17 



Remarks on the "Red Glo^w." 

 By Clemejstt L. WEAaaE, P.E.a.S., F.E. Met. Soc. 

 [Read May 6, 1884.] 



After some preliminary observations, tlie author pro- 

 ceeds : — 



It seems very evident tliat there exists even novr some re- 

 flecting medium in the upper regions of our atmosphere 

 altogether ahnormal and at a great height, as evidenced by the 

 prolongation of the intense glow apart from the ordinary 

 phenomenon of twilight caused by common atmospheric re- 

 fraction. AVhat, then, is this medium ? this great reflector 

 that is the jjrimary cause of these exquisite glows that invest 

 our landscapes with such lurid unearthly tints, and call to 

 mind the idea of life in Mars ? Erom a scanty perusal of the 

 masses of evidence and observation already accumulated, my 

 present belief is that our planet is surrounded by an abormal 

 envelope of dust, either cosmic or telluric. Once prove this — 

 and its proof appears e2i%j — and the "sun glow" phenomena 

 may be explained, as pointed out by Prof. Michie Smith, of 

 Madras, in accordance with facts illustrated by Mr. Aitken 

 before the Eoyal Society of Edinburgh (Trans. E.S.E., vol. 

 XXX., p. 337). The sun's rays as white light fall on the dust 

 particles, whose minute spiculae scatter and absorb, reflect, 

 sift, and split up the rays at the proper angles, and with 

 greater or less intensity, according to the thickness of the air 

 strata and height of the reflecting medium. These spiculae 

 may assist the condensation of vapour into that light haze so 

 generally observed, and cause ice spicula) deep enough to give 

 the effects of absorption, but not to such an extent as to form 

 cloud. Hence I, at present, insist that vapour and meteorological 

 factors, if they influence the displays at all — as I shall pre- 

 sently inquire — ^ve entivelj secondary ; and as such modify and 

 regulate the passage of light, so assisting in the production of 

 that galaxy of varying tint and colour which we have so ad- 

 miringly beheld. The determination of the nature of the 

 primary reflecting layer, and to determine how it came to oc- 

 cupy its present position, are the chief points in the discussion. 

 It has been argued that vapour is the main cause, absorbing 

 certain of the sun's rays. I confess that this hypothesis appears- 

 to me wholly absurd and untenable. The cause, as I have al> 



