2 POPULAR SCIENCE MONTHLY. '
varies from one minute and twelve seconds near New Orleans to one minute and forty-four seconds near Norfolk, on the central line. These durations diminish from the maximum at the middle of the track to zero at the northern and southern limits of it, so that an ob- server must be stationed as near the central line as possible in order to see much of the eclipse. The population of several of the above- mentioned cities is at present as follows: New Orleans, 242,000; Mobile, 31,000; Montgomery, 22,000; Columbus, 20,000; Atlanta, 66,000; Raleigh, 13,000; and Norfolk, 35,000. It is evident that with very little exertion more than 500,000 people can see this eclipse. It is most fortunate that the track passes near so many cities, because, with their facilities for the accommodation of vis- itors, many will be induced to undertake excursions with the pur- pose of taking in this rare sight, and a little enterprise on the part of railroads and transportation companies might easily increase the numbers. If people will go to a parade, yacht race, or an expo- sition, and consider themselves paid for their expenses, then surely they will find in this great spectacle of Nature not only an object of wonder and beauty, but also one of peculiar instruction in many important branches of science. All educators who can induce their pupils to make such an expedition will implant a love of astronomy in many impressionable minds which will become a source of pleas- ure to them for the rest of their lives.
Out of about seventy eclipses of the sun which have occurred somewhere in the world within the nineteenth century, there have been only eight total eclipses of more or less duration visible on the North American continent. The others happened in places often remote from civilization, and sometimes in entirely inacces- sible localities, as over the ocean areas. The difficulty of trans- porting heavy baggage to the remote parts of Asia, Africa, or South America is such as to preclude all but a few scientists from any effort to observe eclipses. The writer was much impressed with the formidable nature of undertaking to establish eclipse sta- tions in places which are distant from centers of population by his own experience on the West African Eclipse Expedition, sent out by the United States Government, for the eclipse of December 22, 1889, to Cape Ledo, on the west coast of Angola, about seventy miles south of St. Paul de Loanda. Nearly eight months were consumed in the course of the preparations at home and in the voyage out and back. The expedition, it should be said, however, went to Cape Town, South Africa, and halted also at St. Helena, Ascension Island, and Barbados for magnetic and gravity obser- vations, so that all this time should not be charged to the eclipse proper. We sailed in the old frigate Pensacola, the companion