OBSERVATIONS OF LUMINOUS METEORS. 145 



A belief that the planet Jupiter had accidentally been mistaken at Rybnik 

 for Saturn (although not participated in by Professor Galle) led Prof, von Niessl 

 to extend his inquiries for descriptions of the meteor to the eastward, and 

 especially to Southern Hungary : but neither in Hungary nor from any 

 eastern towns could he obtain fresh proofs of this early commencement of 

 the meteor's course, nor even any evidence of its having been visible in 

 Steiermark, about half as far off as Raab (in the same direction) from the 

 meteor's point of disappearance, until this was at length furnished to him 

 from Seheinnitz, in Hungary, by Baron A. von Pronay, who had noted the 

 meteor's passage thorc with the greatest care. Although attracted by its 

 light from behind, so as not to see its very first commencement, two thirds 

 of its course, the Baron relates, were traversed with great brightness, but 

 without leaving any very long-enduring streak. It was only in the last 

 third part of its course, near the horizon, that the luminous streak was left 

 which remained visible at his point of view 17 m 20 s . This point of first 

 commencement of the streak must, it appears, have been attended with a 

 considerable increase of the meteor's light, since it was the point almost 

 universally assigned by all the observers in Bohemia and Moravia as the first 

 point of the meteor's course ; and Prof, von Niessl himself, who saw the 

 meteor at Briinn, in Moravia, very favourably, was under no impression 

 whatever that an earlier portion (at least half) of its visible track had 

 escaped his view. A curious illusion also happened in his view of the end 

 point, which he believed to have taken place behind the roof of a house, but 

 which the calculated place shows must have been actually visible close above 

 it from his point of view, aud that the sudden extinction there must have 

 led him to believe that the end of the meteor's course was prolonged behind 

 the roof, and had been hidden from him by its neighbouring obstruction. It 

 is remarkable that but two or three observations of the meteor's early com- 

 mencement — at places as distant as Yienna, Schemnitz, and Bybnik from 

 the neighbourhood of its terminal, streak-leaving course and explosion — should 

 have been made among the many scores which were recorded of the latter 

 portion of its flight, while yet the brightness there, some hundred miles from 

 the point which it ultimately reached, was sufficient to make an observer 

 turn round and see it appearing from behind him. A streak was left on its 

 whole course ; but only for a few seconds, Baron von Pronay states, during 

 the first two thirds of its path across the sky. 



Adopting, therefore, the Bybnik observation as perfectly confirmed, and 

 employing it with all the new materials at his disposal, Prof, von Niessl finds 

 his previous determinations, except in the least significant particular of the 

 total length of course, to require no sensible modifications, and to differ also 

 almost insensibly from those arrived at by Prof. Galle. The apparent radiant- 

 point was at 248°-6, — 20°-2, and the velocity found from the short streak- 

 bearing portion of the flight, of which several well accordant durations were 

 observed, was 19 miles per second, differing little from those found by Prof. 

 Galle, at 246°-7,— 19°-3, and between 18-5 and 28-5 miles per second, ac- 

 cording to two estimates of the duration from which he separately deduced 

 the meteor's velocity in its entire length of flight. The radiant-point is so 

 near the ecliptic, that when corrected for ' zenithal attraction,' one of the 

 positions thus assigned to it is in north and the other in south latitude, so 

 that the meteor's orbit was almost absolutely zodiacal, dr nearly coincided 

 with the plane of the ecliptic. It is perhaps not impossible that the fireball 

 of July 25, 1876, observed in England with a nearly ecliptic radiant-point 

 at 258°, —24° may have had some connexion with the hvperbolic meteor 



1877. l 



