Page:Philosophical Transactions - Volume 029.djvu/427

 which was no other than a Segment of a Ring or Zone of the Sphere, intercepted between two parallel leſſer Circles, cut off likewiſe by the Horizon; or, if you pleaſe, the Segment of a very broad Iris, but of one uniform Colour; viz. a Flame-colour inclining to yellow, the Center thereof being about forty Degrees below the Horizon. And above this there were ſeen ſome Rudiments of a much larger Segment, with an Interval of dark Sky between, but this was ſo exceeding faint and uncertain that I could make no proper eſtimate thereof.

I was very deſirous to-have ſeen how this Phnomenon would end, and attended it till near Three in the Morning, and the riſing of the Moon: but for above two Hours together it had no manner of Change in its Appearance, nor Diminution nor Encreaſe of light; only ſometimes for very ſhort Intervals, as if new Fuel had been caſt on a Fire, the Light ſeem’d to undulate and ſparkle, not unlike the riſing of vaporous Smoak out of a great Blaze when agitated: But one thing I aſſured myſelf of by this Attendance and Watching, viz. that this Iris-like Figure did by no means owe its Origine to the Sun’s Beams: for that about Three in the Morning, the Sun being in the Middle between the North and Eaſt, our Aurora had not follow’d him, but ended in that very Point where he then was: whereas in the true North, which the Sun had long paſt, the Light remained unchanged and in its full Luſtre.

Hitherto I have endeavoured by Words to repreſent what I ſaw, but being ſenſible how inſufficient ſuch a verbal Deſcription of a thing ſo extraordinary. and unknown may be to moſt Readers, I have thought fit to annex a Figure exhibiting that particular Appearance of the two Lamin, which I ſaw at London between the Hours of Ten and Eleven: more eſpeciallv. becauſe I do