38 The Coming Meteor Shower. — The Spectra of Meteors. 



species, to which, undoubtedly many additions will be made. 

 The present season has afforded several novelties. The study 

 is undoubtedly involved in much difficulty, but this will be 

 greatly diminished by a careful study of some typical species 

 in each subgenus, for the determination of which good figures 

 are absolutely necessary. Without some such previous disci- 

 pline, it will be almost impossible to ascertain a species satis- 

 factorily ; and it is to facilitate this that the present series of 

 notices has been prepared. 



THE COMING METEOR SHOWER. 

 OF METEORS. 



-THE SPECTRA 



Great interest attaches to the composition of meteors, and 

 though chemical analysis of the ordinary kind can lend its aid 

 to the examination of meteoric stones, which fall in consider- 

 able masses upon the earth, it cannot avail with regard to the 

 much more numerous class of shooting stars and bolides, 

 which blaze for a moment in our atmosphere, and then dis- 

 appear entirely, or leave for a few seconds the transitory traces 

 of a luminous smoke. To learn something of the composition 

 of these bodies, Mr. Alexander Herschel proposed the employ- 

 ment of a binocular direct vision spectroscope, fitted up with 

 peculiar prisms designed by himself. This plan, which pre- 

 sents considerable difficulties of optical constructiou, has been 

 very ably carried out by Mr. Browning ; and the British Asso- 

 ciation Committee have ordered four of the instruments with 

 a view to their employment in the coming November showers, 

 when a maximum number of meteors may be expected. 



The nature of Mr. HerschePs plan will be obvious from the 

 following diagram. The thick dotted lines represent the path 



THE DEKSCnEl-BKOWNING METEOE SPECTBOSCOPE. 



