April 23, 1896J 



NA TURE 



587 



been rendered necessary, much good exploring work appears to 

 have been done. The deep boring for oil at Athabasca Landing has 

 now been continued down to over 1700 feet, with every prospect 

 of early success when work is resumed this season. Students of 

 Graptolites will welcome the announcement that Prof. Lapworth's 

 work on the Canadian forms is now approaching completion. 



In a communication made before the St. Petersburg Society 

 of Naturalists {Proceedings, November 1895), Prof. Borodin 

 described some interesting species of plants which he had dis- 

 covered during his last summer's exploration of the lakes of the 

 Valdai plateau, namely, the Isoetes echinospora and the Isoetes 

 lacustris, the Lycopodium inundatum, Bolrychitim virginianum, 

 and Luzula angustifolta, Garcke, var. albida, which last seems 

 to have been imported, and now grows in masses along the em- 

 bankment of the Moscow Railway. He especially mentioned 

 the simultaneous occurrence, in Lake Bologoye, of the two 

 species, Caulinia fragilis,^ . {Najas minor. All.) and CauHnia 

 Hexilis (NaJas /lexilis, Rostk.), which. Prof. Borodin remarks, 

 never occur together. The former is known from many localities 

 of Southern and, partly. Middle Russia ; but the second, which 

 is altogether a rare northern species, has only been found until 

 now in the lakes of Finland and Olonets. 



The presidential address, delivered last December to the 

 Geological Society of Washington, by Dr. G. K. Gilbert, has 

 been published by the Society. It is entitled " The Origin of 

 Hypotheses," and illustrates the methods of scientific investi- 

 gation by reference to a particular problem — the origin of the 

 peculiar crater-structure in limestone known as Coon Butte 

 (Arizona). Involving as it does a consideration of all possible 

 methods of the formation of a non-volcanic crater, it will be 

 found to have a more special interest for geologists than the 

 title might suggest. 



The Rugby School Natural History Society is one of the 

 best of the scientific societies attached to our public schools. 

 The report for the year 1895 ^^.s just come to hand, and we 

 recognise in it a spirit of devotion to science worthy of the 

 fullest encouragement. It is no small matter for a school society 

 to spend £2'jo upon the purchase of objects, cases for a new 

 museum, and for the rearrangement of the specimens ; yet that is 

 what the boys at Rugby have done. A rigid economy of many 

 years enabled the Society to meet the entire expenses of the 

 removal and cleaning of the objects, without appealing for help 

 from outside, but as a consequence its resources are entirely ex- 

 hausted. Funds are needed to be devoted to new cases for 

 the entomological collection in the museum, but, we under- 

 stand from the report, unless material assistance beyond the 

 ordinary income is received, it will b* a long time before the 

 Society's exchequer will be sufficiently replenished to warrant 

 any expenditure. We cordially commend the position of the 

 - . iety to philanthropists, believing thit any assistance given 

 lid work for the increase of scientific investigators. The papers 

 i,LiaLained in the report are on the flight of birds, by Mr. W. T. 

 I Loveday ; the contents of the Rugby School Museum, with 

 I suggestions for their improvement and enlargement, by Mr. W. 

 !•'. Collings ; the functions of a school natural history museum, 

 liy Mr. L. Gumming; and on earth-worms, by the Rev. 

 Hilderic Friend. There are also the usual reports of the 

 various scientific sections of the Society. 



The additions to the Zoological Society's Gardens during the 

 past week include a Red-faced Ouakari (Bracftyiirus rubiciindus), 

 from the Upper Amazons, presented by Mr. Ernest E. Austen ; 

 ;i Black-eared Marmoset [Hapale penicillata), a Common 

 Marmoset (Hapale j'acchiis) from South-east Brazil, presented by 

 Mr. R. H. Biddle ; two Ring-tailed Coatis (Nasua riifa) from 

 S )uth America, presented respectively by Captain Hyde and 

 NO. 1382, VOL. 53] 



Mr. James Green ; a Lion (Felts leo, 6 ) from Africa, deposited; 

 an Indian Civet ( Viverricnla tnalaccensis) from India, a Nankeen 

 Night Heron (Nycticorax caledonicus) from Australia, twenty 

 Midwife Toads {Alytes obsletricans) European, purchased ; a 

 Weka Rail (Ocydrointis australis) from New Zealand, received 

 in exchange; two Maholi Galagos (Galago maholi), four North 

 African Jackals {Cams anihus) bom in the Gardens. 



OUR ASTRONOMICAL COLUMN. 



Uranus and its Satellites.— As part of his work at 

 Mount Hamilton during 1894 and 1895, Prof. Barnard took 

 up the measurement of the positions of the four moons of the 

 planet Uranus, and his results have just been published (Asfro- 

 nomical Journal, No. 370). Even with the 36-inch telescope 

 the two inner satellites were usually difficult objects, while 

 Titania and Oberon were also difficult if there was any wind to 

 disturb the telescope. Ariel seems to be generally about half a 

 magnitude brighter than Umbriel, and is the more easily visible 

 notwithstanding that it is nearer to the planet. The com- 

 pared brightnesses of Titania and Oberon seemed at first to 

 show a variation of their relative light, amounting to a whole 

 magnitude, but it is by no means certain that a real change 

 occurs in the brightness of either ; a consideration of the 

 circumstances under which the comparisons were made has led 

 Prof. Barnard to the curious conclusion that his eye has a 

 tendency to make the lower of two equal lights appear the 

 brighter, and he therefore thinks it probable that the two outer 

 satellites are of constant and nearly equal brightness. 



Apparently without being aware of the earlier observations of 

 Schiaparelli and others. Prof. Barnard noticed a very decided 

 ellipticity of the disc of Uranus, and found that the orbits of the 

 satellites deviate some 20 or 30 degrees from the equatorial 

 plane indicated by the major axis of the disc. For the polar 

 and equatorial diameters, the measured values are 3" 93 and 

 4" "1 50 respectively, when reduced to the mean distance of 

 Uranus from the sun equal 19" 18329 astronomical units. The 

 polar compression appears to be greater than that of Saturn, 

 which fact indicates a rapid axial rotation. The mean diameter 

 of the planet derived from the measures is 34,900 miles. 



Comet Swift. — A telegram received from Kiel on April 17 

 announces the observation of Swift's comet at 8h., Echo 

 Mountain mean time, on April 13 in R.A. 3h. 39m., Decl. 

 15° 40' N. The comet is stated to have a tail, and was moving 

 slowly westward. It is a little south of the Pleiades, so that it 

 can only be observed for a short time after sunset. 



A later telegram states that the comet was observed at the 

 Lick Observatory at 8h. 26m. mean time on April 16 ; it was 

 then in R.A. 3h. 38m., Decl. 18° 20' N. 



The Astronomical and Physical Society of Toronto. 

 — ^Judging by the sixth annual report, which we have just re- 

 ceived, this Society is doing good work in popularising the study 

 of science in Canada. The volume contains reports of the semi- 

 monthly meetings and a series of papers read before the Society. 

 For the most part the papers give popular accounts of various 

 astronomical and physical researches, among which " the 

 spectra of nebulse," "celestial photography," and "electrical 

 radiation" may be specially mentioned. One of the communi- 

 cations, by A. Harvey, describing the behaviour of minerals at 

 very high temperatures, is very suggestive. His experiments 

 were made by means of a Barton electrical furnace, in which 

 the current proceeds through water to the negative pole, so 

 that an arc is formed where the mineral at the negative pole is 

 brought to the surface of the water. The mineral in this way 

 becomes surrounded by an intensely heated gaseous envelope, 

 and its surface is quickly melted, while a brilliant light is 

 produced. When removed from the water, the crust on the 

 surface of the mineral greatly resembles that .seen in meteorites. 

 Different minerals give out light of different colours, and usually 

 glowing particles are detached in very much the same way as 

 those which give rise to the trails of shooting-stars. The volume 

 also reports the proceedings of the Committee on the " unifica- 

 tion of time." It appears that of the nine nations publishing 

 ephemerides, six have formally given their assent to the pro- 

 posal that on and after the first day of January 1901, the 

 astronomical day should begin at mean midnight. 



