222 THE GEOLOGICAL STEUCTURE OF THE 



northern and the southern escarpment. Small springs also 

 occasionally break out from the grej sandstones in, and 

 especially near the base of, the BuTnortieria clays ; several 

 of the drinking-pools for cattle being thus supplied. Such 

 is the source of the small spring just above the Elwell 

 spring, and of a spring at the old and dismantled Pick- 

 wick Farm, west of Maes Knoll ; while until recently there 

 was a small spring visible in these beds on the right-hand 

 side of the main road, south of the Butchers' Arms. 



Another occasional level for water is the shales with Tere- 

 hratula Eudesi — that is, at about the junction of the strata 

 of Bajocian age with those of Aalenian date — one of these 

 being just below Castle Farm, on the western escarpment. 



Some of the smaller springs dry up altogether in the 

 middle of the summer, or in very dry seasons ; but the 

 larger springs of Dundry Hill are remarkably persistent. 



4. Suitable Situation for Houses. 



That a deposit of clay should reach nearly to the upper 

 edge of the escarpment round much of Dundry Hill seems 

 to have been a revelation to the inhabitants themselves, 

 who do not necessarily connect a clay with the outburst of 

 springs. But the situation of this clay-bed necessarily de- 

 limits the area suitable for the erection of houses when a 

 dry subsoil is a consideration. Questions on this head have 

 been addressed to us by those interested in Dundry as a 

 health-resort, and we should be inclined to answer that the 

 most favourable situation for houses would be about the 

 edge of the line which we have drawn to mark the com- 

 mencement of deposition in Bathonian time. This should 

 give a dry subsoil, and also water at a reasonable depth. 

 Houses built about this level would not be quite so exposed 

 as those built at higher levels, whilst they would be drier 



