Why didn't the industrial revolution take off earlier? Why

No agricultural revolution to support the urban populations necessary to work the factories that came with the industrial revolution.

Didn't have things like steam and coal yet.

No scientific revolution yet.

Rome lacked a plethora of innovations. The gdp per capita of the Italian peninsula which was the center of Mediterranean trade is estimated at $857 while for medieval England it was around $1000 even before gunpowder and the printing press.

http://brilliantmaps.com/roman-empire-gdp/

http://www2.warwick.ac.uk/newsandevents/pressreleases/medieval_england_twice/

Aqueducts and such are pretty conspicuous but they do not paint a full picture of the economy. They lacked ocean going ship designs, the heavy plow and 3 field crop rotation. I wish I knew more but I can't find a decent objective history of technology and economic growth, only people shilling their heritage.

They had slaves. They didn't need machines to do their labor.

>>2569271
nice meme

>>2569261
>gdp
A useless indicator.

>>2567311
>Why not during Roman Empire or the Song Dynasty

Both get fucked by barbarians and steppe niggers

>>2569327
Rome fucked itself.

>>2569316
Yeah that's why the American south is so effiecent
O wait

>>2568473
This.

Between opening up the Americas for agriculture and the English and Scottish agricultural revolutions, you could finally have large numbers of non-farm workers.

Rome sort of did have an IR, it was just contained within their war machine.