ASTRONOMY AND METEOROLOGY. 305 



name of the three saints of ice (May 11, 12, 13), and the summer of 

 Saint Martin (November 11). In a new work with the above 

 title, presented to the French Academy, May, 1867, he shows that 

 the tact is general, and that this connection or mutual dependence 

 of the four opposite days exists during the whole of the year ; 

 whether we take into consideration a considerable cycle, 110 

 years at Berlin, 90 years at Vienna, 50 at London, 40 at Prague 

 and Edinburgh, 30 at Brussels, 24 at Toulouse, 21 at Paris, or 

 whether we take in this point of view an isolated year (1864) on 

 several European stations. 



The former, depending upon the same data, establishes, in fine, 

 that this connection is evident also when we combine 12 by 

 12 the days separated one from the other by 30 of the ecliptic. 



The latter phenomenon constitutes the meteorological month, as 

 the season was established by the consideration of the quadruple 

 clays. 



METEOROLOGICAL SUMMARY. 



Transparency of the Air. According to M. De la Rive, of Gene- 

 va, the great transparency of the air before rain is owing to the 

 presence of a quantity of invisible vapor, which renders transpar- 

 ent the numerous germs floating in the air, to whose presence 

 light mists are attributed. 



Solar Radiation. From a series of observations made by M. 

 Soret, with the actinometer, it appears that the moisture of the 

 atmosphere influences the intensity of direct solar radiation ; and 

 in general, other circumstances being the same, the more aqueous 

 vapor the air contains, the less intensity there is in the radiation 

 of solar light. Radiation increases with altitude ; but its increase 

 is less rapid than the fall of the barometer. The density of the 

 atmosphere being the same, the radiation observed at a great alti- 

 tude is undoubtedly stronger than at a lower one, and the diminu- 

 tion of radiation as the sun inclines toward the horizon is much 

 less at a high altitude than in the plains. 



Temperature of the Lower Strata of the Air. It appears from the 

 latest observations on temperatures of the air at different altitudes, 

 that at a distance of 24 feet above the ground it is generally higher 

 than at other elevations. Great differences are observed, espe- 

 cially previous to thunder storms. 



Temperature of the last Winter. Prof. Loomis, of Yale, states 

 that the average temperature in the month of February was 7 

 degrees* higher than the average for this month for the last 88 

 years, and that it counterbalances the excessive cold of the 

 2 preceding months ; so that on the whole the past winter must 

 be ranked as an ordinary one. 



Changes of Temperature during Solar Eclipses. According to 

 M. Berigny, " Comptes Rcndus," March 18, 1867, when the sky 

 is free from clouds during an eclipse of the sun, the temperature 

 is lowered, and increased when the sun is obscured by clouds. 



26* 



