Dec. 15, 1887] 



NATURE 



155 



was appointed observer in the old Observatory at 

 Copenhagen, which had been built at the time of 

 Longomontanus, on the top of a high tower, and was 

 therefore, after the lapse of two centuries, greatly be- 

 hind the times, both as to locality and instruments. A 

 few years afterwards he was appointed Professor of 

 Mathematics at the Naval Academy, and Instructor in 

 Geometrical Drawing at the Polytechnic School. These 

 appointments he retained till the time of his death, as 

 well as his position at the Observatory, and though he 

 was in 1875, after the death of Prof D'Arrest, strongly 

 urged by the Minister of Public Instruction to allow 

 himself to be appointed Professor of Astronomy, he 

 preferred remaining as he was, partly owing to the 

 pecuniary loss the change would have entailed, partly 

 because his scientific activity was untrammelled by 

 routine duties, and left him leisure to pursue his studies 

 in whatever direction he chose. 



As long as Schjellerup had only at his disposal the 

 instruments of the old Observatory, he chiefly occupied 

 himself with the computation of orbits of planets and 

 comets, among which his determination of the orbit of 

 the comet of 1580 deserves to be specially mentioned. 

 Tnis was founded on a ccrmplete reduction of Tycho 

 Brahe's original observations of the distance of the comet 

 from stars, and of his time determinations by altitudes 

 and azimuths of standard stars. In 1861 the new 

 Observatory was finished, and furnished with an ii-inch 

 refractor by Merz and a transit-circle by Pistor and 

 Martins. With the latter Schjellerup commenced in 

 September 1861 to observe zones of stars, chiefly of the 

 eighth and ninth magnitudes, between + 15" and - 15'^ 

 declination, and already in the beginning of December 

 1863 he had finished the observation of ten thousand 

 stars, while the reductions had been pushed on with so 

 much energy that the complete catalogue of mean places 

 for 1865 was laid before the Royal Danish Society of 

 Science a month after. When it is remembered that the 

 author of this work during the greater part of the year 

 had to spend three or four hours a day in teaching, it 

 will be conceded that he made good use of his time. 

 The star catalogue is so well known for its fulness and 

 accuracy that it is unneccessary to dwell further on it in 

 this place. After its completion, Schjellerup intended, 

 and had already commenced, to continue the observations 

 no*-th of the limit of + 15', as Bessel had done foriy years 

 before, but about this time his interests took a new 

 direction, which made him d'scontinue systematic obser- 

 , vations, while he may also have been influenced by the 

 circumstance that the great undertaking of the Astro- 

 nomische Gcpellschaft, viz. the observing of all stars in 

 the northern hemisphere down to the ninth magnitude, 

 had just then been planned, whereby zone work on 

 Lalande's plan became of less importance. 



Schjellerup now with his usual energy threw himself 

 into the study of Oriental languages, especially Arabic 

 and Chinese. In the Royal Library of Copenhagen he 

 found a manuscript of the description of the heavens by 

 the Persian astronomer Abd-al-Rahman al-Sufi, a work 

 which up to that time had been very little known among 

 astronomers. Finding that it contained a complete and 

 careful uranometry from the tenth century, or in other 

 words from an epoch nearly equidistant between Ptolemy 

 and Argelander, he resolved to translate it and was fortun- 

 ate enovigh to obtain the use of another manuscript from 

 the Imperial Library of St. Petersburg. The work was 

 published in 1874 by the Academy of St. Petersburg 

 under the title, " Description des etoiles fixes compos^e 

 au milieu du dixi^me si&cle de notre ere par I'astronome 

 Persan Abd-al-Rahman al-Sijfi." It has been found most 

 valuable by the astronomers who of late years have 

 studied the relative brilliancy of the fixed stars, and Sufi's 

 results have been systematically collate 1 with their own 

 by Messrs. Peirce, Pritchard, and Pickering. 



The great value which this old work was found to 

 possess for modern research induced Schjellerup to en- 

 deavour to make other observations of the ancient astro- 

 nomers fruitful for the investigations of the present day. 

 To the journal Copenncus he contributed three papers 

 under the common title, " Recherches sur I'Astronomie 

 des Anciens." The first shows that the time stars of 

 Hipparchus had been so well selected that their culmi- 

 nations gave the correct time every hour of the night 

 within a minute, the second discusses the Chinese 

 observations of the total eclipses of the years -708, -600, 

 and - 548, while the third compares seven conjunctions 

 of the moon with fixed stars recorded by Ptolemy, with 

 Hansen's lunar tables. He further examined the occulta- 

 tions and conjunctions of planets observed by the Greek 

 astronomers, and the principal eclipses of the Middle 

 Ages, but these investigations appear to have been left 

 unfinished at his death. 



Among Schjellerup's minor publications should be 

 mentioned his catalogue of red stars (first published in 

 1866, and in a revised edition in 1874), which appeared 

 most opportunely at a time when the spectroscope had 

 ju:t commenced to be applied to the study of the physical 

 constitution of the stars. 



In addition to being a man of very extensive knowledge, 

 both scientific and general, Schjellerup was a kind teacher 

 and friend, always willing to assist with his vast store of 

 learning anybody who consulted him. His memory will 

 be gratefully cherished by those who had the good fortune 

 to know him. J. L. E. Dreyer. 



NOTES. 



Dr. Asa Gray, we are sorry to learn, has been stricken with 

 apoplexy at his house in Cambridge, Massachusetts. 



Sir George Burrows, F.R.S., died on Monday. He was 

 in his eighty-seventh year. 



We regret to have to announce the death, at the early age of 

 thirty-four, of Prof. Humpidge, of the University College of 

 Wales. Dr. Humpidge was educated at the Grammar School, 

 Gloucester, was for some years in trade, and in spare time student 

 in science clas es, where he obtained a silver medal in geolojy 

 from the Department. He after .vards studied at the School of 

 Mines, and obtained one of the three Jodrell Scholarships. In 

 the etamiuation for B.Sc. at the London University he obtained 

 the second place in the honours list, and the two years' ,^40 

 scholar^iliip. After studying with Bunsen at Heidelberg, and 

 teaching at Hofwyl in Berne, he was appointed in 1879 to the 

 chemistry class at Aberystwith. At Kensington Dr. Humpidge 

 carried on some researches on the coal-gas of the metropolis, 

 under Prof. Frankland, and in Heidelberg he took up the study 

 of the rare metals yttrium, erbium, and beryllium, results of 

 whicli were published in the Journal of the Chemical Society, 

 Philosophical Transaction^, and F'roceedings of the Royal 

 Society. His later work was the preparation of several rare metals 

 in a state of purity for the determination of their specific heats in 

 his calorimeter. The fire which unfortunately destroyed the College 

 in the summer of 1885 caused irreparable loss to Dr. Humpidge, 

 all his papers and results and chemicals being burnt, and he had 

 also a very narrow escape from the flames in endeavouring 

 to rescue people and property. The shock of this accident 

 undermined his health, and although he continued to teach in 

 temporary premises for some time he was finally obliged to visit 

 the South of Europe for a winter, but the relief was only 

 temporary, and he succumbed, after three weeks of great suffer- 

 ing, on November 30. Dr. Humpidge translated Kolbe's 

 "Inorganic Chemistry," which has reached its second edition. 

 Unfortunately his long illness ran away with any provision 



