John Flamsteed, the first English astronomer royal, born at Denby, near Derby, Aug. 19, 1646, died in Greenwich, Dec. 31, 1719. He was educated at the free school of Derby, and at a very early age manifested a strong inclination for astronomical studies. His health was so delicate that he was not sent to a university, but continued for several years to prosecute his astronomical researches at home with great success. In 1007 he demonstrated the true principles of the equation of time, in a tract which Dr. Wall is appended to his edition of the works of Horrocks. Flamsteed appears to have been the first astronomer who brought into common use the method of simultaneously observing the right ascension of the sun and stars, a mode by which the true place of any star is determinable by means of meridional altitudes and transits. In 1669 he communicated to the royal society his calculation of a solar eclipse that had been omitted in the ephemerides for the following year, together with several other astronomical observations. In 1070 he visited London, and was introduced to the savants of the metropolis.

He then entered Jesus college, Cambridge, and made the acquaintance of Wroe, Barrow, and Newton. In 1673 he composed his treatise on The True and Apparent Places of the Planets when at their Greatest and Least Distance from our Earth," a work of which Newton availed himself in his first edition of the Principia. In 1674 appeared his Ephemeris, which, with two barometers previously constructed by him, was presented by his friend Sir Jonas Moore to Charles II. and his brother the duke of York. In 1675 he was admitted to holy orders. Soon afterward, the king's attention having been called to the enormous errors of the astronomical tables then in use, he resolved to found an observatory, of which Flamsteed, through the mediation of Moore, was appointed the first director. The observatory was completed in 1670, but the astronomer had already entered on the discharge of his duties in Greenwich. The new observatory received the name of Flamsteed house. It was so inadequately supplied with astronomical apparatus that its principal, out of his salary of £100 a year, often not regularly paid, and his other limited resources, had to provide most of those instruments which were indispensable.

Here Flamsteed composed his great work, Historia Coe-lestis, the period of whose publication forms an epoch in the annals of modern astronomy. In 1684 he was presented to the small living of Burslow in Surrey, the only ecclesiastical preferment he ever obtained. Mr. Francis Baily's discovery of his papers and correspondence in 1832, published in 1835 by authority of the admiralty, has thrown much light on the history of his differences with Newton and Hal-ley. These documents give us Flam steed's version of those unseemly controversies, and it is not at all favorable to the reputation of those great masters of science; but there is another account in Sir David Brewster's Memoirs of the Life, etc, of Sir Isaac Newton," which makes their conduct toward him appear less culpable, though neither just nor generous, than Flamsteed would lead us to suppose. His Historia Coelestis Britannica (3 vols, fol, London, 1725) was not published complete till after his death, though a partial edition had been issued in 1712, against his protest, by Halley, under authority of a committee composed of Sir Isaac Newton, Sir Christopher Wren, and others.

The first volume contains his observations on the fixed stars, planets, comets, etc.; the second, the transits of stars and planets over the meridian, with their places; the third, an account of the methods and instruments used by Tycho Brahe and himself, and various catalogues of fixed stars, including his own catalogue of 2,934 stars. He also prepared an Atlas Coelestis, as an accompaniment to the above work, which was published in 1729, and again in 1753.