Y: v 
graph Wild A6. The following data were obtained: 91 = 0.685, 
Wi == 1.94c¢, P2 == —0.23¢, wz = —0.80¢. 
To determine whether this tilt could considerably affect the : 
result of the measurements, the errors in a height difference of 
20 m were calculated in accordance with what has been said 
above. The result is shown in Fig. 8. 
+01 edi tte 0 0 +4 
40 J 4 0 
pe NL 
0 
+01 ^3 +/ 
e 25 0 SS 
0 
0 -06 = n NS. 
2 49 4? A à 
ou. 
Qo Le 26 d 
-66 2 0 NT. 
-6 E * 
-4 
-Q, Jo -88 
d£ a7 d = 5 E 
% + 
Figure 8, * 
Errors (dm) in height differences of 20 m, 
P, — 0.687, 9, — 1.915, P, = — 0.23°, w, = — 0.805, 7 = 0, h = 2500 m. 
Focal length 0.15 m. 
The effect of the tilt of the left picture is shown by the left figure. The 
effect of the tilt of the right picture is shown by the middle figure. Resul- 
ting errors are shown by the diagram. 
2. 16. Errors caused by the approximation of the formula. 
The formula used for height difference calculations Ah = pt. 
€ $ 
h Ap! +h? 
'411$ an approximation of the correct formula Ah = : 
b be+ Ap'h 
The approximate formula gives too high values. The errors in- 
crease for decreasing h and increasing Ah. 
3 ; ELE {Ah ^, T 
For corrections the term: — is used. The errors 
1 
amount in some cases to the following values: 
14 
+ +