THE WORLD'S OBSERVATORIES.

Pukekohe & Waiuku Times, Volume 4, Issue 96, 15 October 1915, Page 4 (Supplement)

THE WORLD'S OBSERVATORIES.

The story of the world's observatoiler may be said to begin when, from noticing the movements of the heavenly bodies haphazzard, men began to want to penetrate the secrets of tfiw universe and to form some idea of the movements of the heavenly bodies. To do this it was found to be necessary to collect facts and data by regular and continuous observation. The first observatory was founded at Alexandria, and its work was continued for about 400 years. Hipparchiw of Rhodes, the founder of modern astronomy, by repeating observations made at Alexandria, discovered the precession of equinoxes and laid the foundation of our knowledge of tne motions of the sun, moon, and planets. His work was carried on by more or less distinguished astronomers until, under Ptolemy, it reached its final development. PLANETARY TABLES.

When science again began to flourish after the dark ages which followed, several observatories were founded by Arabian princes, notably those at Damascus, Bagdad, and Mokattam, near Cairo.. The last-named was built by the Caliph Hakim about 1000 A.D., and it was there, thai th» Haklmitttables of the sun, moon, and planets were constructed. The Mongol princes followed suit. This phase of early Eastern civilisation reached its highest development in the splendid observatory at Maragha in the northwest of Persia, founded about 1260 by Hulagu Khan; while in the 15th century the observatory at Samarkand was founded by Ulugh Beg. At Samarkand new planetary tables were constructed and a new catalogue of stars was compiled. FIRST OBSERVATORY IN EUROPE. It was not until the fifteenth century that scientific studies were properly taken up in Europe. Astronomv was taught in all the universities, but the important work of taking observations was left to private individuals. The first observatory in Europe was erected at Nuremberg in 1472 by Bernhard Wafcher, a wealthy citizen, with whom Regiomontanus, the eminent astronomer, co-operated. At this observatory many new methods of observation were devised, and these were improved still further by the practical genius of Tycho Brahe, the famous Danish astronomer. Tycho Brahe was the first to realise the imperative necessity of carrying on for a number of vears a complete and thoroughly organised series of observations with various instruments. Thanks to Tycho Brahe. practical astronomy at last took % its proper place at the universities. Leyden and Copenhagen were the first to establish observatories. Then with the foundation of the royal observatories at Paris and Greenwich the importance of observations was at last fully recognised !>j Government and public bodies.

SPECTRUM ANALYSIS AND PHOTOMETRY.

The continuous improvement of as. tronomical instruments brought into man's purview new worlds which again had to be conquered with still more perfect instruments. The application of spectrum analysis and photometry make it possible not only to study tho heavens with greater precision, but even to study the physical constitution of the heavenly bodies. All this has, however, increased the number and variety of observations to be made, and it has become necessary nowadays for most observatories to devote themselves to one or two special fields of work. In most of the larger observatories the work of observation is distributed among a number of assistants under the general superintendence ot a director. The first great national observatory was that at Paris, founded in 166 V Cassini's observations made it for a time the most celebrated observatry in the world, but later its reputatnu declined, notwithstanding the fact that such eminent scientists as Bouvard and Arago held the post of directors. Since 1854, when Leverrier was appomtt.l director, the observations have bum conducted with a regularity nrd a scientific precision which make he observatory one of the greatest n Iho world. There is a branch observr.tory at Mont Blanc occasionally used for solar work. GREENWICH OBSERVATORY. Our own Royal Observatory wa* founded at Greenwich eight years after that of Paris—in 1675, to be precise. The observatory is under the direction of the Astronomer-Royal, and from the time of its first astronomer, Flamsteed, the institution has always maintained its place in the foremost rank of observatories. Founded for the promotion of astronomy and navigation, the observations at Greenwich have from the first been intended to determine the positions of standard stars, the sun, and planets, and to follow the position of the moon with as little interruption as possible. The observations of Bradley in the eighteenth century formed the foundation of modern stellar astronomy, but it was especially during the long directorship of Airy (18351881) that the observatory reached its present high level of efficiency. The magnetic and meteorological department was founded in 1838. Since 1873 spectroscopic observations and a daily photographic record of sun-spots have been taken. The eighth satelite of Jupiter was discovered by the unsleeping eye of the camera in 1908. Nor does this complete even a mere resume of the manifold activities of Greenwich. It keeps the centre of a system of electrically controlled clocks which are to be found all over the United Kingdom.

Besides the observatories at the principal British and Irish Universities, there is a remarkable and interesting private observatory at Birr Castle, King's County, Ireland, built by the Earl of Rosse in 1839. In 1845 he completed his celebrated reflector of 6ft. aperture and 54ft. in length, then the largest in the world. This huge telescope was used from 1848 to 1878 for the observation of nebulae, and revealed many new features in these bodies. OBSERVATORIES IN EUROPE AND AMERICA. The most famous German obserya tories are inose at Bonn, at which Argelander compiled his great atlas of 324,198 stars; Gotha, where Encke, the discoverer of the famous comet, laboured; and Konigsberg, where Bessel carried out his celebrated investigations. The imperial observatory at Vienna was originally founded in 1756, but owing to the unsuitable locality and want of instruments few observations of value were taken until the observatory was rebuilt, first in 1826 and again in 1879 outside the city. Among the other principal observatories in Europe are those at Rome, where Seechi made a great many observations; Pelermo. where Piazzi compiled his first catalogue of stars and discovered the minor planet Ceres, and

the great Nicholas Central Observatory at Pulkowa, in Russia. This lastnamed observatory was founded in 1839, and is one of the be»t equipped in the world. Some of the American observatories hare attained prominence by their discoveries within recent years. Harvard College observatory at Cambridge, Mass., was founded in 1839. It has always been kept splendidly equipped. As showing the uniform good work, a satellite ot Saturn was discovered iu 1848, and more recently two others, the ninth and tenth. Another wellknown American observatory is the Lick Observatory of the University of California. It is built on Mount Hamilton, California. It was erected through the generosity of James Lick, and was opened in 1888. The fifth satellite of Jupiter was discovered by Lick observers in 1892, and the sixth and seventh by photography in 1904-1905. Still another interesting American observatory is that at Flagstaff, Arizona. It is a private observatory of Professor Lowell's, and is situated 7300 feet above sea-level. There, at that altitude, and in that clear dry atmosphere the conditions are unusally favourable for astronomical work. A SOUTHERN OUTPOST. The most important observatory in the southern hemisphere is that of the Cape of Good Hope, which was erected in 1829 about 3J miles from Cape Town. Under E. J. Stone, who catalogued 12.441 stars, and Sir David Gill, who superintended a complete review of the southern heavens, splendid work has been done at this observatory, a southern outpost of that wonderful chain of observers who ring the earth, watching while others sleep, in that never-ceasing quest for knowledge which can never be satisfied.