ANNIVERSARY ADDRESS. 17 
intervals.(hours or minutes) during the day, and the water so 
collected would form an exact measure of the sunshine, 
Mr. Glashier, in a paper on the mean temperature of every 
day at Greenwich, from observations taken there from 1813 to 
1873, has made a valuable contribution to science. . The results 
have been plotted intoa curve, representing amongst other things 
the variation of the temperature throughout the year. From 
this it appears that in January the curve is normal, but in 
February there is always a considerable rise between the 5th and 
the 10th of the month, and a fall between that and the 15th 
The curve is rather unsteady during March and April, and in 
May it shows a remarkable depression between the 10th and the 
15th, which Mr. Glashier thinks is probably due to some astro- 
nomical cause. The curve also shows rather sudden depressions 
about the 30th June and 8th July, and is then normal until the 
5th or 6th of November, when a remarkable depression sets in 
and lasts about three weeks. (During this time the earth passes 
through the November meteor shower.) During December the 
curve is normal again. Considering the length of the series 
from which these results are obtained, it would seem probable 
that all the irregularities in the curve are due to some external 
cause; or, in other words, to the intervention of something: 
between the earth and the sun, which for the time adds to or 
absorbs the sun heat. 
Turning from these interesting mean results, we find that 
during the year extremes have been reached. both im the earth 
and near the pole. A remarkable series of observations on 
underground temperatures have been taken in a boring made at 
Sperenberg, near Berlin. The bore was carried to the extraor- 
dinary depth of 4,172 English feet. The first 283 feet of it were 
made in gypsum, with some anhydrite, and the remainder’ 
entirely in rock-salt. The greatest depth at which the tempera- 
ioe mapeitiained wee 401 Seah as athe ait part of a bore was 
+n nrovent 
£ 
convection of heat. "Tho et tempersire ma taken at 721 feet 
from the su 
Boe 1 
