1G4 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



a preponderant part is clue to the absorption to whieh they 

 are subjected before traversing our atmosphere; that in fact 

 the absorption which they experience in traversing the solar 

 atmosphere itself has deprived them of a large part of the 

 rays that are absorbable by water. 



We have in former summaries omitted to call attention to 

 an elaborate historical and critical memoir, by Crova, in the 

 Annates de Chimie et de Physique, for August, 1877, on solar 

 radiation and absorption in the earth's atmosphere. A short 

 but suggestive article on the same subject, by Govi, will be 

 found in a recent number of the Paris Comptes Kendus. 



The ultra-violet spectrum has been studied by Cornu. By 

 employing quartz object-glasses, he is able to show that the 

 spectrum varies with the time of day, having a maximum 

 about mid-day; it is also longer in winter than in summer. 



On the subject of solar radiation, the work of Radau, "Les 

 Radiations Chimiques," is to be commended to those who ex- 

 tend their meteorological investigations to the fundamental 

 question of the absorption by the earth's atmosphere of the 

 solar radiations. 



Mr. G. M. Whipple, of the Kew Observatory, communi- 

 cates to the British Meteorological Society a memoir on the 

 Relative Duration of Sunshine at Greenwich and at Kew. 

 He finds that at Greenwich the sunlight is cut off by fog or 

 smoke when the wind blows from west-northwest or north, 

 but by east and southwest winds the fog or smoke is blown 

 over Kew, cutting off its sunlight. 



Rubenson has examined the diurnal variations of tempera- 

 ture at Swedish stations, and finds (1) the non-periodic varia- 

 tion is throughout the year greater than the periodic; (2) 

 the difference of these two variations is greatest in winter; 

 (3) during the remainder of the year the difference is nearly 

 constant; (4) the difference 2.66 in spring, 2.82 in summer, 

 3.03 in autumn can be assumed to hold good apparently for 

 the whole of Sweden. The difference in question is greater for 

 a maritime climate, and least for one of a continental type. 



In a communication to the French Association at Havre, 

 Glaisher mves the results of all his observations in balloons 

 upon the decrease of temperature of air with altitude. He 

 finds an increase during the night-time, and a more rapid de- 

 crease during the day-time than is usually accepted. Eleven 



