ON THE ERRATIC BLOCKS OF ENGLAND AND WALKS. S7 



district by men engaged in cutting deep gutters and drains, and that they 

 were sometimes of such dimensions as to render it much the wisest course to 

 leave them undisturbed and to deviate from the proposed line of excavation. 



From the observations I was able to make, and the information furnished 

 to me, it appears that the boulders occupy a zone, about "75 mile long and •-"> 

 mile broad, south of an east-and-west lino from Leigh Bridge on the east, 

 through and a little beyond the Berry-Stone Hock on the west, and that 

 none have been detected north of that line. 



The Berry-Stone Bock occupies a place in the map of the Geological Survey 

 of Great Britain, but it does not appear that Sir H. De la Beche, or any other 

 Writer, has directed attention to its remarkable character, or to the multitude 

 of boulders lying in its vicinity and undoubtedly connected with it. 



Having learnt that, on account of the proximity of the numerous and very 

 large boulders, its limited extension, its supposed metamorphic character, its 

 dissimilarity to all the other rocks of the district, and its resemblance to 

 certain metamorphic rocks surrounding Dartmoor, it had been suggested 

 that the Berry-Stone Bock was itself an erratic block, and derived probably 

 from Auswell Mod; about 8"5 miles due north, I decided on making it a 

 second visit, and requested that, as a preliminary step, an excavation should 

 be made immediately adjacent to its southern or precipitous side. Having 

 secured the ready consent of Mr. Helyar, of Coker Court, Somerset, who is 

 the proprietor of the land, and of Messrs. E. and E. Whiteway, the tenants, 

 this was done ; and on the 25th May, 1877, I proceeded, with Mr. J. S. 

 Amery, to the spot, where we found Mr. Paige-Browne and Mr. E. Whiteway. 

 Two pits had been dug, one five feet deep and the other somewhat less, the 

 work having been stopped in each case by the occurrence of a mass of rock, 

 which was either a large boulder or a subterranean prolongation of the Berry 

 Stone in situ. In short, there was no indication that the base of the pile 

 had oven been approached. 



The entire mass is rudely rectangular in form, measuring 145 feet long in 

 an east and west direction, 56 feet high from the top of the southern face 

 to the bottom of the deepest pit at its base, 11 feet high on the northern 

 side (the difference in height being clue, not to the form of the pile, but to 

 inequalities in the level of the ground), and 32 feet broad at the top. The 

 beds dip at about 2G° towards the north, and are of considerable thickness, 

 one of them measuring 7'5 feet ; and the numerous well-defined joints are 

 sensibly vertical, in no instance " open," and have a north-and-south 

 direction. 



It will be seen from the foregoing data that the portion of the pile which 

 has been actually examined contains upwards of 250,000 cubic feet, and, at 

 a specific gravity of 2-5, weighs upwards of 18,000 tons — facts sufficient of 

 themselves to show that the Berry-Stone Bock is certainly not a travelled 

 mass, but is distinctly in situ. According to Professor Heer (see his ' Prinmeval 

 World of Switzerland,' edited by James Heywood, M.A., F.B.S., 1876, vol. ii. 

 p. 181), the largest block in Switzerland — the "Monster Block " on the hill 

 of Montct near Devent— contains no more than 161,000 cubic feet, that is, 

 less than two thirds of the volume of the Devonshire pile ; and we learn from 

 the First Beport by the Committee on Scotch Boulders (1872, p. 24), that 

 the largest block they have detected— that at Kemnay, in Aberdeenshire — 

 measures 38x30x10-5 feet, =11,970 cubic feet at most; i. e., less than 

 one twentieth of the bulk of the Berry Stone. 



If these aro the measures of the greatest efforts of Switzerland and Scotland 

 respectively — countries possessed of mountains entitled to look with scorn on 



