him. The results he arrived at were very near the reality.
Time of rotation of Jupiter on his axis[1]—
Herschel.
h. m. s.
9 55 49
Time of revolution in its orbit of —
| d. | h. | m. | d. | h. | m. | s. | |||||
| First Satellite | . | . | . | 1 | 18 | 26⋅6 | 1 | 18 | 27 | 34 | |
| Second satellite | . | . | . | 3 | 18 | 17⋅9 | 3 | 13 | 13 | 42 | |
| Third satellite | . | . | . | 7 | 3 | 59⋅6 | 7 | 3 | 42 | 33 | |
| Fourth satellite | . | . | . | 16 | 18 | 5⋅1 | 16 | 16 | 32 | 11 |
If the white spots on the belts were connected with drifting masses in Jupiter's atmosphere, they would drift as well as rotate. Herschel was aware of this, and, since his day, the amount of drift has been estimated at 270 miles an hour in the same direction as the rotation. In other words, they would take 42 days to go round the planet from this cause alone. Herschel was also persuaded that the four satellites revolve on their axes in the same period as they revolve round Jupiter, resembling in this respect our moon. Laplace was disposed to accept this conclusion.[2]
For more than a century and a half the planet Saturn had been the object and, it may be said, the despair of every astronomer's curiosity, mainly in consequence of the ring which the telescope had shown it to possess, and the singular shapes the ring was found to assume. Five moons were also discovered to be circling round the planet, and
