92 View of the Progress of 



more usual to employ Lagrange's mode of deriving them from 

 the different orders of fluxions. 



XLIII. Chladni's Remarks on Cosmological Circumstances. 



The author collects several accounts of dark substances pass- 

 ing over the sun, though foreign to the solar system ; and of 

 temporary stars, one of which he suspects may have appeared 

 periodically. But the most interesting part of the paper is the 

 notice of some observations of Fraunhofer on the light of the 

 stars, published in the 56th volume of Gilbert's Annals, but 

 hitherto little known in this country. Fraunhofer has discovered, 

 it seems, more than 500 dark streaks crossing the spectrum into 

 which the solar light is expanded by a prism, and of which he 

 gives a figure ; not being, perhaps, aware that they had been 

 before observed by Dr. WoUaston : but the novelty is, that each 

 fixed star has a peculiar arrangement of the streaks, so that this 

 experiment indicates a new mode of distinguishing lights appa- 

 rently of precisely the same nature. Dr. Wollaston has noticed 

 a still more marked interruption of the spectrum produced by the 

 blue light of a candle ; and Dr. Young has observed a similar 

 appearance in light transmitted by several kinds of coloured 

 glasses. 



XLIV. Brandes on the mean Temperature of the different Times 

 of the Year. 



Professor Brandes has computed the mean temperatures for 

 intervals of five days, from the Journal of the Royal Society in 

 London, for two periods of five years each. He has remarked 

 that in London, as well as at Stockholm, there is a temporary 

 elevation towards the beginning, and a depression towards the 

 middle of February : but a similar variation which he notices in 

 March may, perhaps, be partly dependent on the hour at which 

 the thermometer was observed. 



iv. July and August. 



L Littrow on the Right Ascension of the principal Fixed Stars. 

 Deduced from all the observations in the first and second 



