: order to furnish meteors throughout the year. The bodi 
hot have a retrograde motion, else shooting stars would be seen 
- then be 
H, A. Newton on Shooting Stars. 203 
These results should, however, be diminished a little, since the 
mean distance and mean angular length give too large a mean 
length. The smaller of the two limits given is doubtless much 
nearer the truth. 
13, Mean duration of flight, and the mean velocity of the shooting 
artmann of Geneva gives the duration of the flights 
six observers. The aggregate is 180533, which gives a mean of 
0*49 for each flight. ‘I'he mean of 499 estimates made in August 
and November last is 08418. The mean duration of the 867 
flights is 0-45. 
If the estimates of those observers who were accustomed to 
astronomical observation, and hence to judging of small inter- 
vals of time, had been alone taken, the result would have been 
tobable one or more of these three conclusions, viz :— 
st, That the length of track is too long; which seems to in- 
ve that the altitudes on which our computation is based are, 
_ 0 the whole, too large. All the altitudes greater than 150 kil- 
_ ‘Smeters, might, I think, have been safely rejected. 
_ , 4d, That the estimates of time are, in general, too small. This 
_‘Squite probable. The mind may not make proper allowance 
_ lor the time that elapses after the shooting star is seen, before 
_ me eye 18 directed to the place of the path. 
at very many of the meteors move in hyperbolic orbits 
4 7 . 
about the sun. Whatever may be said of the sporadic meteors, 
_ this cannot be true of the members of the August and Novem- 
oups. 
only in the morning hours, and would, moreover, have a very 
Inetly marked radiant. whip : 
‘hey cannot have a direct motion. For their velocity must 
nearly equal to, and yet a little less than, that of the 
In order that more be seen in the morning than in the 
ne Their relative velocity on entering the atmosphere 
