METEORS OF AUGUST AND NOVEMBER. gg 



and asteroid, which may be regarded as common. By the ordinary computa- 

 tions for the transfer of co-ordinates from the centre of the earth to the position 

 of the spectator, or quite as well by neglecting quantities so small, it is always 

 possible to determine three data for the orbit of every meteor that is seen, 

 namely, the node, radius vector, and time of passing the node. To complete the 

 six elements it is only necessary to know, at the same time, three other quan- 

 tities, the asteroid's true or relative velocity in space, and its direction with 

 reference to two given planes, the equator or ecliptic, for instance, and a se- 

 condary to the same. The determination of the first of these three requisites, 

 the relative velocity of shooting stars, was first undertaken in 1798, by two 

 students of Gottingen, Brandes and Benzenberg,^^ and was pursued with a zeal 

 which terminated only in the death of the former. A notice of their labours 

 has been given by Olbers, and by Quetelet. An abstract by Professor Loomis 

 of the results obtained by Brandes, in 1823, may be found in Silliman's Jour- 

 nal,^^ giving the results of corresponding observations in Breslaw and its vicinity. 

 In 1824, Quetelet^^ and others in Brussels and its neighbourhood engaged in 

 similar researches. On the memorable occasion of the display of November 

 12th, 1833, among the myriads of meteors seen, one only was known to have 

 been beheld at several places. It was distinguished by its extraordinary size 

 and brilliancy, and by the duration (ten minutes at least) of its train, which, 

 after assuming various serpentine shapes, " terminated in a luminous nebula 

 of several times the diameter of the moon, floating onwards with a velocity 

 greater than that of the clouds." Mr. Twining,^'* after a full discussion of all 

 the facts connected with this meteor, concludes that its apparent path was about 

 forty-eight geographical miles, and its duration about three seconds, making 

 a mean relative velocity of about sixteen miles per second. Corresponding 

 observations were made at Breslaw and its vicinity by Boguslawski and others, 

 Nov. 13th, 1836, and August 9th, 1837. I have not been able to obtain the 

 single results, and therefore quote the remark of Olbers, ^^ that results obtained 

 for the November meteors of 1836 " show that the periodical meteors also have 

 the same height and relative velocity as the ordinary shooting stars hitherto 



*^ Versuche, die eutfernung, &c., der Sternschnuppen zu bestimmen. Hamburg, 1800. 

 Bestimmung der geographischen Lange durch Sternschnuppen, Von I. F. Benzenberg. Ham- 

 burg, 1802. 



" Vol. xxviii., p. 95. ^^ Catalogue, &c., p. 5. " Silliman, vol. xxvi., p. 46. 



" Schumacher's Jahrbuch, for 1838, p. 322. Note. 

 VIII. — X 



