How am I suppose to complete the part on in's creed 2 where you put together all the codex pages?

it's at the very end of the game, and when you switch to eagle vision, you end up putting together a map of world after all of the pages are put properly. I did that and nothing happened, I also put the little ball in the stool or whatever it's called that's right in front of the codex page map. I've done this part multiple times and I'm still stuck, what am I suppose to do.