164 H. G. POEBHAM ON EECOEDING EEEATIC BLOCKS. 



and many minor changes have, no doubt, taken place ; but, as a 

 whole, there is no reason to believe that any great change has been 

 made. 



These beds of clay, sand, and gravel are the products of that 

 part of the world's existence which we know as the Glacial period. 

 At that time, as far as we know at present, man did not inhabit the 

 earth, or if he did exist, no absolute evidence of his presence has 

 remained to us. The climatic conditions were totally different from 

 those which we now experience in these islands. During this 

 period ice was a dominant power, and it has left clear and un- 

 mistakable evidence of its existence and work. 



The Committee, whose cause T wish to put before you, is 

 occupied in registering the more marked and definite evidence 

 now existing on this subject. When England lay for long periods, 

 during the Glacial epoch, more or less completely submerged below 

 the level of the sea, when all the high land was capped and 

 covered with ice-fields and glaciers, the limited shore-line en- 

 cumbered with coast-ice, and the sea, either wholly or in part, ice- 

 bound, or, where free, laden with ice in the shape of bergs and floes, 

 these beds of clay and gravel were spread out over our hills, and 

 portions of them remain to the present day as evidence of what has 

 been. Contained in, and associated with, the glacial clays and gravels 

 are large fragments of harder rocks, in some cases weighing several 

 tons, and often rounded, worn, and scratched during their travels 

 from the ice-bound hills of which they once formed portions. 

 Carried along, frozen into ice-bergs, or drifting on shore-ice, they 

 have been scattered far and wide over the country. At the present 

 day they are collected in our villages as corner-stones, to protect 

 the angles of houses or walls, are built into walls, and used in 

 paving, or are destroyed. "We can only regret that many boulders 

 have been broken up without any note being taken of them ; and 

 this regret should remind us how necessaiy it is to have complete 

 records of those that exist. By the identification of the materials 

 of the erratic blocks with the rocks from which they have been 

 derived, much may probably be added to our knowledge as to the 

 direction and character of the ice-movements of the Glacial epoch ; 

 and the superficial characteristics of the blocks themselves, their 

 localities, the heights above the sea at which they now rest, and 

 other facts concerning them, will, when properly brought together 

 and arranged, be of material assistance in the construction of the 

 history of that period. 



In recording boulders it is important to state whether they are 

 found in situ, or have been moved by man, and in the latter case any 

 information that can be obtained as to the place from which they 

 have been brought should be noted. Boulders should be accurately 

 measured and described, particulars as to the character of the rock, 

 and its external appearance, and as to whether it is angular, water- 

 worn, rounded, or scratched, should be given. The heights above 

 the sea (especially if unmoved), and the nature of the beds on which 

 they rest, should be noted. Drawings or photographs of large 



