Needham&#x27;s Science and Civilization in China volumes are a fascinating resource.  Particularly interesting, and somewhat inexplicable, is that China was poised on the verge of an industrial revolution during the Song dynasty, in the 12th century.  Steel production reached levels not surpassed until the English and American mills ramped up in the 19th century.  The Grand Canal was possibly the greatest transportation project ever completed, before the invention of railroads.  The banking system used by Song merchants may have been the most complex before the modern era.<p>Much of this progress was destroyed by the combination of the Mongol conquest and the subsequent wave of rebellions that unseated them and brought about the Ming dynasty.  It&#x27;s possibly the most destructive series of wars in history.