Atmospheric Waves 1 1 7 



15 f statute miles an hour. It could carry and fire efficiently, 

 as had been proved by experiments which he quoted, 

 a heavier armament than any other vessel of the same 

 size in the British Navy. As a sister ship had already 

 proved its competency in heavy weather, naval officers 

 had considered such vessels to fulfil all the requisites of a 

 good sea-boat. 



At the sgth meeting (May 22nd) Professor Bond of 

 Harvard Observatory, and M. Metelet were present as guests. 

 The former spoke of the progress made in applying the 

 daguerrotype to astronomical purposes. Attempts made at 

 Boston to photograph the sun had been failures, notwith- 

 standing every precaution, because of the intensity of the 

 light, but the Cambridge telescope of 22 feet focus and 15 

 inches aperture had succeeded well with the moon. Records 

 of the double star Castor and of Jupiter with its belts and 

 satellites had also been obtained. 



Afterwards M. Metelet described the method of tracing 

 atmospheric waves by comparing times of the actual and 

 expected barometric minima at different stations. The 

 atmospheric oscillations appear to proceed from the north, 

 and travel more readily over the sea : large tracts of land, 

 and particularly mountain chains, such as the Urals, pre- 

 senting a barrier to them. In the progress of these waves 

 the oscillating air appears to set up two currents, the upper 

 one proceeding from north to south, and the under in the 

 reverse direction. The lines of vegetation seem to have 

 some relation to these waves, but that has not yet been 

 accurately established. Colonel Sabine remarked that 

 observations in America would be most valuable, because 

 of the peculiar physical character of that continent. 



Professor Plantamour, a guest at the 4oth meeting 

 (June i Qth), mentioned that barometric observations made 

 at Geneva and at the Convent on the Great St. Bernard, 1 

 showed that temperature produced differences, which might 

 amount to 120 feet, between the observed and the calculated 



1 He published an elaborate essay on them in 1860 (Mem. de la Soc. de 

 Physique et d'Histoire Naturelle de Geneve, t. xv.). 



