Thus from the water--literally--I reached the territory of the east coast tribes and southern tribes of the island. What I learned of their manners and customs I shall write in its proper place.[40] But I want here to record my appreciation of the courage and also the cool, matter-of-course calmness of the Ami chief, whose presence of mind undoubtedly saved my life on this occasion, as my own awkward attempts at swimming would never have carried me through those waves. So rough were they that it was with difficulty I was able even to cling to the back of the chief. Had the water been colder I should probably not have been able to do so. But at that latitude--a little south of the Tropic of Cancer--sea-water, even in January, is never numbingly cold. Rather different was my experience on the occasion of another winter vacation during my stay in Formosa. That vacation I spent in the mountains, as I wished to visit certain sub-tribes of the Taiyal that I had not seen. Because of the altitude, it was--certainly by contrast with the plain below--bitterly cold. There had been flurries of snow during the day. I had with me, as guide and luggage-bearer, a Chinese-Formosan coolie, an elderly man, who was supposed to be well acquainted with the mountain trails--to have tramped them since his youth, when as a charcoal-burner he had ventured into the mountains for fuel. Thus had he recommended himself to me. However, perhaps because of the snowy greyness of the day, he managed to lose his way. I had--fortunately--a pocket compass with me. In such Chinese-Formosan dialect as I had acquired--inadequate enough--I attempted to explain the meaning of the pointing needle. My guide declared he understood, and said that in order to regain the trail we must go in a certain direction. Going in this way, it was necessary to cross a stream, which usually was little more than a shallow brook. Because of the winter rains,[41] however, this had become so swollen that it was almost a torrent, and when we reached it we found, instead of a shallow stream that could easily have been waded, or crossed over on stepping-stones, a great body of water, dashing over fallen trees, and swirling around boulders which normally lay far beyond its banks.