Dating the Sir Francis Drake Silver Maps

Abstract

The Drake Silver Maps are 68-mm-diameter silver disks with maps of the sixteenth-century known world featuring Drake’s route of circumnavigation. They were probably stamped with dies. The nine existing medallions have weights from 260 to 424 grains (the heaviest one weighs about 28 g). Each of these medallions has a diameter that is about the same as that of a tennis ball. The lightest one is as thin as a thumbnail, and the heaviest one is as thick as a credit card. This article shows that they were most likely created in 1588–89: the strongest evidence for this is that they used the double-hemisphere equatorial stereographic map projection that was first used by Rumold Mercator in 1587.