Asphalt.

Progress, Volume IV, Issue 6, 1 April 1909, Page 213

Asphalt.

Mr. Woolf of the Neuchatel Asphalte Company wiites to our contemporary "Building" of Sydney on the subject of an article on Asphalts published by it in a recent issue, excerpts fiom which were reproduced in "Progress," objecting to some of the statements in the article. He says fiist that Asphalt is not as described in the article, a semi-liquid substance with sometimes mixtures of earth. His definition of Asphalt is ' ' a pure mineral limestone rock naturally impregnated with bitumen"? which, if it had the least suspicion of earth in its composition, or of refuse, would bs useless for commeicial purposes. Kef en ing to the geographical distribution of asphalt, he says that Trinidad contains no asphalt, but plenty of bitumen, of which its iamous lake is composed: that Switzerland is not "noted for its hai d asphalt, ' ' as the Swiss asphalt is recognised by all experts as being of a particularly elastic nature, and of a consistency of quality which has achieved for it the fame it enjoys: that the American asphalt referred to in the article is only bitumen. Coming to the methods of treatment, Mr. Woolf declares that nobody who knows anything about asphalt would dream of adding fat under any conditions, or of using Stockholm Tar for the purpose of mixing; the chemical nature of the bitumen contained in asphalt being such as to render such additions disastrous instead of beneficial. Eegarding the statement that bitumen makes a very good roofing or damp course, he points out that the subjection of bitumen to atmospheric conditions is such that if used vertically on big areas there is a great risk of "creeping" a thing impossible in the case of real asphalt.