6 Comments

1. floormat_96 says:
   November 29, 2009 at 11:33 am

   coal
2. sephiroth9611 says:
   November 29, 2009 at 11:44 am

   The water wheel at first and then eventually the steam engine.
3. Age of Metternich says:
   November 29, 2009 at 12:21 pm

   A Marxist answer:

   Possessing colonies
4. Fox News is the best! says:
   November 29, 2009 at 1:05 pm

   steam
5. AUGI says:
   November 29, 2009 at 1:52 pm

   The massive use of oil,petroleum.
6. ammianus says:
   November 29, 2009 at 2:06 pm

   Steam power was the main source of energy. Large amounts of coal and water were needed to create steam.