174 Reviews—Hull’s New Red Sandstone, &c. 
It would be altogether impossible in a brief notice to give any 
abstract of what is in itself a:most careful abstract of everything 
important known of some 2,000 places, 1,500 mountain-peaks, and 
250 passes. The completeness is indeed something marvellous; and 
though, of course, there is no such thing as a perfect work, and some 
accounts and statements may have to be modified by personal ex- 
perience, we have seen nothing, in a rapid survey of the work, that 
calls for complaint. We recommend it without hesitation as the best 
companion to the geological traveller in the Central Alps, merely 
suggesting that in future the colouring of the geological map should 
be assisted by figures or letters of reference, since in maps printed in 
colours it is almost impossible to compare by the eye the shades of 
colour used in colour-printing ; and in the repeated printing neces- 
DD? 
sary the blocks do not always exactly fall into their proper places. 
On THE New Rep SANDSTONE AND PERMIAN FORMATIONS AS 
Sources OF WATER-SUPPLY FOR Towns. By Epwarp Hutt, 
B.A., F.G.S., of the Geological Survey of Great Britain. 8vo. 
1864, pp. 20. (From the Mem. Lit. Phil. Soc. Manchester, 3rd 
sec. vol. ii.) 
HE red sandstones and clays of Lancashire, Cheshire, Stafford- 
shire, Warwickshire, Worcestershire, and the south-west of 
England have of late years received much attention from the Geo- 
logical Surveyors, on account of their covering the coal-measures ; 
and in some districts the more perfect knowledge obtained as to the 
exact relations of these beds, which, often shifted by faults, and vary- 
ing in thickness over the coal, still appear to an unpractised eye as 
one uniform mass of ‘red ground,’ has benefited coal-owners very 
considerably. Not only, however, are these red rocks important as 
regards their relation to the coal-beds, but also with respect to the 
ereat water-holding properties of some of their beds. In early geo- 
logical days these red sandstones and clays were all comprehended 
under the name ‘New Red Sandstone,’ and divided into ‘Upper’ 
and ‘Lower;’ the latter, recognized by Phillips as having older fossils 
in it than those of the higher division, was divided off by Murchison 
and grouped, as Permian, in the palaozoic system, the other remain- 
ing as the New Red Sandstone formation or Trias. Now these 
Permian red clays and sandstones are not nearly so porous and 
capable of holding water as the ‘Triassic beds above, which latter 
readily take in rain- and river-water, filter it, and freely yield 
it in wells, sometimes to the amount of 13 millions of gallons a day 
from one well. The bleach-works, factories, and breweries of Man- 
chester and Salford (Mr. Hull says) pump six millions of gallons every 
twenty-four hours from the New Red Sandstone. Lancashire, how- 
ever, has a thicker set of ‘New Red’ beds than some other districts; 
in fact, they thin out as we go to the south-east; being about 1,200 
feet thick in the north-west, they are about 600 feet in Derbyshire 
and Staffordshire, and only 250 feet at the utmost in Leicestershire 
and Warwickshire; hence an enormous difference as to what we may 
