The Comet which has been so brilliant an object during
the last week in the Northern sky, and on the highly eccentric orbit of which we publish speculations elsewhere, was described by Mr. Norman Lockyer in a very interesting letter to Thursday's Times. Mr. Lockyer says that the blue rays are singularly deficient in the spectrum of the nucleus of the comet, from which he infers that its temperature is low, while the lines in the spectrum indicate the presence of "a rare vapour of some kind." Mr. Lockyer hazards a guess which he admits to be a mere guess, that the comet may yet divide, as Biela's did ; and if it should, he gives reasons for thinking that that would show it to be not improbably a "meteor-whirl," in which the points of highest luminosity would be due to the colli- sione of the greatest number of distinct particles. Meteor-showers have been sometimes said to diminish sensibly the heat we receive from the sun. Certainly that has not been the characteristic symptom of the last week.