DEPRESSION AT DOWNING COLLEGE, CAMBRIDGE 407 



stratum in Downing Grounds. This terrace is lost sight of 

 behind the east wing of Downing College, but the slope which 

 represents the eastern margin of it is clearly seen in the yard 

 of the Old Castle Hotel, and although it is not obvious along 

 Downing Street as it now is, when the area on which the Bird 

 Bolt Hotel stood was cleared and excavated for the foundations 

 of the new buildings recently erected at the corner opposite 

 Emmanuel, the old level of Downing Street was seen to have 

 been 6 or 7 feet below the existing road in front of the College. 

 On the other side of Downing Grounds along Tennis Court 

 Road a slight rise may be observed, and thus Downing Grounds 

 lie in a depression which had always a tendency to be swampy. 

 I have frequently seen water standing in winter over a consider- 

 able area near the north-west end of the grounds ; and I have 

 heard it said that in old times there was good snipe shooting 

 here. This area was not built upon until quite recently. 



Before drainage operations were carried out the water that 

 accumulated in the above depression, which narrows between 

 Downing Place and Tennis Court Road, probably ran into the 

 King's Ditch, which is within fifty yards of the north-west 

 corner of Downing Grounds, but in still more ancient times it 

 found its way along the low ground which runs near where 

 Christ's College and Jesus College now stand. 



We need not discuss the question whether the lower terrace 

 of gravel is a newer gravel, laid on at a lower level, or whether 

 it represents an ancient river course which cut a terrace in the 

 widespread gravel of the higher level. This question is ob- 

 scured by the uneven surface of the underlying Cretaceous 

 beds. The terrace of gravel now becomes more conspicuous as 

 we trace it across St Andrew's Street by Christ's College, 

 diagonally over Christ's Piece and Butt Green, and it is sharply 

 defined along the edge of the alluvium to Barn well Abbey 

 Fish Ponds. 



Christ's College was outside the King's Ditch on the margin 

 of the main mass of gravel that sloped down from Barnwell. 

 Other buildings carried the town out along Preachers' Street 

 (St Andrew's Street), so that there were middens and various 

 artificial accumulations over the area, but there was no need to 



