OBSERVATIONS OF LUMINOUS METEORS. 



227 



accurate determinations, and diminishing the scale of modified numbers so 

 obtained to one half of the original figures, in order to bring the crest of the 



A duration of 0^-2 is far the most 



curve within the limits of the diagram 



^300 



common time of flight assigned to about one third of all the observations ; but 

 a tendency to record longer times of flight in the later years (187l'-71) of 

 the Catalogue than in the first year (1869), in which many durations of 

 only 0^-1 were recorded, indicates that these exceedingly momentary times 

 of flight may very probably have been a little underrated. Above 1*5 

 second there are actually noted in the list meteors of great durations in 

 the following numbers : — 



Duration of flight in seconds 1-6. 1-7. 2-0. 2-5. 3-0. Aboye 3 seconds. 



Numbers of meteors recorded 1 2 25 9 11 11 



total 59, or only 3f per cent, of all the appearances recorded. Only 47 meteors 

 with times of flight varying from I'-l to 1^-5 (or 2-9 per cent, of the whole) 

 are noted in the list, the remaining 1506 meteors all having durations not 

 exceeding one second. The longest time of flight observed was 16 seconds, 

 and the average duration of all the recorded times of flight M-as 0^-44. If 

 durations exceeding 1 second are excluded as anomalous and exceptional 

 from the general result, the average time of flight of the remaining 1506 

 meteors was 0*-32. 



The following agreements of radiant-points in Capt. Tupman's list with 

 showers apparently corresponding to them obtained from Zezioli's observa- 

 tions are pointed out by Schiaparelli. The sign and number of the shower 

 in Mr. Greg's last general list to which they correspond is added for refer- 

 ence to that Table ; and although these separate correspondences exhibit 

 very excellent agreements, they afford little confirmation of the distinctness 



q2 



