THE WATER SUPPLY OF ANCIENT DORCHESTER. 8 1 



original form as an open watercourse, and although I at once 

 saw its similarity to a water course, such as is seen in all hill 

 districts of Northern India, I failed at first to realise what it 

 really was owing to a curious delusion by which the course on 

 both sides of the valley appeared to run down towards the head 

 of the valley, but on making a rough test with an Abney's level 

 I found the course to be true, and not as it appeared to the eye. 



In all other cases which I have been able to test with the 

 Abney's level, I have found that the course on one side of a 

 valley corresponds as regards height with the course on the 

 other side, especially I may note from the spot where the 

 aqueduct touches the railway near Bradford Peverell to the 

 opposite side at Longwoods Coppice, which latter appears to 

 the unaided eye to be at a higher level than the former. 



A few small discrepancies can no doubt be found, but I have 

 seen none that cannot be accounted for by such lowering of 

 level as might occur from years of ploughing, or in some cases, 

 possibly, from earth falling from above. 



The aqueduct started from the foot of the masonry dam of a 

 sheep-washing pool at Foxlease withy-bed. 



Assuming that the ground would hold water without excessive 

 leakage, this spot would seem to be an ideal place to form a 

 large reservoir, as a dam of about 25 feet high and less than 

 100 yards long would have flooded about 30 acres. No such 

 dam could, however, have existed without some trace being left. 

 The existing dam is only five feet high, and the water held up 

 quite insignificant. 



The remains of an embankment, which indications show to 

 have been about ten feet high, is to be seen in Home Coppice 

 withy-bed, a few hundred yards higher up the stream. This 

 tank, however, was never large, and if it formed part of the 

 old waterworks could only have held a few days' supply. It is 

 possible that some other small tanks exist in the neighbourhood 

 of Compton Valence Rectory,* but I have not examined the 



* There are tanks, as Major Coates surmises, near the Rectory House. ED, 



