no. l6 meteor-orbits in the solar system — von niessl 3i 



3. The Masses of the Shooting-Stars 



A. Herschel * concluded from the comparison of the hght power of 

 the shooting-stars at a given distance with that of a given mass of gas, 

 that the meteor of first magnitude on the average weighs very few 

 grams and the smaller meteors weigh only a fraction of a gram. 



By similar comparisons with the Drummond light, V. F. Sands,' 

 with reference to the Leonids of 1867, found the following estimates; 



Even if such estimates can give only approximate results, still they 

 confirm the assumption that as a substratum for the shooting-star 

 phenomenon only very small masses come into consideration which 

 probably in their original condition could scarcely attain the earth's 

 surface. 



According to Buchner ^ the smallest of those aereolites that have 

 been found, of which one can assume that they have descended as 

 individual bodies, is 24 grams. Much smaller particles, which under 

 the protection of preceding larger pieces describe their path through 

 the atmosphere in small aggregates and cause a rain of stones, are in 

 this respect not comparable with the shooting-stars. On the other 

 hand they form, together with the larger pieces, one fire ball. 



Experienced observers of shooting-stars frequently expressed 

 themselves that the exterior appearance allows one to infer great 

 original variation in composition," Some points in respect to differ- 

 ence of the velocity might well have been attributed to them. So long 

 as we know nothing more accurate relative to the physical nature of 

 the matter of the shooting-stars, we shall have to consider the differ- 

 ence in the masses between them and the meteorites. 



4. The Average and the Unusual Lengths of the Paths 



Out of 185 computed paths of shooting-stars from the fifth to the 

 first magnitude as given in the last English statistics, I find on the 



^■A. Herschel, Proc. Brit. Meteor, Soc. II, 19. 

 " F. Sands, Wash. Obs., 1867, pp. 19-30. 

 ^ Schiaparelli, p. 203. 

 * Weiss, Beitrage, p. 303. 



