Document pe3gZYqy7xnJ0nqeOrNXOQ3oE

FILE NAME: General Electric (GE) DATE: 1946 Nov DOC#: GE0019 DOCUMENT DESCRIPTION: Southern Power & Industry Newsletter n g y op t i e s bj efficiel require dem af lipm ent n equip e n t s iii^ omv, . in thg! icialistsia ,-f? rvice idations neersaj Vfl e m re*{ s by i| or by| iciiitiefJ quipped| -- s t e els in e rie s | itcetera al boilj EV E AH . , .inifl ,I<E BER. 'Egene W. O'Brien Kj&J,'.;. Managing Director 'neis C. Smith, Editor Minter R. Hughes, Jr. fif:: Associate Editor Richard L Priest Southwestern Editor W. E. Coogier Production Manager Jil/W/itu Rtftrtttniaihru Rogers, 18 East 48th 8t., SOom 1904, New York 17. S ip Y.-- Phone, Plasa 8-2566. K. Hoffman, 28 Bowdoln KistyMaplewood, N. J.-- Phone 1a;i8fe6r,-7 Orange 2-2484. ,/il djiL. Durham, 67 Covlngton'.-Road, Buffalo 16, N. I . -- " hon, Amherst 8332. ii.VBmith, 206 Auditorium Bbllding, Cleveland 14, Ohio j&Phone, Cherry 7362. .Oii.Bi;' Johnson, 168 North ,, JtfMiehiran Are., Chicago 1. ijtJlh-^Pfcone, Central 4131. t f i . ChAppell, Auditorium Bldg., IK427 West 6th St., Los AngeRS'les, Calif. -- Phone, Tucker ^;6363. tlihard L. Prlees, 1341 Liberty (fi.i..Bank Bldg., Dallae. Texas.-- i -tvl Phone, Central 7673. fc'Annnal Bnbacrlptlon-- $1.00 COiPia1-d a-- $1.60 ; Foreign $2.00 -- m-- f :"-' Pvblithed Monthly by J , W R. c. SMITH PUBLISHING CO. A lishers also of : Cotton, ElecdhSouth, Southern Hardware, them Automotive Journal, .hern Building Supplies. M& . 1 Rooke. P r e s i d e n t ; R. P. th, Executive Vice-President ; i>V. M c A ll i ste r, V i c e - P r e s i d e n t ; b*W. O'B rien, V ic e - P re s id e n t : C. S m ith , V ic e - P r e s id e n t . PQCook, V ice-President; 0. A p l e a s , T r e a s u r e r ; A, F. Roh '-Secretary, f.jtoriol rnd Executive 0 ///c i |P,A N T BUILDING IAtLANTA, GEORGIA C A , , .. It V 1 '-1 ,Y . ,:sk i s mostly'ig fleeted) tod o f;e| t raw m3 tali tv aril re Is l i ttlf 1 artisahp of practice! tdy makijj craftsmafi :ult to'iil are int'Cr to develop d by tHs i when tfit erials can e 80) ':1 In In d u strial Hygiene Im portance of D ust B y IV. V . H e n d r ic k s Chief Engineer Industrial Hygiene Service, Georgia Department of Public Health Nearly all types of m odem industry a r e concerned with dust and its control. Courtesy M. S. A. Co. THE M IDG ET IM PIN G ER USED FOR c o l l e c t in g PHERIC DUST SAMPLES, a tm o s- tiate between the o r i g i n of these materials, a defi xtr- 'HE a nnua l cost to industry [fffrdm u n c o n t r o l l e d dust jurits to a staggering figure. In leases the problem of dust is ji&'sed by m a n a g e m e n t as only liife'ance. In other plants, the jjwery of certain dusts is ecohjcally sound, especially where " articulate m atter may conrecious metals or may carry lie processing stock. Aside any nuisance or economic [Resulting from the escape of Sthere are certain dust ex iles which may result in acute [th hazards. This is especial|lie of dusts containing a high Intage of free silica, asbestos, ,,Jfl'er toxic m aterials. W here ,xh considerations are involv|Usuch exposures, legal aspects lant themselves. In most states Ire occupational diseases are [.ensable, specific coverage is J t o those disabilities resultIfrom the inhalation of silica Definitions P y times true dusts are con^tAuth fumes, smokes, mists, s. In order to differen- nition of them is in order. DUSTS are formed by the re duction of earthy materials and are usually produced by such ope rations as crushing, grinding, buffing, etc. The particle size of dusts may vary considerably, ranging from sub-microscopic to visible. FUMES are formed by conden sation and sublimation. Chemi cally, they are metallic and are usually the oxides of such metals as zinc, and lead. The particle size is usually below one micron. Smoke comes from the burning of organic material and its p ar ticle size is usually less than onehalf micron. Misis and Fogs result from the condensation of w ater vapor on suitable nuclei, and the particle size will vary with given con ditions. General Properlies As a substance is reduced in particle size, there are certain general properties of the material which are changed. On breaking up a solid into finely divided par ticles, the surface area is greatly enlarged and therefore the space occupied is greatly increased. As an example, a piece of quartz one centimeter on each side when crushed to w here the particles of one micron in size will present a system containing 10" n u m b e r of particles. The total surface area will be 6 square meters. If these dust particles are dispersed onto the atmosphere in such manner th a t the concentration will be 100 million particles per cubic foot, the space occupied by this dis persed system will be 10 thousand cubic feet. The chemical activity of a solid is considerably increased by a reduction in particle size. Thus the rate of oxidation is increased as is evidenced by occasional dis astrous dust explosions. The phe nomena of adsorption becomes more important as gases are more easily adsorbed on the surface of the smaller particle. From the standpoint of health hazards resulting from dust ex posures, the physiological proper ties of dust vary somewhat with the particle size. It is an accepted fact that with exposures to silica dust, the smaller the particle size, the greater the hazard. Physiological Response Drinker has summarized the re actions resulting from the inhaln- Lion of dust by classifying the re sponse into four groups. These are: (a) Pneumoconiosis-- The dusts producing this type reaction are harmful only when inhaled. The principal materials producing this type reaction are free silica and asbestos dust. On inhalation, these two materials produce specific lung pathology and from the standpoint of disability, present the most important of the dust ex posures. (b) Toxic Reaction-- (As poison ing by lead, cadmium or radium) These materials produce harmful effects when taken into the body both by inhalation and ingestion. With reference to lead and its compounds which may be present in the atmosphere as particulate matter, it has been fairly well established that entrance into the body oy inhalation is more im portant mode of entry than the same material taken by mouth. This is p rim a rily due to the fact that when such materials are tak en into the body by inhalation, the m ajor portion is taken into the blood stream, whereas, a consider able p a rt of th a t taken by mouth is rem oved by certain organs of the body. (c) M etal Fume Fevers-- These conditions result from the inhala tion of finely divided fume par ticles. The importance of metal fume fever has been brought to the attention of industry by the great amount of welding which has been an important industrial tool for the past few years. Where burning or welding is done on su r faces which have been galvanized, the problem of metal fumes be comes immediately important. FIG 7. T H E E LE C T R OB T A T I ' C P R E C I P I T A T O R A S U S E D FOR C O L L E C T I N G A T M O S P H E R I C S A M P L E 8 OF D U S T A N D F U M E8. I N S E R T S H O W S R A T E OF S E T T L I N G OF DUST. A This is also a problem in foundr where the pouring of brass done. ..yij (d) A llergy-- This type reactf, is in general produced by p0i j | and certain organic dusts, -d Common Industrial Dusts Carbonates are usually combif ed with either calcium or t n f nesium. T hey norm ally occuifi n a tu re as calcite and magnS'gj,^ or as dolomite, w hich contain* both magnesium and calciuni|| the carbonate. Limestone marble c o n t a i n consideraijlj am ounts of these carbonates''^ do the materials from w hich'^1 ment is made. Due to the solubility in fluids, these materials are r ed w h e n ta k e n into the body -bwmlii inhalation. The presence of bon dioxide in such fluids is jig im portant factor influencing thej solubility. The same thing applier to the presence of carbon dioxi^f in w ater which comes into contst|j with these materials. In the prg| ence of carbon dioxide the dir);' bonate is converted to the m or1 soluble bicarbonate, thus adding^ to the ease with which it is removal ed by solution. Experimental and practical ob^fs servations on carbonate dust irtip| dicate that these materials are not#! harmful w hen taken into the body!* by inhalation. This is probabm || due to the fact th a t they are easifj;' ly removed due to their solubilityC Sulfates are common Industrial m aterials and this general cla, may be illustrated by gypsum,'. which is calcium sulfate. This a common material and is w used in m a n y industrial opera<j;rjj tions. It is generally consideredM that this type material is non-tox^f ic and does not present any par*jffi ticular problem from a healthjvMJ standpoint. Oxides vary considerably their physiological reaction. general the nature of the reaction.-W; will be dependent on the type';^'|| m etal from which the oxide is de^$&j rived. Where such metals a r i p | | specifically toxic, as would be the:y.;.|,;< case with arsenic or lead, a sprite' cific toxic ' reaction could be cX-ji;S pected from the inhalation of the.bjj^ oxide. However, other oxides pear to be relatively bar rr.l particularly where `he metal of a non-specific type. This is t r u e ^ of iron oxide. The mining of results in the exposure of a num ber of men to !he oxides ass -action pollen Vvf; sis ombin-' :cur gnasite; iiil antains . :um as e and ;|t l 'ierable tes. as s ich ce- r>i' M ' body. M removody by of car- '.-! * is an! {Jig g their applies ;& dioxideW contacte pres-- _ he car? more adding ":I" remov- cal obust in- > ||| are nott':,j|| le body>"$&. robably re easi-,;V,|^ lubility:;^ dustrial;^ il classi;:|*| ;ypsum,-', ;'5: This is..I??., widely-.^ opera-;.r^ isideredy'.|a ion-toxr;.|JP nv par~;hi;| health j f $ ibly in; on. Ini reaction;--^ ie type;;| i | ] ie is de- are. vi>' ; bo the a spefen ex-' , nf the" ides a p r :,^ . armlesSr?y|p| octal = is true c.'S'K <'deS "f t F I G . 3. G E O R G I A K A O L I N D U S T M A G N I F I C A T I O N I 30 X I, this metal. However, it appears jthat exposure to the dust of iron fd.oes not produce pathology u n l e s s such exposure is accompanied "by the pressure of free silica. |V-The mining of coal results in exposure to coal dust which con jo i n s a high percentage of carbon. Epfetailed studies of exposure to eodl dust have been made by the IT. S. Public H ealth Service and oher agencies. It has been found that, in general, coal dust is reItined in the lungs only when Stlch dust contains a high per centage of free silica. Although ^bal dust m a y be deposited in the tings of exposed individuals, the /Condition re su ltin g is usually not r|(jnsidered disabling unless silica |3:,present. pfSilicates make up an important class of industrial m aterials and re used principally in the pro^dction of ceramics and similar iaterials. Talc, kaolin, mica, ilays, etc., are chemically silicates d their widespread industrial ap plication results in a great num ber l-.Bi employees being exposed to Tj,this type dust. W ith the excep tio n of asbestos, which is a silicate, phis general class of materials does mot appear to produce a disabling J|dition, except in isolated cases, p e n taken into the body by in itia tio n . `Sy'Asbestos is the only silicate Ipbown at the present time which I n d u c e s a lung pathology comsi.a ble with that resulting from to' silica dust. all the dust found in indusprobably the most important S w 'ree silica or silicon dioxide. It pS$|Virs in the form of quartz, flint, tfjtstone, and chert; and is as F I G . 4. QUARTZ DU8T (SI 0-) TI ON I30X. MAGNIFICA. sociated with many other miner als and ores. The disabling con dition resulting from the inhala tion of free silica is know n as silicosis and has long been a problem with industries such as stone cutting, granite, foundry, abrasive, and the like, where sili ca is used in processing. There are relatively few industrial ope rations which might result in di rect exposure to pure silica dust. The importance of silica lies in its association with other materials. As an example, in foundry opera tions the dust generally will con tain clay and materials of a nonsilicious character, so that the ac tual percentage of free silica may be relatively low. This is also true in exposures to coal, iron oxide, and the mining of ores. When hard rock or silica is present, these dusts become important mainly due to the presence of silica rather than to the inherent properties of the parent material. Factors Influencing Hazards In evaluating the exposure to a dust there are several factors which should be taken into con sideration. The duration of ex posure is important, as it will in dicate in a general way the total amount of dust which might be expected to have entered the body. Obviously other factors enter into such an evaluation of total dusti ness, and these will be discussed later. History of past exposure is important. This is particularly true where an individual is ex posed to silica dust. This point is of extrem e importance to indpstry due to the fact that a worker may have contracted silicosis under a F I G . 3. C A L C I U M C A R B O N A T E O U S T N I F I C A T I O N 130 X . MAG previous employment. Where sucl a condition exists, the desirability of preem ploym ent exam ination i: obvious. The c o n c e n t r a t i o n of dus breathed is important as this within certain limits, will deter mine the possibility of develop ment of dust diseases. Consider able research and practical obser vations have been m a de in the field of dust exposures to corre late clinical findings with atmos pheric concentrations. F o r fre< silica, asbestos, and some of thi other materials, fairly definiti standards have been established The n a tu re of dust is im portan primarily from the standpoint o free silica content. This is par ticularly tru e of mixed dust: which constitute the majority o industrial exposures. The volumi of air breathed enters into the picture as it directly influenc es the am ount of dust which wil be taken into the body. The rat of respiration or am ount of aii breathed in general will be de termined by the physical effor required on the particular job W here heavy work is being done naturally an individual will re quire more ventilation than wherf less physical effort is involved Dust Measurements In addition to the factors in fluencing dust hazards, it is neces sary to make direct dust measure ments in order to obtain a true evaluation of any dust exposure Such m easurem ents are m ade by the actual collection of du st snm pies, the counting of the dust par ticles, and by the identification oi the materials making up `he dis persed system. For the collection of dust samples, several i ns t r u ments may be employed. Much of the early work done on the control of silicosis in the mining areas of South Africa was 'amoc nut with ihe Konimeter. true instrument has been used omo ir. tins country, however, it .oaf not met with the popularity which .- enjoyed by certain other methods. From the standpoint of collecting efficiency, the electro static precipitator is probably the choice instrument, however, most of the work done on correlating atmospheric dust concentrations with medical findings has been based on samples collected and counted by the Greer,burg-Smith technique. The collecting device employed is an impinger unit which samples at the rate of one "ub.-c foot, per minute. Counting by this technique is done under light field. The pe r centage of free silica in a dust sample is usually determined by either chemical or petrographic methods. Permissible concentrations of ciusl hav^ been established for free silica, asbestos, and other m a terials. For both silica and asbes tos. 5 million particles per cubic fool :s considered as m a x i m u m working concentration. The U. S. i ;b:;c Health Service has suggest ed a procedure by which the total oust concentration in millions of particles per cubic foot is m u l t i plied by a percentage of free sili'a If the resulting figure is more ' r a n 5 million particles per cubic toot, the condition is considered unsafe. If less t han 5 million, the condition is considered safe. There should be considered certain limits of dustiness for any type of dust. wh e th e r it be merel y a nuisance iwo 15-loot Ians arc- installed 1 value or health consideration. To most industrial hygienists, 50 m i l lion particles per cubic foot, is the maximum atmospheric concentra tion of dust under which an e m ployee should work. It should be pointed out that the only way of determining both the nature of the dust and the actual concentration is by direct sampl i ng and similar procedures for the counting of dust. which handle 500 t housand cubic..' feet per minute each. Actually, the material removed by these fans j is made up principally of smoke", rather than true dust. Two electric arc furnaces are operated and these arc equipped with roof fans located immediately above ihe units. These fans handle > 60 thousand cubic feet per minute '! each. Again, the major portion of Case Hisiory the material coming from the arc ' furnaces is smoke rather than true MANY industries having p r o b dust, and comes from the ahoy lems of dust control recog and flux material charged into the ,, nize the existence of such problemfusrnaces to varied degrees. Some take pass A problem of dust control in any ive attitudes, whi l e others apply foundry is the shakeout operatmr.. s o u n d engineering procedures This is particularly true where which result in a real job of dust s h a k e o u t is mechanical and control. Such mo d e rn engineering handled on a vibrating screen or methods are used by Ibe Lc- grate. Here, a line conveyor sys Tour ne au Company of Toccoa. tem is used to bring the castings Georgia. directly to the shakeout grate, A This particular plant ma nufac canopy type hood is installed im tures heavy road grading equip mediately over the grate itself in ment and its major dust problem addition to canopy, side enclosures lies in operation of a foundry for are provided which prevent air : the protection of basic steel parts. leakage. The fan serving this hood It is interesting to note t hat this delivers 35 thousand cubic feet per Company considers the control of minute, which results in a high .; dust as a pa r t of the general o ve r capturing velocity at the entrance'., all production schedule and as a and discharge ports. An excellent ' result has its control methods i nt e job of dust control results on this grated into general plant opera particular operation. tions. Sand conditioning in many Although there are several foundries is a dusty job. With the methods which can be used for LeTour neau Company this is control of dust, ventilation, both handled by means of local exhaust.- in the form of general and local exhaust, probably offers the most ventilation and three bag type in ters handling 6 thousand cubic fee:, satisfactory method and it is this per minute each, Tumbling opera approach which has been used by tions for cast cleaning are also pro- , the LeTourneau Company. For vided with local exhaust voru geneial ventilation in the foundry. (Continued on pane R0' at least 75%. Figure 2 shotys the condition of the tube that Jailed: Other tubes were found eroded adjacent to U bolts holding baffle tiles. The U bolts provided suf ficient interruption in as flow to cause eddy c u rre n ts anfd localized im pingement, (Fig. 3.) Erosion by particles* of fly ash 1 t Candy M aking ( C ontinued from pkge 60) not be taken for granted, a chemi cal laboratory is essential. The Brock Candy Com pany is now in the process of constructing a modern chemical laboratory and training a technician to perform control analyses. The laboratory, which is located in a large air con ditioned room near the candy cooking operations, is equipped with modern stone-topped labora tory benches, the latest chemical glassware, and such special analyt ical instrum ents as. balances, vacuum oven, refraclometer, and pH meter. Provision has been made for such analyses as moisture, in vert sugar, viscosity, pH, melting point, and refractive index. Many of the control tests have been de veloped specifically for the Brock Candy Company, and new pro cedures will be added from time o time as the need arises. The Industrial Research Institute H the University of Chattanooga h'v cooperated . with the Brock C;m dv Com pany in selecting the equipment, outlining and develop ing. analytical procedures, and training a technician to operate the control laboratory. A research and unburned fuel has also been found in stoker-fired boilers. At the time of each shutdown for cleaning and preventitive main tenance (at least once every four months), all areas vulnerable to erosive attack should be examined. Areas most susceptible are:, i 1. Where' flow of gasete njakes a t tu rn , throw ing out particles of ^ Solidk ; " ' ' ' ' 2. B ehind any cracks, breaks, or y gaps* iri a gas bafjfl. , 3 A djacent to any) projection that might divert normal flow of gases. . Should the boiler be provided with an induced draft fan, observe the condition of the blading. Ab n o rm a l w e a r m ay be indicative of erosive attack in the boiler. Careful attention by all engi neers to the. problem of erosion may well prevent a serious acci dent. in the plant. The m odernization program 0f;<p the Brock Candy Company is tak-tf ing place at a time when almost^ any product, regardless of quality/ or cost, can be sold. Tne real bot/J tlenecks today are shortages of raw.w m aterials and skilled personnefijf However, progressive businessmen! know th at these conditions ar^f only tem porary and Lhat within few years, companies which can* not guarantee quality will not bis ablq to sell their products. Thel Brock Candy Company will conlji tinue to be a leader in its field b i | cause it has refused to sacrificed quality of its products in thesjf||| days when consumer demands ardh greater than the supply of raw terials and because it has already/' inaugurated a program of controifi and research which will result inflj constant improvements. Dust >? project on improvement of the quality of candy has been sponsor ed by the Brock Candy Company at the Industrial Research Institute of the University of Chattanooga. Since all raw materials will be analyzed and tested in the com pany laboratory, variation in prop erties will be detected before the m aterial is used. This procedure will assure products of uniform quality, since inferior raw ma terials will be discarded and form ulations will be based on the ac tual analysis of high grade raw materials rather than on standard procedure which do not make al lowance for variation in the in gredients. Analysis and testing will assure high quality of finished products and permit any difference in quality to bo detected. In this way, any unavoidable errors in manufacture can be corrected and adequate controls instituted to pre vent their reoccurrence. The facilities of the control lab oratory will also be available for the evaluation of research and d e velopment work being carried out m the factory. In addition to main taining the production of uniform high quality products, the person nel and equipment, of the control laboratory will be available for many other technical assignments (C ontinued from page 64) tion and dust arrestors as is showri|| in the photograph. Note th a t ex/* haust is applied through the trunnion of the tumbler. In foundry operations or any /S other industrial type processing,.S/!i; housekeeping is an im p o rta n t fac- -fi tor influencing the generation of -;1-, dust. This foundry employs two '!$) five horsepower vacuum cleaners for floor maintenance. By this pro cedure loose dust, sand, and the like, is rem oved from the floor and ,'ga; is not projected into the atmosphere by the movement of machinery, scuffing of feet, and like. This is one impressive point in the operation of this particular foundry. Excellent housekeeping is combined with a good procedure for materials handled. In all of the attempts at dust con trol at the LeTourneau Company, employee cooperation is obtained. Employee c o o p e r a t i o n comes through planned program of em ployee education and employee participation- in affairs involving the health of the worker. Periodic dust samples coiier'ed v . in the LeTourneau foundrv indi- .''-WsS&fc cate atm ospheric concentrations on /i various operations well below ' 'T.w h a t is considered as m a x im u m safe w orking limits. t o d a y s TOUGHER JO B S , HERE S a NEW TOUGHER MOTOR WHERE IT'S WET Wet weather doesn't both er the new totally-en closed Tri-Clad mo tor. Neither do fre quent "washdowns" in food , plants. fi',. WHERE IT'S CORROSIVE Acids, alkalis, and fumes are kept out of these new Tri-Clads. Cast-iron enclosures are corrosion-resist ant, extra strong. WHERE IT'S DIRTY Dirt and dust can't get into these Tri-Clads t<> shorten their life Smooth surfaces are convenient to clean. ta h imsell glass faj tver, s not .- plant do Lava -| hat he cok wok OTitj the -nh, on W rt acity oug creali? art ts c r.a pa$ ' ri th ore satf in Hess inventif nizli his spffig cquiKJ' , ,, .-.Qf ldi W HERE IRO N DUST FLIES H arm ful iron dust and metal filings can't get past the in ner wall. Bearings are protected from dust. WHERE QUARTERS ARE CLOSE W hen space is limited for a totally enclosed m otor, you'll like these trim, com pact new Tri-Clads. |iG -E t r JJc l a d to ta l l y e n c l o s e d m o t o r ip , (1 TO 1000 HP) ll?*:' 1 you welcomed the Tri-Clad open motor with it's Wd'fprotection features. More Tri-Clads have since gone into " lijehthan any other integral-horsepower motor. Now Sos ready with a new line of tough, totally enclosed jSSlad motors for use in adverse atmospheres. We believe Jfoe. industry's most dependable motors. Their longer life Jjjlpyver maintenance will make them a sound investment Sajlnost every job. Apparatus Dept., General Electric K,S.chcncctatiy 5, N. V. W HERE EX P LO SIO N HAZARDS EXIST The new Tri-Clad motors are available in explo sion-proof construc tions where needed. FOR THE COMPLETE STORY' R sg. U . s. Pat. OH- p r GENERAL i irrh V/ r klAWTk JOCD mi ` >les' iid'mWe tt/KU O , which d i c r / k e l new Tfl-Clad ttlly'andbied nttrt*,; Q P Ie tn e s.enda me EA J'.'TMofrV'Hd for Hazardous Locations N A M E .... y ... ' \ v > ^ S $ r v r` ^ A D D R E S S ..... 5 / ' ' ` x w l* K t X ww j ELECTRIC 7 A D V E R T IS E R 'S IN D E X The A dvertisers' In d ex is published as a convenience, and not as a part of the advertising contract. E v e ry care w ill be ta k e n to in d e x correctly. No allow ance u>ill be m a de for errors or failure to insert. A i r e t o e l Mf g . C o ................................................. 12!) A i k e n ' M u r r a y C a r p ............................................ 100 A i31*n B r a d l e y C o ................................................. * A h i i s - C h a m i e r s Mf g. C o .................................. 9 A l l p a x Co., I n c ..................................................... 124 A l u m i n u m Co. of A m e r i c a ......................... * A m e r i c a n b l o w e r C o r p .................................. 32 A m e r i c a n Coa! B u r n e r Co .............................. 133 A m e r i c a n E n g i n e e r i n g Co. ( H o i s t s ) . . . . 35 A m e r i c a n E n g i n e e r i n g Co. ( S t o k e r s ) . . * A m e r i c a n M u u o r a i l C o ..................................... 38 A m e i i c a j i P u l v e r i s e r C o ................................... MO A n a c o n d a W i r e &. C a b l e C o ........................ 33 A.'KIU'MJ!'. C o.. V. \ ) ............................................II!) A r k a n s a s F u e l Oii C o ...................................... * A r m s t r o n g M a c h i n e W o r k s ......................... 85 As b e s t o s T e x t i l e P a c k i n g DW., R a y b e s t o s M a n h a t t a n C o r p ...................... * Ai;i!i;i iV Co., T.hijo ............................................ 130 A u t o m a t i c T r a n s p o r t a t i o n C o .................... 29 e B a b b i t t S t e a m S p e c i a l t y C o ......................... 130 B a b c o c k & W i l c o x (.Boilers) ..................... * B a i l e y M e t e r C o ................................................... * B a l d w i n - U u c k w o r t h D i v i s i o n ..................... * B a y S t a ; e A b r a s i v e P r o d . C o .................... * Bm'-'i I .d u s i : ial E q u i p . D i v i s i o n ........... * B e l m o n t P a c k i n g & R u b b e r C o ............. 106 Bet,., W. H. & U D .......................................... 31 Hi: r! A r c h e r C o .................................................... * B.a-jk S i v a i l s &. B r y s o n .............................. 101 B aw -K nox Co. (O ra tin g D iv is io n ) ... * B r a d - P o o l e G e a r W o r k s ......................... * B r o w n i n s t r u m e n t Co. .'........................... 28 B r o w n e i l C o ............................................................ * B u e l l E n g i n e e r i n g Co., i n c ......................... 91 B u i l d e r s P r o v i d e n c e , I n c .................................127 B u s s m a n M fg . C o ................................. 82 a n d 83 C a r l i s l e C o u n t y Ic e C o ................................... 132 C a r o l i n a K e f r a o l o r i e s C o ............................... 130 C h a p m a n Valve M fg . C o .............................. 30 C h i c a g o B r i d g e & I r o n C o ......................... 117 C i t i e s S e r v i c e Oil C o ....................................... * C l a r k Mfg. C o ........................................................ 11 C la ss lf ie ti A d s .....................................................132 C l e v e l a n d C h a i n A M fg . C o .......................... 123 C l i p p e r B elt L a c e r C o .................................. C o c h r a n e C o r p o r a t i o n ................................... 104 C o m b u s t i o n E n g . Co., I n c ............... 14 a n d 15 C o m b u s t i o n E q u i p m e n t D l v ...................... * C o n t i n e n t a l G in C o ...........................................103 C r a n e C o m p a n y ............................................... 23 D a r t Mfg. Co.. E. M ........................................102 D a v i s R e g u l a t o r C o .......................................... 131 P a y '.nr: R u b b e r Mfg, C o ................................. * De D ava! S t e a m T u r b i n o C o ...................... * D e t r o i t S t o k e r C o ............................................... * P r a v o C o r p o r a t i o n ( H e a t e r D e p t . ) . . . . 89 ' ravo Corporation (Power Dept.) .... 2 e E a g l e P l c h e r C o .................................................... 95 E d g e M o o r Ir o n W o r k s , I n c ..................... 4 f v P ' a r d V a l v e s , I n c ........................................... * E lgin S ' i f i c n o r C o r p ............................................13r. E r. i: !r. <o r C n ........................................................... ` E " -p V a i o - C o b i m n A- G:\eo Co . . . : [is E r ` ;a s ' : ir V a i v i ? C 'n . .............................. * P r ^ d d e r s - Q u I g a n C o r \i........................................\ 1 4 F i s h o r G o v e r n o r C o ......................................... 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S h e p a r d Niles C r a n e & H o l s t C o r p . , UOSv^'Sf S inclair R e fin in g Co...................................... 19'*! S k i n n e r E n g in e Co............. .......................... *` tyv Sm ith, Inc., W infield H .............................. 63'-D>a S m o o t h -O n Mfg. Co................................... 129-;. S n a p On Tools C o r p ...................................... 77 j Socony-V acuum Oil C o.................................... S o u t h e r n N a t u r a l Gas C o .......................... J t f r ? ' S o u t h e r n Rail ay S y ste m ...................... S o u t h e r n S upp ly & E quip . Co................. 133>a . S q u ire s Co.. C. E ....................................... l28A;;ii S t a n d a r d Oil Co............................................. * .S tr ong'. C a r l i s l e & H a m m o n d Go. . . . * S t u r t e v a n t Co., B. F ................................... ' y S y t u r o n C o m p an y ........................................ 119'' Taylor Forge & Pipe W orks .... T erry S te a m T u rb in e Co.. The T e x a s C o .................................................... T o d d S h i p y a r d s C o r p ......................... T r l c o F u s e Mfg. C o ........................... T r o y E n g i n e & M a c h i n e C o ........... u U. S. H o f f m a n M ch y . Co. U n ite d S t a t e s R u b b e r Co. .13? V u l c a n Soot B l o w e r C o r p ............ w W a n t Ads ................................................... WaiTp.n S t e a m T'ssmp Co.. Tnc. W a tc h o m o k e t Optical Co., Inc. AVnhpipr E n g i n e e r l n ? C o .................. W e s t i n g h n u s n . E l e c t r i c C o r p ............ W h o o i e r Mfix. Co., C. IT........................ W i l s o n . Inc.. T h o m a s O ...................... W i n g Mfg. Co.. L. .1 ...................... W r l g l e v J r . , Co . W i l l i a m ............... 1.1! " : : 1is ' . . . f 07 ......... .......... - .; ; ; os Y Vn.rnall-W'arint? f!o .7 a n d 75