John Hevel, or Hevelius, a member of a noble family of Danzic, built an observatory in 1641 in his own house and furnished it with an azimuthal quadrant of 5f t. radius and a sextant of 6ft., with which he measured the meridian altitudes of stars, sun, moon and planets, and their distances from one another in the manner of Tycho—that is, with plain sights, believing this to be superior to the newly adopted telescopic method.
Paris, Greenwich and Others.—Hevelius died early in 1687 and his work was not carried on, but by that date there had come into existence the two national observatories at Paris and Green wich. The former was built in the years 1667-71, according to the plans of Claude Perrault, as an architectural monument. How ever, under Cassinis and others, it has done much for astronomy. The Royal Observatory, Greenwich, was founded in 1675 for the definite purpose of the improvement of navigation. Architectural pride again entered into the design, for Sir Christopher Wren wrote of it to Bishop Fell of Christ Church, Oxford, as built "a little for pomp" referring to the main building. The essential instruments were housed apart from this, and at the present time, Wren's beautiful creation is merely a small item in its extensive domain.
Few establishments of the kind were erected during the next half century. Newton placed his telescope on the roof of the tower over the gateway of Trinity college, Cambridge, and his contemporary, and perhaps rival, Leibnitz, is said to have orig inated at Berlin university in 1705 an observatory of similar mod est dimensions, that became of importance more than ioo years later. The year I 751 is assigned as the date of foundation of the observatory at GOttingen which was supplied by George II. of England with a mural quadrant of 6ft. radius made by the Eng lishman, Bird, and in charge of Tobias Mayer. It was re-estab lished in another situation in 1816. Induced mainly by the occur rence of the transit of Venus in 1769, George III. built and furnished the King's Observatory at Kew. The improvement in reflecting telescopes by Short and the invention of the achro matic object glass in the latter part of the 18th century marked the beginning of many observatories that have since become famous. The Radcliffe observatory at Oxford was erected 1771-74 from funds bequeathed by Dr. Radcliffe, a Court phy sician "for charitable purposes," the words being interpreted somewhat widely. Provost Andrews bequeathed a substantial sum for building and endowing an astronomical observatory for the University of Dublin, which was built at Dunsink in 1783, but not furnished with instruments until many years later. At
the charge of Primate Robinson an observatory was established and endowed at Armagh in Ulster in 1793, whilst the most pro lific British observatory of the period was that of William Her schel at Bath, Datchet and Slough successively.
Early Continental Observatories.—Continental observa tories established during this period were those of Mannheim (1775), which was transferred to Karlsruhe in 188o, and again to Heidelberg in 1896; Lilienthal founded by Schroter in 1779, and furnished with a reflector made by Herschel ; Leipzig where a small observatory existed on the tower of the university in the years 1787-90; Breslau (179o) ; also one at Seeberg near Gotha, founded by Duke Ernest II. in 1788 that was made famous by Zach and Encke. The observatory at Palermo, Sicily, where Piazzi made his famous catalogue of stars, was founded in 179o; and at about the same time Lalande and his assistants were observing transits of stars from an observatory in l'Ecole Mili taire, Paris.
British Observatories.—A full list of observatories, public and private, founded in Great Britain during this next ioo years would be large. An observatory on Calton Hill, founded by a pri vate association, the Edinburgh Astronomical Institution, in 1818, was taken over by the Crown as a Royal Observatory in 1834, and transferred to its present site on Blackford Hill in the years 1889-96 (see Plate), Cambridge university observatory was founded in 182o and under its noted directors, Airy, Challis, Adams, Ball and Eddington has done valuable work, and now well equipped with instruments, has a solar and astrophysical observa tory. The Radcliffe observatory at Oxford was originally in the charge of the Savilian professor of astronomy but this arrange ment lapsed and the offices of professor and Radcliffe Observer became distinct about 1839. In 1875 the University observatory came into existence largely through the liberality of Warren De la Rue, for the use of the Savilian professor. The work of this observatory has been largely photographic. An observatory was established at Liverpool mainly for the time service of the port in 1838, and at Glasgow a small observatory attached to the uni versity of which Dr. Alexander Wilson had been the first director about 1760, was enlarged and transferred to a new site in 1836.