Attrition Tests of Road-making Stones

Abstract

MR. LOVEGROVE'S attrition-tests have been L V I carried out systematically for some years past in the modest but unique museum of the Hornsey Town Council, an institution devoted to the useful arts of building-construction, sanitation, and public works in general. Here the cpmpact machine figured on p. vii makes itself heard from time to time, when the stones undergoing the tests are lifted by the internal flanges of the three revolving cylinders, and fall a distance of eleven inches in their cast-iron prisons with painful iteration. After 8000 revolutions, what is left of them is taken out, and the chips and dust broken from them are separately estimated. The production of chips, as Mr. Lovegrove points out (p. vi), is an indication of brittleness, but may not be injurious to a road. The dust, which is determined in a dry experiment and also by one in water, is so much pure waste when formed on a road-surface or in the layer of macadam itself. The melancholy and pebble-like appearance of certain stones after they have suffered from Mr. Lovegrove's inquisition can be well seen in the Hornsey Museum, or in Figs. 77 and 78 of the pi-esent volume.

Attrition Tests of Road-making Stones.

By E. J. Lovegrove. With Petrological Descriptions by Dr. John S. Flett and J. Allen Howe. Pp. xx + 80. (London: The St. Bride's Press, Ltd., n.d.) Price 5s.