He was also known to be an amateur mathematician
http://en.wikipedia.org/wiki/Napoleon's_theorem
http://en.wikipedia.org/wiki/Napoleon's_problem
weapons of war, locomotive tech and balloon recon.
There was some of that OTL--his experience in artillery gave him skills in math and logistics.
His main failure seemed to be of the imagination--he dismissed Fulton's idea for steamships on the grounds that fire on a wooden ship was insane.
All you need is a receptive Nappy to the ideas of Robert Fulton and you could theoretically have steamships AND submarines. No idea why this isn't done more...
weapons of war, locomotive tech and balloon recon.