Feb. 10: 1 h. 30 m.—A pair of satellites, very small, and both on the east of the planet, were visible, in the following position (Fig. 41). The further satellite was distant from Jupiter 10´, the nearer 0´ 20´´, and they were in the same straight line; but at the fourth hour the satellite nearest to Jupiter no longer appeared, and the other seemed so diminished that it could scarcely be kept in sight, although the atmosphere was quite clear, and the satellite was further from Jupiter than before, since its distance was now 12´. Feb. 11: 1 h.—There were two satellites on the east, and one on the west (Fig. 42). The western satellite was at a distance of 4´ from Jupiter. The satellite on the east, nearest to the planet, was likewise 4´ from Jupiter; but the satellite further to the east was at a distance from this one of 8´; they were fairly clear to view, and in the same straight line; but at the third hour the fourth satellite was visible near to Jupiter on the east, less in magnitude than the rest, separated from Jupiter by a distance of 0´ 30´´, and slightly to the north out of the straight line drawn through the rest (Fig. 43). They were all very bright and extremely distinct, but at 5 h. 30 m. the satellite on the east nearest to Jupiter had moved further away from the planet, and was occupying a position midway between the planet and the neighbouring satellite further to the east. They were all in the same straight line exactly, and of the same magnitude, as may be seen in the accompanying diagram (Fig. 44). Feb. 12: 0 h. 40 m.—A pair of satellites on the east, a pair likewise on the west, were near the planet (Fig. 45). The satellite on the east furthest removed from Jupiter was at a distance of 10´, and the further of the satellites on the west was 8´ off. They were both fairly distinct. The other two were very near to Jupiter, and very small, especially the satellite to the east, which was at a distance of 0´ 40´´ from Jupiter. The distance of the western satellite was 1´. But at the fourth hour the satellite which was nearest to Jupiter on the east was visible no longer. Feb. 13: 0 h. 30 m.—Two satellites were visible in the east, two also in the west (Fig. 46). The satellite on the east near Jupiter was fairly distinct; its distance from the planet was 2´. The satellite further to the east was less noticeable; it was distant 4´ from the other. Of the satellites on the west, the one furthest from Jupiter, which was very distinct, was parted from the planet 4´. Between this satellite and Jupiter intervened a small satellite close to the most westerly satellite, being not more than 0´ 3´´ off. They were all in the same straight line, corresponding exactly to the direction of the ecliptic.