334 



REPORT 1888. 



its exact thickness is difficult to measure, since there is at this place no 

 clear line between it and the shaken chalk of the clifF-top ; but where it 

 extends over the blown-sands it thins to 3 or 4 inches, and in one place 

 seems to disappear for a short space altogether, being apparently cut out by 

 the overlying boulder clay. Soon after leaving the chalk cliff it begins to 

 descend, thickening rapidly in doing so, and cutting into the blown-sand. 

 Thus, at 50 yards from our excavation it has sunk so that its base is only 

 about 20 feet above sea-level, it is composed of finer material, and its 

 thickness has increased to 11^ feet. Beyond this the cliff section seemed to 

 show over 25 feet of this material at the bottom ; but when we commenced 



