1878. | 309 | Kirkwood. 
On the Aerolitic Epoch of November 12th-13th. 
By DanieL Kirkwoop. 
(Reud before the American Philosophical Society, March 1, 1878). 
It is now well-known that clusters of small meteors—the so-called shoot- 
ing stars—move in elliptic orbits about the sun. Catalogues of fire-balls 
and meteoric stones indicate, moreover, that groups of lurger bodies, some- 
what widely dispersed, revolve in like manner about the centre of our 
‘system ; their orbits in certain cases intersecting that of the earth. The 
12th and 13th of November is one of these qerolitic epochs ; the date being 
nearly coincident with that of the great November shower of falling stars. 
The writer until recently supposed the meteorites of this epoch to revolve 
in the same orbit with the nebulous swarm which furnished the showers 
of 1833, 1866 and 1867.* Later study of the facts, however, has rendered 
the theory of this intimate relation extremely improbable. The principal 
phenomena of this epoch (not including star showers) are the following : 
(a.) 1582, meteoric phenomena at Zurich. 
(6.) 1765, an extraordinary meteor at Frankfort. 
(c.) ¢ 1820, a detonating meteor seen in Russia. 
(d.) ' 1822, fall of aerolites at Potsdam and Leipsig. 
(e.) 1828, a great meteor seen in full sunshine in France. 
(f.) 1835, a fall of aerolites in France. 
(g-) | 1849, a fall of aerolites at Tripoli. 
(h.) ©1849, a large meteor seen in Mecklenberg. 
(7.) 1856, a meteoric stone fell in Italy. 
Gj.) 1877, a brilliant meteor seen in Arkansas and another in Wisconsin. 
REMARKS. 
(a.) This so-called ‘ fall of fire from heaven”’ occurred on the 28th of 
October, O. S., or November 7th, N. 8. Making allowance for the preces- 
sion of the equinoxes, the date corresponds at present to the morning of 
November 12th. 
(b.) This bolide was observed November 11th, and is the only one in 
our list which occurred very near the epoch of the great star shower in No- 
vember. 
(c.) See Greg’s catalogue of fire-balls and meteoric stones; also Quete- 
let’s catalogue of shooting stars. 
(d.) Several aerolites fell at this date near Potsdam, and also at Taucha, 
near Leipsig, about 75 miles distant. 
(g.) See Quetelet’s catalogue. 
(f.) This fall of aerolites occurred on the evening of November 12th, in 
the department de l’Ain, France. The meteor was unconformable to the 
* A list of stone-falls, detonating meteors and large fire-balls which have ap- 
peared about this epoch is given in Meteorie Astronomy, pp. 58-60. 
