Iv THE BUILDING OF THE TSAVO BRIDGE 45 
be found, for the whole district abounds in rock, 
but that it was so intensely hard as to be almost 
impossible to work, and a bridge built of it would 
have been very costly. I spent many a weary day 
trudging through the thorny wilderness vainly 
searching for suitable material, and was beginning 
to think that we should be forced to use iron columns 
for the piers, when one day I stumbled quite by 
accident on the very thing. Brock and I were out 
) 
‘“pot-hunting,” and hearing some guinea - fowl 
cackling among the bushes, I made a circuit half 
round them so that Brock, on getting in his shot, 
should drive them over in my direction. I eventually 
got into position on the edge of a deep ravine and — 
knelt on one knee, crouching down among the ferns. 
There I had scarcely time to load when over flew a 
bird, which I missed badly; and I did not have 
another chance, for Brock had got to work, and 
being a first-rate shot had quickly bagged a brace. 
Meanwhile I felt the ground very hard under my 
knee, and on examination found that the bank of 
the ravine was formed of stone, which extended for 
some distance, and which was exactly the kind of 
material for which I had long been fruitlessly 
searching. I was greatly delighted with my un- 
expected discovery, though at first I had grave 
misgivings about the distance to be traversed and 
the difficulty of transporting the stone across the 
