A method of lighting in which the well glass surrounding the bulb is flushed out with compressed air through a special valve before a self-contained generator commences to run; afterwards the exhaust from the turbine is passed through the lamp fitting with a small back pressure of 1-1/2 to 2 psi (10.3 to 13.8 kPa), preventing ingress of methane. The equipment can be used underground where the use of electricity is prohibited and for both roadway and face lighting.