4 2 



NA TURE 



[May ii, 1882 



have approximately the same mean annual temperature every- 

 where, and that in abrupt ascent there is a decrease in mean 

 annual temperature, of about 1" F. for every 300 feet, Mr. 

 Gannett thought to determine the temperature at the timber line, 

 from that of a station'at or near the base (supposed, thougli not 

 always correctly, to represent the average climate round the 

 base), together with the height. The tabulated figures, for 

 thirteen mountains, &c, yield the mean30°'4, which is probably 

 very near the true mean annual temperature of the timber line. 

 Should the result hold good, after wider observation, it will 

 afford, Mr. Gannett says, a very valuable ar.d easily obtainable 

 isothermal, and abo enable one to estimate the height of the 

 timber line from thermometric stations at the bases of mountain 

 ranges. 



On April 26 M. Broch, president, and the delegates of the 

 Bureau International des Poids et Mesures, presented to M. 

 Tirard, the Minister of Commerce, specimens of the facsimile 

 reproductions of the standard metres and kilogrammes preserved 

 since the beginning of the century in the French National 

 Archives. These copies have been executed with an alloy of 

 platinum and iridium, in compliance with the instructions given 

 by MM. Henry Sainte Clair-Deville and Debray. This great 

 work has taken not less than ten years. These facsimiles have 

 been sent to the Bureau at Breteuil, where they will be used in 

 executing the copies ordered by the several nations for their use. 



A new edition of Kelland and Tait's " Introduction to Qua- 

 ternions" has been published by Macmillan and Co. While 

 refraining from making any changes in the late Prof. Kelland's 

 part of the work, Prof. Tait has re-cast his own where he fancied 

 he could improve it. 



The Committee of the Sunday Society are more than usually 

 active just now in connection with the motion for extending the 

 opening of museums on Sundays, which Mr. George Howard is 

 to propose in the House of Commons on the 19th inst. On the 

 17th inst. a National Conference of Delegates from Provincial 

 Towns, Trade Societies, and other organisations, is to be held at 

 the Westminster Palace Hotel under the presidency of Viscount 

 Powerscourt, and in the evening of the same day a large meeting 

 is to take place at St. James's Hall, when addresses are to be 

 delivered by Lord Powerscroft, Lord Dunraven, Lord Dor- 

 chester, Mr. Thomas Burt, M.P., Mr. George Howard, M.P., 

 Dr. Richardson, and others. 



The additions to the Zoological Society's Gardens during the 

 past week include Six Northern Marsh Tits (Panes borealis) from 

 Russia, presented by Mr. A. H. Jamrach ; four Pigmy Pigs (Porcula 

 salviana <$ 9 9 9 ) from Nepaul, a Burmese Tortoise ( Testudo 



eloitgata), a Terrapin (Clcmmys, sp. inc.) from Burmah, 



received on approval ; two Green Monkeys (Cercopitheais calli- 

 trichus) from West Africa, a Grey-headed Love Bird (Agapomis 

 cana) from Madagascar, received in exchange ; a Water Chevro- 

 tain (Hyomoschus aquaticus), a Golden-haired Tiger Cat (Felis 

 chrysothrix) from West Africa, a Mercenary Amazon (Chrysotis 

 mtrcenaria) from Columbia, three Chiloe Wigeon (Mareca 

 chihensis i 9 9 ) from Chili, a Silky Bower Bird (JPtUonorhyn- 

 ckusvialaceus), two Blue-faced Honey-Eaters (Eniomyza cyanolis) 

 from Australia, a Red-handed Tamarin (Midas rufimanus) from 

 Brazil, a Wild Duck (Avas boscas 9 ), British, four Yellow- 

 billed Cardinals (Paroaria capitata i i 9 9 ) from South Ame- 

 rica, purchased. 



OUR ASTRONOMICAL COLUMN 

 Anthelm's Nova of 1670.— The vicinity of this object will 

 soon be in a favourable position for observation, and we may 

 once more direct attention to the small star which occupies very 

 nearly the place given by the observations of Hevelius and 

 Picard in 1670. By a iecent careful reduction of Picard's obser- 



vations, the mean place of the object for the beginning of 1670 

 was found to be in R.A. 19b. 34m. 5s. -3, Decl. + 26 3>'4 2 "» 

 which, accurately brought up to 1S80, give, R.A. 19I1. 42m. 

 4IS/3, Decl. + 27° .0' 56". Near this point we find a tele- 

 scopic star, which is No. 1814 of the Greenwich catalogue of 

 1S72, the place there assigned differing from that reduced to the 

 year from Picard's observations by + 3s.. S in R.A, and 33" in 

 declination, and the right ascension for 1670 is open to an error 

 of quite two seconds, and in greater uncertainty than the decli- 

 nation. The small star is followed by one (/>) 12s. '6, about 4''9 

 N., and a second (c) at 22s. '4, about 2''0 N. Its magnitude has 

 been noted as follows : — 1852, April 24, lo'lim. ; 1S61, May 24, 

 12 m. ; 1872, August 23, — b ; 1S74, November 13, - 5 m. less 

 than b, decidedly less at first view. Another star (d) follows the 

 one nearly in the position of Nova, 32s. '6, and is N. i'.J. Prof. 

 Schonfeld found from the observations of Hevelius and Picard 

 combined, a place differing from that given above by - 2s. 8 in 

 R.A., and + o''3 in declination. 



Variable Stars. — It is known that U Cephei had long been 

 indicated as a probable variable star by the discordant magni- 

 tudes given by Schwerd's estimates of magnitude, as arranged 

 by Oeltzen, and when taken in hand for regular examination, its 

 short period was soon detected by Ceraski. Schwerd's estimates 

 were from 67 to 10m. It appears by no means improbable that 

 if several other stars for which the magnitudes in the various 

 catalogues are very discordant, were systematically examined, 

 similar cases might be found. For instance, we have 17 1 An- 

 dromeda: noted from 3J to 7m., 16 Leonis Minoris 5 to 8m., 

 41 1 Aquilse 3! to 6m., and 35 Camelopardi 54 to 8m. ; the last, 

 a double star, has already been found to be variable, as regards 

 one component at least ; but we have no approximation to the 

 period. 



The Comet 18S2 a. — The following places are derived from 

 the same elements that were employed last week, and are for 

 Greenwich midnight : — 



R.A. Decl. 



1S82. 



May 13 ... o 41-0 ... +74 5 



'4 - 1 47 ... 73 33 



15 ... 1 269 ... 72 51 



16 ... 1 47-5 ... 72 o 



17 ... 2 63 ... 71 1 



18 ... 2 234 ... 69 54 



19 ... 2 3S7 ... 68 40 



20 ... 2 52-5 ... +67 23 



Sun. 



99571 ■« 9'97'S 



9 9539 ••• 9'948i 



9-9518 ... 9'9227 



9-9508 ... 9-8949 



Next week we may probably be in possession of elements 

 which will allow of a close prediction of the comet's track as it 

 approaches the sun. All the later orbits assign for the date of 

 perihelion passage June 10. 



BIOLOGICAL NOTES 

 Fauna of the Suez Canal.— Dr. C. Keller, who is engaged 

 upon a zoological investigation of the Suez Canal, with a special 

 view to determining what exchange of animals may have taken 

 place between the Red Sea and the Mediterranean, has recently 

 sent his first report from Ismailia to the St. Gall Society for 

 Commercial Geography. He states that the exchange is pro- 

 ceeding slowly, owing no doubt to the presence of the lakes of 

 bitter-water through which the canal was traced. The inhabitants 

 of these very lakes seem to have been the first to commence 

 migrations. This fact Dr. Keller has unquestionably ascertained 

 w ith regard to several species of the lower animals ; a particularly 

 interesting case being that of a violet species of sponges, belong- 

 ing to the fauna of the bitter lakes. This is now migrating in 

 the canal towards the Mediterranean. He named this form 

 Lessepsia violacea. Several larger species of fishes, which are 

 now caught in plentiful quantities in the Timsah lake, have 

 migrated there from the Mediterranean ; amongst these are 

 AnarrhUhas lupus, Solea vulgaris, and Polyprion ccrnium. 

 Other species have migrated from the Red Sea to the Timsah 

 lake, perhaps to Port Said ; amongst these Dr. Keller mentions 

 a large dark green mackerel and several brightly coloured but 

 small Acanthopteri. The canal itself, in the direction from the 

 Timsah lake towards Port Said shows but a poor fauna ; that of 

 the bitter lakes is also poor with regard to different specie--, 

 while the representatives of the few species that are there are 

 excessively abundant. 



