114 



made extensive observations of the two recent comets with the Equa* 

 torial, and had computed their elements and ephemeris, and pub- 

 lished them in the daily papers, for immediate circulation among 

 astronomers. 



Mr. Walker concluded by remarking, that a review of the stars in the 

 zone, from the 15th to the 30th parallel of south declination, had been 

 commenced and carried on thus far by Mr. Joseph S. Hubbard, now 

 Assistant of the Topographical Corps. The catalogue now contains 

 about 250 double stars, of which only about 100 can be found in the 

 Herschell's or South's Catalogues. 



Dr. Hare mentioned, that a roseate tint may be imparted to 

 the light from carburetted hydrogen, by the interposition of 

 mica. 



A thin sheet of this substance, curved into the cylindrical form so 

 as to enter a glass chimney, will retain the form thus imparted, in 

 consequence of its elasticity and the confinement of the including 

 glass. Thus employed, mica had been found competent to correct the 

 lurid influence of gas illumination, so much objected to by all who 

 are desirous to appear " couleur de rose." 



Very neat chimneys had been constructed, and maintained in the 

 cylindrical form, by frames of tin plate, secured by rivets. Of course, 

 the more delicate the frames, consistently with due firmness, the bet- 

 ter. However costly at first, mica chimneys, he believed, would be 

 cheaper in the long run, than those in common use. 



When employed within a glass chimney, as he had described, the 

 mica afforded the glass much protection against the flaming gas. 



The mica, by which these results were obtained, when in thick 

 plates, had a brownish red tinge, whether seen by reflected or by 

 transmitted light. 



Dr. Hare likewise entered into some arguments and consi- 

 derations respecting a recent speculation of Mr. Faraday, on 

 electric conduction, and the nature of matter, contained in the 

 London and Edinburgh Philosophical Magazine and Journal, 

 for February, 1844. This speculation will be fully stated and 

 discussed by Dr. Hare, in a forthcoming number of Silliman's 

 American Journal of Science. 



Mr. Kane, on the part of the appropriate Committee, an- 

 nounced that the Commemorative Discourse on the late Presi- 

 dent of the Society, would be ready for delivery in a few days. 



