Keep in mind that it was a very long time before this technology was re-invented. Both the machine work and the knowledge of the movement of the stars and planets, etc.
http://www.eetimes.com/author.asp?section_id=216&doc_id=1331286
Alegria1976's Blog
Dave & Robn on Alegria sail about
Alegria1976's Blog 
Utterly mind blowing. How could that have been made 3000 years ago …but it was!! You may like to see a 1 hour BBC presentation on this discovery that was first broadcast in 2012. Here is the link to YouTube… https://www.youtube.com/watch?v=3T1n7RjCMfQ
Graham