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FILE NAME: RT Vanderbilt (RTV) DATE: 1941 Apr DOC#: RTV028 DOCUMENT DESCRIPTION: Article from the Bulletin of the American Ceramic Society - Engineering Control of Dust with Special Reference to Respirators I 15,1593 - , S S *Ohio 3 a <3081. s s - . * " 1^ g a s- C w -c & -,.. v * -- * * * 5 ; ^ ? o h 7 oee 2 9 - 00 O 430B-8720 40 AMERICAN vuw" 20 or THE CERAMIC APRIL, 1941 SOCIETY Number 4 BELL LEPHOKE SYSTEM System is doing Country's progrom xi W ALTER JO D O K KOHLER, 1875-1940 % For ttory p<9C 1 34 *d o a Uie -re o f m ineral he stonever, may daa-siU ca oxides tem pera. IS. p rw u k a l le*stup 1 'vitrified " 1 fusion s would oxidizing \lo r i--b v' -I de* t th e day xng dam p ro b a b le xm ngthe 5o f glaze t of iron* dations so te-' s to it rf n th e t l z itt io making No. 4 ^GINEERINGcontrol of dustwithspecial referenceto respirators* By A. D . Bsanst Abstract The more common methods of reducing or controlling the respiratory hazard caused by dust are discussed. The specific methods are (1) control of dust a t die point of dust generation, (2) isolation of dusty processes, {3}substitution of nunhazardous processes, and (4) reduction of dust in inspired air by respiratory protective devices. The general methods are (1) general ventilation, (2) good housekeeping, and (3) a rigid inspection of all control devices. A detailed discussion is given of respirators, their proper use, con struction. maintenance, and Bureau of Mines approval. I. Introduction Methods of d o st control arc s o t new, b u t th e proper - -- */ M M ' ^ sifithods is M a f is many cases. Some industries a n reluctant 0 gQ in qualified engineers to lay o u t th eir dust-con* ^,,1plans. No one m ethod, design, o r device will solve gg problem for all industries o r in one large industry, jjjd only a thorough study of th e existing conditions 0$ give the engineer a basis on w hich to determ ine the {estmethod or com bination o f m ethods fo r th e problem * industry in question. _ The im portant m ethods of d u st control are (1) con- ggl at the p o u t of generation o r dissem ination, (2) jpfaflan of dust-producing processes, (3) substitution Itss hazardous m aterials, and (4) reduction of du st in aspired air by m eans of respirators. (2) Ducts and Collector T he ducts indude all piping through which th e dusts are earned from th e hoods to th e collector by the air current created fay the fan. The final p art of to e sys tem is to e collector, which retains the dust and perm its to e dean s ir to escape into the atmosphere. R outine inspection and m aintenance are im portant. T he ducts are dogged all too frequently w ith w orn-out overalls or sim ilar w aste m aterials; properly designed system s are unbalanced by having the tinsm ith p u t in additional branch ducts and exhaust hoods; collectors are no t em ptied; and bags of collectors are tom or even removed and n o t replaced. Inspection and m ain tenance can ensure successful operation for a reasonable period of tim e. JJ. Control at Point of Generation or Dissemination The methods commonly used to control d u st a t th e punt of origin a re (1) local exhaust v entilation equip ment, (2) w ater o r other suitable liquids, and (3) good housekeeping. A local exhaust ventilation system consists o f {1} exhaust hoods, (2) air ducts, (3) cohec- tnr, and (4} fan. (1) H oads The purpose of a a exhaust hood, which is the vital part of the system , is n o t to create "suction" b u t to produce air currents in th e area of d u st generation of ratable m agnitude gT*^ acting in th e proper direction to overcome th e energy o f th e escaping particles and to a n y them in to th e exhaust system . A knowledge tf the laws of a ir flow in to suction openings of various dupes is therefore essential to proper design. A to u g h understanding of th e w ay in which dust isgenerated is also necessary, especially as it pertains toparticle size and to th e velocity a t which th e particles "Be thrown oS. An efficient hood collects th e dusts located w ith Tninimum air flow from th e ineffec tiveor dean air areas and w ith tnrnitnnm power conttmption. A hood is properly designed when i t {1} is iSrieat and (2) does n o t hinder th e operation of the tooi or nTflrfim 'Presented a t the Forty-Second Annual Meeting, The " jniean Ceramic Society, Toronto, Canada, April 8, JftO(General Session on Toxicology). Received April 0, 1*40. (3) Fan T o avoid the wear of fan blades and housing resulting from the abrasive action of th e dust, th e collecting u n it should be located on th e suction or upstream side of th e fan. (4) Spray W etting down in to w ater by hand or by sprays or stnam s is a m ethod of control a t to e point of origin th a t is widely used. W ater helps tem porarily to lay dust, and a stream carries aw ay many particles, but th e procedure is fundam entally im practicable as an effec tive safeguard. I t is im possible to wet m ost of the p a r ticles by toe usual m eans owing to toe gas layer which envelops them . Few particles are collected and con sequently m any of those th a t are tem porarily w etted w ill rem ain in suspension owing to evaporation of th e surrounding layer of w ater before complete settling has taken place. When other m ethods are n o t available or are im practicable, however, th e use of a w ater stream is w orth while. (5) -GoodHousekeeping Good housekeeping as a means of dust control is possibly toe least difficult and least expensive to em ploy and frequently accomplishes rem arkable results. I t prevents dust accum ulations in any p art of toe plan t w berethedust m ay be redispersed by careless operation, shock, or wind currents. Such (tost may be w etted down and removed frequently and perm anently. F re quent and regular use of large vacuum cleaners on !1MI) 123 7 .V ** . *. f -\*4* - *"T* *. SH;' ti ni H: 1 i r 1 134 Bulletin of The American Ceramic Society--Brandt beams, n ite rs , or other inaccessible places is also help wearer. A filter respirator which is to be accept^ j,. ful is solving th is problem . industry as satisfactory should (1) be comfortable Sn? ifS fit the face well, affording an air-tight contact betw-JJ III. isolation of Dust-Produeing Processes The isolation of dust-producing processes lim its the exposure to a few men who m ay be protected by res pirators. T he indosure of these processes in dusttig h t chambers o r room s, such as abrasive blasting cabinets, is effective. The chambers and dust-control devices, however, m ust be kept in good k in g condi tion to ^pam*qm th e ir effectiveness. IV. Substitution of Lest Hazardous Materials The su b stitution of less hazardous m aterials offers an absolute m ethod of dust control, b u t extensive changes in th e m anufacturing process are often required winch m ay n o t be practicable. T his m ethod should not be recommended unless or until it is established th a t the quality of th e m anufactured hem will not suffer by such change. T he replacem ent of sandstone grinding wheels by artificial abrasive wheels and sand by steel shot in abrasive blasting has effected a substantial re daction in th e silicosis ra te of th e pertinent industries. th e face and the m ask, (2) have tittle or no interfere?* w ith vision and perm it the use of glasses or (3) have a highly effective filter which is no t bulky, (Ti have low resistance to breathing over a period of 'VJ (5) have sm all dead a ir space, and (6) have both iab j^' tion and exhalation valves. " D ost respirators are usually constructed of a rubber or part-rubber facepiece and a filtering medium of felted o r paperlike m aterial. Exhalation valves now alm ost universal, and inhalation, or cheek voW. are supplied in m ost respirittors. tn halatiod valv^" are intended to prevent (1} rebreathing exhaled air and (2) the hum id exh aled air from getting into fouling th e filter. R ebreathing exhaled air, which h*, a high carbon dioxide contest, induces panting and causes the wearer to think th a t there is a lack of air or th a t theresistance to breathingis high. H e willattempt m any solutions to elim inate these difficulties, all of wfaidb will seriously im pair the performance of the re s p ira to r. Select!' 1 The bazan 10IS in indust feconanen. t js to expec fo feachdiffe joe rrspiraS wear if b e w t quartz. It -tm y particula e d itio n s as joendations f y . S- Bureau (4 ) Care ar. Because tl jnetbods of * thought is gi qoently goot carefully, ant _ilo tw nvtrl V. Use of Respiraton for Reduction of Dust in Inspired Air (S) Supplied-Air Respirators or Helmets T he air-line respirator and the abrasive blasting Respirators are misused and abused more th a n any helm et are th e supplied-air devices m ost commoolj & other dust-control device. - found in industry. T he respirator consists of a in* The am ount of d u st in the inspired a ir m ay be re m ask w ith an attached hose or rubber tube through ,,one b e a u duced to a safe value by suitable respiratory protective which a ir is supplied, and th e air is pumped or blown security and devices. T hese alone are n o t th e solution to m any of from a source of d ean air to men in the various expo he would tak the dust-control problem s in industry, but they are a sures. These devices afford positive protection if the? In d iv id u a l necessary and helpful ad ju n ct to other m ethods. Al are properly installed and m aintained. The intake toss- s a l system s though there are a num ber of different types of respira supply systems used for th is purpose m ust be located In the indiv tors. the tw o ty pes w hich are used m ost commonly in a t a point where th e a ir is dean and where i t will not be upkeep of th d u st controlare (1) th e mechanical filter or dust respira contam inated by d u st from nearby buildings. For the wash, ste rilii to r and (2} th e supplied-air or air-line respirator and rem oval of oil, w ater, and odors from the a ir, a good air trai m aintem abrasive blasting helm et. These respirators are used cleaner or purifier should be installed in th e supply line. a t one centra *-I.*' echxitpenpsinivge, lyhaonndlijnogbsusseudchstaosraagberabsaivtteerbylapstliantges, , pcraindt wT hheicchlemaanyerbse, hgoivweenvoerf,fdino annottiqreumatoevdeocrawrboornnmcoomnopxriedse ouTt hseomceenwthre: i mium azide m anufacture, welding operations, spraying sors. To avoid th e possibility of carbon monoxide respiratory y of paints and glazes, and m anufacture and use of pig poisoning in men w earing supplied-air respirators, it s which are ms m ents and dyes. T heir m ost im portant use is found im perative th a t th e a ir pump or blower should receive user by stam under conditions where protection is required inter adequate routine inspection and periodic overbading. m etal num bt m ittently, as in cleaning-out operations; sweeping; T he abrasive blasting helm et completely incloses laundry tabs after blasting; rem oving cores from large foundry cast th e wearer's head, fanning a seal a t th e neck and in the m orni ings; shoveling, screening, and handling of m aterials; shoulders or having a directly connected cape which holes in one and the operation and m aintenance of processing equip m ay be tucked in under an over-all jacket or may be num ber) he f m ent. even extended to th e w rist. Blasters move about the dose of t R espirators should n o t be considered to be p art of the very tittle, bu t th e helm et should be tight in weight to r in th e pi; worker's w earing apparel. They are safety devices and the window or p o rt which affords vision should be collected by and should be supplied by the employer. T he em large and correctly placed. If the helm et is too small, room laid o ployer, moreover, m ust see th at they are distributed to a large volume of a ir m ust b e supplied to prevent as worker is so all employees w ho need them , and he m ust td l the undesirable decrease in th e pressure w ithin th e helmet between shif workers when and how to use them , which is a difficult when th e wearer inspires. T he volume of a ir supplied however, ant task and is accomplished-only by incessant instruction. to a helm et should be sufficient to provide a continuous man on th e : leakage outw ard. Some helm ets require only about 100 respirator m (1) Mechanical Filter Respiraton . liters per m inute; others require twice th is amount. worker. He When th e m echanical filter respirator is worn on a The air should be w asted through the collar or d o n or any indiv m an's face, a certain percentage of th e dost is filtered around the neck and out through the clothing. Collas tenance of out from the inspired air. The air movement through sbcul'd be perm eable to air to elim inate the possibility with th a t of the filter is produced by the respiratory action of the of building up a dangerous pressure w ithin th e helmet. hats. In soi Vol. 20. No- < (1941) t -I>ted by : omtortable a>;ij ' onta c t between | p interference ! I s * eegits, bulky, (4) ; i period o f use, : roe b o th in h ala. . I te d of a rubber , n g m edium o f ; v'ou valves are | or check valves | h alatio n valves mg exhaled air ettin g in to and 1 a ir, w hich has | es panting and [ _a lack of a ir or ; -*J,r 'll attem p t j iff. ^es, all of i irm ariee o f the j Imets -asivc blasting ! m ost comm only i m sists of a face ; rr tu b e through um ped o r blown ic various expo- 1 it n if they L i t t to air- a t be located t w ill n o t be uw iigs. F o r the he a ir, a good air | i th e supply line, j carbon monoxide , >r w arn com pres . f t '- poncuide re s,--to rs, it is | er should receive | idle overhauling. ; npletely incloses j it th e neck and cted cape which ; ;tk et or m ay be I a s move about j i lig h t in weight vision should be ' m e t is to o sm all, | id to prevent an' ! vithin th e helm et < * of a ir supplied j rid e a continuous ' re only ab o ut 100 : ice am ount. ie collar o r down clothing. Collars te th e possibility it bln th e helm et. VoL 20, No. 4 Engineering Cmttrcl ej Dusi sti Ecsjrciors 12") tvnosrd escape valves arc unsatisfactory because dust tors are in use, th e maintenance is one of the duties of a a blast may easily be driven into the helm et the nurse. ggainst a strong air cu rren t The advantages of the central over the individual ^3) Selection of R espirator The hazards as well as conditions of use of respir i s in industry are m any and varied. I t is as illogical <0recommend the same respirator fo r all purposes as j, 5 to expect to find a respirator specifically designed {er each different operation. N o w orker would use the 5(0e respirator fa r hay-fever prevention th a t he would 1f=gr if he w ere exposed to a dangerous concentration gf quartz. In th e selection of the proper respirator for ygy particular operation, thc_buyer should specify the additions as fully as possible when asking for recomggjidatioas from respirator m anufacturers or from the y 5. Bureau of M ines. system are obvious. Each worker has a clean, well- kept respirator daily. He will object less to wearing i t and w ill get real protection a t all tim es. T he mone tary saving effected by the increased life of th e p arts and decreased steed for new respirators usually will m ore th an offset the additional cost (if any) o f setting up and m aintaining the central system. The idea of a central m aintenance bureau is uot a new one. Such bureaus have been in use in a number of industries fa r several years. T he results produced are rem arkable, as evidenced b y th e condition of-there5phators-an(H he- apparent satisfaction of the m es. . R espirator m aintenance usually consists o f cleaning, sterilizing, and repairing. Effective m ethods of clean {4} Care and Maintenance of Rcspiraton Because th e use of respirators, compared to other ggthods of d ust control, is inexpensive, little o r no fjjgtsgbf is given to th eir m aintenance. Only too freqooitly good respirators a re purchased, distributed tftdoSy, and then forgotten, and in a sh ort tim e they Hedirty and function ineffectively. The respirator will soon become defective if it is not properly m aintained and w ill fail to give th e necessary protection, even If it is worn correctly and continugosly. A defective respirator, moreover, is worse than gone because the wearer is given a false feeling of security and will n o t exercise th e precaution which ie would tak e if he had no respirator. Individual and central m aintenance are th e two gen* o il systems of respirator m * TM h i use today, jo the individual m aintenance system , th e ease and upkeep of th e respirator is left to th e user, who m ust a sh , sterilize, and repair th e respirator. In th e cen tral maintenance system , all respirators are assembled it one central point fo r cleaning and repairing.! -> The central m aintenance system usually is worked oat somewhat as follows. Each w orker who needs in g and sterilizing are (1) wash in warm w ater w ith a brush and soap; (2) immerse for ten m inutes in a solu tion of fannaK a, m ade by placing 1 p a rt of 40% for maldehyde solution into 9 parts of w ater; (3) dip in a 3% solution o f carbolic acid, a 2% solution of lysol, or a 70% solution of denatured alcohol; o r (4) subject the respirator to sterilization by a m oist atm osphere of an tiseptic gas, preferably formaldehyde, for period of 10 m inutes a t room tem perature. A fter following airy one of these procedures, th e respirator should be rinsed w ith w ater and hung up to dry. The filters, felt screens, and headbands (if clastic) m ust be rem oved before cleaning or sterilizing th e respirator. M any du st respirators employ so-called "long-life" filters which are intended to be used over am i over. Such filters are d ran ed by blowing th e d irt o r du st off w ith compressed air, by brushing th e surface, o r by tapping th e filter. I f th e filters arc m oist, they m ust be dried before th e d u st can be removed effectively. The fitters m ay b e dipped in a dry-deaning solution for a short tim e to rem ove grease and th e like. T his process, however, should be carried out only infrequently be cause i t decreases th e life of the fitter. ' respiratory protection is supplied w ith two respirators xhich are m arked w ith th e em ploym ent num ber of the raer by stam ping th e num ber on m etal parts, riveting netal num ber plates on th e rubber m asks, at sewing handty tab s on the headb ands. W hen he goes to work is the morning, the w orker passes by a row of pigeon holes in one of which (indicated b y his -employment umber) he finds a dean and w ell-kept respirator. A t the dose of the d rift, he again places th e d irty respiretor in the pigeonhole. All of th e d irty respirators are collected by one m an who deans and repairs them in a room laid out for this purpose. One respirator per maker is sufficient if th e m aintenance is earned out between shifts. Two respirators usually are supplied, however, and th e repairs and deaning are done by one an on the regular s h ift T he w orker in charge of the respirator m aintenance need not be a new or special *rier. H e m ay be th e m an in charge of the stock room any individual whose work w ill p e rm it The mainkMocx of respirators m ay frequently be combined *ith that of such equipm ent as goggles~and protective hats. In son industries where relatively few xespira- ' VI. Bureau of Mines Approval D ust respirators are tested and approved by the U. S. B ureau of M ines under Schedule No. 21 entitled "Procedure fo r T esting Filter-Type D ust, Fum e, and M ist R espirators fo r Perm issibility," and supplied-air respirators are tested and approved under schedule No. ISA en titled "Procedure for Testing Supplied-A ir R espirators fa r Perm issibility.'* . - T he only im portant difference between th e air-line respirator and th e abrasive blasting helm et is th a t th e la tte r provides protection to the face and head of the wearer from th e rebounding abrasive. Seven supplied-air respirators of this type are ap proved; tw o are air-line respirators and five are abra sive blasting helm ets. The U- S. B ureau of M ines, through these approval schedules, has done a great deal to raise the standards of the respiratory protective devices m anufactured in the U nited S tates and has been of great service to industry in th e selection of the proper devices. Willson Pita o ci, Incorporated &IABW6, PwnaTANU (1MI)  a i THE BULLETIN OF THE AM ERICAN CERAM IC SOCIETY I^ 1#** SO Contents for August, 1941 Number 8 j r . PAPERS rweriptioa of Hot Modulus of-Rnptnre and Hot-Crashing Strength Tests end Discussion of RewfitP---------- -* * . B. Hunt and R. S. Bradley........................................................................................... , ................... 267-69 jjultiple-Tunnel Kilns--M . S. Nelson and Hewitt W ilson........................................................................... 270-74 pairing Fine Clay Bodies in the Plastic Form--E. A. Hawk...................................................................... 274-75 prefabricated Structural Clay Tfle Floor System--E. F. Wanner.................................................................. 276-BO gjperimenta] Study of the Inhibitory Effects of Aluminum Compounds in Silicosis--Leroy V. Gardner, Mortis Dworski, and Anthony B. Delabant...........................................................................................281,284 Industrial Health Service for the Small Plant In the Ceramic Industry--Huntington Williams, W. H. Schulze, and J. M. McDonald................................................................................................................ 2S5-S7 A ? ON fi_ las Stains rtlszc Colon n M edium s a and Lastre u 1 Chemicals Equipment id L ia ia p tex M in ZJbBcs i >i i the Ceri mie Discussion on "Symbolism in Chinese Porcelain Decoration"--Lawrence E . Barringer............................. 287-88 J lia d m ' Indes................................................... ................................................................................................. |no' Guide................................................................................................................................................. 12, 1 6 ,1 8 , 6 20 Intuef Cwporatioa Member.................................................. ........................................................................... 294-95 INDEX TO CERAMIC HISTORY, ACTIVITIES, NOTES (naie histdry, Pittsburgh Plate C la n Cmpuy, pp. 2U"H. te a k schools, New York S a te Ceflcsc of C e t e o . Icn ro Rfractants ft Alleys Carp. fellowship, p. 296: Studeat Breach teovitics d ario f 1949-W1, p, 396. hmtt U n te , aam al boaocas m cctiat. p. 291. Urnfapi a t Edward Orton, Jr.. Ceramic fondation far 1941*1942, p, 396. Boira Rcfractarim & Alloys fellowship a t K. Y, State CoUoft of Ceramics, p. 396, (ha, p h te .|k it manufacture by P ittsburfb Due G lu t Company, pp. 396-30. k te h ft Ceramic Enginecra, jeiat omettes with Industrial Mineral* Divffteo f t A.I.M.M.E., p. 39ft. new member, p. 391, Members, mcmbeiMp wer k a z * record, p. 292. new, far July, p. 392. paid membership record, p. 293. reetcr e hufe* doriaf Joky. p. 292. Metal 4 Thermit Corporation, new research laboratory, photo, p. 296. ' Katfoaal Ceramie SA ttiti Heath annual) a t Syracuse Mueeom of Elm An*, p . 297, Orton, Edward, Jr.. Ceramic Fonodatiee, fellowship for 1941*1942, p. 296. Photepaphe, Brown. Chirlcs. W ,, p. 289. Q a u x , Robert L., p. 290. O aum , W . U , p. 389. K w ttM ic h laboratory of M etel & Thermit Corporation, p, 298. K te u n , John. A uran cover. Wberrett. K . S.. p. 290. P H a in , John pioneer in plstc-gU a m u u . facture, p. 288: photo. A ufust cover. Pittsburgh Plato Glee* Compenyt history, pp. 288190. R e t earth, Metal 4 Thermit Carp, research laboratory, photo, p. 296. Syracuse Mvaeom of Fine Arts sponsors tenth u s u a l Katiooai Ceramic Exhibition, p. 397, X-ray analyaia in industry, p. 297. ROSTER OF PAID CO RPO RATIO N MEMBERS Abb Engineering Co., N e York. N. Y. Abingdon Sanitery Mfg. Co., Abingdon, HI. A C Spark Plug C o, Flint, Mich. Adamston Fiat Glass Co., Clarksburg, V . Va. Akron Porcelain C o, Akron. Ohio American Gas A ssn, N e York, N. Y. American Glass Corp, Greeasburg, Pa. American ta r a Carp, Chattanooga, Tenn. American Kepheline Corp, Rochester. N . Y. American Porcelain Enamel C o, Muskegon, Mich. American Potash A Chemical Corp, N e York. N . Y. American Refractories InatrtuterlPittsburxh. Pa. ' American Rolling M SI C o, Middletown. Ohio American Store Company, St. Louis, Mo. Amsler-Morton C o, In c , Pittsburgh, Pa. Anchor Hocking Glass C orp, Lancaster. Ohio Aricetex Ceramic Corp, Brazil. Ind. Armstrong Cork C o, Lancaster, Pa. ' Atlantic Terra Cotta C o, Perth Amboy, N . J . Empire Sheet A Tin Plate C o, MancK.p, n , . Engelhard, Charles, In c, Newark. N. J. English China Clays Sales Corp, New York, N v Eureka Flint A Sper C o, Trenton. N .J. ' * Exolon Company, Blasdell. N. Y. Fabriea de Ladrilloc Industriales y R efract,.;-. terrey, N. L , Mexico " '`tnct, Feirfaete Company, Inc., Trenton. N. J. Federal Seaboard Terra Cotta Corp., Perth A,,u.. , Ferro Enstnrl Corp, Clevdand, O hio' -* - Feno Enamels (Australia) Ply. J-td, Alexaudri. v A ustralia Findlay Clay Products C o, Washington, Pa. ' Foote M ineral C o, Philadelphia, Pa. Forda Porcelain Works, Perth Amboy, N . J Fostoria Glass C o, Moundsvtile, W. Va. ' Frazier-Simplex, In c , Washington, Pa. Babcock &`Wilcox Co, N e York, N. Y. Bail Blathers C o, Mancie, Ind. BaJthnore Enamel A Novelty C o, Baltimore, MA Bardin, Paul, e Hijos, Soc. Anon. C om , Buenos Argentin*# South America B auch &Lomb Optical C o, Rochester, N . Y. Bclden Brick C o, Canton, Ohio . Bh Ridge G lass Corp., Kingsport, Term. Bonnot Company, Canton, Ohio Brean Corp, Los Angeles, Calif. , Brockway Glass Company, In c , Brockway, Pa. Buck Glass Company, Baltimore. Md. Buffalo Pottery C o, Buffalo. N . Y. Aires, ' Gtreo Products, Inc., Butler. Pa. Gayner Glass Works, Salem, N. J. General Ceramics C o, New York,N . Y, General Electric C o, Lamp Dept., Pitney Glam Nela Park. Ckveland. Ohio " " it. George, W. S , Pottery C o, East Palestine, Ohio GBiinderBrothers, In c , Port Jervis. N . Y. Gladding, McBean A Co., Lincoln, Placer Count, r Gleasou-Xiebout Glass C o, Maspeth, N. Y. " C*- Glenboig Baton Fireclay C o, L td, Glenboig Stntlur Great lak es Foundry Sind C o, D etroit, Mieh. Greet Lakes Steel C orp, Detroit, Mich. * Green, A. P , Fire Brick C o, Mexico. Mo. Cenadien General Electric C o, L td , Peterborough, Ontario, Canada Canton Stamping A Ernimrlmg C o, Canton. Ohio Carborundum Company, Niagara Falls. N . Y. Carnegie-Illinois Steel Corp., Pittsburgh, Pa. Carr-Lowrey (Hass C o, Baltimore, l i d Cel Mines, In c , Burnsville, N . C. Central Silica Company, Zanesville. Ohio Ceramic Color A Chemical Mfg. C o, N e Brighton. Pa. Ceramics Publishing C o, Lie., Newark, N . J . ' Certain-Teed Products C orp, Buffalo, N. Y. Champion Spark Plug C o, D etroit, Mich. Chattanooge Glass C o, Chattanooga, Tenn. Chicago Hardware Foundry C o, N orth Chicago. IH. Chicago Pottery C o, Chicago, BL Chicago Vitreous EnamelProduct C o, Cicero, IQ. Clark, K , A Sons, San Francisco, Calif. Colonial Insulator C o, Akron, Ohio Commercial D ecal Products, Inc., E ast Liverpool. Ohio Consolidated Feldspar C orp, Trenton. N . J. Coots Porcelain Company, Golden, Colo. CorhaitRefractories C o, In c , Louisville, Ky. Coming Glass Works, Corning, N . Y. Crane Enamelware Company, Chattanooga, Tenn. Crooksrle China C o, Crooksville, Ohio " Crossiey Machine C o, Trenton, N. J. Crossmxn Company, South Amboy, N. J. Crown Potteries C o, Evansville. Ind. DeVtlhics C o, Toledo, Ohio Dixon, Joseph, Crucible C o, Jersey City, N. J. Diakeafeld, B. F , A C o, N e York, N. Y. Du Pont de Nemours, E. L, A C o, R. & H. Chemicals D ept, Wilmington. Del. Edgar Plastic Kaolin C o, Metucben. N . J . Electric Auto-Lite C o, Fostoria. Ohio Electro Refractories A Alloys Carp, Buffalo, N. Y. Haegcr Potteries, In c , Dundee, Ilk H ill Chine Company, East Liverpool, Ohio Hancock Bride A lR e C o, Findlay, Ohio Hanley Company, Summerville. Pa. Hanoria Chemical A Mfg. C o, Newark, N. J. Hirdmge Company, In c , York, Pa. H arsha Chemical C o, Cleveland. Ohio Hartford-Empire C o, Hartford. Conn. Haws Refractories Company, Johnstown. Pa. Haxel-Atla* Glass C o, wheeling, W. Va. Hommel, O , C o, Pittsburgh, Pa. Home, L. J , Convex Glass C o, Print Morion. Pa. Humphryes Manufacturing Co, Mansfield, Ohio Hygrade Syhrania C orp, Emporium. Pa. Ulinou Clay Products C o, Joliet, Ilk Industrial Ceramic Products, E tc, Columbus, Ohio Ingram-Richardson Mfg. Company of t,, Frankfort. Ind. International Clay Machinery Co, Dayton, OKo International Smelting A Refining C o, Akron, Ohio fronton Fire Brick C o, Columbia. S. C. Isolantite, Incorporated, Belleville, N. J. Jova Brick Works, Rosetoo, N. Y. Kaolin, Incorporated, Spruce Pine, N. C. Kentucky Clay Mining C o, Mayfield. Ky. Kentucky-Tennessee CUy Co, Mayfield. Ky. Knowles, Edwin M , China C o, Newell W. Va. Kohler Company, Kohler, Wis. Koppers Company, Pittsburgh. Pa. K riitile Company, Niies, Calif. Ladede-Christy Clay Products Co, St. Louis, Mo. Lancaster Iron Works, Lancaster, Pa. Lapp Insulator Co, In c , Le Roy, N. Y. Laughlin, Homer, China C o, Newel], W. Va. Lave Crucible Co. of Pittsburgh, Pittsburgh. Pa. 291 ` Voi. 20. S ` jir s n . Ar* ^ gssss? fO*** S u a m e iin . A Mungei 0^ donai Engine* 2 i d 2 Firepro* J'rio aal G jP * t gSSK B " Tota Ka; S^hA m enesn. VA Caroto F j,toa Company Ohio CUy C o, C S io Hydrate A S o Insulator D Ob ,, Old Hickory Ctoj oictf Tile C o, ( Oooadsge Potter Otvfnetion, me.. Orna, Edward, } Qy-n,-Illinois Gl QTCBg.]jlsnois Pi PacificClay Prod Pacific Coast Boi Pacific Tile A Po paper M akers Ire P us A Seymour, Pennsylvania Pul pesnsytvania Sai piaudler Compan Pittsburgh Piate PocelainE nam e Pettelain Produt Portsmouth Clay Putten Supply C< Precuiaa Grindii Qalgiey Compia; Stmtite C o, Chi Rentme Cocer Remmey, Richer ( ^ AI i194li *&. * bulletin of The American Ceramic Society--Rosier oj Corporation Members 295 Company, Clearfield, Ky. TolKio- 0hjo Gl*** C o, Toledo, Ohio w r'^juf corp-, Baitimore. Md. fZP tTdtcBBn>e Co., East Liverpool. Ohio l A ^ C a , LosAngeles. Calif. ^ cidtuy Pottery, Inc., Perrysvle. Ohio /a nw UflltimAeo M<4 Republic Steel Corp, Youngstown, Ohio Rickman A Rappe, Kln-Kalk. Germany Riddell, W. A., C o, Bucyms, Ohio RosevillePottery Co,, Z u csrille, Ohio Rot-Teooy Crucible C o, Philadelphia, Pa, , Rtmdle Manufacturing C o, Milwaukee, Wie. Rustless Iron C o, L td , Keighley. England S d eij Grinding Wheel t Machine C o, Springfield, Ohio G , * Co, Cleveland, Ohio !l{&5**LBottl*t C9 o-, ?Jer"sey City.NN-.YJ.. <e5tCtories Co., Mexico, Mo. Co, N e* York, N . Y. y & h iltitl- Coi S t. Louis, Mo. -------- * & Mfg. C o , West L abyette. Ohio 5* K e n t . N " York. N . Y. L d v L Company, Zanesville, Ohio - P^fltfieiH Pottery C o, M ount Clemens, Mich. *** gapseeiing C o, Chicago, I. reproofing Corp, Pittsburgh, Pa. f i ansata Co, Clarence Center, N . Y. ^ ta f is tr is l Sand A ssn, Washington. X>. C. C_o,eBtA._ro_onkl,ynw. N_. Yti_. ^ Worl*, hio Pubcrixing C o, New York, N . Y. **Ijtri KabnaMM K aisht, Nagoya, Japan `P. C*. yds Xaisha, L td , Nagoya. Japan iguntsn Refractories C o, Cleveland. Ohio "dland J?Ccolsa Feldspar C orp, Erwin, Term. - *" company, Worcester, M ass. . .Off Co, Cleveland. Ohio ^Hydrate A Supply C o, Woodville. Ohio ^yslator Company M r , Ohio Brass Co., Barberton, w&E>dtorr Clay Co., Paducah, Ky. i*nT C o, Olean. N .Y . Pottery Co, Syracuse, N . Y. -nctios, b e ., Pittsburgh, Pa. Z gdvazd, J r , Ceramic Foundation, Columbus, Ohio ^ ffia o is Glass Co, Alton, HL ^.ijninoitPacific Coast C o, San Francisco. Calii. giidry Products, In s Angeles, Calif. . 'hio *aa, Ine, kdt Coast Borax C o, New York. N. Y. gie IBe A Porcelain Cow, Los Angeles, Calif. !yeHaken Importing C o, In e , Easton, Pa. taiSeymear, b e , Solvay, N. Y. taqfnais Pulverising C o, Lewistown, Pa. hupnais Salt Mfg. C o, Philadelphia, Pa. AderCompany, Rochester, N . Y. o SettatghPute G lu s C o, Creighton, Pa. sakn Enamel A Mfg. C o, Baltimore, Md. 'hio huhia Products, In e , Findlay, Ohio ttauuth ClayPreduets C o, Portsmouth, Ohio * ' Co, East Liverpool, Ohio iding Wheel C o, Philadelphia, Pa. igleyCompany, Ine, New York, N . Y. I Co, Chicago, IH. ' . . J e Concrete Machinery C o, Dundlen, N. J. j riaej, Richard C , Son C o, Philadelphia. Pa. _ , Joseph E , A Sons, lac. Louisville. Ky. Shetungo Pottery Company, New Castle. Pa. Simcnds Warden White C o, Dayton, Ohio . Smith A Stone, L td , Georgetown, Ontario, Canada Sol-ray Process Company, Syracuse, N. Y . .. Spinks, H .C , Clay C o, Newport, K y i'""*' Square D Company, D etroit, M ich. - Standard Brick and Tile C orp, Evansville, Ind. Standard lim e A Stone C o, Baltimore, Md. Standard Sanitary Mfg. C o, Louisville, Ky. StarPortelain C o, Trenton, N. J. Stark Brick C o, Canton, Ohio Stauffer Chemical C o, In e , New York, N. Y. Steele, J. C , A Sons, Statesville, N . C Sterling Grinding Wheel C o, Tiffin, Ohio Structural Clay Prodncts Institute, Washington, D. C. Stupakoff laboratories, In c , Latrobe. Pa. Snmmitville Pace Brick C o, Suramstvfile, Ohio Sur Enamel A Stamping W orks, Ltd., Calcutta, India Surface Combustion Corp, Toledo, Ohio Swindell Brothers, Baltimore. MA Swindell-Dretsler Corp, Pittsburgh, Pa. Taylor, Smith, A Taylor Co., Chester, W. Va. Texas Mining A Smelting C o, Laredo, Texas Titanium Alloy Mfg. C o, N iagara Falls, N. Y. ToyoTokiKaisha, Kokura City, Japan Trenton Potteries Co., Trenton, N . J . Twyfordx, lim ited, Stoke-on-Trent, England Tyler, W. S , Company, Cleveland, Ohio Union Electrical Porcelain W orks, In c , Trenton. N. J. United ClayM ines C ore, Trenton, N . J. United Glass Bottle M xrs, L td , London. England United States Gypsum C o, Chicago. IB. Universal Clay Preducts C o, Sandusky, Ohio Universal D entil C o, Philadelphia, Pa. Universal Sanitary Mfg. C o, New Castle. Pa. '^In ^u p ^f riek lA 'T ie freeligm g, Transvaal. South Africa Yesrreias Crucible Cow, Svrissvale, Pa. Victor Insulators, Inc., Victor. N. Y. Vitrefmx Corporation, Los Angeles, Calif. _ Vitreous Steri Products C o, Cleveland, Ohio Vitro Manufacturing C o, Pittsburgh, Pa. Wallace China C o, L td , H untington Park, Calif. Waltham Grinding Wheel C o, W altham, Mass. Washington Porcelain C o, Washington, N. J. Wayne Laboratories, Waynesboro, Pa. Western Brick C o, Danville, HI. Western Electric C o, Chicago. HI. Wcstingbeuse Electric A Mfg. C o, Derry, Pa. West Virginia Briek C o, Charleston. W. Va. Wheeling Steel Corp., Yorkville. Ohio Wisconsin Porcelain C o, Sun Prairie, Wis. CORPORATION MEMBERSHIPS ARE PROFITABLE INVESTMENTS _v ''o S MRn