SOILS OF CAMBRIDGE 395 



river was not suitable for ordinary dwelling-houses, and was 

 consequently assigned to monastic fraternities and colleges, 

 and the buildings connected with them ; and the waste land 

 which seems to have extended in many places along the King's 

 Ditch, both on the inside and on the outside, was but slowly 

 encroached upon. 



Let us now consider what was the condition of this ground 

 before it was raised and reclaimed. It was not necessarily all, 

 nor indeed any of it, always a swamp. Any one who has 

 ever been familiar with an extensive village common in some 

 far off district, previous to sanitation being enforced, will 

 realise the condition of waste land like this, close to a town 

 such as Cambridge then was. Wherever a hole had been dug 

 to procure earth or stone it was immediately utilised to receive 

 any rubbish which it might be thought desirable to remove to 

 a little distance from the front door. If a donkey or a cow 

 died the carcase was left till its whitened bones got scattered 

 over the surface. Thus natural and artificial hollows got filled 

 with the accumulations of ages over ground where anything 

 could be got rid of and where many things were lost. Over 

 such an area as that we are dealing with, holes dug for any 

 purpose, or natural depressions into which all the odds and 

 ends which are scattered over waste land sooner or later 

 gravitate, would be filled with water at times, and the bottom 

 would be full of black sludge containing much organic matter. 



Such was the low alluvial land through which the river 

 meandered by Cambridge, and the objects found in the black 

 silt at the bottom of the holes and depressions in that old 

 waste land are of course relics of the time when the town did 

 not extend beyond the natural gravelly ridges that, without 

 being artificially raised, offered suitable sites for houses. Many 

 traces of the old conditions still remain. Loops representing 

 old river courses and ditches, some natural and some artificial, 

 traverse it, but they generally fall into an arrangement having 

 a definite relation to the direction of the underground waters. 

 If we could sweep the valley clean of all the recent river 

 deposits, we should find that old channels groove the surface 

 of the underlying clay, often trending down valley in approxi- 



