424 H. A. Newton— Biela Meteors of Nov. 27th, 1885. 



and 10th and recorded 226 meteors, a portion of which he has 

 classified as radiating from R A. 22°, Dec. + 55°. If from the 

 meteors recorded by him on those two nights we select all those 

 whose paths produced backward would pass near Cassiopeia or 

 Andromeda, and at the same time make a considerable angle 

 with the meridian, we have about 27 which cross the 20° hour 

 circle north of 50° declination, and 9 south of 50° declination. 

 The large north declination of 55° assigned by Heis for the 

 radiant is, therefore, required by the paths as recorded. There 

 is no indication of the time of maximum. In 1867, Zezioli 

 on the evening of November 30th, saw seven meteors, which 

 Schiaparelli assigns to the radiant, E. A. 17°, Dec. +48. 



The great shower of 1872 had its maximum at Nov. 27'34, 

 Gr. m. t. The mean of 90 assigned radiants considered as 

 single points was given by Professor A. S. Herschel as R. A. 

 24° -54 Dec. +44° -74 (Monthly Notices R. A. S., xxxiii, p. 504). 



The longitude of the earth at the times of these several dates 

 is given in the following table (equinox 1885*0) : 



Table of sun's longitudes at the dates of meteor displays. 

 Tear. Long. O Tear. Long.© Tear. Long.© 



1798 256°2 1847 257-°7 1872 246°1 



1838 256-1 1867 248'4 1885 245'8 



Since the Biela meteoroids are encountered at the descending 

 node of the comet's orbit, the longitude of the ascending node 

 and the longitude of the sun are quantities to be compared. 

 It will be seen at once that on the first three of the six dates, 

 viz : 1798, 1838, and 1847, the sun's longitude was about that 

 of the node of the comet's orbit in 1772, differing from it by an 

 amount easily explained by the action of Jupiter at some dis- 

 tance. On the contrary, the few meteors seen by Zezioli and 

 the two grand meteor showers of 1872 and 1885 are related to 

 the orbit of the comet since its near approach to Jupiter in 

 1841-42. 



The change of declination of the radiant shows the same fact. 

 Professor Weiss gives the radiants for the Biela orbits as fol- 

 lows (eq. 1850) [Beitrage, etc., p. 15] : 



ear 1772 



R. A. 18-7 



Dec. + 58-1 



" 1826 



" 22-8 



" +47-7 



" 1852 



" 23-4 



" +43-0 



The meteors of the years 1838 and 1847 have a radiant cor- 

 responding very well with that of the 1772 orbit, while the 

 radiants of 1867, 1872 and 1885 are well represented by that 

 belonging to the orbit of 1852. 



The comet approached Jupiter and was greatly perturbed in 

 1794, 1831, and 1841-42. It is very difficult to conceive of 



