Document qkB8DwnrVd1wN7Og5OkeZxn0R

Research L abo rato ry Sta n d a r d D a t a -- A m e r ic a n So c ie t y o f H e a t in o a n d V e n t il a t in g E n g in eer s Result of Cooperative W ork W ith U. S. Bureau of Mines Experiment Station, Pittsburgh, Pa. C o pyr ig h t 1921