HALLEY'S QUADRANT.
(From an old print.)
His astronomical work apart from the Observatory was of the first importance. He practically inaugurated the study of terrestrial magnetism, and his map giving the results of his observations during his voyage in the Paramour introduced a new and most useful style of recording observations. He joined together by smooth curves places of equal variation, the result being that the chart shows at a glance, not merely the general course of the variation over the earth's surface, but its value at any spot within the limits of the chart.
Another work which has justly made his name immortal was the prediction of the return of the comet which is called by his name, to which reference will be made later. Another great scheme, and one destined to bear much fruit, was the working out of a plan to determine the distance of the sun by observations of the transit of Venus.
Of attractive appearance, pleasing manners, and ready wit, loyal, generous, and free from self-seeking, he probably was one of the most personally engaging men who ever held the office.
The salary of the Astronomer Royal remained under Halley at the same inadequate rate which it had done under Flamsteed—£100, without provision for an assistant. But in 1729 Queen Caroline, learning that Halley had actually had a captain's commission in the Royal Navy, secured for him a post-captain's pay.
JAMES BRADLEY.
(From the painting by Hudson.)