ON THE CIRCULATION OF UNDERGROUND WATERS. 401 



fore, retained in the stone, -whilst the water of solution niters out. Bat if 

 excess o£ pure water be allowed to run through the stone, the salts are 

 again taken in solution and carried away by the water. I simply offer 

 this as an hypothesis which may explain the results obtained in the ex- 

 periments. 



Report on the Jurassic Bocks. 



The geology of the oolitic districts has determined, as pointed out many 

 years ago by your chairman, " the sites of most of the villages. Thus 

 along the valley of the Evenlode villages are planted wherever there are 

 copious springs combined with a dry situation, circumstances generally to 

 be found in the small lateral valleys which are excavated in the oolite 

 and lias, and in these most of the villages are grouped. In other parts of 

 the district similar advantages have determined the sites of Bnstone, 

 Kiddington, Glympton, Wotton, Woodstock, Bladon, Steeple Barton, &c. 

 Some of these villages are perhaps as old as the Norman Conquest, and 

 have not altered much in size through several centuries." * 



At Trowbridge, a well was sunk to a depth of 160 ft., and an 18 in. 

 bore-hole a further 40 ft. ; a salt water spring was met with in the shaft, 

 but the water is still brackish, yielding no less than 6 lbs. of common salt 

 from 1,000 gallons of water, 3 oz. being the usual average, the hardness 

 being 571 parts per 100,000. 



This quantity of salt is of course exceptional ; there are no records 

 of a good and plentiful supply being obtained from the Lias. In those 

 which yield a large quantity, the water is invariably derived from over- 

 lying porous gravel. 



At the base of the Inferior Oolites powerful springs are thrown out, 

 and flow in streams and rivulets. over the Lias plain at their base. The 

 commissioner gives several examples of clay-land parishes of this 

 character in the valley of the Severn, which at present do not receive 

 their water supply until it has been hopelessly contaminated, with one 

 marked exception, that of Coaley, near Frocester. 



The common lands of this parish were enclosed under the superin- 

 tendence of a Deputy Commissioner of the Enclosure Office. The frontages 

 to the highways were fenced in, and the footpaths to the brooks closed ; 

 the several landowners who benefited by the enclosure in return laid a 

 two inch iron pipe from the spring through every hamlet in the parish, 

 and built a small reservoir at the spring head. 



That landowners should be able to charge their property as a land 

 improvement with the cost of such proceedings as may be necessary for 

 the provision of pure water to villages and hamlets, is a matter of 

 great importance, recommended as it is by Her Majesty's Enclosure 

 Commission, and supported by the Rivers Pollution Commission. 



The well at Witney is at Messrs. Clinch and Co's. Brewery, and is 

 65 ft. deep. The water, which through the depth of the well has been 

 tolerably filtered, is derived from the upper part of the Great Oolites. 

 None of the wells of this district, however, supply water as pure as that 

 flowing past the town in the Windrush. In this district a good supply 

 of water might be obtained by carefully constructed wells of sufficient 

 depth. 



* Professor Hull, F.R.S., Mem. Geol. Surv. Exp., Sheet 45 S.W. 

 1878. D D 



