boot of elevator E, which discharges via a chute to two bagger bins, H. To re move any rock or unexpanded vermiculite, a small fan forces air upward through pipe F through a slot opening in the bottom of the chute to the bagger bins. 'Directly j below the slot and closing off the lower half of the I chute, there is a 12-mesh screen over which the ex panded vermiculite is carried by the force of the air I cun-ent. The rock, being heavier, falls against the air stream down pipe, G. The unit is capable of expanding 500 bags, 4 cubic feet in size and weighing approximately 5'/4 lb. per cu. ft. The tops of the two elevators and the expanding unit are connected to an exhaust fan which removes the dust. The dust loss is approximately 2% and the rock loss 7% in the operation. V I. Uses and Properties As usual with new products, many uses have been suggested and are being tried with varying degrees of success. The principal use has been as "loose-fill" in sulation for dwellings and buildings, refrigerators, and furnaces. Size No. 1 is used for these purposes. Table II gives the therma1-conductivity values of the material. Table II Thermal Conductivity of Loose-Fill E xpanded Vermiculite Test N o. 1 is " U nifil," teste d by P. C. P eebles, m echanical engi neer, A rm o u r I n s t i t u t e o f T e c h n o lo g y , C h ic a g o , 111,; N o s . (2 ) a n d {3) re p re s e n t " U n if il," te s t e d b y W . T . M ille r , p ro fe s s o r of h e a tin g ad ventilating, P u rd u e U niversity, L afay ette, Ind. (1) (2) (3) * Density (lb./cu. ft.) 6.2 5.59 5.59 Mean temperature of test (F.) 24 70 90 Thermal conductivity (B.t.u./hr./F./sq. ft./in.) 0.317 0.245 0.263 Size No. 2 is being used for aggregate in insulating plasters, in insulating concrete for basement floors and 1 furnaces, and in the tropics for homes. This size is also i beingused with suitable binders, generally cement, high| alumina cements, etc., for heavy-duty insulating brick on furnaces. The fusion temperature of vermiculite is cone 11. With gypsum and similar binders, it is being formed into steam-pipe coverings. The total output of the smaller size, No. 3, is being used with a wood-fiber base in the manufacture of fireresistant, insulating wall-boards and acoustical tile. The large size, No. 1A, finds its chief use in acoustical plasters, wall finishes, and as acoustical tile. Coeffi cients of sound absorption of a 33/4-inch loosely com pacted layer of Zonolite, for various frequencies of sound waves, are shown in Table III. T able III Sound Absorption* F req u en cy of test tone Coefficient of sound absorption 128 dv 0.34 256 .45 512 .58 1024 .57 2048 .56 4096 .56 * Tests by V. O. Knudsen, November 21,1928. Some of the less important uses are sound insulation for motor cars, grease lubricant, fillers for tires and rub ber goods, and fireproofing. Depending upon the conditions during the expansion of the material, colors ranging from near silver to gold can be produced. Very fine sizes are being used for ex tenders in gold and bronze paints and inks and in wall paper printing. "Lamisilite" (laminated silica) is produced by leach ing unheated vermiculite with hot concentrated sul furic acid, which leaves nearly pure SiC>2 in flake form. I t is used as a dehydrating agent in air-conditioning units and industrial applications. Lamisilite will ab sorb about 20% by weight of water and may be renewed by heating. Acknowledgment The writer wishes to express his appreciation for the courtesies and assistance of R. R. Mount, plant superintend ent, Unifil Division, Asbestos Supply Co., Spokane, Wash., and J. B. Meyers, Superintendent of Operations, UniversalZonolite Insulation Co., Libby, Mont. M ontana B u rea u or M in u s and G eology B utte, M ontana awn in Fig. 2. The t per, A, by wheelbarectric-vibrator feeder . of elevator B, which i flight conveyer into the expanding unit, able-walled cylinder, aonical baffles which :. The products of up through the fall- gas burners is preinular space between X BULLETIN OF THE CERAMIC SOCIETY I f LEON J. HOUZE, SR., 1857-1940 I For story, see pages 104-105 WiMmm Ti rHiEt Bo ULLETIN OF THE AMERICAN CERAMIC SOCIETY March, 1940 Number 3 CONTENTS i v ^ S ^ - t S j& c tin g Physical Properties of a Dry-Mixed Body--C. H. R app...................................................... 87 *!Sfacr ^De__v__eil-o---p---m----eIn*.tsTi\n___D____r_y_AM/Thi-x!^invgmofPCae*a ravmi4/ic7B/m o4d ieps__--__.FTT.. AA. FTTiixr .. . . . ................ ...................................... 9900 * '^i-fliitton ol Intprfacial Reactions to Counteract Crazing--R. M. Campbell..................................**.---- 91 : >-Reports from, the Electrotechnical Laboratory, Bureau of Mines, Norris, Tenn.--Hewitt Wilson, M S. Ndtpn, and S taff........................................................................................................................................... 92 , (I|..iuypfOccurrence, Properties, and Uses of Vermiculite a t Libby, Montana--W. w . Knegel................. . 94 sHLiilual ftiaskite Kaolin Deposits of North Carolina--C. E. Hunter . ............................... ........... 98 Y} ;nIji^Hpuze, Sr., 1857-1940. 104 - itWSii^mTPioner Medalists f sarJ'B1.^Relier Receives Modern Pioneer Award.................................................................................................... 105. r ionics Slayter Recipient of National Association of Manufacturers A w ard..................................................... 106 Hjioi1ale University Clayworkers' School, 1896 Retrospect and a Prospect. . . ....................................... . 107 Arti*ci of The Society .H ^pricalfcata on The American Ceramic Society (Meeting Place and Officers, 1899-1940)............................... 103 nnera Club : Chaupcey E. Frazier Award--Ceramic Exhibit Information and Officers..................................... 18 r ^ %"%iicrca5!Srain5cSociety OfficeExhibits : Pennsylvania German P o t t e r y ................................ ..................... 108 - sitfflbcrdiip Data ^eTvMeDabcrs for February--Roster Changes 109 il^.S!;M0nbership Record.......... *.................... 110 ArnericamGeramic Society Condensed Balance Sheet.......... ...... . . I_._Iw_a,iil U. cfo'n J.j.r.., C. e_r_a_m_i_c_F_o_u_n_d_a_tion Condens_e_d Balance-Sheet __.________._.._.._.._.._..._...._....._...._...._...._....._.. ._.._.v._.h.._:.i._-.._`.V._. _ 111 111 American Ceramic Society Nominations for Officers, 1940-1941........................................................ , ............ I l l fallows--Institute of CeramicEngineers--Ceramic Educational Council--Art Division............................... I l l hnanid^Division--Materials and Equipment Division--Refractories Division--Structural Clay Products Division--White Wares Division....................................................................................... I . , ................... 112 Srtrpiogy^ Mrs. W. E. S. Turner............................................________ ; ...................................................... 112 fwajl&cfctioDs: Michigan-Northwestern Ohio--Southern California--Pittsburgh and Art Division Joint .............. ................... ........ t.................... ........................................................ ............................ 112 ./ -Dtrthuc.School Notes: Ohio State University--University of Washington--Iowa State College--St. Pat's festival at New York State College of Ceramics.; ...............................J........................................................ 113 Universityof Illinois, Sixth Conference on Glass Problems............................................. `................................. 113 Rutgers University, L E. Barringer, Speaker.................. ...................................... s..................................... 114 College, Cci'aniicb D.vLeuaiun Texcbuuks Reviewed................. ........., ........................... ij.4 Northrup, Director, Mineral Industries Extension, Penn State........ ............................................ 115 McNamara, Supervisor of Ceramics Extension, Penn State......................*.............'.................. li5 Russdl, Jr., Program Chairman, White Wares Division.................................: ............ ............... 115 liters fromthe Secretary: Why Ceramic Graduates Should BeActive Members in This Society.................... 116 Rulesfor Presentation and Preparation of Papers at TechnicalSessions ofThe American Ceramic Society......... 118 Bureau of Mines Lectures...........,.v.................... .............. ........................ . . . . . . . ..... ...........................'.. 116 forcelaih Enamel Forum Proceedings Published--Porcelain Enamel Institute, 1940 Meeting........................ 117 0. Homrael at Eastern Enamelers Club--Ceramic Archaeology Studies--National Sculpture Society Festival.. 117 Judex........... ................ .................................................................... ................................................... . 6 qr<n' G u i d e . . ..................... ..................................................... ................. ........... 12, 14,16, 18 -m,*.).: 0}for: 20th & N o rth am p to n 5 ts., E aston, Pa. Jr* - yi Advertising Ojjicc: 2525 N . H igh S t,, Columbus, Ohio. 0ce: 2623 N . H igh S t., Columbus. Ohio. oii Piifiticafionj: J. D . S oixivaK] Ciiairtwou; . E . M arbaeeb, E. db F . C ortis, W. W. W rv saiP , SLoss C. P urdy. Entered a s second-dass m a tte r a t th e p o st office a t E aston, P a ., under th e a ct of M arch 3. 1879. Published monthly. Subscription 11.50 a year. .Single numbers twenty-Gve cents. (Foreign arid C anadian postaget S0 additional o k subscriptions) (CoJ>yritht 1940. 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