Part of a Letter from Mr Gray, concerning an Unusual Parhelion and Halo

IV. Part of a Letter from Mr Gray, concerning an unusual Parhelion and Halo. Canterbury, May 4th, 1699. SIR, I had scarce thought the account I sent you of the Parhelia I observ'd the 26th of February last, worth your notice, had I not been prompted to think so by the instigation of my friends, for I find they are frequently seen, tho this is the first I ever saw. But what I am now going to relate, is that which so rarely happens, that I cannot think it unworthy your cognizance. April the 7th, 1699. between 4 and 5 of the clock, I first perceived, and afterwards shewed to several others the following Phænomena. There appeared on each side the Sun a Parhelion, connected by an Halo of the usual diameter; they had each of them a tail of a whitish colour, extended opposite to the Sun, of about 15 or 20 degrees in length; the upper part of the Halo was touched by the arch of a Circle, whose ends were turned towards the Zenith; it had the colours of the Iris but faintly, betwixt this and the Zenith was another portion of a Circle, which had the colours of the Iris with greater vivacity than the former; the appearance may not be altogether unfitly represented by figure 2. where A is to be supposed the Sun, B C the Parhelia with their trains, D the coloured arch touching the Halo B D C, E the more vivid arch that past betwixt D and the Zenith Z.