August Gallery

The Plough asterism in Ursa Major

The Plough. This asterism (group of stars) is part of the much larger constellation Ursa Major, most of which is out of frame. The asterism is familiar to amateur astronomers as it is bright and can be used to find other important stars in the sky. A line drawn through the two stars at right can be extended upwards to meet the pole star Polaris (not seen), while the handle of the Plough can be followed round to find the bright star Arcturus (not seen)

© ECKHARD SLAWIK/SCIENCE PHOTO LIBRARY

Skull anatomy by Leonardo da Vinci

Skull anatomy by Leonardo da Vinci. Historical artwork and notes on the anatomy of the human skull and teeth, by the Italian artist and scientist Leonardo da Vinci (1452-1519). This bisected skull shows the external structure (right), and dissected facial sinuses (left), the air-filled spaces inside the bones of the face. The diagram at lower left shows the teeth present in one half of the mouth: 4 incisors, 2 canines, 4 pre-molars, and 6 molars. Da Vinci was the first anatomist known to have correctly noted the number and root structure of human teeth. The notes are an example of his mirror writing, which was written backwards from right to left, and could be read in a mirror

© SHEILA TERRY/SCIENCE PHOTO LIBRARY