TRANSACTIONS OF THE SECTIONS. 37 
' Thus the Slate at all depths appears to be about 8°9 warmer than 
the Granite at the same level. 
The progressive increase of temperature in descending is on a mean 
of 
95 Observations in the Slate 1° for 6°5 fathoms 
39 » »  Granitel® , 69 ,, 
ee 
Statement of the Proceedings of the Meteorological Committee, consisting 
of Prof. Forses, Mr. W. S. Harris, Prof. Powrxz, Lieut.-Col. 
Sykes, and Prof. Puriuirs, during the past year. 
Prof. Phillips then presented a statement of the Proceedings of the 
Meteorological Committee during the past year. The objects proposed 
by the Association in the appointment of the Committee were two-fold : 
first, the institution of uniform experiments, for the acquisition of accu- 
rate data concerning the distribution of temperature, from the surface 
of the earth downward to the greatest depths attainable by human en- 
terprise; secondly, the establishment of well-arranged observations on 
the varying phenomena of the atmosphere, which can be elucidated 
by combined exertions on one plan, and for the same object. The 
Committee had thought it best to employ the sum placed at their dis- 
posal on one of these objects only, so as to effect with regard to it a 
real advance, reserving to themselves the hope that, by a further grant, 
they might be enabled effectually to turn their attention to the second 
branch of investigation—viz. atmospheric phenomena. One hundred 
pounds had been granted, and seventy-two thermometers, and proper 
tables for being filled up, had been distributed by the Committee. 
Confining himself to the principal points disclosed by the results yet 
received from the several observers, it appeared that the general truth 
of the regular augmentation of temperature in proceeding downwards 
from the surface of the earth, was confirmed; but that, in addition, 
the different distribution of water, the nature of the rocks, and other 
causes, produced local discordances. The last of these causes ap- 
peared to the Committee of such importance, not only for the expla- 
nation of these differences, but for purposes of general reasoning 
in physics, that Professor Forbes was requested to institute a complete 
_ series of continuous experiments, which he had devised, similar in ge- 
neral principle, and at corresponding depths below the surface of the 
ground, to those established by M. Quetelet, at Brussels, so as to de- 
termine the rate of communication of heat, in one uniform mass, from 
the surface downwards to the depth of 26 feet; and further, to ascer- 
tain the differences of this rate in materials of different kinds, by a 
triplicate course of observations in trap-rock, sandstone, and a uniform 
mass of sand. 
The observations established by Professor Forbes have been regu- 
larly registered at the Botanic Garden, in Cragleith Quarry, and on the 
Calton Hill, from February to September 1837, and the register was 
laid before the meeting. Particular precautions were taken not only 
