AEROLITES. 1 1 1 



compressed air, appears at first sight as the consequence of 

 Some unknown tangential force, propelling bodies from the 

 earth ; but Bessel has shown by theoretical deductions, con- 

 firmed by Feldt's carefully conducted calculations, that owing 

 to the absence of any proofs of the simultaneous occurrence 

 of the observed disappearances, the assumption of an ascent of 

 shooting stars was rendered wholly improbable, and inad- 

 missible as a result of observation.* The opinion advanced 

 by Olbcrs that the explosion of shooting stars and ignited fire 

 balls not moving in straight lines may impel meteors upwards 

 in the manner of rockets, and influence the direction of their 

 orbits, must be made the subject of future researches. 



Shooting stars fall either separately and in inconsiderable 

 numbers, that is, sporadically, or in swarms of many thousands. 

 The latter, which are compared by Arabian authors to swarms 

 of locusts, are periodic in their occurrence, and move in 

 streams, generally in a parallel direction. Amongst periodic 

 falls, the most celebrated are that known as the November 

 phenomenon, occurring from about the 12th to the 14th of 

 November, and that of the festival of St. Lawrence (the 10th 

 of August), whose "fiery tears" were noticed in former times 

 in a church calendar of England, no less than in old tra- 

 ditionary legends, as a meteorological event of constant re- 

 currence, f Notwithstanding the great quantity of shooting 



* Bessel, in Schum. Astr. Nadir., 1839, Nr. 380 und 381, s. 222 und 

 346. At the conclusion of the Memoir there is a comparison of the 

 Sun'd longitudes with the epochs of the November phenomenon, from 

 the period of the first observations in Cumana in 1799. 



t Dr. Thomas Forster (The Pocket Encyclopaedia of Natural Phe- 

 nomena, 1827, p. 17) states that a manuscript is preserved in the library 

 of Christ's College, Cambridge, 3 written in the tenth century by a monk, 

 and entitled Ephemerides Rerum Naturalium, in which the natural 

 phenomena for each day of the year are inscribed, as for instance, the 

 first flowering of plants, the arrival of birds, &c. ; the 10th of August 

 is distinguished by the word " meteorodes." It was this indication and 

 the tradition of the fiery tears of St. Lawrence that chiefly induced 

 Dr. Forster to undertake his extremely zealous investigation of the 

 August phenomena. (Quetelet, Correspond. Mathem., Serie III. t. i. 

 1837, p. 433.) 



a [No such manuscript is at present known to exist in the Library 

 of that College. For this information I am indebted to the inquiries of 

 Mr. Cory of Pembroke College, the learned editor of Hieroglyphics of 

 Horapollo Nilous, Greek and English, 1840.]-^. 



