The illustration taken from the New Organon of Francis Bacon shows the Columns of Hercules (squidged up at moment for Technical Reasons). 

The Columns represent the Straits of Gibraltar, and for Bacon they symbolise the transition from the (Aristotelian) era into a new ocean (not a harbour). The Spanish coat of arms include  this same symbol with a scroll around them, which (it is said) is the origin of the symbol for the American dollar.