Jami' al-tawarikh
Harriott is known as one of the owners of the key manuscript of the "Jami' al-tawarikh", an important medieval manuscript dealing with Mongol history. How he came into its possession is not clearly known. According to Sotheby's, he found it in Danapur in 1813. William Hook Morley noticed it in the Royal Asiatic Society's manuscript collection in 1838. From 1948 it was at the British Museum, on loan, and then was sold, to an unknown purchaser.