SILURIAN, DEVONIAN, AND CARBONIFEROUS ROCKS NEAR LONDON. 283 
the problem would be simplified, but it consists of a series of 
such parallel lines, and therefore whether or not the one which 
traverses the Boulonnais, and is probably prolonged under our 
Wealden area, is one of the many central ones, or the lateral 
one, immediately flanking the coal trough, is uncertain. Any 
attempt made to solve this great problem must be hailed with 
satisfaction ; but it is not by one experiment, however, but 
rather by several, that the line of the great trough of productive 
coal measures will be determined.” 
These petitions to practical science, aided by capital and 
necessity, have at last partly helped to solve the long-discussed 
problem, and we now have four if not five well-determined sites 
within the London area where the Palaeozoic rocks have been 
definitely touched. They are Tottenham Court Road, Ware, 
Turnford, Crossness, Kentish Town, and another distant but 
equally important trial at Burford, where the coal measures were 
satisfactorily proved.* 
Old British Terrestrial Surfaces or Areas . 
There seems to be good reason for believing that a once 
continuous north and south range of older Palaeozoic land 
extended from the Polar regions to the Mediterranean. The 
only portion remaining entire is the Scandinavian peninsula, 
ranging through about 15° of latitude; it is known “beneath 
newer and overlying deposits of Northern Germany, the Vosgean 
and Schwarzwald ranges, and expands into the elevated plateau 
of Central France.” 
Mr. Godwin- Austen believes it to be traceable to the islands 
of Corsica and Sardinia, north of the African coast. 
Westward of this another mass of old land occurred “ to the 
north-west of the British Islands, and probably in its range 
formed the western boundary of the great European basin.” 
The sources of these oldest sedimentary strata will ever remain 
a mystery ; such are now either concealed beneath the Atlantic, 
through depression, or entirely removed through denudation. 
“ The materials that supplied these oldest British strata have 
wholly disappeared,” for doubtless the stratigraphical arrange- 
ments of these early deposits was in subordination to masses re- 
moved, and “ the extent and dimensions of the Palaeozoic masses 
afford an indication of how vast a region has disappeared.” f 
* See section from north to south (Sussex to Bedfordshire), across the 
London Basin (Reigate to Biggleswade), showing the places of the five trials 
by vertical lines, PL VII., sec. 2. The section is copied from Professor Prest- 
wich’s work on the water-bearing strata of the country round London. — 
Pop. Sci. Review, vol. xi. t. 75. 
t Vide “ Quarterly Journ. Geol. Soc.” vol. xii. pp. 42 and 43. (Austen.) 
