Intelligence and Miscellaneous Articles. 



479 



on entering this atmosphere may be expressed by saying that a 

 bundle of rays having a section of a square inch would in one minute 

 raise the temperature of a cubic inch of water by 0*733 of a degree 

 Centigrade. 



3. The loss of heat in the passage of the rays through the atmo- 

 sphere, according to measurements made on different days and in 

 different seasons, with apparently clear days, diminishes by amounts 

 which materially differ from one another. The logarithms of the 

 factors which denote the absorption on a path the length of the 

 earth's radius vary between —3 and —38. 



These results were finally compared with those of Pouillet, and it 

 was found that for the factor mentioned, the latter denote indeed 

 much narrower limits, but still values which coincide with those de- 

 veloped here. Pouillet, on the other hand, found the heat of the 

 sun's rays to be one-eighth less ; and this difference appears to be 

 explained by the fact that the height of the atmosphere was taken 

 too high, and put equal to the eightieth part of the earth's radius. — 

 Berichte der Berliner Akademie, November 1863. 



STATE OF METEORIC SCIENCE. BY A. S. HERSCHEL, ESQ. 



It is a saying of Arago, founded originally upon observation, and 

 confirmed by constant experience in later years, that the earth en- 

 counters more shooting-stars in going from aphelion to perihelion 

 than in going from perihelion to aphelion. In point of fact, be- 

 tween the north latitudes of 49°'5 and 54°'2, Dr. Julius Schmidt, 

 the indefatigable Director of the Observatory at Athens, observed, 

 during eight years, from 1843 to 1850, on an average 470 meteors in 

 every year. His observations were distributed in the several months, 

 according to the following average of the entire series : — 



Anomalistic 

 Year. 



Aphelion 



to 

 Perihelion 



Perihelion 



to 

 Aphelion 



Shooting- 

 Month, stars. 



July 49 



August 188 



September. ... 41 



October 37 



November .... 54 

 December .... 31 

 January 17 



Total 

 Shooting-stars. 



> 400 



February 

 March . 

 April . . . 

 May 

 June 



5 

 11 

 11 

 12 

 14 



70 



I 



Total 470 



Supposing, with Arago, that shooting- stars are meteorites or 

 particles describing planetary orbits in all directions round the sun, 

 no one of these meteorites can overtake the earth, if the native 

 velocity of all is less than the planetary motion of the earth itself; on 

 the contrary, the earth will overtake, in a greater or less degree, the 

 whole of those which it meets, if we suppose its velocity to be 

 greater than that of every individual shooting- star. Even upon 



