March i8, 1875 J 



NATURE 



395 



power from wave motion, by B. Tower ; Notes on polar dia- 

 grams of stability, &c., by John McFarlane Gray ; On com- 

 pound engines, by R. Sennett ; On the Bessemer steamship, by 

 K. J. Reed, C.B., M.K, vice-president. 



M. Wai-LON, the new French Minister of Tublic Instruction, 

 is an old University man ; he was for years Professor of History 

 in the Normal School. His appointment has given great satis- 

 faction to the French savants, and the reception which he had 

 ( n his installation on the 13th inst. was something more than a 

 formal congialiilation. 



An interesting study has lately been made by Prof. Holden, 

 nf the Washington Observatory, on the observations of Sir 

 William Hefscliel upon the satellites of Ur.anus. It is well 

 liuown that the latter astronomer sixty years ago announced 

 that Uranus was accompanied by six satellites ; but of the 

 existence of four of these there has always been considerable 

 doubt, since no one was ever able to confirm the observations 

 of Herschel. In 1847 Lassell discovered two interior satel- 

 lites, which were, however, different from those which Herschel 

 suspected ; and since that day the four problematical satellites 

 of Herschel have been generally discarded by astronomers. 

 Prof. Holden now brings testimony to the high excellence of 

 Ilerschel's observations, as, by computing backward, he has 

 shown that probably this distinguished astronomer actually 

 observed the two interior satellites of Lassell (named by him 

 Ariel and Um.briel) ; but that he was unfortunately prevented 

 from identifying them as satellites because his telescope could 

 not show them on two successive nights. The extreme diffi- 

 culty of observing these objects makes us wonder at the mar- 

 vellous skill and patience manifested by the elder Herschel in 

 this laborious research, which was carried on by him from 1787 

 to 1 8 10. 



The Imperial Astronomical Observatory of Brazil is a de- 

 pendence of the Central College of Rio Janeiro, and is destined 

 not only to teach practical astronomy to the students, but to 

 make and publish astronomical and meteorological observations. 

 The chronometers of the navy and army are there regulated, and 

 the time is given daily by signal to the city. The building is 

 situated on an eminence within the city, and the Government is 

 now taking measures to improve its scientific character. The 

 director is at present in Europe with a view of procuring such 

 instruments and apparatus as may be adapted to the studies 

 required of the institution. An entire reorganisation of the 

 Observatory is under way, with the purpose of training more 

 thoroughly the persons charged with geologic and geodetic 

 works. There is also an observatory at the capital of the pro- 

 vince of Pernambuco. 



We have received the Catalogue of the Library of the Man- 

 chester Geological Society, compihd by Mr. John Plant, F.G.S. 

 We are glad to see that the members of this Society possess so 

 good a collection of works connected with the various depart- 

 ments of geology, and we hope a large proportion of them take 

 advantage of the privilege. Mr. Plant has arranged the books 

 in eleven divisions, which will no doubt facilitate the work of 

 rerercnce, though it seems to us that divisions for works in 

 German, works in French, &c., are unnecessary. 



Mr. Henry Chichester Hart, B.A., one of the natu- 

 ralists appointed to the Arctic Expedition of 1S75, has pub- 

 lished an enumeration of all the flowering plants and ferns 

 known to occur in the Arran Islands, Galway Bay. The flora of 

 the whole of the west of Ireland is extremely interesting on account 

 of the south-west European types it includes, indicating the pos- 

 sible former existence of a connection between the British Islands 

 and the Continent. The Arran Isles flora includes no endemic 

 species, and, on account of their peculiar'geological formation, the 

 numbes of species is scarcely so large as might otherwise have 



been expected. The formation belongs 'to the Upper Carboni- 

 ferous Limestone, and consists of deeply-fissured platforms or 

 terraces, paved with large flags. Mr. Hart's list contains 372 

 species, including Dabeocia polifolia and some other West Euro- 

 pean forms. Ajifi^a pyramidalis and IleliantJumnm caiuitn are 

 at home here, and Gentiana verna is reported to be one of the 

 commonest weeds. One of the principal features of the flora is 

 the luxuriance of the ferns in the deep fissures of the rocks. The 

 true maiden-hair (AJiaiitiim capillus-veiieris) is said to be 

 common on all three islands, and often found with fronds two 

 feet long. In the same situations the fronds of Asplenium 

 marinum attain a length of three feet, and those of Cetcrach 

 officinarum a foot or more. Mr. Hart himself adds about 

 twenty-five undoubtedly indigenous species to those previously 

 known. 



With regard to the conservancy and working ot the East 

 Indian rubber-trees (Ficiis elaslica), the yield of which forms one 

 of the most important products of the Assam forests, we learn 

 that there have been three proposals made to Government ; the 

 first is that Government should annually sell the right to collect 

 the rubber ; the second, that the rubber should all be purchased 

 by Government ; and the third, that Government officers should 

 manage the forests. In opposition to this, however, it is said 

 that much of the rubber is brought in from forests by wild and 

 half-subjugated tribes, and still more by tribes that are under 

 no subjection at all ; so that conservancy is impossible, and a 

 Government monopoly very difficult. Only two courses seem 

 possible : either to allow speculators to make their own bargains 

 i\iih the hill men as they liked, or to enforce an effective Govern- 

 ment control. Sir George Campbell considers the latter course 

 to be the right one. The exports of caoutchouc, it appears, 

 which amounted to 21,000 maunds in 1871-72, fell in 1872-73 

 to 11,000, this decrease being attributed to the closing of the 

 Luckimpur forests with a view to preventing frontier compli- 

 cations. 



The quantity of sandal-wood sold in the provinces of Mysore 

 and Curg during the year 1S72-73 was 889 tons, valued at 

 27,896/. 



The growth of beet-root in Belgium for the manufacture of 

 sugar appears to be falling off, owing to its prohibition by land- 

 owners and the unwillingness of the farmers to cultivate it in 

 consequence of its exhaustive nature, a crop of beet impove- 

 rishing the soil considerably. It is said, however, that if the 

 fanners could act independently, considerable quantities of beet 

 would be grown, for not only would it then be advantageous to 

 them in a pecuniary point of view, but it -would furnish them 

 with a new and valuable food for the use of their cattle and 

 horses. In France, on the other hand, tlie cultivation of beet is 

 being extended, the pulp, after the extraction of the sugar, 

 proving very serviceable for fattening cattle. 



Dr. R. a. Pryor intends publishing a new "Flora" of 

 Hertfordshire, and to enable him to make it as complete as 

 possible, he has issued a circular containing lists of plants 

 respecting which further information is needed. Critical species 

 ■wall be thoroughly studied out. Webb and Coleman's "Flora 

 Ilertfordiensis" (1849), supplements to which appeared in 1851 

 and 1859, is a very good work, and the only "Flora" of the 

 county hitherto published ; but so much has been done in critical 

 botany of late that it is, in this respect, out of date. 



On Friday the I2th inst. an icy cloud passing before the sun 

 exhibited the laws of the formation of halos with an extraordi- 

 nary precision. The cloud, driven by an upper wind, was 

 travelling at a slow rate from south to north. A partial halo 

 was first seen on the northern edge, developed itself, lasted as 

 long as the cloud, occupied more than i6^° north and 164° south 



