XVIII.—HOW THE TWO BROTHERS AND MESSER MARCO TOOK LEAVE OF THE GREAT KAAN, AND RETURNED TO THEIR OWN COUNTRY 34 NOTES.—1. _Mongol Royal Messengers._ 2. _Mongol communication with the King of England._ 3. _Mediæval Ships of China._ 4. _Passage from China to Sumatra._