HARDWICKE'S SCIENCE-GOSSIP. 



21 



GEOLOGY, &c. 



The Mammoths at Guildford. — There has 

 just been an exhumation of the great teeth, tusks, and 

 portions of the skulls of these marvellous elephants, 

 in the railway cutting a few hundred yards from the 

 spot whore I am writing. Excitement has given rise 

 to the most wonderful stories, and one good woman 

 has been dreadfully shocked to think that these 

 prodigious beings were exterminated by man, and 

 not all drowned by the deluge. There is some little 

 geological interest attached to the matter. When 

 Mr. Godwin Austen came across mammoth remains 

 in the Peas Marsh by the banks of the Wey, the 

 occurrence seemed natural enough ; this time the 

 existence of an elephant bed is not so easy to account 

 for. As is known, the plastic clay overlaps in a 

 ribbon the northern slope of the Downs. East of 

 Guildford this ribbon consists of mustard-coloured 

 sand traversed by a layer of bluish, red mottled brick 

 clay, evidently incipient clay-slate, averaging ten feet 

 in thickness. In this clay are vast heaps of shells 

 here and there, as if washed together. As you 

 approach the town this seam of brick clay thins out 

 and leaves the sand reposing in hollows on the chalk, 

 which rises in little waves. The sand-bed here is 

 composed of elements which bespeak rest and dis- 

 order. First there are noticed traversing it, rice-like 

 layers of minute chalk-pebbles, and others of small 

 flint pebbles, with here and there a bit of iron-stone, 

 perchance derived from the greensand. There are 

 likewise beds of angular flints and shingle patches. 

 All this would seem to indicate that the arenaceous 

 accumulation had taken place in tranquil water, on 

 the shore of the tertiary sea that drowned the north 

 of France and Belgium. Otherwise the deposition 

 of the sand has not so tranquilly proceeded ; for the 

 layers are sometimes tilted up at an angle, and great 

 detached masses of chalk plainly suggest that the 

 earthquake heaved the while. Now I think that 

 when it is borne in mind that there is no perceptible 

 demarcation in the sand-bed from the plastic clay 

 onwards, as seen in section ; and save that oysters 

 disappear, its consistence is uniform, and when it is 

 likewise taken into consideration that the mammoth 

 remains were dug up forty-two feet deep in the sand, 

 and consequently near the level of the plastic clay, 

 some confusion in geological ideas will naturally arise. 

 My friend, Mr. Kidd, and another gentleman who 

 appears to have given attention to local geology, 

 suggested to me last spring that the Wey may 

 anciently have flowed though this sand-bed, which 

 now is raised upwards of two hundred feet on the 

 flank of the Downs. We all know that elephant- 

 beds do occur at intervals along the slope of the 

 English and Continental chalk hills, but no one 

 seems to have furnished an adequate reason for their 

 existence, while those who revert to a deluge to 



explain the chaos on a hill-side, seem to ignore the 

 earthquakes that were invoked to raise the hills. — 

 A. H. Swiiitou, Guildford. 



THE BATTLE OF THE ATOLL.* 



Ls there a moral from the coral 



Reefs and Atolls we can quote? 

 Were they stable or unable 



To withstand the seas that smote 

 At their base and living face 



With oft-repeated shock ? 

 Did they shiver, did they quiver? 



No, the seas they mock ! 

 In the battle of the Atoll 



Which the little creatures wage 

 In a strife for their life, 



They tame the breakers' rage 

 As on they rush as if to crush 



The fabric at one bound. 

 But Polypifer built it stiffer 



And made it safe and sound. 



Moral. 



So Darwin's theory builded up with care. 

 Facts piled on facts and nothing left to chance, 

 Good Master Geikie pray beware ! beware ! 

 Your trivial efforts cannot but enhance. 

 The minute labours of the master mind, 

 That first the facts explained, the truth divined 

 Will most assuredly win in this small battle 

 And breast your breakers like the living Atoll. 



A. Conifer. 



Supposed Animal Tracks, — At a recent meeting 

 of the Geological Society, Professor Hughes made 

 some observations on certain pits in the district about 

 Cambridge which are filled with the fine mud 

 produced in washing out the phosphatic nodules from 

 the " Cambridge Greensand " — a seam at the base of 

 the Chalk Marl. As the water gradually dries up, 

 a surface of extremely fine calcareous mud is exposed. 

 This deposit is often very finely laminated, and occa- 

 sionally among the laminae old surfaces can be dis- 

 covered, which, after having been exposed for some 

 time to the air, had been covered up by a fresh 

 inflow of watery mud into the pit. The author 

 described the character of the cracks made in the 

 process of drying, and the results produced when 

 these were filled up. He also described the tracks 

 made by various insects, indicating how these were 

 modified by the degree of softness of the mud, and 

 pointed out the differences in the tracks produced by 

 insects with legs and elytra, and by Annelids, such as 

 earthworms. The marks made by various worms 

 and larvae which burrow in the mud were also de- 



• See ' Origin of Coral Reefs,' " Nature," Not. 3 and Dec. 6. 



