280 Astronomical Notes. 



may be accounted for by the repellent force of light. After 

 a great many observations on that mag'nificent comet of 

 recent years, which was first observed in South Africa in 191 1, 

 and the comets Borelly, and Morehouse (1908, c), we felt that 

 the following conclusions were to our mind the most reason- 

 able to account for the tail in its various aspects : — That the 

 rays of the sun in passing- through the head of the comet are 

 changed, or refracted in such a way as to render the ether of 

 space luminous and visible to the eye, on the same prin- 

 ciple that a ray or beam of light is refracted when passing 

 through a lens. Suppose this to be admitted. There are 

 certain phenomena which require to be explained, such as a 

 curved tail, a forked tail, and sometimes several tails. A 

 curved tail would be accounted for by both sides of the head 

 of the comet not being of equal density, when the refractive 

 index would be different on each, and we know that if the 

 glass forming a lens is wavy, or not homogeneous, that the 

 refracted rays do not all follow one course. The same effect 

 would follow in the case of the comet. If some portions of 

 the head were m.ore susceptible to the influence of the sun's 

 rays than others, oblique, direct, or refracted rays would 

 produce different effects as seen from our point of view. 



When we consider the extreme tenuity of comets, almost 

 imponderable, light as thistle-down, we find it impossible to 

 understand how any amount of initial impetus given to a 

 comet when first launched on its voyage through space could 

 continue to keep it moving amid so many interrupting 

 influences, which act on it from time to time (I refer to the 

 great attraction of the more ponderable spheres) to which 

 they often come so comparatively near. We are therefore 

 led to the inevitable conclusion that when a comet is at peri- 

 helion that it (in some mysterious way) receives from the 

 sun accelerative force sufficient to continue it in its orbit, 

 and to overcome the gravitational force of other bodies it mav 

 pass on its journey. 



A New Star. 



On the evening of the 12th of March a new star was 

 discovered by M. S. Enebo, of Dombas, Norway, in R. A. 



