Great Inventions: The Fence

This video is a little dated, referencing 1996, but the principle remains the same.



Remember that fantastic marvel known as the Great Wall of China? Most of it was built more than 2,000 years ago, and it is about 4,000 miles long. It helped repel the Huns, who bounced back westward and gave the Roman Empire so much trouble.

And that was before the advent of cameras and infrared, motion and vibration sensors.

We can't keep illegal aliens out of our country? We don't want to keep illegal aliens out of our country.