Evening Republican, Volume 22, Number 314, Rensselaer, Jasper County, 1 January 1920 — Differing Types of Marble. [ARTICLE]

Differing Types of Marble.

/Tn ifs tests of 52 different types of marbles, the United States bureau of standards has found the compressive strength of the dry,material to range between 7,850 and 50,250 pounds per square inch. Wet specimens were usually somewhat weaker, and in a few instances loss of strength from soaking was as great as 25 per cent After 30 -freezings and thawings, most specimens were much weakened, though some were little affected, while a few were actually strengthened- The electrical resistance varies so greatly that care is necessary in selecting material for switchboard. Marbles expand irregularly on heating, and part of the increase is permanent