accumulation of the Cambridgeshire Pleistocene Deposits 71 



D. Surface Implements. 



Implements of all ages from earlier palaeolithic to recent 

 times are found lying together on the surftice. Some no doubt 

 have got there from the erosion of deposits which contained them, 

 others belong to the surfece. My object is to insist on their 

 careful collection, with exact records of their localities, even to 

 the particular position in a field where thej^ lay. 



If they can be shewn to be limited to heights above those of 

 a particular deposit, they may yield valuable information as to 

 geological changes. 



Two areas in which surface implements are abundant are 

 found very near Cambridge, one on the tract between Castle End 

 and Girton on either side of the Huntingdon Road, on the ground 

 occupied by the Observatory gravels and loams, the other a little 

 south of Fen Ditton, between the railway and the river, and at 

 no great height above the latter. They have not been yet 

 sufficiently studied to enable one to draw definite conclusions, but 

 the former group does not seem to occur below the level of the 

 Barnwell village terrace, which suggests that the river may have 

 eroded its valley below that level to its present position since 

 those implements were made. The other set marks the position 

 of a site on a terrace, which is I believe the terrace of the 

 Barnwell Station deposits, and would indicate the formation of 

 that terrace before this set of implements was manufactured. 



As the above is merely a preliminary account of these deposits, 

 I have not burdened it with references, nor have I acknowledged 

 the many friends who have helped in the collection of implements 

 and other objects. 



The bulk of the implements on which my conclusions are 

 based were collected by myself, and the rest by friends chiefly 

 under my supervision, and in no case has any implement been 

 purchased from workmen, so that the collection, which will be 

 deposited in the Sedgwick Museum, is of value, inasmuch as each 

 implement is known to have been obtained from the locality 

 assigned to it. 



