ALTHOUGH I quoted Capt. Winchester's figures as to the diameter of the circumsolar bow, mentioned in my letter on p. 436, I may add that this measurement was checked by that of the chief officer (Mr. Grant), who took the distances from the horizon to the inner rim of the bow on both sides, and subtracted them from 180°. In the case of the Captain's measurements, in the first instance, he measured from the inner rim of the bow to the edge of the sun. This was doubled, and the diameter of the sun added to it. Under these circumstances I can hardly believe there could have arisen the mistake suggested by Dr. Ingleby.