REDUCING NOISE.

Press, Volume LXVIII, Issue 20493, 11 March 1932, Page 5

REDUCING NOISE.

SILENT CARS NEEDED. CAUSES OF IRRITATION'. If one dav, when the weather is kiml, you should sit beside a main road a:id close your eyes, you would hear many sounds. You would find that the noise of traffic is due chiefly to exhaust notes, and you would realise that, in spite of much progress iii general design, we have not had any radical improvement in silence among the mass of ears, says a writer in the "Motor." Exhaust notes arc still noisy, horns are still high-pitched find piercing., tyres still hiss, bodies still rattle. There was a time, not so long ago. when the horn ot' the "peep-peep" variety was the monopoly ot only the fastest and most powerful motors. Xow they are fitted to all and sundry. No more do drivers jump in their seats and swing hastily across to the left when they hear sucfi 'ft horn. It. has become the high-pitched voice of the crowd. Afain, yon would hear that, on some cars, the incessant and often extraordinarily loud hiss of the tyres is accentuated. And, if you half-opened your eyes and took a sly glance, you would find that luxury limousines are the chief offenders. However, special silent treads for the tyres have been developed, and it has also been found that mudguard design is an important factor towards improvement. Increasing Comfort. Perhaps listening to all these sounds, you would wonder if we shall ever obtain complete rilence in motoring. There would be a tremendous fascination in cruising smoothly along, without any vibration or engine noise to indicate the motive power. The comfort of travel would be enormously increased. Conversation would bo easy at all speeds. Most people would welcome such a change, but we would inevitably lose the impression of power reserve and speed, which the faint unleashed throb of a willing engine imparts. Among the general roar of traffic, you may. still dozing, hear an uneven

whine, sometimes rising to an animalliko shriek, sometimes dying to a steady roar—the sound of a supercharger I If. as the noise grew louder and tho motor nearer, you heard the- healthy note of the exhaust, the cutting in and out of the "blower," the engine "revved" for the changes up and down— a sports | car, sportingly driven! Would you not open wide your eyes and watch her accelerate in out among the more slovenly saloons! Watch her roar past. you in third, change up, with that inevitable "whiff" of racing oil, which somehow is so infinitely more pleasing than the most delicate perfume? And would you not invariably come to the conclusion that if such a motor were to be made entirely silentj it would lose much of its appeal ? It is obvious, however, that every car cannot be a supercharged sports. an 3 such a type must always bo limited. So in the interest of the majority, it is' time we had more silent cars. The ordinary, mass-produced model is too noisy, and it will be a triumph for tho manufacturer who can tackle this problem adequately and successfully—and who can give us silent motoring for the masses. FABRIC BODIES. A fabric body can be grea'.i/ improved in appearance after it ha.? been in uso for twjs or three years by painting it with cellulose, but it is essential to use the special fabric grad'j of material; this has a flexible base, jrhich will "give" with the material to which it is applied, so that cracks do not appear in a short time. To use ordinary paint or ordinary cellulose lacquers would be unsatisfactory. It is essential to have a perfectly clean surface. First ' wash the fabric with soap and water, which should bo lukewarm. Wipe perfectly dry, and finally go over the body thoroughly with petrol or turpentine to remove any greasy deposits. Make sure :l e grain is free from dust, and the fabric is then ready to be painted. The fabric cellulose should not' be thinned down; this would have no bearing upon whether the material would eventually be brittle or otherwise, owing to the fact that it has the same base as that from which the fabric i.? manufactured. It is only possible to obtain flexibility by the use of certain ingredients, and these are embodied in fabric cellulose. Tho lacquer is applied quickly and evenly to'.the .fabric surface, and in cages where a fabric is to be finished in tho same colour as that existing, one coat should bo sufficient. To change the 'colour, two coats at least' of the new tint are advisable, but a marked alteration is not recommended.