SUPPLEMENTARY REPORT ON METEOROLOGY. 119 
nomenon wus observed. Under these circumstances, it is plain 
that we must use the term periodicity, as applied to these me- 
teors, with caution. It is quite possible that some cause may 
determine their recurrence in November in preference to other 
seasons, and yet that the repetition may not be annual. 
245. It is well known that Chladui*, Brandes}, and Ben- 
zenbergt, have devoted their attention for a long time to these 
singular meteors; and it is perhaps surprising that we still 
know so little respecting them. The November periodic me- 
teor has of course given a fresh interest to these; Biot has pub- 
lished an astronomical theory §. Bessel has shown that it is 
improbable that these meteors ever ascend ||. JKirman has given 
a meteorological hypothesis connected with them, which we 
have before adverted to§]; and Olmsted** and Wartmann Tf 
have likewise written memoirs on the hypothesis of their pe- 
riodicity. 
246. But M. Quetelet, of Brussels, examining the records of 
this subject, has classified the frequency of meteors at different 
seasons of the year{{; and whilst he finds the middle of No- 
vember the most prominent period, yet that from the 10th to 
the 15th August is also well marked. This observation, com- 
municated to the Brussels Academy 3rd December, 1836§§, 
was confirmed by M. Arago next year ||||, and, I believe, every 
subsequent one§jf]. In 1839 they appear to have been very 
generally observed. M. Quetelet has quoted no less than six- 
teen years in the present century down to 1837, in which the 
August meteors have been specially noticed***. 
* Feuermeteore. See Kimtz, Meteorologie, Band iii. 
+ See an Abstract of his Researches, Silliman, xxviii. 95; and in Quetelet’s 
Annuaire for 1887. 
t He has published a new work, which I have not seen, “ Die Sternschnup- 
pen.” Hambourg, 1839. 
§ Comptes Rendus, iii. 668. || Poggendorff, xlvii. 525. 
@ See above (44), and Comptes Rendus, x. 21. 
¥* Silliman’s Journal, passim. 
+t Bibliothéque Universelle, N.S. ix. 373. 
tt Catalogue des principales Apparitions d’Etoiles filantes. Mém. de U Acad. 
de Bruxelles. 
§§ Bulletin de V Acad. de Bruxelles, December, 1836 and 1837, p. 79. 
\|\| Comptes Rendus, v. 183. 347; Silliman, xxxiii. 133; Bulletin de Acad. 
de Bruvelles, 1838, p. 567. 
qq Ibid., vii. 443. tom. ix. passim. 
*et Bulletin, 1837, p. 379. M. Littrow, of Vienna, has observed the me- 
teors of August, and states that their direction of motion is contrary to that of 
the earth in its orbit, whilst those of November move parallel to it. (4tt 
degli Scienzati Italiani, 1839, p. 19.). I learn, by letters from Sir John 
Herschel and M. Quetelet, that the meteors of August, 1840, have been ob- 
served both here and in America to radiate from a point.near y Persei. Whilst 
