220 THE MAN-EATERS OF TSAVO CHAP. 
carrying out the work. The crossing on which I 
had decided had to be approached by a somewhat 
sharp curve in the line, and in laying this out with 
the theodolite I experienced considerable difficulty, 
as for some reason or other I could not make the 
last peg on the curve come anywhere near the 
tangent-point where the curve should link up 
with the straight. I repeated the whole operation 
time after time, but always with the same result. 
Eventually I came to the conclusion that there must 
be some mistake in the table of angles from which | 
had been working, so I started to work them out for 
myself and soon discovered a_ serious misprint. 
This being rectified in my calculations, I proceeded 
to lay out the curve again, when at last everything 
came out accurately and to my satisfaction. 
After I had pegged out this temporary diversion 
of the line, I thought I richly deserved a few hours’ 
play, and accordingly determined to try my luck after 
lions up-stream towards the source of the Athi. 
The river—which runs almost due _ north here, 
before taking a turn eastward to the Indian Ocean— 
forms part of the western boundary of the Athi 
Plains, and is fringed all along its course by a belt 
of thorny hardwood trees. In some places this 
fringe is quite narrow, while in others it is about a 
quarter of a mile wide, with grassy glades here and 
there among the trees. | Every now and again, too, 
