Science: Planet P?

Far out on the sea of space sluggish Uranus, wallowing along on the track that takes it 84 years to circumnavigate the sun, rocked in its sidereal course. Uranus was too distant from its sister planet Neptune to have been affected at the time by Neptune's gravitational influence. This circumstance suggested that, unseen by human eye but suspected by a few human brains, some great unknown heavenly body was making its attraction felt. One of the human brains belonged to the late Percival Lowell, another to William...