"How Much Is the Pedometer?"

A man came up to me, gestured towards one of our glass cases, and asked, "How much is the pedometer?"

I thought to myself, "Pedometer? The thing that tells you how far you've walked? We don't sell those." My mind raced frantically as I tried to figure out what he could be referring to.

At my blank look, the man elucidated, "The thing in the glass case shaped like a lightbulb, with the spinning thing."

Oh! Now I knew what he was talking about. But it's not a pedometer. It's not even close to being a pedometer!

I politely replied, "The radiometer?" and pointed to it in the case.

He said, "They used to be called pedometers, but yeah."

Considering "pedometer" means "measuring feet", and a radiometer spins when place near heat (or light? Whatever.), I'm guessing radiometers were never called "pedometers".

I diplomatically told him, "Well, this company calls them 'radiometers'."