the angle of lateral inclination of the left and right photograph* 
being the result of the relative orientation, made by the usual 
methods and 
th9 additional angle of inclination, necessary to the levelling of 
the model. 
After these two operations for the outer orientation we obtain as a re 
sult the sum, according to the equation/2/. This sura gives the angle of 
the outer, lateral inclination of the air photograph. 
U) - 
og 
Flight ^aXtijtude_/H/ 
If, after the final orientation, we read on the ^ scale 100^, that 
og 
is, if the basis of the stereogram was horizontal, then the flight heights 
for the both photographs above a horizontal plane of reference would be 
equal. This height can be read from the Z - column of the autograph; the 
index of the column would show then on the scale the proper flight height of 
\ 
8