On Finding the Way. 299
The epitome of the whole is this:-I. If you can only answer the question A, you must seek for the lost path by the tedious circle plan; or, what is the same, and a more manageable way of setting to work, by travelling in an octagon, each
side of which must be equal to four-fifths of P D. (See fig. 2.) That is to say, look at your compass and start in any direction you please ; we will say to the south, as represented in the drawing. Travel for a distance, P D ; then, supposing you have not crossed the path, turn at right angles, anq. start afresh,-we will suppose your present direction to be west,travel for a distance 140 of P D, which will take you to 1; then turn to the N.W. and travel for a distance -10 of P D, which will take you to 2 ; then to the N. for a similar distance, which will take you to 3 ; and so on, till the octagon has been completed. If you know B to eight points, and not C, adopt the L M system; also, if you know A and C, and B to within thirteen points (out of the sixteen that form the semicircle), you may still adopt the L M system ; but not otherwise. A rough diagram scratched on the ground with a stick would suffice to recall the above remarks to a traveller's recollection.