In writing of the possibilities of the white race in the equatorial zone it is understood that the problem relates to the lowlands. There are, of course, favoured highlands, such as those of Colombia, where the temperature is at the same time moderate and equable and the climate appears admirably adapted to white men.
A healthy city life in the tropics would be easily attainable in a new country settled wholly by white people and under a medical despotism.
The general, but non-specialist, opinion upon the Isthmus is not as sanguine as that of Colonel Gorgas upon the hygienic future of the white race in the tropics. The general opinion among Americans seems to be that, as far as they are concerned, they would, if engaged in the tropical parts of South or Central America, avail themselves of the improving means of transit to revisit frequently the United States, and would rely upon such vacations in higher latitudes for the retention of their native vigour.
CHAPTER VI
ON THE SHORTENING OF DISTANCES BY SEA, AND ON THE STEAMSHIPS AVAILABLE FOR CANAL TRANSIT
The Shortening of Distances by Sea.
AS the sole object of a ship canal is to shorten sea distances, the figures given in this section are of primary importance to a proper understanding of the subject. The figures here given are those for steamships following the actual or prospective routes. They are adopted from the figures supplied to the Canal Commission from the United States Hydrographic Bureau and are expressed in nautical miles. It is perhaps not wholly superfluous to warn the reader that the apparent relative distances as shown on charts of the world, especially those on the usual Mercator projection, are very different from the real relative distances. Moreover, it is impossible to see correctly the relative distances between places far apart on a globe, for the foreshortening of the rounded surface produces distortion. By applying a measuring tape to the globe the true relative distances can be readily ascertained. This is a salutary exercise and serves to correct the erroneous notions which tend to fix themselves in the minds of all of us owing to the appearance of the surface of the globe on the plane of the paper or on the plane of vision. Such a measurement of shortest distances would give a very fair notion of the actual reductions due to the Suez and Panama Canals, but there would still be considerable differences between these figures and the distance calculated from the actual courses pursued by steamships, which in what follows will be referred to simply as "the" distance between ports.