A slight mistake in exceedingly small measurements may cause serious errors in the calculated times of revolution.
It should not be forgotten that the King's equerry whom Miss Burney, in her gossip from Windsor Castle, calls Colonel Welbred, foretold that time would do justice to Herschel, and turn the laugh at him against the laughers. And time has done him justice with a most ungrudging hand. Eight years after his death, it was asked by a leader of modern enlightenment, "What length of time must the cosmologist suppose necessary to reduce a gaseous nebula into a permanent planetary system? Experience shows pretty clearly the inutility of such speculations." . . . Of the moon's "origin and internal structure we neither know, nor ever can know, anything whatever. And if such is the result of our researches respecting a body placed almost in our immediate vicinity, there is little reason to hope that we shall be more successful with regard to those whose distances are so great that the most powerful telescopes are required to render them even visible."[1] This was written in 1830; it was ill-natured disparagement of a noble attempt to solve the mysteries of the universe, and to give practical proof of man's kinship with God; it was wholly unscientific. In 1842 another greatly-extolled writer declared that in that region of inquiry there did not exist any discovered, or even, without doubt discoverable phenomenon.[2] The equerries of Windsor might be laughed at and forgiven; the scepticism that prompted men of science to bid their brethren fold their hands and do nothing, was an unpardonable sin against truth. It
