﻿10 



MR. W. HILL ON A BEEP 



[Feb. 1908, 



from the Gault-plain to 

 distance between the two 



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Green and Norton Green 

 worth. On this line ther 



over 450 feet above Ordnance-datum, the 

 headlands being rather more than 4| miles. 

 Referring to a contoured map, it will 

 be seen that from the headlands above 

 mentioned the 300 -foot contour-line (if 

 for the moment the sinuosities of lateral 

 valleys are disregarded) takes roughly 

 the form of a Y, reaching back in a 

 south-easterly direction into the Chalk- 

 escarpment, and its apex, somewhat 

 drawn out, nearly touches Langley, 

 4 miles south of Hitchin. Along the 

 w^estern side of the Y is a Chalk-ridge 

 indented by lateral valleys, rising to 

 400 and sometimes 500 feet above sea- 

 level, within half a mile of the 300-foot 

 contour. This ridge, which may be re- 

 garded as a buttress of the Chiltern 

 Hills, continues for 2 miles to the south- 

 ward, its slopes gradually passing into 

 those of the Lea Yalley. On the eastern 

 side the ground, though rising consider- 

 ably above 300 feet, does not, with the 

 exception of two knolls near the apex 

 of the Y, attain a height of 400 feet for 

 some 2 miles eastward. 



This Y-shaped valley is, in fact, only 

 part of a wider depression or gap in the 

 escarpment of the Chalk, a feature which 

 has been called the Hitchin and 

 Stevenage Gap. The width of this 

 gap, from the 400-foot contour-line near 

 Langley to the same contour-line east of 

 Stevenage, is about 2 miles ; and it is 

 occupied by the heads of two valleys, 

 the one drawing towards the north, the 

 other towards the south, but overlapping 

 one another by a space of a mile or 

 more. 



The western of these two valleys runs 

 from Newton Wood east of Langley by 

 Ippollitts and Hitchin into the Ouse ; 

 the eastern rising at Stevenage opens 

 southwards into that of the Kiver Beane, 

 which is a tributary of the Thames. The 

 actual watershed between the heads of 

 the two valleys is a sinuous line running 

 from the north of Stevenage by Symonds 

 to the ridge between Langley and Kneb- 

 e are two cols, or low divides between the 



