162 Proceedings of the Royal Physical Society. 



" it is an object of some importance to ascertain the direction 

 of these ruts " even on single boulders, has given unwearied 

 attention to certain minutiae of boulder-glaciation, which 

 few others have thought worthy of notice, — not only the 

 direction of the strise, but their arrangement on the stone, 

 their limitation — or the reverse — to its upper sides, the 

 direction of its longer axis and pointed end — to all the 

 particulars, in short, to which attention had been called by 

 the early school of observers, of which he is happily a 

 survivor. These observations, however, remain scattered 

 and undigested. 



By writers on glacial subjects the "striated pavements" 

 have been chiefly referred to as a remarkable phenomenon that 

 at least must not be left out of sight. Each writer has been 

 quite able to find a place for them in his own hypothesis. 

 By some of the advocates of till-formation under half-floated 

 glaciers they have been viewed as records of the intermittent 

 pressure exerted on the accumulating materials.^ By Mr 

 Goodchild, who regards the till as one great charge of materials 

 incorporated into the ice and left behind when it melted, like 

 the litter of the St Petersburg streets after the spring thaw, 

 they are considered as due to fits and starts of subsidence in 

 the melting mass.^ In Professor James Geikie's great work 

 they are referred to among the non-marine beds intercalated 

 with the Scottish till, of which, as all geologists know, he 

 supports the sub-glacier origin ; ^ and by Dr CroU they were 

 viewed as a sort of supplementary evidence of long pauses 

 and interglacial periods during its formation. * They have 

 not been deemed of sufiicient importance to merit notice in 

 any text-book of geology. 



Pavement-Boulders in the Till of the North of England. 



My interest having been excited by my father's observa- 

 tions on boulder-pavements, I have for a number of years 



1 See at length Rev. R. B. Watson, F.R.S.E. (Trans. Roy. Soc, Edinb., 

 vol. xxiii., p. 539), where this view is ably put forth, 



2 On Drift, Geo. Mag., 1874, p. 508. 



3 The Great Ice Age, 2d ed., p. 130. 

 * Climate and Time, p. 255. 



