many a vessel, whose crew gazed with astonishment at the unwonted spectacle. Here the conditions of good observation, so far as celestial requirements are concerned, would have been of the most desirable nature. The sun would have been overhead and the fervid glories of the equatorial noon would have been suspended for the space of nearly five minutes. Splendid indeed must have been the view of the corona obtained by those who were fortunate enough to be in the right position on the ocean, with a clear sky overhead. But from the astronomer's point of view the observations which can be made on board ship are of but little importance; the deck does not offer the stable foundations that are required for elaborate photographic or spectroscopic apparatus.
For the space of an hour, therefore, while this ocean passage was in progress, there were but few opportunities, if indeed any, for valuable contributions of facts to illustrate our theories of the corona. The speed with which the shadow traversed the sea happened to be not so great as that with which it crossed South America. The consequence was, that rather more than an hour was occupied by its journey from the American to the African coast. This ocean distance is only about half as long as the track pursued across the South American continent; but owing to the curvature of the earth the incidence of the shadow makes it travel more quickly at the beginning or the end than in the intermediate stages, so that in consequence of the decline in speed about the middle of the eclipse, the time required by the ocean journey was about the same as that needed for the previous land journey.
A few minutes after half-past three, Greenwich time,
