Greatest Invention

[Sonny]

Three professors were arguing between themselves as to the greatest invention in the history of man.

The first professor argued that controlling fire was the greatest, since it opened the way for man to rise above the apes. The second argued that it was the wheel, since it paved the way for man to travel. The third insisted it was the internal combustion engine, since it opened the doors to the industrial revolution.

Finally, in a deadlock, they decided to seek an outside party to help them decide. The only person available was the old man who cleaned up the lab every day. After a short debate the agreed the old man would do so they posed their question to him.

Each professor argued his point passionately. Finally, after hearing each of their cases the old man stroked his chin thoughtfully and said, "I don't know, fellers. I really think man's greatest invention was the

Thermos bottle."

"The Thermos bottle!" the professors exclaimed. "How on earth can the Thermos bottle compare to fire, the wheel or the internal combustion engine?"

"Well, it keeps hot things hot an' when you put cold things in it it keeps 'em cold".

The professors looked at each other and then to the old janitor said, "Well, OK. It does that. But . . .well . . . so what?"

The old man just shrugged and said, "How do it know?"