NO. l6 METEOR-ORBITS IN THE SOLAR SYSTEM VON NIESSL 33 



the case of the meteorite of Pultusk for whose path J. G. Galle ' has 

 shown that the minimum value of the excentricity equals 2.277. 



The average of 26 of the best determinations of the paths and 

 mostly large detonating fire balls, gives for the heliocentric velocity 

 59.05 km., and therefore a= —^ very nearly. For those few cases of 

 meteors for which sufficient observational material is at hand to 

 enable us to draw any conclusion as to the form of the orbits, the 

 hyperbolic form is beyond all doubt. 



For 154 large meteors whose paths are derived from older material 

 or were first computed by myself, there resulted on the average 

 59.8 km. as the heliocentric velocity. 



Schiaparclli^ more than jd years ai:;o, said " It is in fact remark- 

 able that whenever we have been able to investigate with any approxi- 

 mation the velocity with which a meteorite or a group of meteorites 

 have penetrated into the atmosphere, we have always found that the 

 corresponding absolute velocity is greater than the parabolic would be. 



Therefore, in general, the large meteors are undoubtedly of inter- 

 stellar origin. xA.s opposed to this conclusion, we find that streams of 

 shooting-stars pursue the same orbits as those of certain well-known 

 comets of well-known periodicity. They are, therefore, interplane- 

 tary shooting-stars. Hence we are inclined to consider the large 

 meteors as interstellar, but the smaller shooting-stars as interplane- 

 tary. Still we must call attention to the undeniable fact that most 

 of the radiation points of meteors and detonating fire balls as well as 

 the other large meteors, as far as they can be safely determined, agree 

 zvith IV ell- established shooting-star radiants. It is difficult in such 

 cases to ascribe interplanetary orbits to the corresponding small 

 phenomena when the hyperbola described by the large meteors issues 

 from the same radiant points in the cosmic space. 



In attempting to solve this apparent contradiction, one might per- 

 haps assume that we have included under the name of shooting-stars 

 diflferent phenomena that are only superficially similar, but whose 

 dynamic basis and cosmic significance are probably not all similar. 

 From the many experiences of the last ten years we may at least draw 

 the conclusion that in the phenomena as a whole there make them- 

 selves felt both the limited and minor interplanetary meteors as well 

 as the extended interstellar meteors having particles of the greatest 

 variety as to size, mass, quality, and velocity. 



^J. G. Galle. Uber die Bahn des am 30. Jainiar 1868 beobachteteii n. bei 

 Pultusk im Konigreicbe Polcn als Steinregen neidergefallenen Meteors. 

 Breslau, 1868. 



^ Schiaparelli. Pp. 207 and 209. 



