The two discs were perfectly rounded and separately discernible until they touched.

Moreover, I was able to distinguish upon one of the darker bands the disc of the satellite itself, while upon a lighter band its round black shadow was at the same time perfectly defined.

This wonderfully clear presentation of one of the most interesting of astronomical phenomena so absorbed my attention that I watched the satellite and shadow during their whole course, though the former, passing after a time on to a light band, became comparatively indistinct.

The moment, however, that the outer edge passed off the disc of Jupiter, its outline became perfectly visible against the black background of sky.

What was still more novel was the occultation for some little time of a star, apparently of the tenth magnitude, not by the planet but by the satellite, almost immediately after it passed off the disc of the former.