FLAMSTEED (John)

, an eminent English astronomer, being indeed the first astronomer royal, for whose use the royal observatory was built at Greenwich, thence called Flamsteed House. He was born at Denby in Derbyshire the 19th of August 1646. He was educated at the free school of Derby, where his father lived; and at 14 years of age was afflicted with a severe illness, which rendered his constitution tender ever after, and prevented him then from going to the university, for which he was intended. He nevertheless prosecuted his school education with the best effect; and then, in 1662, on quitting the grammar school, he pursued the natural bent of his genius, which led him to the study of astronomy, and closely perused Sacrobosco's book De Sphæra, which fell in his way, and which laid the groundwork of all that mathematical and astronomical knowledge, for which he became afterward so justly famous. He next procured other more modern books of the same kind, and among them Streete's Astronomia Carolinæ, then lately published, from which he learned to calculate eclipses and the planets' places. Some of these being shewn to a Mr. Halton, a considerable mathematician, he lent him Riccioli's Almagestum Novum, and Kepler's Tabulæ Rudolphinæ, which he profited much by. In 1669, having calculated some remarkable eclipses of the moon, he sent them to lord Brouncker, president of the Royal Society, which were greatly approved by that learned body, and procured him a letter of thanks from Mr. Oldenburg their secretary, and another from Mr. John Collins, with whom, and other learned men, Mr. Flamsteed for a long time afterwards kept up a correspondence by letters on literary subjects. In 1670, his father, observing he held correspondence with these ingenious gentlemen, advised him to take a journey to London, to make himself personally acquainted with them; an offer which he gladly embraced, and visited Mr. Oldenburg and Mr. Collins, who introduced him to Sir Jonas Moore, which proved the means of his greatest honour and preferment. He here got the knowledge and practice of astronomical instruments, as telescopes, micrometers, &c. On his return, he called at Cambridge, and visited Dr. Barrow, Mr. Isaac Newton, and other learned men there, and entered himself a student of Jesus College. In 1672 he extracted several observations from Mr. Gascoigne's and Mr. Crabtree's letters, which improved him greatly in dioptrics. In this year he made many celestial observations, which, with calculations of appulses of the moon and planets to fixed stars for the year following, he sent to Mr. Oldenburg, who published them in the Philos. Trans.

In 1673, Mr. Flamsteed wrote a small tract concerning the true diameters of all the planets, when at their greatest and least distances from the earth; which he lent to Mr. Newton in 1685, who made some use of | it in the 4th book of his Principia.—In 1674 he wrote an ephemeris, to shew the falsity of Astrology, and the ignorance of those who pretended to it: with calculations of the moon's rising and setting; also occultations and appulses of the moon and planets to the fixed stars. To which, at Sir Jonas Moore's request, he added a table of the moon's southings for that year; from which, and from Philips's theory of the tides, the high-waters being computed, he found the times come very near. In 1674 too, he drew up an account of the tides, for the use of the king. Sir Jonas also shewed the king, and the duke of York, some barometers and thermometers that Mr. Flamsteed had given him, with the necessary rules for judging of the weather; and otherwise took every opportunity of speaking favourably of Flamsteed to them, till at length he brought him a warrant to be the king's astronomer, with a salary of 100l. per annum, to be paid out of the office of Ordnance, because Sir Jonas was then Surveyor General of the Ordnance. This however did not abate our author's propensity for holy orders, and he was accordingly ordained at Ely by bishop Gunning.

On the 10th of August, 1675, the foundation of the Royal Observatory at Greenwich was laid; and during the building of it, Mr. Flamsteed's temporary observatory was in the queen's house, where he made his observations of the appulses of the moon and planets to the fixed stars, and wrote his Doctrine of the Sphere, which was afterward published by Sir Jonas, in his System of the Mathematics.

About the year 1684 he was presented to the living of Burslow in Surry, which he held as long as he lived. Mr. Flamsteed was equally respected by the great men his contemporaries, and by those who have succeeded since his death. Dr. Wotton, in his Reflections upon Ancient and Modern Learning, styles our author one of the most accurate Observers of the Planets and Stars, and says he calculated tables of the eclipses of the several satellites, which proved very useful to the astronomers. And Mr. Molyneux, in his Dioptrica Nova, gives him a high character; and, in the admonition to the reader prefixed to the work, observes, that the geometrical method of calculating a ray's progress is quite new, and never before published; and for the first hint of it, says he, I must acknowledge myself obliged to my worthy friend Mr. Flamsteed. He wrote several small tracts, and had many papers inserted in the Philosophical Transactions, viz, several in almost every volume, from the 4th to the 29th, too numerous to be mentioned in this place particularly.

But his great work, and that which contained the main operations of his life, was the Historia Cœlestis Britannica, published in 1725, in 3 large folio volumes. The first of which contains the observations of Mr. William Gascoigne, the first inventor of the method of measuring angles in a telescope by means of screws, and the first who applied telescopical sights to astronomical instruments, taken at Middleton, near Leeds in Yorkshire, between the years 1638 and 1643; extracted from his letters by Mr. Crabtree; with some of Mr. Crabtree's observations about the same time; and also those of Mr. Flamsteed himself, made at Derby between the years 1670 and 1675; besides a multitude of curious observations, and necessary tables to be used with them, made at the Royal Observatory, between the years 1675 and 1689.—The 2d volume contains his observations, made with a mural arch of near 7 feet radius, and 140 degrees on the limb, of the meridional zenith distances of the fixed stars, sun, moon, and planets, with their transits over the meridian; also observations of the diameters of the sun and moon, with their eclipses, and those of Jupiter's satellites, and variations of the compass, from 1689 to 1719: with tables shewing how to render the calculation of the places of the stars and planets easy and expeditious. To which are added, the moon's place at her oppositions, quadratures, &c; also the planets' places, derived from the observations.—The 3d volume contains a catalogue of the right-ascensions, polar-distances, longitudes, and magnitudes of near 3000 fixed stars, with the corresponding variations of the same. To this volume is prefixed a large preface, containing an account of all the astronomical observations made before his time, with a description of the instruments employed; as also of his own observations and instruments; with a new Latin version of Ptolomy's catalogue of 1026 fixed stars; and Ulegh-beig's places annexed on the Latin page, with the corrections: a small catalogue of the Arabs: Tycho Brahe's of about 780 fixed stars: the Landgrave of Hesse's of 386: Hevelius's of 1534: and a catalogue of some of the southern sixed stars not visible in our hemisphere, calculated from the observations made by Dr. Halley at St. Helena, adapted to the year 1726.

This work he prepared in a great measure for the press, with much care and accuracy: but through a natural weakness of constitution, and the declines of age, he died of a strangury before he had finished it, December the 19th, 1719, at 73 years of age; leaving the care of finishing and publishing his work to his friend Mr. Hodgsou.—A less perfect edition of the Historia Cælestis had before been published, without his consent, viz, in 1712, in one volume folio, containing his observations to the year 1705.

Thus then, as Dr. Keil observed, our author, with indefatigable pains, for more than 40 years watched the motions of the stars, and has given us innumerable observations of the sun, moon, and planets, which he made with very large instruments, accurately divided, and fitted with telescopic sights; whence we may rely much more on the observations he has made, than on former astronomers, who made their observations with the naked eye, and without the like assistance of telescopes.