IV. Extracts of several letters to the Publisher, from the Reverend Dr. Langwith, Rector of Petworth in Sussex, concerning the appearance of several arches of colours contiguous to the inner edge of the common rainbow

Abstract

When the Primary Rainbow has been very vivid, I have observ'd in it, more than once, a second Series of Colours within, contiguous to the first, but far weaker, and sometimes a faint Appearance even of a third.