SHORT MEMOIRS ON METEOROLOGICAL SUBJECTS. 



387 



Influence of Eain on Pressure in Batavia. 

 I.— EAINS BETWEE:N" 9 A. M. AND 9 P. M.» 



II.— EAIXS BETWEEN 9 P. M. AND 9 A. M. 



32 



1866 



18G7 



1868 



Mean 



8.60 

 9.26 

 9.66 



8.70 

 9.29 

 9.79 



8.86 

 9.41 

 9.92 



9.00 

 9.48 

 9.75 



9.00 

 9.58 

 9.85 



8.72 

 9.51 

 9.85 



8.85 

 9.53 

 9.71 



10.3 

 11.2 

 15.9 



2.6 



21.5 



6.1 



5.4 

 9.6 

 3.7 



5.6 

 4.7 

 0.9 



5.0 

 2.4 

 0.2 



3.6 



Here also, during tbe rainfall, the pressure rises, and after the rain 

 stands higher tbau before. If we start with the pressure before the 

 beginning of the rain, and compute the hourly changes, we obtain the 

 following variations of pressure: 



The pressure rises at the beginning and during the first hours of the 

 rainfall by about 0.35; it falls* within the two hours following the rain 

 by 0.10, and therefore after the rain it always stands 0.25 higher than 

 before. The changes at night-time are somewhat smaller than during 

 the day-time. I have also combined in one average thirteen cases of 

 the heaviest rains (over 20 millimeters an hour) ; they give the following 

 changes: 



The barometer stands 0.22 higher after the rain than before it. 



