Document N2EExdLyQwJrm7y715zOyyK2y

FILE NAME: Trade Publications (TR) DATE: 1942 Apr DOC#: TR022 DOCUMENT DESCRIPTION: Trade Journal Article - Protection Against Industrial Dust Vol. 66 w ith WHICH is INCORPORATED THE IRON AND STEEL TRADES __________________________________________________________________________ V , Thursday, April 16, 1942 No. 1339 THE FOUNDRY TRADE JOURNAL 49, W ellin g to n S treet, London, W .C.2. WARTIME ADDRESS to which all communications should bo sent until further notice 3, Amersham Road, HIGH W YCO M BE, Bucks. Telegraphic Address : " Zaeatecas, High Wycombe." Telephone : HIGH WYCOMBE 1792 (3 lines). # PUBLISHED WEEKLY Subscription Terms (Home and Overseas) : 21s. per annum. AU Subscriptions are payable in advance. OFFICIAL ORGAN OF The C ouncil of Ironfoundry A ssociations The Institute of British Foundrymen The Institute of V itreous Enam eliers T he W elsh Engineers' and Founders' A ssociation The Foundry Trades' Equipm ent and Supplies A ssociation Institute of British Foundrymen PRESIDENT : 1941-42 Major R. Miles, M.Eng., Head Wrightson & Company Limited Thornaby-on-Tees. LIST O F SECRETARIES-- General Secretary : T. Malcemson, Saint John Street Chambers Deansgate, Manchester, 3. London Office : 49, Wellington Street, W.C.2 BRANCHES Birmingham, Coventry and West Midlands : A. A. Timmins, F.l C , 21-23, St. Paul's Square, Birmingham, 3 Ease Midlands: S. A. Horton, "T h re e," Mostyn Avenue, Little- over, Derby. Lancashire : A. Boyes, " Roseville," 7, Kirkstall Road, Davyhulme, Manchester. London : V. C. Faulkner, 3, Amersham Road, High Wycombe. Middlesbrough (pro tem.) : J. K Smithson, North-Eastern Iron Refining Company, Limited, Stillmgton, Stockton-on-Tees. Newcastle-upon-Tyne : C. Lashly, Sir W. G. Armstrong, W hit w orth & Co. (Ironfounders), Ltd., Close Works, Gateshead Scottish : J. Bell, 60, St. Enoch Square, Glasgow. Sheffield : W. Webb, B.Sc, 20, Brookfield Avenue, Swinton, Mexborough, Yorks. Water and Monmouth : J. J. McClelland, 12, Clifton Place, Newport. W est Riding of Y orkshire: S. W. Wise, tIO, Pullan Avenue, Eccleshift, Bradford. South Africa : F. C. Williams, Mutual Building, Corner of Harrison and Commissioner Streets, Johannesburg SECTIONS Bristol : A. Hares, 167, Ridgeway Road, Fishponds, Bristol. Burnley : H. Buckley, Ellsmere, Norfolk Avenue, Burnley, Lancs East Anglian : J. L. Francis, 12, Glenhurst Avenue, Colchester Road, Ipswich. Falkirk : T. R. Goodwin, " Viewfield," Falkirk Road, Bonnybridge, Scotland. Lincoln : E. R. W alter, M.Sc , The Technical College, Lincoln. The Institute of Vitreous Enameliers President : Professor J. H. Andrew, D.Sc., Department of Applied Science, The University, St. George's Square, Sheffield. Chairman : W. H. W hittle, W. H. Whittle. Limited. Eccles, near Manchester. Hon. Secretary : Dr. G. T. O. Martin, 21-23, St. Paul's Square Birmingham. 3. Foundry Trades' Equipment and Supplies Association P resident: G. E. France, August's, Limited, Thorn Tree Works, Halifax. Acting Secretary : Miss L Cox, 52, Surbiton Hill Park, Surbiton Surrey. Welsh Engineers' and Founders' Association President : W. E. Clement, C.B.E., Morfa Foundry, New Dock, Llanelly. Secretary : J. D. D. Davis, 9, Royal Metal Exchange, Swansea. BRITISH CAST IRON RESEARCH ASSOCIATION The Registered Office end Laboratories of the B.C.I.R.A. are:-- 21-23, ST. PAUL'S SQUARE, BIRMINGHAM Telephone; Colmore 4274-4275 Telegrams: C IRA The B.C.I.R.A. Scottish Laboratories are:-- Foundry Technical Institute. Meek's Road Falkirk (Phone: 332) Council of Ironfoundry Associations Chairman : FitzHerbert Wright, The Butcerley Company, Ripley, near Derby. Secretary : V. Delport, 2, Caxton Street,Westminster, S.W. I Participating Associations : National Ironfounding Employers' Federation. British Ironfounders' Association. National Association of Malleable Ironfounders. Ironfounders' National Confederation British Bath Manufacturers' Association. British Malleable Tube Fittings Association. Cast Iron Chair Association. Greensand Pipe Founders Association of Scotland. Cast Iron Heating, Boiler, and Radiator Manufacturers' Association. Case Iron Segment Association. National Ingot Mould Association. Cast iron Axiebox Association. Institute of British Foundrymen (affiliated). British Cast iron Research Association (affiliated) British G rit Association (affiliated). Agricultural Engineers' Association (affiliated). One More Committee ? It appears to us that for the better prosecution af the war, there is need for the creation of still one more committee. This, superficially, does not have the appearance of adding to our popularity, but there is a serious gap in the organisation of the steel foundry industry, which requires filling. Through lack of foresight on the part of past Governments, the not incon siderable steel foundry industry of the last war was allowed to shrink during the slump to dangerously small proportions. Just before and during this war there has been a very consider able expansion; moreover, old-established firms are being required to tackle new types of jobs, and some make an immediate success of them, whilst others require more time than can be spared at the present for getting into produc tion. The weights of some castings vary in order to take care of machining allowances by more than 25 per cent. This, inter alia, causes much coming and going between foundries in specting each other's methods. A comparison with the iron foundry organisation reveals exactly where the steel foundry industry is weak. In ironfoundry, research work is carried on by the B.C.I.R.A., which additionally and probably preferentially is undertaking much development work. That is, it makes itself familiar with new jobs, and where difficulties in production arise, it sends its officers to the actual foundries to get things going. Then the Directors of Iron Cast ings have their own technical advisory com mittee, and so has the Council of Iron Foundry Associations. Moreover, a committee of the Institute of British Foundrymen has been ener getically employed in creating, what eventually turned out to be a group of steel foundries! . The steel foundry is well served for pure re search work, through the joint auspices of the British Iron and Steel Federation and the Iron and Steel Institute, supported by the General Steel Castings Association--but th e r e is no de velopment and advisory work in progress such as there is with iron castings, and this is the very committee we suggest should be formed. Moreover, the committee we visualise would not be merely a periodic assembly of half-a-dozen or so of the better known foundry managers, but the reinforcement of such a body by a high grade competent official supported by a staff. The work of this permanent and perhaps some what curious committee would include questions of standardisation, of design, and o) methods of moulding, composition of metal fuel economy, and technical help in achieving the production of high grade castings. It would advise the Director of Steel Castings and co-operate with the fighting services in the simplification of design. We leave the obvious utility of such an organisa tion for post-war development to the imagina tion of the leaders of the steel foundry industry. The American counteipart of the General Steel Castings Association has provided all the neces sary pointers. It is obvious, that by the creation of such an organisation as we have outlined, that the industry will gain in status, for it must be borne in mind that employers' associations (except those negotiating with the trade unions: exist for three purposes only. One is to ensure an economic return for their efforts; the second to provide a voice to speak for the industry in matters concerning Governmental orders and other influential bodies, and the third, which wi rate as of equal importance, the giving of service to its customers. At the moment, the allimportant customer is the Government through its various departments, and we have even reason to believe that the step we propose will be enthusiastically received by the clientele We sincerely hope that our proposals will K equally well received in steel castings circles. Book Review New Methods for Sheet Metal Work, by W Cookson. Published by The Technical Press, Limited, " Piccancot," Gloucestei Road, Kingston Hill, Surrey Price 7s. 6d. 'ihe reviewer often wonders whether or not an engineer's patternmaker could derive advan tage from a study of the methods used by sheet metal workers in setting out their jobs The main difference, of course, is that metallic sheets can be bent, and wood cannot, yet when one examines the patternmaking for a propellti, consisting, as it does, mainly of sweeps, one sees that there can be a connection. This book appeals to the reviewer as being much more practical than the average treatise on the sub ject; the illustrations, which are so very im portant in this type of book, are particularly clear. Added interest is given by the fact that entirely new methods are disclosed. Contents One More Committee? Book Review Old M etal and New Notes from the Branches . Random Shots ... Foundry Production Problems with Special R eference to H ig h Duty-Alloy C ast Iro n ... World Directory of the Enamelling Industry Tin Smelting in South Africa ............ M etallurgical L ite ra tu re . .................................. The Foundry Industry and Air W arfare Protection Against Industrial Dust A ir-Conditioned B la st .. A M inistry of Fuel Magnesium Dust Extraction . . . . . . The New P aten ts and Designs Act Cathodic Protection of Pipe Lines O rganisation of Production W holesale P rice C hanges m 1939-1941 South A frican lio n and Steel W iring of Foundries P aten t Specifications Accepted C lothing Coupons fox In d u stria l W orkers American Ferroc lirome The W eek's New.' in B rief H igher Prices for High-Speed Steel Scrap Ban M ateria! M arkets p\tn 239 23'; 24C 2+0 24d 24! 244 244 24u 24" 249 25U 25": 2.,2 2,j2 2!>2 14 254 Protection Against Industrial Dust coal, sugar, dextrine, cocoa, various cereal dust' cork, shodd) and lags, sulphui, wood tloui, vaiious icstns and d>cs and plastics, malt. tea. magnesium and aluminium, to name but a few By KENNETH L. GOODALL, M.Sc.. F.lnst.P.t Oxidation ol combustible mateiial is a suilace phenomenon, and so is most rapid and capable ot causing explosion with material in the fine)) divided Industrial dust presents two main ha/aids to the other pa is ol the room, or the plenum system in state. with dusts, and paiticukuly when these porkers m factory and mine- (I) risks to health. which clean, warmed and possibly humidified air are m suspension in an as dust clouds. I he in risks lo life and limb through fue and explosion in blown into the work loom unde/ slight positive crease of surface area with decrease in constituent fiom ceitain types of dust. Many factory opera piessuie through a ducting system, the air finding particle size, for a given weight of dust, is striking tions give rise to dust, the chief including crushing, its wa> out vm doors, windows or other openings. Thus Bergei. on the basis of certain assumptions, ^breaking, disintegrating, grinding, abiading. dulling, 1hesc methods of dealing with dust in workrooms, shows that the surface of a cube of aluminium awing, turning, mixing sieving, rumbling sand- or a combination of them both, are of strictly weighing 1 grm. is approximate!) 3 sq cm., wheieas tor shot-blasting, and almost any operation in limited application and are only success!ully applied il the cube is comminuted until the thickness ol volving material which is it>elf a dust 01 contains where the dust concentrations aie generally dis the resulting lamella? is 20 " (coarse stamped a percentage of dust. seminata! in the workrooms Even then, the use powder), the surface increases to 420 sq. cm 11 The risks to health fiom nulustiial dusts arise of general mechanical ventilation is often a con the process is continued until the thickness of the [from the damage the) can cause to the respirators fession of failure to provide what is more effective, lamella; is reduced to U.6 (line stamped powder) system, and from the action of certain dusts as namely, adequate localised exhaust ventilation the surface of the 1 grm of metal becomes 14,290 general systemic poisons ot skin irritants Thus the sq. cm., while for the finest pow'der (prepared in inhalation of silica oi asbestos dusts, which is localised Exhaust Ventilafioii dustrially in large quantities) with lamellar thick cumulative in effect, can cause the incurable lung Localised exhaust ventilation is the commonest ness 0.3 u, the surface of a gramme becomes 28.570 diseases of silicosis and asbestosis respectively, in and most usually effective way of protecting sq cm. The increase in intensity of explosion ol which the lung tissue is gradually destroyed, with workers against local dust concentrations The dust clouds with decrease in constituent particle size the result that blood aeration diminishes; the basic idea is to capture the dust or fume us near is also of interest in this connection. Ghwitzk) inhalation of animal or vegetable dusts, and ot as possible to its point of origin by means of obtained the following figures from experimental some mineral dusts such as limestone, glass, cement, concentrated air currents flowing into suitable ex explosions of three types of commercial aluminium garble, and emery may affect the respiratory haust hoods, which need to be designed on sound pigment pow'der in a bomb of 53.000 c.c. capacity, passages and give rise to bronchitis, asthma, oi physical principles to suit each individual case, for two pow'der concentrations catarrh. The breathing of certain metallic oxide fhe collected material is sucked away through fumes such as zinc oxide, magnesium oxide, man ducting by a fan and passes to filtration plant. It 1 Duration oi ! Explosion pres.sme (atm. ganese dioxide, and copper oxide, can give rise to is found that most industrial dusts can be captured Particle i explosion r ---------- --- metal fume fevers, while the inhalation or swallow by exhaust hoods designed to produce a lineal ait size , (sec.) for 700 imr. S0 mg ing of certain toxic dusts such as lead, arsenic, speed of from 100 ft. to 500 ft pei min. at the fl t 700 mg. jHM1. por 1 p,,- 1. cadmium, or manganese, and theii compounds, point of origin of the dust. leads to poisoning. Of these dangers to health the Ducting resistance is an important item contri 1 -2 (MM> 7 7 7 7 s most serious are undoubtedly those due to silica buting to running costs, and proper application of 0-0 o-ua S-h 9-2 I and asbestos dusts and to the poisonous dusts such the laws governing the flow of dust-laden air in o:j 0-012 10-0 11 - \ Las lead. pipes will enable resistance to be reduced to a Physical principles are involved at many stages minimum by securing a symmetrical layout of The maximum pressure of 11.6 atmospheres foi in the estimation and control in the working atmosphere. of dusty conditions adequate sectioned piping, fed by branch ducts at small angles in the direction of air flow' and pro a powder concentration of 580 mg./I is higher than vided with gradual bends, tapered connections to the maximum pressures recorded tor the explosion of gas/air mixtures, including the hydrogen,oxygen Protection Against Industrial Dust fans, cleaning panels suitably sited, smooth joints mixture with which 6.7 atmospheres has been By a suitable combination of the physical and and the like. The type of fan used for dust obtained. Pressures up to 18 atmospheres have physical-chemical methods which the Paper, a fair assessment of are the described in amount and exhaust systems is the paddle type, receiving the dusty air approximately radially and discharging been recoided foi coal dust and flour explosions nature of the dust clouds being breathed by it tangentially against resistances which may reach at certain concentrations and finenesses. Much greatei values still have been measured foi starch workers in any particular case can be made. Methods of protection to suit can then be devised. as high as 14 in. w\g. In many cases the fans are placed downstream from the aii cleaning plant, dust. The dangeious potentialities of the finely This is the ideal approach to the problem which which is thereby kept under suction, an advantage divided carbonaceous and metallic dusts for fire and explosion are manifest, since factory buildings, un can only be adopted at present in a limited number of cases on account of the time involved in such w'here filters are, against the times located in workrooms. best practice, some The fan itself also like mines, are not capable ol withstanding such surveys. In practice a selective survey of dusty thereby handles practically clean air. high pressures and rates of pressuie rise. For each combustible material there is an upper and a low'er conditions associated with typical processes in an industry offers valuable guidance for more general The main types of dust collecting apparatus are all based on physical principles and include gravi limit of concentration and beyond these limits the application of protective measures to general!) tational and centrifugal settling chambers, ineitial separators, viscous type filters, wet scrubber material will not burn. Within these limits there is also a minimum temperature or " ignition tem similar conditions in a whole industry. In the normal individual the human nose, throat, filters, bag filters and electrostatic precipitators. perature,*' below' which the material will not ignite. -and lungs in themselves provide a defensive Considerable use is also made or the wetting of Safety measures against dust cloud fires and ex plosions therefore aim fundamentally at keeping mechanism for arresting fine dust and preventing its reaching the ultimate air sacs in the lungs. The materials to prevent dust creation, but Watson has pointed out that in certain cases this practice may concentiations outside (and in practice usually be nose traps large particles in the nostrils and finer be more dangerous than dry working. In some cases safe material may be substituted foi dan low') the inflammable concentration limits, and avoiding sources of ignition; and if this should not particles in the maze of passages above the nostrils in which dust is deposited from eddy current action, gerous dusty material, for example in the classic be successfully achieved and a fire or explosion particle aggregation, and from impingement on the cases of the substitution of steel shot for sand in the operation of sandblasting iron castings, and should result, one should aim at so designing the plant concerned and arranging the mannei of woik- sticky secretion of mucus which lines all the aii passages from the nose downwards. The wind of alumina for powdered flint in the process of ig the process that there is a minimum of damage pipe and air tubes of the lungs are also lined with china bedding in the pottery industry. to workers and plant minute whip-like processes known- as cilia, whose All dusty processes should, of course, be Electrostatic Charges ifunction is constantly to sweep upwards to the separated from other processes so as to limit the ;windpipe for expectoration the mucus and the dust number of workers exposed to any particular dust It is of inteiest. in connection v*1th sources of [particles it has trapped, the process being aided fby the rhythmic contraction of the smaller mus risk. gieat By what is called **good housekeeping " a deal can be done to protect workers from ignition, to mention that electrostatic chaiges arc known to be formed when powdei issues from cular air tubes. Fine particles which succeed in dust; foi example by widely spacing dust producing machines, by storing dusty materials not in imme nozzles, or is blown into a dust cloud, or rubs fiictionally against machine surfaces. Belts running ^reaching the ait sacs of the lung are attacked and ingested by phagocytic cells, some of which manage diate use outside workrooms, and by keeping plant over pulleys also accumulate charges. Discharges To carry the dust back into the air tubes where and workrooms as clean as possible, preferably with of such accumulations may ignite dust clouds, and They can be expelled. The importance of nose the aid of vacuum methods of cleaning. The although very little is known about this danger, it breathing in dusty atmospheres, in order that all periodical medical examination of w'orkers now- needs to be taken into account. Safety measures .the natural defences of the respiratory system ma> required statutorily in a number of dusty industries take the form of keeping the air as humid as pos sbe Drought :nto full play, will be appreciated, is of great value, whilst much may also be achieved sible. or in special cases ionised, using electrical!) though individuals diffei widely in the powei oi b> the education of workers in the risks they run. conducting belting or suitably earthed collectors, these defences. and in their personal responsibility for preventing and of bonding all plant to eaith to prevent accu The main methods of protection against indus and suppressing dust clouds. A respirator of good mulation of charges. It has also been claimed by trial dust take a wide variety of forms. The design and with high filtering efficiency for low Wolf that, where aluminium foil or powdei is pro purpose of general ventilation is to dilute with breathing resistance is useful as a secondary line of duced, it can be ignited not only by fire and sparks, fresh air the dust laden air liable to be breathed, defence against dusty conditions. but also by the effect of light. so that the resulting dust concentration is below 5the toxic or otherwise harmful limit Such ven Fire and Explosion Risks In the case of grinding particularly dangerous dusts, such as magnesium, the only safe piactice is tilation can take two forms, the extraction system The extent to which protection is needed against to prevent any worker being in the mill room w'hilst with wall fans amoving the contaminated woik- the risk of file and explosion from many industrial grinding is in progress, to which end the grinding *-Toom air, which is replaced by warmed fresh air. dusts under ceitain conditions is not generally mill dooi should be so interlocked with the elec ^entering through suitably disposed openings in realised, yet such dust fires and explosions fre trical control to the grinding mill motor that, unless quently involve serious loss of life and injury to the door is shut, the grinding plant cannot be set K.xtuiets horn ,i Paper m t-lie ' .tournai of Soientifv lit^tiu- workers, and extensive damage to factory premises in motion, and the doot cannot be opened until M aiU i, 1U12. and plant Examples of dust liable to burn or the current has been switched off and the mill has t U,M KHtlinemtiL' Inspector of Fa^tone* explode undet appropriate conditions are pulverised come to iest. CONVERTOR STEEL CASTINGS The quality of convertor steel castings depends on the skill of the steelmaker and the grade of raw material at his disposal. The regular application of the Sodium Carbonate Process to cast iron before blowing ensures a low sulphur content and freedom from objectional non-metallic inclusions so that the finished product possesses a high degree of ductility and shock resistance. Skill is thus enabled to build on a sound foundation. For further information apply to IMPERIAL CHEMICAL INDUSTRIES LIMITED LONDON, S.W.l a new re-circuiating FAN for HEAT TREATMEP FURNACES A very strongly made pro peller type fan for internal circulation of high tempera ture gases and air in various types of heat treat ment furnaces. liCU LAT INC KEITH BLACKMAN LTD., MILL MEAD ROAD, LONDON, N.17. In sheet or cast metals. E xpessly designed for handling extremely high tem perature gases. WRITE for PARTICULARS. TN: TOTTENHAM 4 f22. T A : " KEITHBLAC PHONE LON PAGE Adaptable Moulding Machine Co., Ltd., The .. .. -- A. E. B. Products, Ltd. . . . . 26 A er graph Co. Ltd. . Albion (Mansfield), Sand Co. Allduys <fe Onions. Ltd. . . .. -- .. 1 .. I Allen, Edgar A Co., L td.........................-- Allen, T. Fearmey & Son . . . . -- Ander*on-Gnce Co., L td, . .. -- Anelardia, L td......................................... 6 Armstrong, W hitworth, Sir W. G., <fe Co. ilronfounders). Ltd. .. -- Armstrong, Whitworth (Pneumatic Tool!, L td............................................23 Ake. Wm. A Co. l t d . -- Atlas Preservative Co., Ltd. .. -- August's. Ltd. 16 Ballard. E. J., A Co.. L td ...................... -- Beakbane, Ltd., Benry .. -- Bllston Stove & Steel Truck Co., Ltd 28 Birmingham Electric Furnaces. Ltd. -- Blythe Colour Works L td ... Bradlev A Foster Ltd. .. -- .. 4 Bradley, Thomas A Isaac, Ltd. -- B rassert H A . A Co., Ltd. British Insulated Cables Ltd. .. -- .. 9 British Moulding Machine Co., I .t d ...........................................................1 British Oxvgen Co., L td .. . . -- British Pigirons I.td. .. 3 British Rema Manufacturing Co., L t d ........................................ -- Brlttsn Steelmaker The . . .. 21 British Thomson - Houston Co., L td ......................................................... -- Brockhouse Casting- L td .. . . -- Butterworth Pros. Ltd. .. . -- Carborundum Co., I td.. The .. -- Climax Rock Drill & Eng. Works, Ltd......................................................... -- Cnggon Foundry Equipment. L td ... -- Cohen Sons & Co., Ltd., George .. 20 Coleman Foundry Equipment Co Ltd. Commercial Structures Ltd. -- Coneett Iron Co., Lid. .. . . --- Constructional' Engineering Co., Ltd., T h e ........................ Copper Development Association ., 22 INDEX TO ADVERTISERS Core Oi's, Ltd. Corn Products, L t d ... Cumming. M m., A Co. Ltd. PAGE -- .. -- .. -- Davidson A Co., Ltd. The ... District Chemical Co.. Ltd.. Durrans, Jam es A Sons, Ltd. Durrans. John A C Ltd. 0 U(t-R ' 20 Easton A Johnst on, Ltd. Electric Furnace Co , Ltd. Electromagnets, 1 id. Ether, Ltd. . Every. H>. A Co., Ltd. Eyre Smelting Co., Ltd. .. -- .. -- 1 24 F A M. Supplies ltd . -- Findlay, A., A Co. Ltd. Fordath Engineering Co., Ltd .. -- Foundry A Engineering Co. (Wes Bromwich), I.td. . Foundry Plant A Machinery Foundry Service. I.td. Fullers' Earth Union, Ltd., The Gadd. Thus. . General Electric Co., I td., The General Gal\anir.ers ltd . .. General Refractories Ltd. .. Gibbon* Bros. L t d ... Gray, Thos F,., A Co., Ltd. Green George, VCo Guest, Keen Baldwins IroD A Steel Co., Ltd .. Hammond, Alex. Earf*r, M in., Son A Co. (Widen hall), L t d ..................................... Hawkins, M T.. A Co. Ben!! Sand Co., Ltd., The Herbert, Alfred. l t d Heywood, S. H , A Co., Ltd. Hill Jones. Thos.. Ltd Hill Patent Glaring Co , l t d . Holmes, W. C. fe Co., Ltd 12Ilford Ltd. & 13 Imperial Chemical Industries, Ltd Incandescent Heat Co., Ltd. International Alloy* I.td. International Furnace Equipment Co., L td ........................................... Jackman, J . W ,, A Co., T.td. Jack, William, fe Co., Ltd. PAGE 2 19 Keith Blackman. L td ........................ 16 King Bros. (Stourbridge), Ltd. Laisrgr Aluminous Cement Co. 1M ..................................................... -- Laldlaw Drew A Co., Ltd. .. -- Langley Alloy* L td ... 25 Lavino (London). 1td. 24 I lo v d .F H., A Co., L td.................. -- lo rd , K. 8 . L td ................................. -- Lukt A Spencer Ltd., -- Macnah and Company Limited . -- Major. Robinson fe Co., 1 td. -- Mansfield Standard Sand Co , Ltd. Marco Conveyor <S Engineering Co. I td .................................... -- Metr< poliran-Vickers Electrical Co., Ltd. Midland Monolithic Furnace Lining Co . Ld The . .. I & Mirrlee-, Bhkerrontfe Day. I td. Mirrlees Watson Co.. Ltd..The Modern Furnaces and Stm es Ltd. Molineaux Foundry Equipment, Ltd.. W. J. Mnnd Nickel Co., Ltd,, The Morns, Herbert, Ltd. Nctld, G. Notcutt Walter P , Ltd. .. Norton Grinding Wheel Co,, L t d . . , Parivh. J . A Co Parker, Frederick Ltd. Paterson Hughes Engineering Co., Ltd. .................................... Pearson. E. J . <fe J ., Ltd P h illip . J . W. A O. J., lt d . Piokford, Holland 6 Co.. Ltd Pneulec, 1 td. Port wav C., A Sons Precision Presswork Co., Ltd. Price J . T., <fe Co., Ltd. .. Rapid Magnetting Machine Co., Ltd Reavell A Co. Ltd . Richardson, R. J . 6 Son, Ltd. Ridsdale A Co , Ltd. Riley Stokei Co., Ltd, Robson Retractones, Ltd. .. Roper, E. A., & Co. Rowland, F. E., A Co., Ltd. Rustless Iron Co. Ltd.,-The page 21 8 t George's Engineers, Ltd. Safetv products. Ltd. Sleepbrldge Coal A Iron Co., Ltd Smith. Albert, fe Co. Snieeton, John A. Ltd. Smooth*On Mig. Co. Somnieriieul. H <.. Ltd. Spencer fe Halstead, Ltd. 8}>erniolin. Ltd Stanton ironworks Co., Ltd., The Staveley Coal <fe Iron Co., Ltd. Steel, John . Steele fe Cowlishaw . . Stein & Atkinson, Ltd Stein. J . G. fe Co., Ltd. .. Sterling Foundry Specialties, Ltd. 6 Sternol. Ltd. 17 Stewarts and Lloyds, Ltd. Surrey Industries, The Tei*en, Th. . Thermic Equipment <fc Engg Co Ltd .... TRghman's Air Compressor Co. Tiighman's Patent. Sand Blast C Ltd. .............................. 2 `J Trenman- Ltd. Tuugum Sales Co , Ltd. 26 United Steel Companies. Ltd., The Vaughan. Jones <fe Co. Victor X-Ray Corporation Ltd Walker, 1. A I ........................ WalBaU Sandblasting Co,, Ltd Ward, Thos. W., Ltd. 30 The 9 i t 20 W aring Bros. Warner <fe Co , I td. . M atson's (Metallurgists), Ltd Webster A Oo (Shetbeld), Ltd M engers. Ltd. West Midland Refining Co. Ltd. M ilklnsou, Thus, v Co., Ltd Woodward Bros fe Copelm, Ltd. Workington Iron A Steel Co. (Branch ot The United teel Companies, Ltd.) NOTICE ___T h e fact t *, a i Sds made of raw materials in short supply owing 1 W I I V * to war conditions are advertised in this paper should not be taken indication that they are necessarily available for export.