Besides the miscellaneous poets, the dramatic ones numbered Congreve, Vanbrugh, Farquhar, Colley Cibber, Nicholas Rowe--already mentioned--Savage, Lansdowne, Ambrose Philips, and others. In many of the plays of these authors there is great talent, wit, and humour, but mingled with equal grossness. Congreve's dramas are principally "The Old Bachelor," "The Incognita," "The Double Dealer," "The Way of the World," comedies, and "The Mourning Bride," a tragedy. Vanbrugh, the celebrated architect, produced "The Relapse," "The Provoked Wife," "The Confederacy," "The Journey to London," and several other comedies. Farquhar's principal plays are "The Beaux's Stratagem," "Love and a Bottle," and "The Constant Couple." Savage was the author of the tragedy of "Sir Thomas Overbury;" Nicholas Rowe, of five or six tragedies and one comedy, the most popular of which are "The Fair Penitent" and "Jane Shore." Rowe also translated Lucan's "Pharsalia." As for Colley Cibber, he was a mere playwright, and turned out above two dozen comedies, tragedies, and other dramatic pieces. Lord Lansdowne was the author of "The She-gallants," a comedy, and "Heroic Love," a tragedy of some merit; and John Hughes wrote "The Siege of Damascus," a tragedy, which long remained on the stage. James Bradley (_b._ 1692), who succeeded Halley as the third Astronomer Royal, held that post till 1762, when he died. He had in 1728 distinguished himself by his discovery of an unanswerable proof of the motion of the earth by his observations on the apparent alteration in the place of a fixed star. His second great discovery was that of the mutation of the earth's axis, showing that the pole of the equator moves round the pole of the elliptic, not in a straight but in a waving line. Bradley gave important assistance to the Ministry in their alteration of the calendar in 1751, and the vast mass of his observations was published after his death, by the University of Oxford, in two volumes, in 1798. [Illustration: COSTUMES OF THE PERIOD OF GEORGE II.] Halley's quadrant was constructed and made known by him to the Philosophical Society, in 1731, though Thomas Godfrey, a glazier, of Philadelphia, is said to have made a similar instrument a year before. As early, however, as 1727 Newton had described such an instrument to Halley, that is, a very little time before his death. This invaluable instrument has since been improved, first into a sextant, and ultimately into a complete circle. In 1758 appeared John Dollond's corrections of Newton's views of the dispersion of refracted light, and in the following year his achromatic telescope, based on his accurate discoveries.