482 



NATURE 



{Sept. 18, 1879 



The apparent diameter of Mars, assuming the diameter 

 at the mean distance 9"-4iS, will be i7"-8 on October 10 

 and i9"-5 on October 31. The value adopted depends 

 chiefly upon the double-image measures, and is smaller 

 than that introduced in Leverrier's Tables of Mars, which 

 ■was derived from observations with meridian instruments. 

 The period of revolution oi Deitnos is 3oh. 17m. 54s., and 

 the mean distance from the centre of Mars 14,500 miles, 

 so that the average orbital velocity is 50 miles per minute. 

 The excentricity appearing to be very small. Prof. Hall 

 assumes a circular orbit for prediction in 1879. 



The First Comet of 1699. — This comet was observed 

 at Paris by Cassini and Maraldi from February 20 to 

 March 2, and at Pekin by the Jesuit missionary, De 

 Fontenay, from February 17 to February 26. The single 

 orbit which figures in our catalogues was calculated by 

 Lacaille ; the following elements by Mr. Hind depending 

 upon the observations of February 19, 24, and March 2, 

 are very similar to Lacaille's, the only noticeable differ- 

 ence being an increase of rather more than 1° in the 

 inclination : — 



Perihelion passage, 1699, January 13-3998 G.M.T. 



Longitude of perihelion 212 8-8 



,, ,, ascending node 321 41-5 



Inclination 7° 36'6 



Log. perihelion distance 9-87426 



Motion — retrograde. 



The re-examination to a certain extent of the cometary 

 orbits resting upon a single calculation appears by no 

 means a futile work, as was shown by the circumstance 

 pointed out in this column some time since, that Halley 

 had inadvertently given the longitude of the descending 

 node of the comet of 1698, in his " Synopsis of Cometary 

 Astronomy," in place of that of the ascending node, and 

 the mistake has been continued in all our catalogues. 



NOTES 

 The latest conflagration at Irkutsk has destroyed all the 

 libraries of the town — the Public Library, the private one of M. 

 Vaghine (which contained the unpublished MSS. of Gedenstrom), 

 and that of the Siberian branch of the Russian Geographical 

 Society, which latter contained a great variety of works about 

 Siberia, some of them being very rare, a great number of works 

 and MSS. on Buddhism, numerous collections of publications of 

 foreign scientific societies (Kuropean, Asiatic, and American) 

 who exchanged their publications with the Siberian branch, and 

 a large assortment of works on physical sciences and natural 

 history. The destruction of this library will be a very great loss 

 to science altogether, if a new one be not immediately created. 

 It would be difficult for a man of science inhabiting a great city 

 or even the smallest town in Western Europe to understand the 

 important services which this library — the only one in Central 

 Asia — has rendered in the development of scientific knowledge 

 and in giving a scientific character to the geographical explora- 

 tion of Siberia. Many scientific men when staying in Irkutsk 

 have largely made use of the library (we may name among them 

 the well-known president of the Berlin Geographical Society, 



Prof. Bastian, and quote his interesting notice on Irkutsk), and 

 the writer of these lines can testify, from his own experience, 

 how immense were the services rendered by this library to him 

 and to his young friends when they began their studies for 

 scientific geographical explorations of Siberia at Irkutsk, i.e., at 

 a distance of some thousand miles from all intellectual centres. 

 We think that all those who have the further development of 

 scientific exploration at heart, should do their utmost to assist 

 in creating a new and good library in. that centre for the explora- 

 tion of Siberia. 



On August 20 last, the centenary of the birth of Berzelius 

 was celebrated in a fitting manner at Stockholm. All the 

 principal newspapers commented on the event in leading articles, 

 and reminded their readers in enthusiastic terms that through 

 LinnjEus and Berzelius Sweden obtained citizen-rights in the 

 world of science. At Vafversunda in the province of SmSIand, 

 the birth-place of Berzelius, a monument to the great chemist 

 was unveiled on the same day, in the presence of a large con- 

 course of country people. 



The steamship Faraday, whicH has successfully laid the new 

 transatlantic electric cable from Scilly to Newfoundland, returns 

 to Woolwich to take on board the shore end and the cable to be 

 laid from Newfoundland to America. The Siemens electric 

 works at Charlton are just now busy completing the preparation 

 of these parts, which will be ready by the end of this mon'h, 

 when the Faraday will be moored in the Thames to receive 

 them. 



The steamer Dacia left Greenwich a few days ago in order to 

 lay the second electric cable which is to connect Marseilles and 

 Algiers. When this communication has been established the 

 tariff of telegraphic messages between France and Algeria will 

 be diminished by half, being reduced to \d. a word instead of 2d. 

 as now. It is supposed that the augmentation of traffic with the 

 colony will result in an increased income to the Government. 



On September i snow fell in the village of Neustadt 

 (Holstein). 



A TERRDiLE whirlwind is reported from the village of 

 Hopsten, near MUnster (Westphalia). It occurred on Augrst 

 26, at seven p.m. The largest oaks were uprooted and broken 

 down ; many houses were partially destroyed, and debris of all 

 kinds marked the path of the atmospheric disturbance, whi.ch 

 proceeded in an easterly direction. Strange to say, the most 

 complete calm reigned everywhere around at the time. 



Phylloxera has now made its deplorable entry into Italian 

 vineyards. The destructive insect has appeared in the province 

 of Como. The local authorities are making every effort to 

 combat the plague. 



It was proved some time ago by M. de Ileen that, for metals 

 belonging to the same natural group, the product of the coeffi- 

 cient of expansion by the absolute temperature of fusion is a 

 constant quantity. In another memoir just presented to the 

 Belgian Academy, M. de Keen inquires how the coefficient of 

 expansion of water varies with the nature and quantity of sub- 

 stances dissolved in it. He proves that there is also a re- 

 markable relation between the coefficient of expansion of organic 

 liquids belonging to the same homologous series and their boil- 

 ing point ; the product of the one by the other is a constant 

 quantity. In connection with this, M. Spring points out that 

 M. Pictet, guided simply by ideas introduced into science by 

 thermodynamics, has come to the same conclusions as M. de 

 Ileen. M. Pictet shows (l) that temperature is represented by 

 the length of calorific oscillations of the molecules of a sub- 

 stance ; (2) that the temperatures of fusion of solids correspond 

 to equal lengths of oscillations ; and (3) that consequently, the 

 product of the lengths of oscillation by the temperatures of 



