176 
LIFE OF DEAN BUCKLAND. 
[CH. VII. 
chasms give the appearance of castles, towers, and pinnacles. 
The upward movement of the reef was simultaneous with 
the downward movement of the land. A similar elevation 
of a reef was produced in March 1790 by the subsidence of 
about eight acres of chalk in the parish of Beer, three miles 
west of Axmouth. A third example of the same kind 
but on a minor scale took place last February in the day¬ 
time at Whitlands, about a mile and a half west of Lyme. 
The most decisive confirmation of the theory of hydrostatic 
pressure causing the elevation of reefs beneath the sea was 
afforded at Whitlands by the rising of two reefs at a short 
distance from the shore, which were seen to rise as the 
undercliff descended.” 
Buckland concluded his address by giving a list of land¬ 
slips which have occurred along the coast at various times, 
and by stating that similar landslips, under similar conditions, 
often occur on the sides of inland valleys. A stratum of 
solid stone, resting on a bed of permeable sand, beneath 
which is a bed of impermeable clay, are the conditions of 
most of the landslips from the sides of hills into the 
adjacent valleys. 
In the cause of his beloved science a journey to the 
extreme North of Great Britain was nothing to Buckland. 
A large artificial lake under the Pentland Hills, some 
sixty feet deep, had dried up after a season of great 
drought. As many parts of the bottom of this lake were 
calculated to throw much light upon several important 
phenomena in geology, an opportunity occurred of acquir¬ 
ing evidence of which Buckland was not slow to avail 
himself. One of the phenomena which were thus illustrated 
was the manner in which several species of locomotive 
fresh-water shells were found congregated in one dense 
