The progress which was making in the art of war had created an unprecedented demand for the ingredients of which gunpowder is compounded.

It was calculated that all Europe would hardly produce in a year saltpetre enough for the siege of one town fortified on the principles of Vauban.

[157] But for the supplies from India, it was said, the English government would be unable to equip a fleet without digging up the cellars of London in order to collect the nitrous particles from the walls.

[158] Before the Restoration scarcely one ship from the Thames had ever visited the Delta of the Ganges.

But, during the twenty-three years which followed the Restoration, the value of the annual imports from that rich and populous district increased from eight thousand pounds to three hundred thousand.
The gains of the body which had the exclusive possession of this fast growing trade were almost incredible.