294 Proceedings of Societies. 
amounted to a fog, they should register a fog any day on which it was 
necessary to ring the fog-bell ! 
This paper was followed by others, among which was one by Mr Tom- 
linson of King’s College, London, ‘‘On Lightning Figures,” which we 
have presented to our readers in full at page 254. Another on the 
microscopic structure of copper, by W. Vivian, from which it appears 
that that structure is rather cellular than crystalline. Another on an 
electri¢-resistance thermometér with balancing coil, by C. W. Siemens. 
Another on a panoramic lens for photographic purposes, by T. Sutton, 
exhibited and explained by Mr C. Brooke. It consisted of a glass capsule 
containing water, with a diaphragm in the centre, and was affirmed to be 
perfectly achromatic when properly adjusted, and preventive of all dis- 
tortion. Besides these, there was a paper by D. Vaughan, on cases of 
planetary instability indicated by the appearance of temporary stars, in 
which the author endeavoured to explain temporary stars, meteors, and 
other phenomena, by the approach of revolving planetary bodies to the 
central in a course of ages, and their breaking up into fragmentary por- 
tions. In reference to the speculation, the Astronomer Royal said that 
he would not attempt to decide on the possibility or impossibility of 
events occurring in a course of ages in accordance with those dwelt on 
by the essayist. Under ordinary circumstances, the preservation of the 
plane in which a planetary body moved, and the permanency of the 
eccentricity, were established facts; but some of the phenomena of the 
satellites and rings of Saturn showed that it would be hazardous to deeide 
off-hand a subject so very speculative as that discussed in this essay. 
On Friday, in this Section, the interest was chiefly about meteors, in- 
troduced by the reading by Mr Glaisher of the report of the committee 
on luminous meteors. He commenced by expressing his regret that so 
few observations had been made by members of the British Association, 
and then dilated on the labours of others, especially Mr Haidinger. The 
report was followed by a paper by this gentleman—viz., ‘‘ An Attempt to 
explain the earlier Physical Conditions of Meteorites, as well as some of 
the Phenomena attending their Fall on our Planet.” 
Mr Haidinger, in a paper read on the 19th of April, 1860, spoke of a 
typical form ot a metcor, as exemplified in the stone which fell at Stannern, 
in Moravia, on the 22d of May 1808, which on the foremost part appeared 
rounded off, the crust showing streaks parallel to the probable line of 
direction through the air, and was much puckered up, like kneaded 
dough, behind; and then observed that there must be a starting-point, 
from some fundamental considerations proved by the phenomona them- 
selves, in order to arrive at an understanding of their forms and con- 
ditions. There are, first, the stone leaving the extra-terrestrial space as 
a solid; secondly, its velocity being greater on entering the earth’s at- 
mosphere; thirdly, it is retarded by the resistance of the air; fourthly, | 
the fireball is formed by the compression of the air behind it, and the 
rotation of the stone resulting therefrom; fifthly, the termination of the 
first part of the path is marked by a detention from the so-called ‘‘ ex- 
plosion,”’ caused by the collapse of the vacuum from the air rushing in 
with great violence. 
The discussion on Meteorites was followed by a paper by Mr Gassiot 
“ On the Deposit of Metal which takes place from the Negative Terminal 
of an Inductive Coil during the Elective Discharge in vacuo,”’ the title of 
which contains the substance of it. And that was followed by others of 
a purely mathematical or else very questionable character. 
Section B.—The Chemical Section was presided over by Professor W. 
A. Miller, who delivered an opening address on the progress of chemistry 
