Prest-O-Lite and Gas Powered Head Lamps
When looking at photographs of old Harley-Davidson motorcycles (I’m talking the teens or older), you’ve probably noticed that a lot of them have a cylinder mounted to the frame or handlebars, about the size of a kitchen fire extinguisher. You may have even thought that this was a fire extinguisher, but it is actually just the opposite. The cylinder was made by a company called Prest-O-Lite and was filled with acetylene gas. If you’ve done any welding or metal work, then your are probably familiar with acetylene as it is commonly used for cutting and brazing. In the early years of motorcycling, before electrical lighting was perfected, acetylene gas was also used to light the head lamps and tail lamps of Harley-Davidson motorcycles.
The first motorcycle head lamps used an older technology which relied on a chemical reaction between water and calcium carbide. A special canister held both the water and the calcium carbide in separate compartments with a mechanism that allowed the water to mix with the calcium carbide at an adjustable rate. When the two compounds mixed, the result was acetylene gas which was then piped to the head lamp and where it was lit was a built in striker. This worked well as long as you kept everything adjusted correctly and filled with water and calcium carbide.
In 1904, the Prest-O-Lite Company was founded and their acetylene filled cylinders eliminated the need for a carbide reactor. The cylinders originally sold for $10, held 10 cubic of gas and lasted for 40 hours. Once the tank was empty, you could exchange it for a full tank for $0.60. Once filled, the cylinders were safe to use, but the process of filling the cylinders proved quite dangerous. There were several major explosions at their Indianapolis plant, one resulting in the death of an employee and another causing injuries to a fire fighter.
Luckily by the early 20’s, electric headlights became common and acetylene gas was no longer needed to light your way home.