IN THE SOLAR SYSTEM. 



93 



other was scarcely 4° ; their axes formed together a very obtuse angle of 160°. Near the 

 comet the abnormal tail could scarcely be seen; its brightest point was 2° from the nucleus. 

 In the early days of February, the tail opposite the sun could alone be seen ; the other 

 had disappeared, or had become so feeble that the best night glasses, in clear weather, gave 

 no trace of it. These results are a summary of observations made at Paris, Marseilles, 

 Marlia, Bremen, Gottingen, and Prague. No comet had up to that time presented so 

 extraordinary an appearance."* 



The second comet of this class was that of 1825. The inclination of its orbit was 89° 

 22' 10", and its perihelion distance 0.02689. M. Arago gives the following account of it. 



"The tail of the comet of 1825 (No. 145 of the catalogue), observed in New Holland 

 by Mr. Dunlop, consisted of six distinct branches of different lengths. On the 19th Octo- 

 ber, the rays proceeding from the tails on the extremes, seemed to cross behind the comet 

 like rays which diverge from the focus of a lens. On the 1st November, we find in Mr. 

 Dunlop's account expressions not less explicit. At one degree and a half from the head, 

 rays from the different tails diverge indefinitely, in such a way that the rays forming the 

 right border of the tail come from the left of the head, and reciprocally. "f 



It would not be easy to describe more precisely the probable effect upon a comet's tail 

 of being caught in a vortex of ether. 



The last comet of this class was the fourth comet of 1851, discovered by M. Brorsen. 

 The inclination of its orbit was 73° 59' 44". Its perihelion distance was 0.14132. 



It is No. 193 of M. Arago's catalogue, who states "that it had two unequal tails, of 

 which the shorter was directed towards the sun."J 



We have it recorded of many comets, as was the case with Hallcy's in 1835, that a ray 

 of light was ejected from the anterior surface of the nucleus, which finally became involved 

 with the tail ; but no other comets seen in the present century have exhibited the appear- 

 ance of those just described. 



ETHER. ITS RELATIONS TO THE SEASONS. 



The subject of ether in its bearings upon the zodiacal light and comets, is one which 

 interests alone the man of science; if it can be shown, however, that the amount of heat 

 which our planet receives from the sun, is supplied partly by the agency of ether, and if 

 the periods when these accessions of caloric are likely to occur, can be pointed out, the 

 subject increases in importance, and the agriculturist, the physician, and, indeed, the world 

 at large, will share with the astronomer the interest which the subject inspires. 



In my efforts to trace out the course of the grand ethereal circulation, I arrived at the 

 conclusion that the ascending current has nearly the form of a plate whose sides decline a 



* Astronomio Populaire, vol. ii, p. 407. f Id., p. 408. I Id., p. 408. 



