709 



appeared to be marked by causes of perturba- 

 tion. We now know that this assertion de- 

 mands some restriction for Rio Janeiro. Hi- 

 de Freycinet, who stopped at this port in his 

 last voyage round the worlds found in the 

 month of August, consequently in more serene 

 weather, the greatest regularity in the horary 

 variations *. 



OBSERVATIONS AT RIO JANEIRO, JN 1820. 



HOURS OF THE 

 OBSERVATIONS. 



HEIGHTS OF 

 THE BAROME- 

 TER in hun- 

 dredths of 

 millimeter. 



OBSERVATIONS S. 



HEIGHTS OF 

 THE BAROME- 

 TER in hun- 

 dredths of 

 millimeter. 



11 



+ 766.71 

 766.77 

 766.59 

 766.15 



— 765.65 

 765.67 

 765.78 

 766.00 

 766.35 

 766.49 



-{- 766.91 

 766.96 



23 



76665 

 765.96, 

 765.76 

 766.04 

 764.28 

 764.28 

 764.49 

 764.43 

 765.33 

 764.69 

 766.38 

 766.55 



midnight 



13 



noon 



1 



14 ...... 



2 



15 



3 



16 



4 



17 



5 



18 



6 



19 



7 



20 



8 



21 



9 



22... 



10 



* Barometer of Fortin. The heights are reduced to the 

 temperature of zero. If we would have them corrected of 

 the error of the level, it would be necessary to add 0 mm ,922„ 



