Report on the building and ornamental stones of Canada (1912)
Parks, William A. (William Arthur), 1868-1936, Canada. Mines Branch (1901-1936) · Ottawa : Dept. of Mines, Mines Branch · leaf 38
owhich a half-inch -\- bitted drill sank into the stone in 30 seconds whenpressed down by a weight of 8 lbs. and actuated by a size A Barre pneu-matic tool under an air pressure of 60 lbs. to the square inch. The drillswere sharpened and tempered as nearly alike as possible and while inoperation… … Apparatus for corrosion tests. 17 physical characteristic. Readers are warned that the drilling factor can notbe taken as a direct measure of the relative ease with which the stones canbe worked: it in only an expression indicative of the behaviour of thedifferent stones under the conditions…
Building stones · Geology, Economic · Stone industry and trade
Internet Archive · University of Toronto, Robarts Library · Public Domain Mark 1.0. Free to use for anything.
