fuel efficient

On the way to work this morning I was passed by two Toyota Priuses. I was still commuting more efficiently than them, though, for I was on my Tour Easy:

check source

It occurred to me that, ironically, the most radioactive thing in the lab is...the side of the Geiger counter. To the side is affixed a small radioactive source, the “check source,” which is used to verify that the thing is working, a step which historically both minor screwup and horrific tragedy have shown is very important, particularly if your work environment (unlike mine) contains sources a great deal more dangerous than the one on the side of the survey meter.