oscar said:Also, I'm assuming that a technology gets harder to research each step you go down it's 'tree'?
e.g Farming Technique 2 would take more time to be discovered then Farming Equipment 1?
Yes. You are not really meant to discover them all. Especially as those more northern provinces, since the light of technology comes from Mediterrean.
Its a really complex system too, with designated trade routes among which technology is spread - there are maps on paradoxplaza. Some provinces can receive advances from six others and some from only one.