Coal for Shop Heat

When I was a kid up here in Winnipeg, Canada my folks heated the house with a coal burning furnace. The coal was carried from the delivery truck in burlap sacks. They would pour the briquettes, like Kingsford BBQ briquettes but about 2 1/2 inches square, down a chute to the basement coal bin. Dad would order 3 tons for the winter. It cost $5 a ton. That was the late '50's and early '60's. Good heat but wasteful as the coal was still burning when the furnace fan shut off.