The engine did not use a typical coil-on-plug setup, but rather two coil/igniter assemblies mounted near cylinder four, and provided spark via normal high-tension cords (spark plug wires).
His first successful patented inventions, patented in 1909, were an electrothermostatic heat regulator for more effective control of stove and toaster heating elements and a thermostat for high-tension power cables.
Traditional underground high-tension cables are constructed either with internal oil ducts or channels or by the use of a pipe through which the insulated conductor is installed.