'392 Bed Star— Planets of the Month. 



known that the rays of light, when reflected at a certain angle 

 from a surface of glass, become polarized, and consequently 

 will be either transmitted through, or reflected from, a second 

 similar surface, according to the angle under which the latter 

 receives them. In Merz's new solar eye-piece, 2 pairs of plane 

 glass mirrors (of course, un-silvered), are so arranged as by 

 the rotation of one pair relatively to the other, to intercept at 

 pleasure the whole, or any required part, of the light trans- 

 mitted through the telescope. SecchFs opinion of this con- 

 trivance is decidedly favourable. He says, " your helioscopic 

 polarizing ocular is preferable, because it shows the sun of its 

 true colour ; thus films which appeared blue in the ordinary 

 oculars with blue glass, are seen with yours of a rosy hue, the 

 same tint as the protuberances which are seen during eclipses. 

 This is an important fact." It is to be hoped that Mr. Browning 

 or some other skilful optician will turn his attention to this 

 construction in our own country, where the solar phenomena 

 are at present attracting so much notice. 



RED STAE. 



In an extract from the Memoirs of the Astronomical Society, 

 Yol. iii. p. 1 87, I find the following statement on the authority 

 of H. "No. 895 {%) R,A. 6h. 12m. P.D. 84° 12' [=D. 

 N. 5° 48'] L full ruby red, or almost blood colour. S fine 

 green, which it loses when the large star is concealed." This 

 object from its double character may possibly have been in- 

 tentionally omitted from the catalogue of Dr. Schjellerup, of 

 which an abridgment was given in our Sept. number ; but it 

 seems likely to repay the search. It will be found near the 

 nose of Monoceros. 



PLANETS OF THE MONTH. 



Mars is now rapidly approaching the earth, and becoming 

 a telescopic object of much interest. As the opposition, which 

 occurs on Jan. 10, will be somewhat more favourable than the 

 last, as well as those for some years to come, we trust that all 

 available telescopes will be employed in the scrutiny and de- 

 lineation of his features. 



The following remarks, by one so pre-eminent in the art of 

 design as De la Rue, are too valuable not to find a place in 

 relation to this subject. Speaking of the disagreement too 

 frequently observable in astronomical drawings, he says, " These 

 discrepancies no doubt arise in some measure from differences 

 in the aperture and defining power of the telescopes employed; 

 in other instances, much is attributable to the state of the 

 atmosphere at the places of observation. The discordances 



