RAMBLES OF A GEOLOGIST. 281 



wards athwart the face of the quarry ; and the arched band 

 of boulder-clay which so mysteriously underlies the deposit 

 was, save in a few parts, wholly covered up by the debris. 

 The occurrence of the clay here as an inferior bed, with but 

 the cornstone of the Old Red beneath, and all the beds of 

 the Weald resting over it, forms a riddle somewhat difficult 

 of solution ; but it is palpably not reading it aright to regard 

 the deposit, with at least one geologist who has written on 

 the subject, as older than the rocks above. It is, on the con- 

 trary, as a vast amount of various and unequivocal evidence 

 demonstrates, incalculably more modern ; nay, we find proof 

 of the fact here in that very bed which has been instanced 

 as rendering it doubtful : the clay of which the interpolation 

 is composed is found to contain fragments, not only of the 

 cornstone on which it rests, but also of the Wealden lime- 

 stone and shales which it underlies. It forms the mere fill- 

 ing up of a flat-roofed cavern, or rather of two flat-roofed ca- 

 verns, for the limestone roof dipped in the centre to the 

 cornstone floor, which, previous to the times of the boulder 

 clay, had lain open in what was then, as now, an old-world 

 deposit, charged with long extinct organisms, but which, dur- 

 ing the iceberg period, was penetrated and occupied by the 

 clay, as run lime penetrates and occupies the interstices of a 

 dry-stone wall. It was no day for gathering fossils. I saw 

 a few ganoid scales, washed by the rain from the investing 

 rubbish, glittering on fragments of the limestone, with a few 

 of the characteristic shells of the deposit, chiefly Unionidae ; 

 but nothing worth bringing away. The adhesive clay of the 

 Weald, widely scattered by the workmen, and wrought into 

 mortar by the beating rains, made it a matter of some diffi- 

 culty for the struggling foot to retain the shoe, and, sticking 

 to my soles by pounds at a time, rendered me obnoxious to 

 the old English nickname of " rough-footed Scot" And so, 

 after traversing the heaps, somewhat like a fly in treacle, I . 



