Measuring distance from ship to shore, 1535.

GERMANY - APRIL 29: Hand-coloured woodcut illustrating a method for measuring distance to land from two positions on a ship. The upper measurement, (�Oculis superior�), is taken from the crow�s nest), the lower one, (�Oculis inferior�), from the deck of the ship. From the book Astronomy, part of the �Margarita Philosophica� by Gregor Reisch (1467-1525). First printed in 1503, it is divided into twelve 'books', with each one dealing with the Sciences of Grammar, Dialectic, Rhetoric, Arithmetic, Music, Geometry, Astronomy, Principles of Natural Philosophy, Origin of Natural Objects, Psychology, Logic and Ethics. (Photo by SSPL/Getty Images)