784 



OBSERVATIONS OF THE CYANOMETER. 



Days. Cyanom.Th. R. Hygr. 



18 Jug. 

 noon. 



29 noon. 



30 noon. 



31 noon. 

 11 Sept. 



7 h m. 



5* 



9 

 10 

 11 



3e. 

 14 



7 m. 

 9 



10 



noon. 

 16 



8 m. 

 9 



r 11 

 18 



6| m. 

 7 



H 



8 

 9 



91 

 11 



noon. 

 1 



3 



21o 



22.40 



38° Deluc. 



22 



24.5 





19 



OA Q 

 Z'i.O 





16 





O-CJ ft 



38,9 



11.3 



18 



42 



14 



20.3 



41.5 



13 



20.2 



41 



14 



22 



36 



14 



23 



31.5 



17.7 



22.9 



30 



18 



23.6 



30 



13.7 



18 



47 



17 



21.2 



40 



18 



21.7 



35.4 



23 



23.8 



30 



14.5 



17.5 



43 



18.5 



20.8 



41 



19-5 



22 



34 



15 



18.4 



43 



16.3 



19.2 



41.7 



17.0 



20.3 



41 



17.8 



21.3 



40 



17 



21.4 



38.2 



18 



21.7 



36 



22 



23.5 



32 



22 



23.8 



29 



23 



24.5 



29 



17 



24.3 



32 



Days. Cyanom.Th. R. Hygr. 



19 Aug. 

 7 



n 



8 



H 

 9 



9| 

 11 



15° 



16.8 



18 



20 



20 



20.4 



19 



18 



18 



16.7° 

 17.5 

 19.4 

 19.5 

 21.2 

 21.7 

 22.6 

 23.5 

 23 



40.7° 



39 



38.5 



37.4 



36 



35 



33 



30.2 



29 



The observations of the cyanometer 

 were extremely fatiguing, on account 

 of the intensity of the light in those 

 regions. Calm and serene days were 

 chosen. The observation always at the 

 zenith, or near the zenith. When the 

 wind rises, the tint of the sky becomes a 

 little paler, without any change in the 

 hygr., or the vesicular vapors becoming 

 visible. The colour of the sky is gene- 

 rally at Cum ana, from 22° to 24° at 

 noon, by the cyanometer of Saussure, 

 while at Paris (by 20o R. of tempera- 

 ture) it is most frequently . 1 6°. Some- 

 times (the 31st of August, and the 19th 

 of September) the sky was singularly 

 pale, without there being the least breath 

 of wind. See above, vol. ii. p. 95, 109. 



