1318 



For the stratosphere it was assumed that temperature should 

 increase regularly with altitude, so much so that at the level of 

 26 km. it would reach the value — 57°. 2 C,, as was observed on 

 the 4''' of December 19J3. 



Month 



Height Temperature 



Month Height 



Temperature 



89.1 C. 



88.1 



87.4 



86.9 



86.4 



85.1 



July 



Aug. 



Sept. 



Oct. 



Nov. 



Dec. 



16.0 km. 

 16.5' 



n.o 



17.4 

 17.6 

 17.7 



— 82.8 C. 



— 80.8 



— 80.5 



— 82.8 



— 86.6 



— 88.8 



Having calculated this table of monthly values of airpressure, 

 I made an attempt to draw isothermal charts of the Archipelago 

 for Jan. /Febr. and July/Sept, with the aid of the results of tempe- 

 rature observations made at meteorological stations in the Neth. 

 Indies and the surrounding regions. 



Founded on these charts as well as on corresponding isobaric 

 charts drawn by Dr. Bk.\ak ^), isobars have been calculated for 

 each km. -level up to a height of 10 km., the required values for 

 the vertical gradient of airpressure being taken from table III. 

 Moreover it has been taken into account that in the same season 

 the atmosphere has a contrary character (dry and wet) north and 

 south of the equator. 



The uncertainty, unavoidably attached to the isothermal lines 

 designed, and to the values of the vertical gradient, was evidently 

 much too great not to render the results wholly unsatisfactory. On 

 the surface of the earth isotherms and isobars run somewhat 

 parallel to each other, but their horizontal gradients have contrary 

 signs. Consequently, when rising in the free atmosphere, the in- 

 fluence of increase of airpressure in any direction at the bottom 

 being positive, it is counterbalanced partly by the negative influence 

 of temperature. 



The result, being a difference, is extremely susceptible to small 

 variations in the bottom values of isotherms and isobars, so that it 

 is the uncertainty attached to them, which is greatly increased and 

 spoils the results. 



Wesimonsoon. In the westmonsoon the direction of the wind at 



^) Observations at Secondary Stations in N.-l. Vol. I. 



