Meteorological Obfervations.. 627. 
CALENDAR of FLORA, for M.DCC-:XCIII. 
kept at Dumfries. lob 
a 
May 3d. and for the three following days, 
the common Swallow (Hirundo ruftica) came. 
— 8th. The large Martin or Swift (Hirundo 
Apus) came, and the fame day the Cuckoo, 
( Cuculus canorus) was firft heard. UAW 
rita oo June 
gealed water: the internal heat of the earth.t The general 
heat of the fprings of water fituated deep in the bowels of 
the earth, is about forty-eight degrees. In mountainous coun- 
tries it may be fomewhat lefs, but fufficient notwithftanding 
for the purpofe here mentioned. When the fnow incumbent 
on any {pot of ground, is but thin, it may fo far cool the 
earth, that the internal heat may not be able to diffolve it ; 
but when the bed is thick enough to proteét the earth from 
the influence of the atmofpherical cold, that furface of the 
earth may, even in the coldeft winters, receive more heat 
from the earth than cold from the atmofphere, and be 
therefore diffolved at all feafons of the year, . 
‘Now we know that faéts are in favour of this reafoning 5 
for ftreams of water, and even rivers iflue from the bottom 
of the Glaciers in the Alps, in the greateft feverity of 
winter; fo that whether this be allowed to depend upon 
the internal heat of the earth or not, a conftant thaw of the 
ice or {now which is contiguous to the furface of the earth, 
cannot be denied; and this added to other caufes, may 
render it probable that the quantity of congealed water has 
its limit even in the coldeft country. 
+ Watfon’s Chemiftry, vol, IIL. p, 184 
