The Panama canal project's most serious problem is tropical disease, particularly malaria and yellow fever.

Since it is not known at the time how these diseases are contracted, any precautions against them are doomed to failure.

For example, the legs of the hospital beds are placed in tins of water to keep insects from crawling up; but these pans of stagnant water make ideal breeding places for mosquitoes, the carriers of these two diseases, and so worsen the problem.