An Ottawa historian’s discovery of a 19th-century manuscript previously unseen by scholars has shed new light on the 1867 unearthing of “Champlain’s Astrolabe,” the navigational instrument famously — though controversially — believed to have been lost by French explorer Samuel de Champlain during his pioneering journey up the Ottawa River exactly four centuries ago this year.

The 13-centimetre-wide, 629-gram circle of brass, repatriated from a U.S. collection in 1989 for $250,000 by the Canadian Museum of Civilization, is widely considered one of country’s most important and evocative historical artifacts — though there is no direct proof it ever actually belonged to Champlain, the 17th-century founder of New France.

And Carleton University historian Bruce Elliott’s discovery of an 1893 document penned by Capt. Daniel Cowley — an Ottawa Valley steamboat entrepreneur who had been a key part of the astrolabe saga when it was found 26 years earlier — appears to strengthen the case against Champlain’s ownership of the object....