An Aqueduct system while necessary for the proper function of this (modern marvel), but it dose not include the "Silent Valveless Water Waste Preventer" (No. 814) was a siphonic discharge system that allowed a toilet to flush effectively when the cistern was only half full. British Patent 4990 for 1819 was issued to a Mr. Albert Giblin for this product.
But you can’t forget Crapper’s contribution:
http://en.wikipedia.org/wiki/Thomas_Crapper