234 



Scientyic Notice$^^MisceIianeous, 



I^Sbpt. 



lions of the second comet of 1825 ; an account of the actual state 

 of the great nebula in Orion, compared with the observations of 

 former astronomers ; and observations of the nebula in the 

 girdle of Andromeda. The account of the comet, and that of 

 toe ffreat nebula in Orion, are accompanied with illustrative 

 drawmgs, and the latter also with a kind of map representing 

 the whole as a constellation, in which the parts are named, 

 agreeably to a rude resemblance which the whole nebula presents 

 to the head, snout, and jaws, of some monstrous animal. Aided 

 by these drawings, the verbal account presents an instructively 

 perspicuous description of the truly interesting phsenomenon to 

 which it relates. 



Article VII. 



SCIENTIFIC NOTICES. 



Miscellaneous. 



1. Solar Spectrum — Light and Heat. 



Prof. Leslie exhibited some interesting experiments in his 

 Glass-room this week, with the view of showing the inaccuracy 

 of the received opinion with regard to the heat of the solar 

 spectrum. Profs. Jamieson, Russel, and Monro, Mr. Adie, opti- 

 cian, Mr. Stevenson, engineer, and several other gentlemen were 

 present. We had also an opportunity of witnessing the experi- 

 ments, the nature of which we shall endeavour to explain, with 

 the help of the following diagrams. 



R. 



By some experiments made about thirty years ago, Dr. Her- 

 schel was thought to have established a conclusion, which has 

 ever since been regarded as extremely curious. On trying the 

 temperature of the different coloured rays, which form tlie solar 

 spectrum (V, R, iBg. 1), he found that the heat was very 

 unequally divided, that it was smallest in the violet rays, V, 

 rather greater in the indigo, and went on increasing through the 



