56 PROCEEDINGS OF THE COTTESWOLD CLUB 



Probably the highest effective drainage or contour hne 

 giving a reHable supply is about 400 feet, although prolific 

 springs issue at a much higher elevation. The Syreford 

 Spring on the Coin issues at 665 feet above the sea, and 

 often yields 4,000,000 gallons per day. 



The Churn at the Seven Springs, half-mile E. of the 

 watershed, is 750 feet, and Sevenhampton 600 feet. It is 

 from this long and extended easterly slope of the Cottes- 

 wolds that the powerful springs of the lower Jurassic rocks 

 rise, and constitute the head waters of the Thames. 



The larger springs such as those of Bibury, Ablington, 

 Boxwell, the Ampneys, Foss Bridge, and Syreford, &.C., 

 quite characterise their respective areas, distinguishing it 

 from those localities where the waters rapidly pass off and 

 down surface channels, broad flats, or plains, as those 

 composed of the Lias, Oxford, and Kimmeridge Clays, 

 and the Gault. 



The highest issue of these springs and rivers is that of 

 the Coin at Charlton Abbots, south of the Winchcombe 

 Valley, the Windrush at Taddington, two miles north of 

 Guiting Power, and the Evenlode at Moreton-in-lhe-Marsh, 

 and each of these Rivers rises close to, and nearly breaches 

 the line of the watershed — where the tributaries to the 

 Thames and Severn nearly meet, the Coin nearly uniting 

 with the Isborne, a little south of Winchcombe, the 

 Churn almost joining the Chelt at Dowdeswell, the Seven 

 Springs or Wells east of Leckhampton, and the Cubberley 

 branch at Ullen Farm. The steepness of the escarpment 

 on the western or Severn side of the line of the 

 watershed giving rise to no less than 20 streams which 

 traverse the Lower Lias Plain to the Severn. 



Rivers confluent to the Thames above Lechlade 



BASIN of the churn 



The Churn rises at the Seven Springs, within a quarter- 

 of-a-mile of, or south of the Thames and Severn divide, a 



