The first of a series of rules he established and enforced was: "To endeavor, by every fair means, to cultivate a friendship with the natives, and to treat them with all imaginable humanity." He was largely dependent upon the resources of the islands he visited for the sustenance of his people; but nothing, except in dire necessity, was ever taken from the natives by force. Persons were appointed to trade with them, and no others were allowed to barter or exchange goods with them, and a proper equivalent was always to be given. His own men were put under the strictest discipline in order to control their relations with the natives who constantly surrounded them. Generally the most friendly spirit prevailed on both sides. The inhabitants of all the islands seemed to have a natural inclination to steal, and most of the trouble with them grew out of this tendency. Cook judiciously repressed theft from the beginning, and almost invariably compelled the restoration of the property. On the other hand, his own men were sometimes tempted to desert; but he hunted them down, secured one or more chiefs as hostages, or by some common-sense method recovered the absentees. At some of the islands Cook was extremely popular with the inhabitants, and was regarded as a superior being, even a demigod, in many of them. When he was compelled to resort to extreme severity, he did not begin with cannon, loaded with grape, but trusted first to the loud report, terrific to the savages, fired over their heads, or had the muskets loaded with small shot which would hurt, but did not kill. No slaughter that could possibly be avoided was permitted. If he erred at all it was on the side of humanity, and if he had been less forbearing he might have added more years to his length of days. The astronomical work at Otaheite was successfully accomplished, and in July Captain Cook departed, taking with him Tupia, a native of some distinction, who proved to be valuable to him as an interpreter, and for his general knowledge. During this voyage he visited many of the islands of the Pacific, including New Zealand, where he encountered no little hostility, so that it was often difficult and sometimes impossible to establish friendly relations with the natives. But he obtained what he needed, and proceeded on his voyage. He gave names to islands, bays, straits, and harbors, some of which seem strange at the present day, but most of them were suggested by the circumstances of the visit. Of many of the islands he took possession in the name of his sovereign, leaving memorials of his landing.