439 
the velocity of sound , made in Holland. 
In the AUKN 
UNs= 22987“, 369 metres by General Krayenhoff’s Survey. 
The angle AUN = 6i° 23' 56", 324, measured by General 
Krayenhoff, # / „ 
A U K = 49 10 25,200 
</-KUN = i2 13 31,124 
ZlUKN = 95 43 25, 7 
Z_ U N K = 72 3 3, 2, concluded angle. 
Now calculating U K we have it 21978,2 metres. 
Further, in triangle U BK, we have 
0 t n 
UBK=76 4 6 23,24^ 
BKU = 5^ 43 32,73 >by calculation above-mentioned. 
BUK = 51 30 4,03^ 
This gives BK = 17669,3 metres. 
d. Fourth triangle. 
Kooltjesberg. 
K 
In this triangle, U A K, the distance U A from Utrecht to 
Amersfoort, is known from General Krayenhoff’s Survey, 
19574,090 metres. 
