io8 



NATURE 



\Pec. 6, 1877 



from north to south, which was closed with shutters when 

 not in use. The axis was made of conical iron pUtes 

 lighter and more inflexible than in the old transit. The 

 pivots were conical and iitted into brass holes on the 

 sides of the pillars, into <vhich the axis was tightly pressed 

 with screws. The axis could be shifted a little both in 

 altitude and azimuth. Romer had afterwards occasion to 

 regret that the instrument was supported oa wooden 

 pillars and not on stone. The tube was not fixed imme- 

 diately to the axis but to the circle. It was five feet long, 

 and allowed stars of the second magnitude to be observed 

 during the day. It had three horizontal wires in the 

 focus and seven vertical ; the intervals between these 

 were twenty-four seconds in the equator, and the time 

 was noted to a fraction of a second. There were three 

 good clocks in the observatory. The circle which was 

 fastened to one end of the axis was about five feet in 

 diameter. It is not unlikely that Romer afterwards con- 

 sidered a smaller size preferable. He disapproved alto- 

 gether of the use of the quadrant and sextant, and said 

 that a circle of four feet was superior to a quadrant of 

 ten. This circle had been divided to ten minutes with 

 Romer's own hands, and in the microscopes three seconds 

 were easily discerned. It was read by two microscopes 

 fixed side by side to one of the supports of the axis. 

 Before the observations were mide the circle was ascer- 

 tained, by means of a plumb-line, to be vertical. The 

 errors of collimation and azimuth were determmed in 

 the same way as with the old inbtrument, and R5mer 

 had fixed two meridian-marks, which were besides used 

 to discover whether the microscopes had changed their 

 position. Romer was the first who determmed the 

 azimuth from culminations of circumpolar stars above 

 and below the pole. 



Besides this instrument Romer had also a transit 

 instrument placed in the first vertical, but that was not 

 used much because it had been so badly made by the 

 woikmen that it disturbed the meridian circle with which 

 it had one of the supports in common. Romer intended 

 to observe declinations of fixed stars with it and compare 

 them with those observed in the meridian, and thereby 

 determine the refractions. He would also have observed 

 the sun with it 



After Romer's death, on September 19, 1710, his obser- 

 vatory was neglected and the instruments were spoiled, 

 when at last they were sent to Copenhagen. Romer was 

 to have pubhshed a description of tfce observatory and 

 his methods, but was prevented by the illness which ter- 

 minated his active career, and the descriptions were after- 

 wards given from memory by his little gifted pupil and 

 successor, Horrebow, who did not fully understand all 

 the precepts of his great master. All his observations 

 and instruments were ultimately destroyed by the con- 

 flagration of the observatory in 1728, except three days' 

 observations, which Romer had intended to use for his 

 description of the instruments. Thus it came to pass 

 that this great genius passed away without any adequate 

 influence upon the progress of the science. These three 

 days' observations have been carefully reduced by Dr. 

 Galle ; their accuracy is shown to be almost equal to 

 that attained at the present day. 



In England the methods adopted by Flamsteed were 

 followed until Bradley permanently introduced Romer's 

 transit at Greenwich. He continued, however, to use the 

 quadrant for declinations, and in most other observatories 

 of this country the right ascensions and declinations con- 

 tinued to be observed with different instruments. We 

 may also trace to this circumstance the immovable heavy 

 mural instruments so common in this country.^ The 

 French astronomers adheied to Picard's methods until 

 lately, and used quadrants even for the right ascensions ; 

 the transit in the first vertical was not used before it was 



» On the accompan-ying piat* s are represented one of the formerly mor 

 common mural circles (Kig. 2), an i also a meridian circle (Kig. 3) ; both 

 initrumei.ts of the U.S. Naval Observatory, Washington. 



rediscovered by Bessel. On the whole we may say tha 

 no observatory fully expressed Romer's ideas before 

 Bessel's and Struvc's practical talents had altogether 

 changed the face of the science. W. Doberck 



NOTES 



Prof. Kirchhof has been created a Knight of the Order 

 of Maximilian (or Science and Art, by King Louis of Bavaria. 



M. Bkunet, the late French Minister of Public Instruction, 

 nominated M. Giamme, the inventor of the well-known machine 

 for gener«iting eleccric light, a Chevalier of the Order of the 

 Legion of Honour. 



Nearly 200/. have already been promised for the Darwin 

 Memorial Fund at Cambridge. 



A MONUMiENT was inaugurated on November 23 at Rouen 

 in honour (f M. Pouchet, the celebrated naturalist, who 

 organised the Rouen Mu-€um in 1828, and died director in 1872. 

 M. Pouchet was a correspondent of the French Insiitute. He 

 was a supporter of ttie theory of spontaneous generaiion. 



The Rhine Provincial Museum in Bonn has succeeded in 

 purchasmg the famous collection ot prehi-.toric remains from the 

 Neander Valley, hitherto m the possession of the late Prof. 

 Fuhlrott, of Elbeifeld, although a high price had been offered 

 from England. 



Preparations are being made at the Champ de Mars, Pari?, 

 for executing Foucault's pendulum experiments on an enlarged 

 scale. His appiratus was suspended in 1851 under the dome of 

 the Pantheon. It was in operation for a long while and removed 

 only when the builriing was transformed into a church after the 

 coup d'etat in 1852. The weight of the pendulum will be 300 

 kilogrammes, and it will oscillate at the end of an iron wire from 

 65 to 70 metres long. Thus a special construction will be re- 

 quired for its suspension. The pendulum will be suspended above 

 a grooved pipe which will move freely on an axis in its centie. 

 The penduium in oscillating will displace this pipe, which will 

 remain, like the pendulum it:^elf, fixed in space, in reference to 

 the constellations. Underneath the pendulum will be arranged 

 a large terrestrial globe, from 25 to 30 metres in diameter. This 

 globe, resting on the ground, will necessarily follow with the 

 spectators the movement of the earth. The pipe, on the con 

 trary, sup[jorted by a pivot at the extremity of the axis, will 

 carry large indexes, which will appear to be displaced with it. 

 The glotie, which will represent the earth, having a consider- 

 able volume, the movement of these indexes will be visible ; 

 it will render tangible in some degree to the least attentive, the 

 rotation of the planet on is axis. 



In the Times of Monday is a pleasant leader on the Royal 

 Society h propos of the anniversary last Friday. The article con- 

 tains nothing striking, the drift of it being that the Royal 

 Society has done much to foster science, but that science never 

 was altogether, and is now not at all, dependent on the Royal 

 Society for its progress — which is probably true. The article 

 couL-ludes with a strongly -expressed desire to see literature, " the 

 old learning," recognised by the Royal Society, that, in fact, it 

 should be turned into a sort of academy, after the pattern of 

 that of Paris. Eat practically the French Academy is a collec- 

 tion of societies, one of which, like the Royal Society, devotes 

 itself wholly to science. 



An article in Tuesday's Times describes some experiments 

 which are being made at the Fulham gas-works in the lighting 

 of lamps by eleoncity. The pateat is that of Mr. St. 

 George Lane Fox, the distinctive feature being an electro- 

 magnetic apparatus atiacued to each lamp, and connected with 

 a central station, at wtucH an electdc current is generated. \i 

 the experiments prove successful and the apparatus is adopted, a 

 great savmg is likely to be etfecttd. All practical diiiiculties 

 seenj, however, to have been solved in America Electricity 



