A lunar eclipse, 1551.
© Science Museum / Science & Society Picture Library
Illustration from 'Breve compendio de la sphera y de la arte de navegar' (1551) by Martin Cortes (1532-1589). A lunar eclipse is where the Earth comes between the Moon and the Sun, casting a shadow on the Moon. The 'Breve compendio' ('Short compendium of the world and of the art of navigation') consists of three parts: the first twenty chapters deal with the composition of the world and the universal principles of the art of navigation; the second twenty chapters consider the movements of the sun and the moon and the effects they produce; and the final fourteen chapters deal with the construction and use of instruments and the rules of the art of navigation.