£40,000,000 DAMAGES.

Auckland Star, Volume LIV, Issue 213, 8 September 1923, Page 13

£40,000,000 DAMAGES.

SMOKE HAVOC IN BRITAIN. EFFECT ON PAINTWORK. The Government has just appointed a committee to report on the best methods of preventing the serious damage to the stone work of public buildings and monuments, over 50 per cent of wnicn is due to black smoke. But in fact black smoke has a most destructive effect on everything relating to buildings—for example, paint work; a very proportion of the national paint bill is d-.e entirely to this cause, writes David Brownlic, in "The Daily News," London. Paint consists essentially of finely ground insoluble inorganic pigments, largely "white learl." mixed with a dryin" oil (boiled linseed oil) and diluted, or "thinned," with turpentine, lhe action of black smoke and the sulphur acids present in it on the thin film of paint is extremely rapid, causing disI coloration, seriously diminishing the value of the paint as a protective covering, and destroying it from a decorative point of view. The action consists in the sulphuric acid present acting on the lead and forming lead sulphate, so that the paint ie decomposed whilst the sulphuretted hydrogen, a normal constituent of smoke° also combines with the lead to form dark-coloured lead sulphide, thus ruining the colour. Certain paints are | now made from white oxide of titniura instead of lead, which is not discoloured by sulphur. The most elaborate experiments on toe action of black smoke on paint were carried out a number of years ago in Pittsburg—no more smoky than our own towns to-day—and it was proved that the action of smoke cost the inhabitants of this town 330,000 dollars a year more for painting than a town of similar size where the smoke nuisance was not excessive. Thus, for example, in thf average American city, the period between the original painting and the first repainting of woodwork is live years, with subsequent repaintings every seven years. In Pittsburg, the better class buildings have 1 to be painted every year, and practically j every building is painted once in three I years. I Some very interesting investigations lon this point were also carried out in j Manchester, and it appears that this city, typical of our large industrial towns —is a paradise for painters. Under decent conditions, as regards the purity of atmosphere, outside paint work in Great Britain ought to last three years, but in Manchester it looks shabby in one year and has to be rernewed every J two years. A very detailed survey i showed that the paint bill of Manchester jis 25 per cent to 50 per cent more as compared with towns like Ilarrogate, Bu.xton and Southport. The total damage due to black smoke in Great Britain from all causes is at least £40,000,000 per annum.