4 46 
Dr. Moll’s account of the experiments on 
the accelerating or retarding effect of wind, on the 27th of 
June, 1823, equal to 51 " ,96. And as the basis was equal to 
17669,28 metres, or 9664,7044 fathoms, we have the velocity 
of sound, found by experiment as above, equal to 340,06 
metres, or 1116,032 English feet per second. 
Now, whilst these 22 shots were fired, the mean tempe- 
rature of the air was 
At Zevenboompjes = ii°,2i-i 
Kooltjesberg =11 11 
>■ Of centigrade scale. 
{ 
11 16 
Mean temperature 
on both stations 
The mean altitude of barometer corrected of the effect of 
capillarity, and reduced to the temperature of o° of centri- 
grade scale, was as follows : 
Station of Zevenboompjes . . o m ,74 39 
Kooltjesberg . . . o 7456 
Mean altitude of barometer . o 74475 == p. 
The mean tension of aqueous vapour in the atmosphere, 
as determined by Mr. Daniell’s hygrometer, was at 
Station of Zevenboompjes = 0,00901235 metres. 
Kooltjesberg = 0,00949378 
Mean tension of aqueous vapour, 0,00925307 = /. 
The effect of gravity, calculated for mean latitude of 
Amersfoort and Naarden, by the formula 
g = (g) (1 — -0,002837 cos. 2 /) 
9808,8 
■jl — 0,002837 COS. 2 ^52°! 3' 33" 35 J j 
1,000378864 
g = 9812,03 = effect of gravity in lat. 52 0 13' 33 ", 35 * 
