Show roes of the sand blaar the use of the sand blast Is now nor found to be a very convenient and effective method of cleaning buildings A pump which forces a blast of air at a pres pressure of tour four ounces to the square inch through a system of flexible pip papua removes the unclean surface of stone readily ono one square foot of stone can thud thua b bo sc cleaned scleaner in ton minutes 1 and the rapidity of the proem process ican can bo be in creased by the use of a higher pressure ot of another though an older application the sand blast ta is for the whitening white ining of the incandescent ining bulbs and outside of introduced by decorative effects olives a are re often fastening leaters lectors or ornaments upon the outside new york telegram |