298 METEORS AND AEROLITES. 



respectively suggested. Such, however, was the difficulty of 

 establishing identity, that in 1823 (a year particularly de- 

 voted to this research) out of 1,712 shooting-stars actually 

 observed, only thirty-seven could be conclusively regarded 

 as the same seen at different stations. Nevertheless many 

 valuable results were obtained, sufficient to indicate the 

 general character of these meteors, and to associate them 

 more closely with the fire-balls before described. Their 

 height varying, of course, in different shooting-stars, and 

 at the moments of appearance and disappearance of each 

 was found to range from 15 to 140 or 150 miles (some 

 statements much higher than these are made doubtful by the 

 smalmess of the parallax) ; their velocity to be that of plane- 

 tary bodies, reaching frequently to thirty miles in the 

 second. These conditions, together with the directions of 

 the paths they describe in reference to the motion of the 

 earth, suffice to assign their place in the planetary system, 

 however small or attenuated the aggregations of matter thus 

 presented to us. 



A far more striking evidence, however, to this effect speedily 

 followed, from the discovery of a periodical character in 

 some of those showers of meteors, which at certain times 

 startle the spectator by their number and brilliancy. The 

 earliest suggestion of this arose from an extraordinary appa- 

 rition of such meteors in New-England on the nights of the 

 12th and 13th of November, 1833; the description of which 

 in much detail was given by Professor Olmsted of Newhaven 

 and other observers. The asteroids composing this fiery 

 shower graduated from the simple phosphorescent line of 

 the shooting-star to luminous globes of the moon's diameter ; 

 all of them conforming to one condition (the most im- 

 portant of the facts observed), that of issuing from the same 

 point in the constellation Leo; and continuing to proceed 

 from this point, though the rotation of the earth during the 



