Eclipses are still, as they have ever been, very important phenomena for the astronomical observer; partly on account of the crucial test which they afford for the examination of the truth of the theory and calculation of the motions, real and apparent, of the Sun and Moon, partly also for the special opportunities which they furnish of inquiring into some of the arcana of the physical characteristics of those bodies.

For the former purpose, a partial eclipse will serve almost as well as a total one; while the continued improvement of the observation of meridian passages is now raising these daily measures fully to the importance of the other occasional phenomena, as a test of the theory. But for inquiry into the physics of the Sun, a perfectly total eclipse of that body is necessary; revelations may then happily be procured, which no observation of any other phenomena at any other time, can hope to afford any suspicion of.