Abstract: A process of making a combustion element and the resultant element which includes heating a body of felted graphite fibers to a temperature of between 1500 degrees and 2100 degrees F. in an inert atmosphere and thereafter contacting the body at the elevated temperature with an atmosphere of a decomposable gaseous source of silicon atoms for a time and at a concentration to in situ convert the graphite fibers to silicon fibers and silicon carbide fibers.

Abstract: A water heater secondary control device which terminates the flow of gas to the heater thermostat when water has not been withdrawn from the tank for a period of time. The secondary control device includes a temperature sensor attached directly to the outside of the cold water inlet pipe and a tube to be attached to the heater tank pilot line to provide a continuous pilot light. The secondary control device is inserted between the natural gas pipe inlet and the heater thermostat and prevents flow of gas to the burner through the thermostat when the temperature of the water in the cold water inlet is above a predetermined threshold.