Show Concrete That Float Floats 1 A block of concrete floated on water water wa wn ter tr bobbing up anti down like n a c. c cork rk at the school of practical science University of elf Toronto recently when Prof G O. O It It Anderson carried out an nn unusual experiment Known as ns cellular concrete this floating stone was made on 01 n system Ilem ana sun logons to raising n bread with yeast yeut Tho cement nt gravel water and sand were wre put Into n a mixer and a carbon dioxide forming chemical was add add- ed The cement then set Into a hard porous suh substance tance lighter than wood Professor A Anderson says It has lias remarkable remarkable re re- resistance to sound BOund |