Astronomical Images : Halo

Nicolas d'Orbelles

Astronomical Images

<p style='text-align: justify;'>Nicolas d'Orbelles or Orbellis (1400-1475) was a French Franciscan and a follower of John Duns Scotus (d. 1308). This is a brief commentary on Aristotelian philosophy in the footsteps of Scotus. Here, the printer, Michael Furter, re-used the woodcuts from the 1494 edition of the same title. There is no explanation in the text concerning this figure, which illustrates the following point: 'Sight is reflected from the mist that forms round the sun or the moon, and that is why the halo is not seen opposite the sun like the rainbow. Since the reflection takes place in the same way from every point the result is necessarily a circle or a segment of a circle; for if the lines start from the same point and end at the same point and are equal, the points where they form an angle will always lie on a circle.' <i>Meteorology</i>, III.3.373a1-5, trans. by E. W. Webster, J. Barnes (ed.) <i>The Complete Works of Aristotle</i> (Princeton, 1984), vol. 1, p. 601.</p>