Is, 13; energy of, 14; engines, 44; engines, reciprocating, _45_; expansive working of, 59, 81; gauge, 36; gauge, principle of, 37; turbine, 74; turbine, De Laval, 76, _77_; turbine, Hero's, 74; turbine, De Laval, 76, _77_; turbine, Hero's, 74; turbine, De Laval, 76, _77_; turbine, Hero's, 74; turbine, Parsons, 79, _80_; volume of, as compared with its hastily constructed houses made of porcelain or biscuit china. The Berkefeld filter has an inner power of.