PHYSICAL AND METEOROLOGICAL RESEARCHES. 



205 



spots, the faculte, and the eruptions are certainly an indication of a 

 greater activity of the sun. It is not surprising-, then, if the epochs 

 of the maximum correspond with years of higher temperature. An 

 increase of heat may, however, produce cold; for instance, the melting 



10.5' 



9.5° 



9° 

 1400 

 1200 

 1000 



800 

 600 

 400 

 200 

 



10.5° 



10° 



9.5° 



9° 



1400 



1200 



1000 

 800 

 600 

 400 

 200 

 



1878-73 79-80 81-81 81-82 82-83 83-84 84-85 85-86 86-87 87-88 88-89 89-90 90-91 91-92 92-93 93-94 9495 95-96 

 Fig. 6. — Relation between temperature and sun spots, using 2-year averages. 



of ice in the polar regions, resulting in the detaching of icebergs by 

 causing cold currents in the sea, will produce a low temperature in 

 some region. 



STUDY OF THE SOLAR RADIATION. 



It is possible, by means of proper apparatus, to measure the caloric 

 and luminous radiations of the sun. This can be effected either by 

 allowing the radiations to act together or by separating and distin- 

 guishing their relative actions. The apparatus at the station con- 

 sisted of a Yiolle actinometric register, a brilliant gilded and black 

 combined thermometer, two vaporizing actinometers, a sunshine regis- 

 ter, an horal photometer, and a Cooke radiometer. A record made in 

 1896 showed the following amounts of heat, by months : 



Total amount of heat at Juvisxj during 1896. 



Month. 



Calories. 



January j 2,582 



February , 6. 4G7 



March 9,862 



April ! 11, 776 



May 18,606 



June 14, 778 



July 15, 393 



Month. 



Calories. 



August j ».j|"{ 



September ^68 



October | ?<V 7 



November y™' 



December Z ' 03i 



Total > m. 837 



