11 



Rev. Prof. Hailstone, sixth occupant of the Woodwardian chair 

 at Cambridge; this is entitled — "Outlines of the Geology of 

 Cambridgeshire," read before the Geological Society in 1816, 

 and published in the Trans. Geol. Soc, Vol. ill. p. 243. 



Herein he observes that "upon some of the highest hills 

 near Cambridge a deposit of gravel and loose stones in horizon- 

 tal layers has been found resting immediately upon the chalk." 

 He notices that it contains many pebbles derived from strata 

 lying to the North and N.W., and remarks upon the difficulty 

 of conceiving how the more tender fragments can have been 

 transported without having been entirely destroyed, (the 

 agency of ice did not apparently suggest itself to his mind). 

 " The gravel," he says, " contains numerous fragments of strata 

 belonging to the Oolitic series, which occur in the neighbouring 

 counties of Northampton and Rutland..., but the prevailing 

 material is the pale blue or light grey variety of flint with traces 

 of alcyonium »fec., which is chiefly to be found in Lincolnshire 

 and Yorkshire, according to my observation." 



From the great difference in character as well as in level 

 between this gravel and that dispersed over the plain below, he 

 rightly concludes that they belong to different epochs. The 

 two localities he mentions for this gravel are the summit of the 

 Gog Magogs and a hill near Harston about 5 miles S. W. of the 

 former; the latter spot was visited by Mr Warburton, whose 

 observations upon it are given in the paper, together with a 

 list of the derived rocks and fossils found there. 



1818. In a paper "On the Strata of the Northern Division 

 of Cambridgeshire," Trans. Geol. Soc. v. p. 114, Mr Lunn 

 treats mainly of the Lower Greensand and Gault, but he 

 evidently confused the Boulder Clay with the latter formation, 

 since he speaks of it as overlying the ferruginous sand at 

 Gamlingay, and describes the villages of Hatley, Great and 

 Little Gransden, and Caxton as situated on the Gault; since 

 however these all stand on Boulder Clay, we may take his 

 description as chiefly applying to this formation. He mentions 

 that in the parish of Long Stow are many beautiful septariae, 

 together with rounded flints embedded in the clay, and that the 

 fossil cornu-ammonis is also abundant. 



1825. Next we come to the papers previously mentioned 



