archiving as opposed to backing up

Innfogra> Actually it was ethe Egyptians who calculated the Innfogra> diameter of the world and knew it was round. And the Innfogra> Library in Alexandra had over 400,000 books covering the Innfogra> knowledge and technology of the time. 600 to 300 BC was a Innfogra> real high point in civilization with a real understanding Innfogra> of the world and technology. The Greeks adopted much of the Innfogra> Egyption technology. The Mediterainian area even had geared Innfogra> differential chronometers for navigation. Hm, I'd love to see a reference for that. (What's a "differential" chronometer?) My understanding is that the first recorded measurement of the earth's size was done by Eratosthenes, a Greek living in Alexandria; I wouldn't call him an Egyptian. paul