412 PROFESSOR HUGHES 



still earlier times. As a matter of fact we know that there are 

 several ditches along the general line of what is called the 

 King's Ditch. There were some natural channels carrying off 

 the water which ran out of the gravel, or collected on the more 

 clayey portions of the surface, and produced hollow places in 

 various parts of the town. As the ditches were taken through 

 the lowest ground that could be found along the line which 

 convenience in other respects pointed to, they are apt to coin- 

 cide with these natural depressions. It will be noticed that 

 the line of the ditches has the straight course which we should 

 expect in an artificial cut as we trace it from the King's Mill 

 across the gravel spur to the low ground by St Tibb's Row, where 

 it must have received the water from what we now call Down- 

 ing College Grounds. Beyond this it has a slightly sinuous 

 course, such as we might expect if it followed the ancient line 

 of drainage from the swampy area by Downing College to the 

 alluvium of Butt Green. It had to be used as a drain, to be 

 periodically flushed from the river above the town, and to have 

 an outfall below. The ancient leet that served the King's Mills 

 provided abundant fall for the purpose, but the depth of the 

 Ditch is such that even before the water was carried in that 

 high channel, the Ditch could have been flushed from Newn- 

 harn Pool. We must remember that although the system of 

 locks may not be ancient, some holding up of the water was 

 provided by the "hards" and fords. 



Even if building along the King's Ditch had not been 

 prohibited, it is obvious that this was not at first a desirable 

 site for residential purposes, and it is interesting to note how 

 few dwelling-houses there are along it even at the present day. 

 Streets have been carried along it and modern public buildings 

 mark its course the Pitt Press ; the corner of Pembroke 

 College; the Chemical Laboratory; the Old Physic Garden; 

 St Tibb's Row ; the Post Office ; Hobson Street ; Sidney Sussex 

 Grounds are on one part or another of it. 



I have already placed on record 1 the results of some recent 

 excavations along the line of these ditches, which, for our 



i C.A.S. Proc. and Comm. Vol. vm. (1895), pp. 32, 255; Vol. xi. (1904), 

 p. 173. 



