Are not the real enemies to human life and happiness in the Torrid Zone, plants and animals rather than temperature and humidity? If this is admitted, no one who is imbued with the spirit of modern science, would seriously doubt that the improvement of conditions of living and of man himself in the warmer parts of the world is possible provided the solution of the problems is attempted in the right manner. As for the animal enemies the scientist will ask those who may give him information: What are the peculiar habits of each species which we desire to rid ourselves of? What is their food and what is the history of their reproduction? Has each of them any natural enemies either animal or bacterial or fungal? When he has secured such information as is available, he sets himself to study in the minutest detail, every character which may enable him to overcome his enemy whether it be a serpent, worm or insect, and ultimately, as the result of the accumulation of data which seems dry and uninteresting to anyone but the specialist, he is able to control the pest or to exterminate it. When the human mind of a certain type is freed from interference, and is given resources, and a specific problem to solve, the result is practically a certainty.

When we turn to plant enemies, we find the tropics filled with them. Conditions for vegetable growth are so favorable that human strength cannot cope with them. But nowadays we do not regard it as necessary to struggle by means of living flesh with the weeds which seek to choke our useful plants. We harness and direct the forces of nature. There are abundant sources of energy available to relieve mankind entirely of the necessity of laboring with his hands. The energy of mountain torrents, of most of the large and small rivers, of the tides, of the winds, and of sunlight, are as yet very little utilized because the stores of fossil plant tissues in the form of coal have made it cheaper to use it prodigally rather than seek to compete with this source of energy in other directions. But who is so faint-hearted as to think that it cannot be that energy will be made available to turn the soil as often and work it as thoroughly as is necessary in order to eradicate the dragon of vegetable growth which discourages the would-be farmer of the tropics? I can see no great difficulty in the use of numbers of large lenses, cheap and relatively imperfect, for concentrating the sun's rays to several times their existing dispersal, and thus creating temperatures sufficient to destroy all existing vegetation over the area so treated, and within a very short space of time, and very little human effort. With the destruction of plants in the axils of which water constantly exists, the mosquitoes which come from these receptacles would disappear.

Just suppose we were able to successfully cope with our animal and vegetable enemies in the tropics, and that the soil were made to yield the great return of useful produce of which it is capable. Suppose that the diseases which harass and destroy domestic animals and which undermine the health of man were eradicated. Suppose this were accomplished and mechanical energy were made available sufficient to perform all the necessary labor of agriculture, and of manufacturing processes. Would there then stand anything in the way of developing in the less hospitable parts of the warm regions of the world, a creditable civilized society? We should certainly not be despondent over the task until it has been tried.