526 
Fig. 5. A cross-section of the defence wall on the grassfield near the Lamco 
Saw-Mill. 
4.1 The Lower Grassfield at Nimba Headquarters Camp 
The stereoscopical pair of pictures show the Headquarters Camp on 
the Upper Grassfield at Nimba and the Airstrip on the Lower Grass- 
field. Along this field the run-way is represented by the light-coloured 
band. Clearing work has partly destroyed the original wall. 
At the end of this area, also light-coloured, a semicircular contour is 
perceptible indicating the remains of an old ring-shaped town wall. 
The sketch illustrates its position and dimension. Stereoscopically ob 
served, the height of the wall can be perceived, fig. 2. 
4.2 The Grassfield near the Lamco Saw-Mill 
In the middle of the grassfield a single tree can be observed. A close 
study in a stereoscopical way will reveal an oval ring-shaped wall 
touching the tree. This wall has been examined on the place as men 
tioned. Its position and approximate dimensions appear from the 
sketch. The perception of the wall can be brought into strong relief by 
means of a stereoscopical study, figs. 3 and 5. 
4.3 The Savannahs at the Guinea Border 
On the open savannah fields a ring-shaped feature of a similar type 
indicating an old settlement is clearly visible. It is interesting, however, 
to observe that two near concentric walls are recorded on the pictures. 
The explanation why two such walls have been built might be that the 
original defence wall was successively extended resulting in a claim to