Quote Originally Posted by MikeV View Post
It's worth re-testing: try removing all the Observatories except the one in your home Capital. It would be good to know if it is the only one that provides the global bonus.
Ok,

1. the estimated time for the research of "Abolition of Slavery" was 9 turns in my best university in my home province.
2. I removed all Observatories (~ 8 or 9) except the one in my capital
3. the estimated time jumps from 9 to 12 turns.

q. e. d.