56 



Between Bottisham and Quy it bends to the S.W., and extends 

 about a mile in that direction, terminating a little beyond Quy 

 Church, where the height of the surface is given as 60 feet 

 above sea-level. At Quy-Water Bridge it is cut through by a 

 more recent line of drainage; but gravelly soil is again found on 

 the hill to the S.W., and another elonrated outlier of gravel and 

 sand extends along the Newmarket road from Greenhouse Farm 

 to within half a mile of the railway bridge. 



The direction of this patch and consequently of the old 

 valley which it represents, strikes directly west across the 

 present valley of the Cam, so that we might expect to find its 

 continuation about Castle hill, and the Observatory. This is 

 indeed the case, a small patch of gravelly soil being observable 

 when the coprolites were worked opposite the Alms-houses 

 at Mount Pleasant, while just beyond the Observatory there are 

 large pits by Gravel Hill Farm, which have been worked for 

 many years, and where the gravel is said to be 20 feet deep. 



A recent excavation here discloses about twelve feet of 

 gravel, the lower six feet being fine and irregularly bedded, 

 containing nearly 50 per cent, of chalk pebbles, the rest being 

 flints with a few pieces of hornstone, quartzite, &c. The upper 

 six feet are disturbed and piped, the pockets being filled with 

 brown sand and occasional flints, and their bottoms lined in 

 places with films of carbonate of lime, from which we may 

 conclude that the contortions have arisen from the solution of 

 the chalky portion of the mass, the carbonated water having 

 probably been guided by roots of trees in the first instance. 



I did not succeed in finding any shells, though Mr Seeley 

 states that he found fresh-water shells under the Observatory. 



It is remarkable that the base of the gravel here is some- 

 what higher than it is further back, for its surface being 85 

 feet above sea-level, its base would be 05 feet, while near Quy 

 Church it is not quite 60 feet; this would apparently indicate 

 that there has been a slightly unequal upheaval of the area at 

 some subsequent time ; other facts bearing in the same direction 

 will be noticed in the sequel. 



In 1873 I was fortunate enough to see the northern bank 

 of the old watercourse exposed in the coprolite diggings then 

 opened behind the Observatory ; the section ran from N.E. to 



