Heh...
You should try playing in the game I have with Kiddiarni, Titan :P
I have 17 cities, had production of an average of 38 in 2 600 B.C, this caused global heating and almost poluted the entire area I ruled over. I also had Steam Engine in 700 B.C. 8)
Now I have an average production of 48. The city with the most has 53...
And all this is done without the Great Library :P
(Kiddiarni has that one...)