Rensselaer Republican, Volume 18, Number 41, Rensselaer, Jasper County, 17 June 1886 — Variations in Granite. [ARTICLE]

Variations in Granite.

Prof. Winchell's comparative trials of the granite of New England and Minnesota have shown some surprising differences in strength. Two inch unpolished cubes were taken, and crushed between wooden cushions, the average strength of Minnesota granite was found to be 94.272 pounds, or 23.218 pounds per square inch; crushed between steel plates, the average strength w-as 104*800 pounds, or 26,200 pounds to the square inch of surface. A like number of specimens of New England granite gave an average strength of 59,755 pounds, or 14,759 pounds to the square inch. ~~~