Helen Wallis

What Columbus Knew

Master mariner or dedicated amateur? Helen Wallis examines the state of geographical knowledge when Columbus set sail, and outlines his use of it.

Did the Portuguese Discover Australia?

Two hundred years before Captain Cook, Dieppe map makers placed the Portuguese flag on a large land-mass called Java-la-Grande approximately where Australia appears on today's atlas. Helen Wallis sifts through the cartographic evidence to examine the intriguing question.