To test this he increased his magnifying power from 227 to 460 and
932, finding that, unlike the fixed stars near it, its definition was
impaired and its size increased. This convinced him that the object
was a comet, and he was not surprised to find on succeeding nights
that the position was changed, the motion being in the ecliptic. He
gave the observations of five weeks to the Royal Society without a
suspicion that the object was a new planet.

For a long time people could not compute a satisfactory orbit for the
supposed comet, because it seemed to be near the perihelion, and no
comet had ever been observed with a perihelion distance from the sun
greater than four times the earth's distance. Lexell was the first to
suspect that this was a new planet eighteen times as far from the sun
as the earth is. In January, 1783, Laplace published the elliptic
elements. The discoverer of a planet has a right to name it, so
Herschel called it Georgium Sidus, after the king. But Lalande urged
the adoption of the name Herschel. Bode suggested Uranus, and this
was adopted. The new planet was found to rank in size next to Jupiter
and Saturn, being 4.3 times the diameter of the earth.

In 1787 Herschel discovered two satellites, both revolving in nearly
the same plane, inclined 80 degrees to the ecliptic, and the motion of both
was retrograde.

In 1772, before Herschel's discovery, Bode[1] had discovered a curious
arbitrary law of planetary distances. Opposite each planet's name
write the figure 4; and, in succession, add the numbers 0, 3, 6, 12,
24, 48, 96, etc., to the 4, always doubling the last numbers. You
then get the planetary distances.