FREE BOOKS

Author's List




PREV.   NEXT  
|<   12   13   14   15   16   17   18   19   20   21   22   23   24   25   26   27   28   29   30   31   32   33   34   35   36  
37   38   39   40   41   42   43   44   45   46   47   48   49   50   51   52   53   54   55   56   57   58   59   60   61   >>   >|  
eas in 1861 we found it thick and dry (excepting a few small basins containing water) and evidently permanent, in the middle of a very hot August. The low part of the cave was so completely protected from the current, that the candle burned there quite steadily for an hour and a half: still, like the others, the column at that end of the glaciere was broken down, and it therefore became necessary to attribute its fall to some other agency than the current of external air. There had been a very large amount of rain, and the surface of the rock in the fissures was evidently wet; so I have no doubt that the filtering through of the warm rain-water had thawed the upper supports of the ice-cascades, and then, owing to their slightly inclined position, the pedestal had not provided sufficient support, and so they had fallen. One of them, perhaps, had brought down in its fall the free column, which had stood two days before on its own base, without any support from the rock. Very probably, too--indeed, almost certainly,--the fall of the large mass of rock, which once formed the bottom of the basin on the north side of the road, has affected the old-established fissures, by which rain-water has been accustomed to penetrate in small quantities to the glaciere, so that now a much larger amount is admitted. On this account, there will probably be a great diminution of the ice in the course of future summers, though the amount formed each winter may be greater than it has hitherto been. Constant examination of other columns and fissures has convinced me, that, before the end of autumn, the majority of the glacieres will have lost all the columns which depend upon the roof for a part of their support, or spring from fissures in the wall; whereas those which are true stalagmites, and are self-supporting, will have a much better chance of remaining through the warm season, and lasting till the winter, and so increasing in size from year to year. Free stalagmites, however, which are formed under fissures capable of pouring down a large amount of water on the occasion of a great flood of rain, must succumb in time, though not so soon as the supported columns. A curious appearance was presented by a small free stalagmite in the retired part of the cave. The surface of the stalagmite was wet, from the drops proceeding from a fissure above, and was lightly covered in many parts with a calcareous deposit, brought down from the fissures in
PREV.   NEXT  
|<   12   13   14   15   16   17   18   19   20   21   22   23   24   25   26   27   28   29   30   31   32   33   34   35   36  
37   38   39   40   41   42   43   44   45   46   47   48   49   50   51   52   53   54   55   56   57   58   59   60   61   >>   >|  



Top keywords:
fissures
 

amount

 

formed

 

columns

 

support

 

stalagmite

 
evidently
 
winter
 
stalagmites
 

brought


surface

 

column

 

current

 
glaciere
 

convinced

 

admitted

 

larger

 

glacieres

 

lightly

 

majority


deposit

 

autumn

 

Constant

 

depend

 
greater
 

diminution

 

future

 

summers

 
hitherto
 

proceeding


examination

 

fissure

 
account
 

capable

 
pouring
 

appearance

 

increasing

 

occasion

 
supported
 

succumb


lasting
 
retired
 

curious

 

spring

 

supporting

 

covered

 
chance
 

remaining

 

season

 

quantities