[Raleigh]

It occurs to me that an early maker of radio batteries was the Union Carbide and Carbon Company. I think they used the name Eveready then; I know they did later, because in the 1950s my Dad worked for them making radio batteries at their plant in Charlotte, NC. Could your mother have remembered the name "carbide" from the battery and mixed it up with the "carbide" of a miner's lamp?

A carbide miner's lamp does not operate on electricity. Instead it uses a chemical reaction between water and calcium carbide to produce acetylene gas, which burns with a very bright flame. The process is described on this web site.

http://www.showcaves.com/english/explain...Lamps.html

Early cars, before around 1915, used carbide headlamps. You would often see a brass cylinder mounted on the running board. This cylinder had two chambers. The driver would put calcium carbide pellets in the lower chamber and water in the upper one. Water would drip slowly into the carbide compartment, and a hose would carry the resulting acetylene to the headlamps. It is hard to see how this process could run a radio.