The Smoke of Cities

Abstract

WITH reference to Prof. Cohen's article on smoke abatement in Nature of August 26, p. 269, I should be much interested to know why Manchester smoke is qualitatively so much worse than London smoke. Comparing Guy's Hospital and Gower Street with the University of Manchester—the three places of which I have had sufficient experience to judge—I should judge that the quantity of dirt in one's laboratory is about the same; at any rate it is not obviously less in London and, so far as I remember, the published measures of atmospheric pollution confirm this impression. But the Manchester dirt is far more unpleasant and destructive to one's hands, papers, and apparatus. It seems to contain more very fine sticky particles, which get in everywhere and are difficult to clear off: the London dirt is more gritty and granular, makes things dirty enough but is comparatively easily removed. Any one who has spring-cleaned laboratory cupboards in the two places and essayed afterwards to clean themselves will have realised that the dirts are of quite diverse characters. From what Prof. Cohen says I should judge that London smoke is relatively less domestic in origin than the Manchester' product, but it seems difficult to reconcile this with what one knows of the two places. Does the sort of coal make a difference, or the length of time it is kept before consumption? Or is much of the London dirt dust from other sources than coal fires, dispersed more widely than in the damper Manchester atmosphere?