tar-impregnated

Updated: May 13, 2025

"Current was supplied to the road by underground feeder cables from the dynamo-room of the laboratory. The rails were insulated from the ties by giving them two coats of japan, baking them in the oven, and then placing them on pads of tar-impregnated muslin laid on the ties.

Frank Lewis Dyer - Edison, His Life and Inventions