We are now at an elevation of about four thousand feet, and steadily nearing the equator, although the climate gives little sign of it. It is a popular mistake that the nearer one goes to the equator the temperature must necessarily increase. Were this so, Africa, which is the most tropical continent in the world, would also be the hottest; while the torrid zone, which occupies so large a portion of it, would be almost insupportable to the European. On the contrary, the nearer one goes to the equator in Africa it becomes the cooler. The reasons for this are twofold--the gradual elevation of the continent towards the interior, and the increased amount of aqueous vapor in the air. Central Africa is from three to five thousand feet above the level of the sea. Now for every three hundred feet of ascent the thermometer falls one degree. It is immensely cooler, therefore, in the interior than at the coast; and the equatorial zone all over the world possesses a climate in every way superior to that of the borders of the temperate region. At night, in Equatorial Africa, it is really cold, and one seldom lies down in his tent with less than a couple of blankets and a warm quilt. The heat of New York is often greater than that of Central Africa; for while in America a summer rarely passes without the thermometer reaching three figures, in the hottest month in Africa my thermometer never registered more than two on a single occasion--the highest actual point reached being 96°. Nowhere, indeed, in Africa have I experienced anything like the heat of a summer in Malta, or even of a stifling August in Southern Germany or Italy. On the other hand, the direct rays of the sun are necessarily more powerful in Africa; but so long as one keeps in the shade--and even a good umbrella suffices for this--there is nothing in the climate to disturb one's peace of mind or body. When one really feels the high temperature is when down with fever; or when fever, unknown to one, is coming on. Then, indeed, the heat becomes maddening and insupportable; nor has the victim words to express his feelings towards the glittering ball, whose daily march across the burnished and veilless zenith brings him untold agony.