Hardware and such… Stanley (generic fire tube) Liquid fuel under pressure is converted to vapor in the vaporizer tube, which is heated by the burner.  Upon exiting the nozzle, the pressurized vapor expands to high velocity (lower right) and carries primary air through the mixing tube to a space beneath the burner plate.  A number of small perforations in the burner plate allow the fuel /air mixture to pass upwards, where it is ignited, producing rising hot gasses which draws secondary air through larger holes to combust unburned fuel.  A strong drum encapsulates tubes through which the hot combustion gasses pass; water introduced into the shell is transformed into steam by contact with the exterior of the hot tubes. The steam collects at the top of the drum and on its way to the engine passes through a superheater just above the burner. Fire and water tube boilers date to the early 19^th century, the fire tube was initially more popular with water tubes gaining popularity in the second half of the century.  Fire tube boilers are typically easy to operate, containing a large amount of saturated water which flashes to steam upon a sudden drop in pressure; they are not sensitive to sudden changes in demand.  Fire tube boilers are slow to reach operating temperature because the heavy shell and large mass of water absorbs much heat.  The sudden pressure loss accompanying a boiler shell failure presents a significant hazard; part of the heated water instantly expands into steam with explosive force. Recognizing these potential dangers, the Stanley twins wrapped piano wire around the shells to provide great strength and installed copper fire tubes which fail before the shell and harmlessly channel the boiler contents to the ground beneath the car.              Stanley steam car images