PHYSICS AND NATURAL HISTORY OF GENEVA. 191 



the lines of the solar spectrum, which, at an elevation of four miles above the 

 ground, remain identical with those on the surface of the earth, only the spectrum 

 diminishes in extent in proportion to the elevation attained ; sixthly, on the dis- 

 covery of a satellite of Procyon ; on the light of >j of the Ship, which, in the 

 space of twenty years, has passed from the first to the sixth magnitude ; and 

 finally, on a deviation of 10" of the plumb-line in the environs of Moscow, at a 

 distance from any description of mountain. 



Meteorology. — Memoirs. — The great and valuable labors of our future 

 president. Professor Plautamour, on the climate of Geneva, pertain by peculiar 

 right to our society, and would have occupied a distinguished place in the col- 

 lection of our memoirs, if their extent had not compelled the author to have them 

 printed and published separately. This work, oue of true scientific importance, 

 inasmuch as it is based on observations executed with improved instruments, 

 and repeated every day and several hours of each day for thirty- five consecutive 

 years, and finally discussed with all the resources of modern science, could not 

 be analyzed in a report necessarily so much circumscribed as the pi'esent; 

 besides that, it would now be the more useless to attempt such analysis, since 

 Professor Aug. de la Rive has recently given, in the archives of the physics and 

 natural sciences of the Bibliotheqae Vniversclle, a detailed and highly interesting 

 account of the enterprise. 



Verbal reports. — Professor Plantamour communicated some of the results 

 obtained during the month of January last, at the meteorological stations of the 

 valley of the higher Rhone. Some singular anomalies of temperature have there 

 been realized. Thus, among others, it was found that it was colder at the vil- 

 lage of Rechingen (valley of Conches) than at the hospice of Saint Bernard, 

 though the latter is situated i,140 metres highe«r than the village. ,• These anom- 

 alies may be explained sometimes by the presence or absence of the sun, and 

 sometimes also by the cold air flowing from the mountains anC accumulating 

 gradually in the iDosom of the narrow valleys. Professor Marcet informed us of 

 the results of M. Glaisher on the diminution of the temperature of the air in pro- 

 portion to the elevation attained — results gathered in England and by means of 

 balloon ascensions. The diminution is not regular, most probably from circumstan- 

 ces purely accidental, such as momentary currents of cold air, or enormous strata of 

 vapor, which arrest the solar heat and reflect it toward the higher spaces. After 

 traversing cold mists of some thousands of feet in thickness, M. Glaisher found at 

 11 or 12,000 feet of elevation the same temperature as at the surface of the earth. 

 Professor Wartmann reports, in relation to atmospheric electricity on high 

 mountains, that it had been observed this year in an ascension of the Jungfrau, 

 as had been done the year before on the Diablerets, that at the approach of a 

 Btorm the iioned staves of the tourists commenced intonating, and that singular 

 sounds were heard in the air. Professor Gautier spoke of torrents of rain hav- 

 ing fallen in Italy, in February last, accompanied, at Rome, by a furious hurri- 

 cane, which transported thither sand entirely similar to that of the desert of 

 Sahara. Prdfessor Marcet remarked upou the relatively very mild temperature 

 of the winter of 1863-64, in Canada, a fact which navigators believe they ac- 

 count for by a change observed*, as they suppose, in the direction of the Gulf 

 Stream. M. Chaix read to us a report on the results of late travels in Arabia, 

 and particularly those of Palgrave, who succeeded in traversing the country by 

 passing for a Syrian. 



Mathematical and Experlmental Physics. — Mc?noirs. — M. Ch. Galopiu 

 ■ read an extract of a memoir on the mathematical theory of double refraction. 

 After reciting the principles on which rests the theory of Fresuel, and having 

 indicated the process followed by that eminent physicist for applying analysis 

 to transcendental researches, our colleague adopts as his own the views of Cau- 

 chy, who regai ds the movement of light as a particular case of the movement of 

 a system of molecules, very slightly diverted from their position or equilibrium, 



