132 



In this case it is not necessary for him to proffer an explanation 

 of the change of the phase with the height, as shown bj the variation 

 of the air pressure. 



Of this he only says (p. 37) : "This diminution is probably 

 due in part to the greater resistance to motion near the earth's 

 surface; it may be due in part also to a change in the phase of 

 the semidiurnal temperature variation in the free atmosphere". 



As regards the latter, there are, in effect, only two determinations 

 available for the free atmosphere, ^) i.e. at Lindenbeig and at Batavia. 

 No trustworthy results may be derived from mountain stations. 



Phase of the semidiurnal variation. 



Height 



Lindenberg 



Temp. 



Airpress. 



Batavia 



Temp. 



Airpress. 



At Batavia, therefore, the phases of temperature and pressure 

 move in opposite direction and at Lindenberg there is no pronounced 

 sense of change for the temperature. 



On p. 39 Gold writes: "The difference of phase (between tempe- 

 rature and pressure variation) ought to diminish only slowly with 

 the height ; for latit. 45° this decrease would only be 45° at a height 

 of 10 km.". 



Lindenberg feebly agrees with the above, but at Batavia the 

 diminution in difference of phase is too pronounced, the change 

 in phase (with the height) of the airpressure agreeing indeed, although 

 to a smaller degree. 



Thus Gold finds (see p. 38, note) from a graphical combination 

 38° diminution in phase for an increase in height of 3 km.; for 

 Batavia-Pangerango (difference in height also 3 km.) 18° has been found. 



Further from Gold's results we find for the North and East 

 components of the horizontal wind variation at the latitude of 

 Batavia's (phase as compared to the one of the pressure variation) 



1) See Observatory Batavia Verhandelingen 4, pg. XXXIX. 



