PLANE TABLE SURVEYING. 
101 
by joining them. In this case the point will lie outside the triangle 
of error. 
The same condition holds that the distances of the point from the rays 
will be proportionate to the distances of the respective fixed points, but 
there is another condition which must be satisfied; that is, that the point 
must be so situated that all the rays have to move in the same direction 
round their respective fixed points in order to reach it, when the table 
is turned in azimuth. 
Taking the second condition first, a glance at Fig. 3, p. 101, will show 
that there are only two possible positions of the fixing which fulfil it, i.e., 
in the space C eg, where all the rays would have to swing to the right 
or in the space A dfi, where they would all have to swing to the left. 
Now the first condition of the relative distances will decide which 
