In the 1870's, there came into existence something that I would have to call a fundamental automotive invention. And this is fascinating, because it pre-dated the discovery of the automobile by a couple of decades.

You might think the automobile was invented, but it was really discovered. The light bulb was invented. The radial arm saw was invented, but not the automobile.

This device was not developed for the automobile, but it wasn't long before every single automobile manufacturer began using it. In fact, every car driven everywhere in the world today uses this device-- and not just one of them, but several.

Here's the interesting part: In over 100 years of use, the basic design has not changed. Even more interesting, in the 1890's or 1900's, when the thing began to be used widely, it cost a dime. In 2006, it costs a dime.



There are plenty of hints here, and hardly any obfuscation, but I'll give you one more hint: Most cars today use 6 or 7 of these.

What is it?

I do not know the answer, But would like to know it.