COMBS AND DILUVIAL VALLEYS ON THE COTSWOLD HILLS. 257 
that of the great escarpment of the Cotswold Hills, crosses nearly at 
right angles all the valleys that descend from them towards the 
south-east, into the main trunks of the Thames or Avon; and in 
no part of it are the features of diluvian action more strongly 
displayed than between North Leach and Stow in the Wold. It is 
obvious that such valleys cannot possibly be attributed to the action 
of springs or rivers that now flow through them, since they often 
take their origin many miles above even the highest springs: their 
magnitude and depth bespeak the agency of a mass of waters in¬ 
finitely more powerful than even the most violent water-spouts of 
modern times could produce: their form also differs entirely from 
the deep and precipitous ravines which are excavated by mountain 
torrents ; and if it should be contended that the bursting of a series 
of water-spouts would be competent to set in action such masses of 
water as might have been sufficient for this effect; unless we can 
suppose them to have fallen universally and contemporaneously, not 
only over the district under consideration, but over the whole earth, 
they will afford no solution of the phenomena of these and similar 
contemporaneous systems of valleys, which occur on strata that are 
similarly circumstanced in every part of the known world. 
The chalk downs of England, and the upper portions of the 
chalky and oolitic plains of France, are universally covered with a 
series of dry valleys exactly similar to those that occur on the back of 
the inclined planes of oolite in the Cotswold Hills; and the uniform 
texture and moderate degree of inclination which usually attend 
both these formations will explain the regularity of the diluvian 
valleys that have been excavated on their surface. 
