i bought this book last summer, published 1921, explains the purpose for Bills of Exchange were so you didnt have to sail your GOLD across the sea and risk having your BOAT(Scott loves that word) sink, and more convenient than lugging around your GOLD-bars(i suspect safer, too)..
http://books.google.ca/books/about/Promissory_Notes_Bills_of_Exchange_Chequ.html?id=dijVMwEACAAJ&redir_esc=y
Printed copy · Anthology Volume 4, page 432Printed copy from The Tender For Law Anthology, Volume 4, page 432 (printed 13 June 2014). Added by this site; not part of the Facebook export.