THE APPARENT POSITION OF THE ZODIACAL LIGHT. 155 



lively wide, near the longitude 0'. The zodiacal light usually attracts most atten- 

 tion by its brilliancy near that longitude; but we need careful photometric 

 observations in both hemispheres to determine whether this apparent brilliancy is 

 not wholly due to the favorable position of the zodiac in the sky of the northern 

 hemisphere during the evenings at the end of winter. 



No remarkable relation between the longitudes and latitudes of the perihelia 

 was noticed. The accumulation just mentioned occurs both in north and in south 

 latitude. The mean distances and eccentricities, also, are not apparently connected 

 by any relation with the longitudes of the perihelia. There is a slight prepon- 

 derance of large eccentricities with perihelia in north latitude between the lon- 

 gitudes 300' and 3G0', and a similar preponderance of large eccentricities with 

 periheUa in south latitude between the longitudes 0' and 60\ 



The number of perihelia in north latitude is 131, in south latitude lOG. As 

 asteroids will be most readily discovered near their perihelia, and at a consid- 

 erable altitude, the excess of perihelia in north latitude may be due to the north- 

 ern stations of the discoverers. This consideration, however, fails to account for 

 the remarkable distribution of the ascending nodes of asteroids with southern 

 perihelia which has already been discussed. 



The principal fact noticed with regard to the mean distances was that the 

 more recently discovered asteroids have on the whole larger mean distances than 

 the others, as might naturally be supposed. Taking the distance for which log a 

 = 0.437 as the limit between small and large* distances, we find among the first 

 120 asteroids 71 relatively near, and 49 remote ; the corresponding numbers for 

 the next 117 are 51 and 66. It is also noticeable that the remoter asteroids 

 have less eccentric orbits than the rest. If the value of the eccentricity for 

 which (^ = 9° is taken as the limit, there are 57 of the nearer asteroids with 

 orbits of small eccentricity, and 65 with decidedly eccentric orbits; for the re- 

 moter asteroids the corresponding nlimbers are 67 and 48. But these peculi- 

 arities have no apparent connection with the present subject. 



It may be shown mathematically that if the zodiacal light is due to meteoric 

 dust difi'used through the Solar System, those particles far beyond the orbit of 

 Jupiter can add little to its brightness, upon any reasonable hypothesis with regard 

 to the distribution of the meteors. But at mean distances of 2 or 3, the effect 

 would not be relatively insignificant, and the existence of the asteroids, as has 

 been said, suggests the possibility that very minute planets may accompany 

 them in large numbers. It scarcely needs to be said that meteoric dust in the 



