Hence it appears that the numerical amount of our population, their varied occupations, and the fundamental sources of their industry and wealth, depend, in a great degree, upon the geological character of the strata on which they live. Their physical condition also, as indicated by the duration of life and health, depending on the more or less salubrious nature of their employments; and their moral condition, as far as it is connected with these employments, are directly affected by the geological causes in which their various occupations originate.
From this example of our own country, we learn that the same constituent materials of the earth are not uniformly continuous in all directions over large superficial areas. In one district, we trace the course of crystalline and granitic rocks; in another, we find mountains of slate; in a third, alternating strata of sandstone, shale, and limestone; in a fourth, beds of conglomerate rock; in a fifth, strata of marl and clay; in a sixth, gravel, loose sand, and silt. The subordinate mineral contents of these various formations are also different; in the more ancient, are veins of gold
affords similar examples of the dull uniformity that we observe in a journey along the line of bearing of the chalk, from near Bridport on the coast of Dorset, to Flamborough Head on the coast of Yorkshire.
In the same line of direction, or line of bearing of the strata across England, a journey might be made from Lyme Regis to Whitby, almost entirely upon the lias formation; and from Weymouth to the Humber, without once leaving the Oxford clay. Indeed almost any route, taking a north-east and south-west direction across England, will for the most part pass continuously along' the same formation; whilst a line from southeast to north-west, at right angles to the former, will no where continue on the same stratum beyond a few miles. Such a line will give the best information of the order of superposition, and various conditions of the very numerous strata, that traverse our island in a succession of narrow belts, the main direction of which is nearly north-east and south-west. This line has afforded to Mr. Conybeare the instructive section, from Newhaven near Brighton, to Whitehaven, published in his Geology of England and Wales; along which nearly seventy changes in the character of the strata take place.
