8 On the Caves Perforating Marble 
although frequently covered with reddish and yellow earthy 
sediment. Throughout this cave, at about G feet above the 
present bottom and water-level, are masses of mud conglo- 
merates, -with waterworn pebbles and boulders from |-inch 
to 3 inches in diameter, and made up of the porphyries and 
slates which exist in situ on the surrounding hills. These 
mud conglomerates evidently are the undenuded remnants 
of what was for a long time the original deposit forming the 
floor of the ancient cave, and may yet be found to contain 
fossils of scientific value. I have indicated their position on 
Diagram No. 5. The beds, where visible within the cave, 
seem to be much thicker than on the weathered surface, 
and are still full of the parallel earthy seams before re- 
ferred to. 
TEMPERATURE OF THE CAVES. 
During two visits I made some observations on the tempera- 
ture of the caves examined. On the first occasion, in August, 
1882, when the suiTOunding hills were covered with snow, 
the thermometer at the entrance to caves Nos. 1 and 2 stood at 
50° Fahr. ; at a distance of 100 feet within the caves it rose 
to 58° Fahr. During November of same year the thermo- 
meter at entrances registered 62°, and at the same place as 
before, within the caves, it fell to 54”, thus giving a difference 
of 8° between the external and internal air in each case. 
This seems to agree with the i-esult of observations recorded 
elsewhere, “ that the air in caves is generally of the same 
mean temperature as that of the district in which they occur, 
and consequently cool in summer and warm in winter,”* 
For instance, during August, the minimum degree of cold 
registered during a severe frost at the Limestone Ci’eek was 
20°, or 12° below freezing point, while in November the 
maximum registered was 80°. Taking the mean of these 
observations as an approximate mean annual temperatm-e, 
we have 50°, which I anticipate is about that of the regular 
mean temperature of the caves, and also that of the Lime- 
stone Creek valley in which they are situated. Of course 
this determination is not to be taken as strictly correct, as 
a more extended series of observations are required to ascer- 
tain the mean temperature of the place, and it is probable 
that the maximum and minimum heat is greater and less 
* Boyd Dawkins’ Cave Hunting, p. 71. 
