112 CELESTIAL PHENOMENA. 



in Bremen, the same general parallelism of the paths of the 

 meteors, and the same direction from the constellation of the 

 Lion, were recognised. The periodical falls of shooting stars 

 which take place at other parts of the year, are also supposed 

 to show greater parallelism of direction than is the case with 

 those which appear sporadically at other seasons. A periodical 

 recurrence, similar to that of November, has been noticed in 

 the month of August; in which month, in 1839, it was 

 observed that the meteors came from a point in the heavens 

 situated between Perseus and Taurus, towards the latter of 

 which constellations the Earth was then moving. This pecu- 

 liarity of the phenomenon (viz., the retrograde direction, 

 both in November and in August), is especially deserving of 

 being confirmed or refuted by very exact and careful obser- 

 vation on future occasions. 



The heights of shooting stars, i. e. the heights at which 

 they first become visible, as well as those at which their visibility 

 ceases, are exceedingly various, fluctuating from 16 to 140 

 miles. This important result, and the enormous velocity of these 

 problematical asteroids, were first shown by Benzenberg and 

 Brandes, from simultaneous observations and determinations 

 of parallax, at the two extremities of a base line of 46000 

 (49020 English) feet in length ( 6 ?) . The relative velocity of 

 their motion was from eighteen to thirty-six miles in a 

 second; and similar, therefore, to that of the planets ( 6S ). 

 This planetary velocity, and the retrograde or opposite direc- 

 tion of the paths of the meteors to that of the Earth, are the 

 principal grounds which are considered subversive of that 

 hypothesis wliich attributes the origin of aerolites to the 

 supposed active volcanoes of the Moon. All numerical 

 hypotheses of a greater or less volcanic force on a small 



