September 3, 2015: Phillipine Fire Piston
Artifact of the Week: Fire Piston
Cabanatuan, Luzon, Philippines
Collected in WWII by Dr. Earnest Head, Agricultural Engineering, UC Davis
This fire piston, made from horn, was collected by former UC Davis professor Earnest Head, from the Agriculture Engineering Department during World War II and later donated to the museum. According to Dr. Head, it was used to light cigarettes and originally came with kapok tinder. The indentation on the side of the exterior chamber was used to hold wax, which was used to grease the tape piston.
Fire pistons are a form of fire-starting technology that use adiabatic compression of air to flash heat the interior chamber to temperatures in which kindling can catch. By slamming the interior piston, sealed air-tight, into the exterior casing, the air inside the chamber makes up for the loss of volume with increases in both pressure and temperature, as described by the ideal gas law [PV=nRT]. The interior rod is quickly withdrawn and the lit kindling tended to. This makes the fire piston a quick, easy, and reusable way to start a fire.
The fire piston was used aboriginally by people of South East Asia and the Pacific islands, who used this technology long before the ideal gas law was formalized. An overlap in the distribution of fire piston technology and blowgun technology has led some to speculate that they might be related in origin, as both require the making of hollowed chambers. Perhaps the fire-starting capacity of adiabatic compression was first recognized when smoothing the interior chamber of a blowgun during manufacture.
Interestingly enough, the modern European version of the fire piston was also related to gun technology. In 1745, Father Augustin Ruffo, Conservator of the Cabinet of Natural Philosophy in Rome, was experimenting with an air gun that needed a wooden plug inserted into the barrel of the gun before compressing air with a piston to charge the shot. Smelling smoldering wood, he realized that the plug, the only wooden piece on the gun, had been burning as a result of the air compression. From this experiment, he developed a fire starter, which would later be made from glass and used as a parlor trick throughout Europe.
Fire pistons represent a type of technology that takes advantage of a basic natural law to perform a common, useful task, which makes the potential for independent innovation quite high. But also in the case of fire pistons, day-to-day experiences do not make it completely intuitive that quickly compressing air has the potential to start a fire. Resultantly, as a technology, fire pistons have probably given our species a good deal of “holy crap, look at this!” moments.