Here it is only necessary to distinguish halos from coronae.
Halos was added to the number of Early Iron Age sites in Thessaly in 1912 (Wace and Thompson).
That Newton must have begun early to make careful observations of natural phenomena is sufficiently testified by the following remarks about halos, which appear in his Optics, book ii.
The chromatic halos which frequently encircle these images are due to diffraction.
The two halos are the only phenomena which admit of explanation without assigning any particular distribution to the ice-crystals.
