Natural History of Volcanos and Earthquakes. 77 
ture, or at all events, one which varies only 4°.5 Fahr., ina whole 
year. Since the conjecture is probable that the lias and the va- 
riegated marl present the first entirely impermeable strata, we may 
also conclude, that not only the chalk formation, but also the 
green sand, which is equally fissured, are filled by the reservoir, 
and that its bottom is formed by the above mentioned impermea- 
ble strata. Lastly, the high temperature of what are called the 
warm Pader springs (54°.5-61°.25 Fahr.) indicates also an or- 
igin from a greater depth, if they do not flow in distinct chan- 
nels, but come from warm streams, which rise from the base of 
the reservoir. 
The copious springs, which rise on the western declivity of 
the Teutoburger Wald, owe their abundance of water, even in 
dry seasons, to these vast subterraneous reservoirs; and what is 
derived from these reservoirs, is abundantly replaced in the rainy 
Teasons, when nearly all the water collected in a district so much 
fissured, penetrates into the interior. 
These large masses of water, whose temperature exceeds, by 
Several degrees the average one of the district under which they 
are collected, and which brings so much the more heat to their 
Surface the deeper they penetrate, have doubtless the effect of 
Warming the hills under which they exist. It is therefore per- 
haps a Phenomena of universal occurrence, that all chalk hills, 
Which are much fissured, and into which brooks, rivers, and most 
of the meteoric water sink, maintain a relatively higher temper- 
ature. ~The Pader springs alone, however, show how inexhaust- 
ible taust be the sources which warm such vast masses of water. 
hese springs furnish in a year at least 8688 millions of cubic 
. of water, whose average temperature exceeds by at least 
75 Fahr., the average temperature of the ground at Pader- 
™ and this excess would melt a cube of ice, having a side of 
934 feet, This heat is irrevocably withdrawn from the interior, 
and yet the thermal springs of Paderborn have sustained no 
Which could there give rise to such inexhaustible sources of heat 
: the youngest secondary formations, must be, or have been, 
“attied on to a great extent indeed ! 
- . . . 
“ By far the greater number of the remaining copious springs, which rise on the 
iy ™ declivity of the Tutoburger Wald, are also thermal ones. Some, for in- 
“im Lippspring attain a temperature of 54°.5, 
