#: 
. e = 
ut : ai 
818 «© Proceedings of the British Association. * 
= = re 
4 
London, after similar precautions. The later researches Forbes. 
and Melloni on this subject, related to the connexion of these dis- 
coveries and the facts thus developed, with the gndulatory theory. 
The report contained some remarks on the clearness with w ich 
the sect, pe order of.the discoveries is marked in this case, 
and the consequent impossibility of any of those disputes which 
have sometimes tended to disturb the harmony of pee in- 
quiries. The continental philosophers have the merit of devising” 
and bringing to perfection the instrament, by the aid of which 
alone, any discoveries in this very delicate field of resear could | 
have been expected. Prof. Forbes is the author of the over 
of the polarization of heat in all its branches, and from all its 
sources. . ‘ 
Prof. Forbes gave an abstract of his Supplementary Report on 
Meteorology. At the last meeting of the Association, he had 
been requested to make a report on the progress of ‘meteorology 
since the period of his former report, which was drawn up in 
1833. In obedience to that request he now came before them. 
He had distributed the matter of this reportgunder the same gell- 
eral heads as those under which he had formerly treated of the 
several subjects. These were Temperature, Pressure, Humidity, 
Wind, Clouds, Rain, Electricity, Meteors, and suggestions on the 
first of these heads. In the report he had entered fully into the 
subject of the instruments used for measuring temperature, with 
their improvements, defects, and the cautions to be observed in 
using them. He enlarged on the decrease and accumulation of 
heat, and the curves which were used for elucidating these sub- 
jects. He spoke ofsthe temperaturé decreasing in a geometrical 
series as you ascend through arithmetically increasing heights, 
the temperature being supposed constant, and entered on an ex- 
amination of the paradoxical conclusion at which Poisson had 
arrived, that the upper surface of the atmosphere was, in conse- 
quence of the extreme cold there existing, in a state which he 
termed liquefaction. He observed that there are reasons for con- 
cluding that the temperature of space itself entirely beyond the 
atmosphere of the earth, was not so cold as Poisson seemed to SUP” 
pose the highest portions of our atmosphere ; but that, indepen- 
dent of this opinion, there were other causes in operation quite 
sufficient to limit the extent of the atmosphere, without the a} 
of this startling supposition, and which limited height might 
* 
* 
