So it follows that the hammock, in company with an adequate tarpaulin and two trustworthy stakes, will survive the heaviest downpour as well as the most arid and uncompromising desert. But since it is man-made, with finite limitations, nature is not without means to defeat its purpose. The hammock cannot cope with the cold--real cold, that is, not the sudden chill of tropical night which a blanket resists, but the cold of the north or of high altitudes. This is the realm of the sleeping-bag, the joy of which is another story. More than once I have had to use a hammock at high levels, since there was nothing else at hand; and the numbness of the Arctic was mine. Every mesh seemed to invite a separate draught. The winds of heaven--all four--played unceasingly upon me, and I became in due time a swaying mummy of ice. It was my delusion that I was a dead Indian cached aloft upon my arboreal bier--which is not a normal state of mind for the sleeping explorer. Anything rather than this helpless surrender to the elements. Better the lowlands and that fantastic shroud, the mosquitaro. For even to wind one's self into this is an experience of note. It is ingenious, and called the mosquito shirt because of its general shape, which is as much like a shirt as anything else. A large round center covers the hammock, and two sleeves extend up the supporting strands and inclose the ends, being tied to the ring-ropes. If at sundown swarms of mosquitoes become unbearable, one retires into his netting funnel, and there disrobes. Clothes are rolled into a bundle and tied to the hammock, that one may close one's eyes reasonably confident that the supply will not be diminished by some small marauder. It is then that a miracle is enacted. For one is at last enabled, under these propitious circumstances, to achieve the impossible, to control and manipulate the void and the invisible, to obey that unforgotten advice of one's youth, "Oh, g'wan--crawl into a hole and pull the hole in after you!" At an early age, this unnatural advice held my mind, so that I devised innumerable means of verifying it; I was filled with a despair and longing whenever I met it anew. But it was an ambition appeased only in maturity. And this is the miracle of the tropics: climb up into the hamaca, and, at this altitude, draw in the hole of the mosquitaro funnel, making it fast with a single knot. It is done. One is at rest, and lying back, listens to the humming of all the mosquitoes in the world, to be lulled to sleep by the sad, minor singing of their myriad wings. But though I have slung my hammock in many lands, on all the continents, I have few memories of netting nights. Usually, both in tropics and in tempered climes, one may boldly lie with face uncovered to the night.