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Fig. 1. Old and New Ghapa Town. The American photograph (left) shows Old
Gbapa but also the embryo of New Gbapa. The Lamco photograph (right), taken
by Mapping Consultants Ltd about five years later, shows New Gbapa as well as
the remnants of Old Ghapa. The pictures are stereoscopically orientated by means
of the road and the creek at the top of the photograph. Scale about 1 : 40,000.
series of photographs were three places of which one, Gbapa Town,
did not correspond to the others at all.
The town of Gbapa was well defined, too, but unfortunately its
locality in the both editions of photographs did not correspond to each
other. After a long time of analysing this unexpected discrepancy of
some 800 m was explained by the Liberian Goverment. As a matter
of fact the Gbapa Town had simply begun to be moved just in 1953, a
fact that actually could be proved by a stereoscopical study of the
pictures.
This fact was checked photogrammetrically in the following way.
An excerpt of the American picture of 1953 including the Gbapa Town
and the corresponding picture of 1957 of the same place were studied
stereoscopically together, fig. 1. In this way, changes during the passed
four years could be studied closely. It was evident that the Gbapa Town
of 1953 had no obvious equivalence to the corresponding photograph
of 1957. However, the stereoscopical study revealed a very small em
bryo of the new Gbapa Town already in 1953 caused by a decree by
the medicine-man on moving the town because of the risk of being-
overflowed by the river contigous to the town.