49 






SEA AND SHORE: A STUDY OF COAST 
EROSION. 
(InuustRaTED By THE LanTERN). 
By Mr. J. A. OSBORN, B.A. 21st March, 1905. 

Having lived some twelve years at the seaside in Essex, Kent, 
Sussex and Devonshire—and paid many summer visits to other 
parts, the Lecturer had enjoyed unusual opportunities for the 
study of this process. The wasting of the shore was going on 
with a rapidity which, in some cases, gave reasonable grounds for 
alarm to the inhabitants, and in all cases formed an interesting 
subject of study to the geologist and the engineer. Accordingly 
he proposed to consider (1) the mode of its operation ; (2) its 
results, as shown both iu the localities of which he had personal 
knowledge, and in others which were classic instances of the 
geologists. 
The forces of atmospheric denudation were continuously at work 
wherever there was land for them to act upon. The heat and 
cold, the wind and rain would, in time, were there no counteract- 
ing forces at work, reduce all land to the sea-level. ‘The rainfall 
of this country was now very well ascertained, and from the 
solvent action of the rain, as shown in the amount of solid matter 
held in solution by the water of the various rivers, it had been 
calculated that no less than 123 million tons of lime, and cther 
rock-forming minerals, were carried into the sea every year. Add 
to this all that was carried out in suspension. and that would be 
a great deal more in amount, and it was easy to form some idea 
of the waste due to the action of the rain and running water. 
Great as it was, however, it was hardly perceptible to casual 
observation. 
The effects of rain were greatly increased by the action of the 
wind, and especially by frost. The alternate action of heat and 
cold had a disintegrating effect on the rock surface The water 
penetrated the joints and froze there, splitting the rock in all 
directions, causing great falls along steep surfaces. Or the water 
% 
