28 AN HISTORICAL DISQUISITION

SECT. the latter of these objects, (as I have already observ-I. ed,) that he examined the navigation of the Indus•with so mir b attention. With the same view, on his, return to Susa, he, in person, surveyed the courseof the Euphrates and I igris , and gave directionsto remove the cataracts or dams, with which theancient monarchs of Persia, induced by a peculiarprecept of their religion , which enjoined them toguard with the utmost care against defiling anyof the elements, had constructed near the mouthsof these rivers, in order to shut out their subjectsfrom any access to the ocean 41 . By opening thenavigation in this manner, he proposed, that thevaluable commodities of India should be conveyedfrom the Persian Gulf into the interior parts ofhis Asiatic dominions, while by the Arabian Gulfthey should be carried to Alexandria, and distri-buted to the rest of the world.

Grand and extensive as these schemes were,the precautions employed, and the arrangementsmade for carrying them into execution, were sovarious and so proper, that Alexander had goodreason to entertain sanguine hopes of their provingsuccessful. At the time when the mutinous spiritof his soldiers obliged him to relinquish his ope-rations in India, he was not thirty years of agecomplete. At this enterprising period of life, aprince, of a spirit so active, persevering, and inde-fatigable, must have soon found means to resume

41 Arrian, lib. vi. c. 7. Strab. lib. xvi. p. 1074. &c.See NOTE IX.