Saint Lawrence Power Project: various shots of Premier Leslie Frost of Ontario speaking, Governor Dewey speaking, crowd listening. Shot of Governor Dewey pressing button. LS of explosion in water. Various shots of dais, Prime Minister Louis Saint-Laurent, Governor Dewey, Premier Leslie Frost waving, Prime Minister Saint-Laurent turning first sod, newsmen, Indigenous men in feather, one holding newspaper saying "St Lawrence power project launched". LAS of fireworks, daytime.