A — 
C 
E 
r 
A 
A 
. 
• 
• 
• 
, 
A A 
A l 
S 
» 
» 
■ 
• 
» 
L 
i A 
— B 
— D 
• 
» 
• 
• 
» 
1 
• 
» 
A 
» 
• 
• « 
« 
• 
« 
< 
A 
i 
• 
• 
« 
« 
« 
• 
• 
A A 
A 
A 
A 
A 
7“*— 
. • 
• 
• 
• 
• 
• 
A A 
A control point 
pass point 
. lateral pass point 
After having prepared the photographs for the second strip, and 
examining also those of the third, the second bridging can be effected 
always in the direction of the flight, this time using for the planimetric 
orientation of the first stereogram, the known points in common with 
the last stereogram of the preceding strip or any 2-^3 lateral pass 
points substituting them. 
After completing the second bridging, we shall carry out the ana 
lytical connection between the two strips A and B, by using the same 
sequence of calculations and using the various lateral pass points 
common to the said strips (the 2-^3 lateral pass points of the first 
stereogram for the calculation of r Q , s Q , a and b\ the others to de 
termine the functions r and 5). 
After effecting this closing up, the operational cycle will restart 
from the beginning by preparing the photographs for the third strip C 
at the same time examining the fourth D; then the bridging by making 
use of the 2-^3 initial points of lateral passage derived from B; the 
closing up of this strip with the preceding one on the other lateral pass 
points, and so on till all similar operations to complet the bock are 
exhausted. 
9