Page:A Comprehensive History of India Vol 1.djvu/41

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INTRODUCTION. HISTORY OF INDIA
7

Basaltic trap. upper part of the Western Ghauts, and the adjoining ramifications of the Vindhya range. Here basaltic trap, in its various forms of prismatic, columnar, globular, tabular, porphyritic, and amygdaloid, spreads out as an overlying rock, to an extent unequalled, it is believed, in any other part of the world. A very large portion of the table-land of the Deccan is entirely covered by it. Not unfrequently both the trap and the granite pierce the surface abruptly, and rise in precipitous isolated masses of considerable height. Many of these standing out prominently from the surrounding plains and crowned with hill-forts, form the most remarkable features in the landscape.

Secondary and tertiary strata The more regular strata of the secondary and tertiary periods are largely developed on the lower sides of the Himalaya, and occupy considerable tracts in various other localities. Many of the sandstones and shales of the former period belong to the coal measures; and coal has not only been found at several places, but is actually worked, particularly in the valley of the Damooda in the district of Burdwan, where a coal field with a main seam 9 feet in thickness has been carefully explored, and found to extend over a large area. The proximity of this field to the capital, from which it is about 150 miles north-west, and the facility of carriage by water, and now also by rail, have brought it early into notice; but there cannot be a doubt that there are many other fields equally promising, and, at all events, productive enough to supply the demand about to be created by the establishment of an extensive system of railways. The tertiary formation appears to obtain its greatest breadth in the north-west, towards Seinde and the Punjab, from which, and the mountains of adjacent districts, fossil remains of singular forms and gigantic dimensions have recently been brought to enrich our museums.

Minerals It must be admitted that, as a mineral country, India has not yet proved its title to a prominent place. Though in ancient times gold was so abundant, that the Indian was the only one of the Persian satrapies which paid its tribute in that precious metal, it has now only a few washings, which are by no means productive. Its diamond mines also, once so famous, have long been exhausted. Besides the coal already mentioned, the only mineral products of much economical value are copper, of which several mines are worked; iron, from which steel of the finest quality is manufactured; nitre, so abundant as to form an important article of export; and salt, said to exist in beds which are inexhaustible.

Climate. Of the 28° of north latitude over which India extends, 15½° are within the tropical, and 12½° within the temperate zone. Taking this fact only into view, it might be easy to give the theory of its climate; but it would merely be to show how widely in this case, as in many others, theory differs from reality. The position of a country relatively to the equator, simply shows how long and how intensely the sun during its annual revolution will shine upon it, but gives no information as to the modifying causes by which, often far more than by degrees of latitude, its climate is determined. In regard to India