Ice blasting: various shots of men cutting channel up centre of frozen Rideau River; explosions as ice is blasted; ice floes going over Rideau Falls. CUs of man pressing detonator. LS looking across open stretch of water, of several men standing on the ice. MLS of ice boat sailing on the ice. Side view of water pouring over Rideau Falls. Shots of ice floes breaking up as they hit cement abutments of dam at Rideau power plant.