SHOOTING STARS. 217 



120) generally estimated at 16 miles (over 97,388 feet), must 

 be greatly contracted. Some, according to measurement, de- 

 scend very nearly to the level of the summit of Chimborazo 

 and Aconcagua, to the distance of four geographical miles 

 above the level of the sea. Heis remarked, on the contrary, 

 a falling star seen simultaneously at Berlin and Breslau on 

 the 10th of July, 1837, had, according to accurate calcula- 

 tion, a height of 248 miles when its light first became visi- 

 ble, and a height of 168 on its disappearance; others disap- 

 peared during the same night at a height of 56 miles. From 

 the older labors of Brandes (1823), it follows that of 100 well- 

 defined shooting stars seen from two points of observation, 4 

 had an elevation of only 4 to 12 miles ; 15 between 12 and 

 24 m, ; 22 from 24 to 40 m. ; 35 (nearly one third) from 40 

 to 60 m. ; 13 from 40 to 80 m. ; and only 11 .(scarcely one 

 tenth) above 80 m., their heights being between 180 and 

 240 miles. From 4000 observations collected during nine 

 years, it has been inferred, with regard to the color of the 

 shooting stars, that two thirds are white, one seventh yellow, 

 one seventeenth yellowish red, and only one thirty-seventh 

 green." 



Olbers reports, that during the fall of meteors in, the night 

 of the 12th and 13th of November, in the year 1838, a beau- 

 tiful northern light was visible at Bremen, which colored 

 large parts of the sky with an intense blood-red light. The 

 shooting stars darting across this region maintained their 

 white color unaltered, whence it may be inferred that the 

 northern light was further removed from the surface of the 

 Earth than the shooting stars were at that point where they 

 became invisible. (Schum., Astr. Nadir., No. 372, p. 78.) 

 The relative velocity of shooting stars has hitherto been es- 

 timated at from 18 to 36 geographical miles a second, while 

 the Earth has only a translatory velocity of 16*4 rniles. 

 (Cosmos, vol. i., p. 120, note *.) Corresponding observations 

 of Julius Schmidt at Bonn, and Heis at Aix-la-Chapelle 

 (1849), gave as the actual minimum for a shooting star, 

 which stood 48 miles vertically above St. Goar, and shot over 

 the Lake of Laach, only 14 miles. According to other com- 

 parisons of the same observer, and of Houzeau in Mons, the 

 velocity of four shooting stars was found to be between 46 

 and 95 miles in the second, consequently two to five times 

 as great as the planetary velocity of the Earth. The cos- 

 mical origin is indeed most strongly proved by this result, 

 together with the constancy of the simple or multiple points 



VOL. IV. -K 



