Oct. lo, 1878] 



NATURE 



619 



is ~t^^. The latest value of the mass resulting from 

 theory is that given by Leverrier {Atinales, vol. xi. p. 3), 



Prof.' Hall compares his elements with the observa- 

 tions made at other observatories, of which those of Cam- 

 bridge, U.S., Glasgow, U.S., Pulkowa, and Mr. A. 

 Common, of Ealing, were the most successful. The mag- 

 nitudes of the satellites, free from the glare of the planet, 

 were estimated at about 12 and 11^, Phobos being the 

 brighter of the two. On October 15, when their distances 

 from the centre of the planet were respectively 23" and 

 S7"*5, they were of nearly equal brightness. Prof. Hall 

 further remarks : " The chief difficulty of observing these 

 satellites is on account of the brilliancy of the planet. At 

 their elongations at opposition in 1877, they appeared to 

 me brighter than the outer satellites of Uranus and much 

 brighter than Hyperion, and on October 31 Deimos 

 resembled Umbriel, the second satellite of Uranus, 

 which, at elongation, is fainter, I think, than any other 

 satellite." 



With the angular values of the mean distances given 

 above, the real distances of the satellites from the centre 

 of their primary will be for Phobos, 5,800, and for Deimos, 

 14,500 miles ; the former, from the rapidity of its motion 

 (it performs more than three revolutions in the Martian 

 day) will appear to rise in the west, meeting and passing 

 the outer moon, and setting in the east, and it will have 

 a horizontal parallax amounting to 21°. 



Prof. Hall has definitively adopted the names proposed 

 by Mr. Madan, of Eton, in the columns of Nature. 



The Saturnian Satellite, Titan.— The following 

 are the approximate times of conjunction of the great 

 satellite of Saturn, with the perpendicular to the plane of 

 the ring, during the next month, at which times occulta- 

 tions by the planet, or transits over its disc take place. 

 The elements used are very nearly those of Bessel, but 

 with a somewhat larger ellipticity of the planet. 



WINGLESS INSECTS OF THE FALKLAND 

 ISLANDS 



WHILST on an excursion to Port Darwin, in the 

 Falkland Islands, during the visit of H.M.S. 

 Challenger \.o that group, I found at Darwin Harbour, 

 Choiseul Sound, some insects which are of considerable 

 interest, since, as I believe, they are closely allied to 

 those of Kerguelen's Land. Amongst them were a gnat, 

 practically wingless (Tipulids), and a fly with rudi- 

 mentary wmgs. The gnats were found crawling on the 

 rocks on the sea-shore, in sheltered places, and also on 

 the sunny, sheltered side of a fence composed of a peat 

 bank, with furze growing on the top of it. They run 

 quickly, and, when in danger, draw up their legs and 

 drop in order to escape, and they are not by any means 

 easy to catch amongst the grass. 



The flies were found only on the sea-coast, in hollows 

 under overhanging slabs of the sandstone rocks, shelter- 

 mg themselves in crevices. They have short wings 

 which they seem to use in jumping, and they spring 

 nimbly, like fleas or small grasshoppers, and are difficult 

 to catch. On comparing specimens of these flies with 

 specimens of Atnalopteryx maritwta, one of the flies of 

 Kerguelen's Land, with rudimentary wings, described by 

 Mr. Eaton (Rev. E. A. Eaton, the Entomoloptsf s 

 Monthly Magazine, August, 1875), I have Uttle doubt that 



they are very closely allied to this species, and to be referred 

 at least to the same genus. Dr. Kidder describes the 

 habits of the Kerguelen Avialopteryx as closely similar 

 (J. H. Kidder, M.D., Bulletin United States National 

 Museum, No. 3, 1876, ii. p. 52). Von Willemoes 

 Suhm found a species of the same genus in Marion 

 Island, and we all observed the fly at Kerguelen's Land as 

 well as the wingless gnat which Mr. Eaton has named 

 Halyritus amphibius, and which lives on the Kerguelen 

 sea-shore amongst sea-weed constantly wetted by the 

 tide. It would be interesting if the Falkland Island 

 gnat proved allied to the Kerguelen one on further 

 examination. 



I found one beetle with wings at the same locality in the 

 Falklands, and one wingless species. All the Kerguelen 

 beetles are wingless. Two genera and all the species of 

 that island are endemic (Mr. C. O. Waterhouse, Ento- 

 mologisfs Monthly Magazine, August, 1875, P- 5o)- The 

 close connection between the Fuegian flora and that of 

 the far distant Kerguelen's Land is well known from the 

 investigations of Sir Joseph Hooker. It is interesting 

 to find a further connection in the insects. The four 

 wingless flies of Kerguelen's Land are assigned by Mr. 

 Eaton to four new genera. I believe, though I am no 

 entomologist, that the Falkland Island and Marion 

 Island fly will come under one of these, and possibly 

 further search may prove the existence of representatives 

 of some of the other genera in Fuegia or the Falklands. 

 I see from the " Histoire Nat. des Insecte's Dipt^res " of 

 the Suitesa Bufibn, the only authority immediately at 

 hand, that a wingless gnat, Chionea araneoides, is found 

 in Sweden in woods on the snow throughout the winter, 

 whilst two flies with rudimentary wings, Apterina pedes- 

 iris of France and Germany, zxvdL Myrmemorpha brachyp- 

 tera of Spain, exist in Europe. These merely as 

 examples. Prof. Westwood tells me many other such 

 diptera are known to entomologists, and he has shown 

 me a specimen of a wingless fly, Borborus apterus, which 

 occurs in England. 



Exeter College, Oxford H. N. Moseley 



SUN AND EARTH 



'HP HE Meteorological Reporter of the Bombay Presi- 

 ■*■ dency, Mr. F. Chambers, at the end of his recently- 

 published report for 1877-78 gives us the first results of 

 some important researches which he has not yet been able 

 to complete, owing to want of clerical assistance. In a 

 brief sketch of the meteorology of the Bombay Presi- 

 dency in 1876 prepared for the Bombay Administration 

 Report for 1876-77, he showed that the abnormal meteoro- 

 logical conditions which produced the famine of 1877 

 were of the same type as those which produce the usual 

 alternations of seasons, and therefore are attributable to 

 similar causes. 



A commencement was made some time ago with the 

 discussion of the Kurrachee wind observations. One of 

 the most important results already obtained is that the 

 numerical relation existing between the abnormal wind 

 and abnormal barometric movements is exactly similar to 

 the relation between the annual variations of the wind 

 and barometer leading to the same conclusion as above, 

 viz., that most of the abnormal variations of weather in 

 India are due to causes which are similar to, if not iden- 

 tical with, those which produce the normal variations. 

 The comparison of the normal and abnormal barometric 

 movements at different stations points decidedly in the 

 same direction, and Mr. Chambers believes that further 

 investigation will prove this to be a general law, affiecting 

 perhaps all abnormal meteorological variations which are 

 not cyclonic. He adds : — 



" The fact that a famine has been raging in China, at 

 the same time that one has ravaged Southern India, does 

 not appear to be without its significance, in pointing to 



