The St. Johns Herald

Top-Floor Air.

An Authority Who Says Smoke Smut Is Thickest the Higher One Climbs.

In view of the agitation over "sky scraping" buildings in Chicago, and the claims of some that high buildings are essential for pure air, an article in the Pall Mall Gazette on the air of London is interesting. At what elevation is the air of London purest? asks the Gazette. According to Mr. W. J. Prim, who gave evidence before the select committee on house of commons ventilation, at about thirty or forty feet from the ground. Lower than that you get the dust; higher than that you get the smoke from the chimneys. Mr. Prim made certain experiments with frames of wood covered with blanketing material put at different elevations—one on the top of the clock tower at Westminster, another on the highest point of the roof, and others at various heights down to the court yard. After five hours' exposure there were found to be more smuts at the high elevations than at the low, but on the court yard there were considerable quantities of dust. On the whole Mr. Prim came to the conclusion that the purest level was between thirty and forty feet, and that nothing was gained by going higher unless you went very high indeed—say some four hundred or five hundred feet. All this is rather fatal to the common notion that the highest stories of the tallest blocks of flats are especially desirable for their salubrious air.