20 Scientific Proceedings, Royal Dublin Society. 
(xvi). To find the position and depth of the intersection of 
two lodes with parallel strike. 
The case of lodes with parallel strike, being excluded in the . 
foregoing, must be separately considered. Take OC , 09 
(fig. 8) equal to the breadth of the protractor, and on 
a line at right angles toit lay off OP and OQ for the 
hades of the two lodes, using the cotangent-scale. 
We obtain thus a diagram drawn to scale representing c 
the lodes, PC and QC, and the depth of their intersec- F14- 8. 
tion, OC, with the position of O relatively to the out-crops at 
P and Q. The distance PQ between the outcrops being sup- 
posed known, the other particulars can be determined by measure- 
ment. 
