May IS, T879] 



NATURE 



personally presented to the King and Queen, who con- 

 versed most graciously with each of them. On the 22nd 

 the Minister of Agriculture entertained the Congress at a 

 State dinner. On the 20th the Syndic of Rome had 

 given a reception in the Capitoline Museum, which was 

 illuminated for the occasion. For their own part the 

 foreign delegates invited their ItaUan hosts to a dinner at 

 the Hotel de Russie on the 19th. 



The proceedings were closed by a very graceful and 

 munificent act of hospitality. The entire Congress, with 

 the ladies who had accompanied some of the members, 

 received free tickets for Naples and became the guests of 

 the Italian Government for two days and a half. An 

 expedition to Vesuvius, which was arranged for them, 

 proved a complete success. The courtesy and fore- 

 thought of the Italian officials extended to every detail 

 which could contribute to the comfort of their visitors. 

 The day was one of unclouded enjoyment ; the weather 

 was a perfect specimen of an Italian spring, and Vesuvius 

 was tranquil enough to allow the more adventurous 

 members of the party to explore every part of the crater, 

 only deigning to eject a few stones as Parthian arrows at 

 the descending meteorologists. 



The Congress at Rome will remain in the memory of 

 all who took part in it as one of the pleasantest and most 

 successful opportunities of international scientific inter- 

 course which has ever been organised. 



OUR ASTRONOMICAL COLUMN 



Tempel's Comet (1867 II). — The following ephemeris 

 of this comet is deduced from M. Gautier's elements, but 

 with the perihelion passage corrected to May 6'9537 

 G.M.T. to accord with the appro.ximate position observed 

 ')y Dr. Tempel on April 24 : — 



At Greenwich Midnight 



The intensity of light is at a maximum about May 26, but 

 is not then very materially greater than on April 24, 

 when the comet was described by Dr. Tempel as a faint 

 object. In 1867 it was observed at Athens until the 

 theoretical intensity of light had diminished to o-2i, so 

 that with the larger telescopes in the southern hemisphere 

 observations may be possible in August. The position 

 for August 13s is in R.A. i6h. sS'Sm., Decl. - 29° 11'. 

 When brightest in 1867, the nucleus was star-like and of 

 9-7 m., the value of I. at the time being 1-23. 



During the ensuing revolution considerable perturba- 

 tion may again result from the action of the planet Jupiter, 

 though not to so great an extent as in the revolution 

 1867-73. Using the above time for perihelion passage in 

 the present year and taking the mean daily motion, 

 593"-l84, it appears that the least distance of the comet 

 trom the planet will be about 0-58 of the earth's mean 

 distance from the sun, in the middle of October 1881, and 

 that from the beginning of July, 1881, to the middle of 

 January, 1882, the comet will always be within 0-65 ; this 



will again necessitate a rigorous calculation of the pertur- 

 bations to insure a near prediction of the comet's track in 

 the heavens in 1885. 



It was at one time suggested that the object detected by 

 M. Goldschmidt on May 16, 1855, while searching for De 

 Vico' s comet of short period, might have been the comet 

 of which we are writing ; but the late Dr. von Asten 

 undertook the calculation of the perturbations backward 

 for two revolutions from 1867, and found that the comet 

 being in perihelion on February i, 1856, with elements 

 not very different from those of 1867, could not have been 

 identical with Goldschmidt' s nebulosity. So far, there- 

 fore, as is known at present, there is no recorded observa- 

 tion of Tempel's comet previous to April 3, 1867, notwith- 

 standing it may have performed many earlier revolutions 

 in the restricted orbit it now describes ; but the case is 

 similar with other comets of short period. 



Brorsen's Comet. — Dr. Krueger has kindly sent us 

 two meridian observations, made at Helsingfors, of the 

 star over which Major Tupman witnessed a nearly central 

 transit of this comet on May 3 (Nature, vol xx. p. 27). 

 The star was rated 8-7 mag., and its mean position for 

 1875-0 was R.A. 6h. 9m. I4-84S., Decl. -h 61° 28' 8"-5. 

 Whence the apparent position of the comet by Major 

 Tupman's observation was on May 3, at loh. urn. 14s. 

 G.M.T. in R.A., 6h. 9m. 39-153., Decl. +61° 28' 3o"-9, 

 showing corrections to the ephemeris, published in this 

 column, of -I- 13s. in R.A., and -f- 2' in decUnation. 



AnNUAIRE pour L'AN 1879, PUBLIE PAR LE BUREAU 



des Longitudes.- — It has not been from want of appre- 

 ciation of the astronomical contents of this small volume, 

 so ably edited by M. Loewy, that earlier allusion to it has 

 not been found in this column. It provides information 

 of a kind which is not to be met with in so collective a 

 form elsewhere, and must be a valuable adjunct to the 

 astronomical amateur, who needs reference to 'a really 

 reliable authority on such details as the maxima and 

 minima of variable stars and the general elements of the 

 solar system, including periodical comets. M. Loewy pre- 

 sents in one list the positions and limiting magnitudes of 

 the variable stars of which the periods are known, and in 

 a second list similar particulars of a large number of stars 

 known to be variable, but of which the periods have not 

 yet been determined ; these lists are followed by an 

 ephemeris of maxima and minima, arranged in order of 

 date, with the minima of the more rapid variables, Algol, 

 X Tauri, S Cancri, S Librae, and U Coronas. There is 

 also a carefully-prepared list of the elements of the minor 

 planets to No. 191 inclusive, such a catalogue, in fact, as 

 has often been inquired for by those who do not see the 

 Berliner Astronomisches Jahrbuch. The general contents 

 of the Annuaire are as full and varied as usual, but for 

 the reasons named it has now an especial value for ama- 

 teurs of astronomy, and its almost nominal price places it 

 within reach of all. M. Janssen makes an important 

 addition in his " Notice sur les Progr^s rdcent de la 

 Physique solaire," which is accompanied by a photo- 

 graph of a portion of the sun's disc, taken at the observa- 

 tory at Meudon, June i, 1878, illustrating the rapid trans- 

 formations occurring in the photospheric network and 

 granulations within less than an hour. 



AN INTER-OCEANIC CANAL 



TO-DAY the long-talked-of International Congress on 

 the subject of a canal across the Central American 

 Isthmus meets in Paris under the presidency of M. De 

 Lesseps. This question is a very old one, but the move- 

 ment which has led up to the present Congress com- 

 menced only in 1875, at the instigation of Lieut. Lucien 

 N. B. Wyse, of the French Navy. At the International 

 Congress of Geography of that year the subject of the 



