35 
tells us that Xerxes dug a canal across the isthmus of Mount 
Athos for the passage of his fleet. We know how the Boman 
satirist ridiculed this as a fable. “ Creditur olim Veliflcatus Athos 
et cjiiidcjuid Grcecia mendax Audet in historia.” The discovery, 
some years since, of a large number of Persian Darics and Attic 
tetradrachms, in the line which still indicates an ancient excava¬ 
tion, must surely establish the authority of the old historian. # 
Dec. 4.—Dr. Procter read a paper on “ Meteorites.” Ho 
commenced by indicating the identity of the various bodies known 
as shooting or falling stars and aerolites, and described the 
characteristics and chemical constitution of the different kinds of 
the latter, and the general phenomena attending their fall. He 
then remarked upon the theories which have been proposed to 
account for these remarkable facts, such as the old notion that they 
were solidified in the atmosphere,—that put forward by several 
distinguished physicists, that they are projected from volcanoes in 
the moon, an opinion negatived by the fact that our satellite 
appears to possess no active volcanoes, and still more strongly by 
the calculations of Olbers and others which show that the velocity 
of aerolites is nearly three times as great as would be attained by 
bodies projected from the moon with sufficient initial velocity to 
reach our planet,-—and those which attribute the production of 
meteorites either to terrestrial volcanoes or to the sun, neither 
of which is tenable. The generally received hypothesis is that 
which regards meteorites generally as cosmical bodies revolving 
round the sun in one or more orbits, intersected at certain points 
by the orbit of the earth; by this hypothesis the remarkable 
periodicity of the appearance of meteors is accounted for, as also 
the fact of their starting from particular points in the heavens. 
In passing through the earth’s atmosphere these bodies become 
incandescent, giving rise to the luminous phenomenon, known as 
shooting or falling stars: —when they descend within a certain 
distance of the body of our planet they fall to its surface, generally 
undergoing an explosion, and constituting aerolites. The evidence 
in favour of there being several belts of meteorites revolving round 
the sun, in orbits nearly approaching that of the earth in their 
radii, is to be found in the occurrence of considerable numbers of 
shooting stars at particular periods in the year, the chief of these 
* Mommsen Romisch.es Miinwesen, p. 9. 
