Camping and woodcraft - Scoutmastercg.com

.right angle,ROUTE SKETCHING 93and must therefore be of equal length.Since your readings on a small compass may notbe quite true, check them, if the ground permits, bywalking east till A bears northwest from D. If theFig. 19.—Measuring Width of River by Compass.two observations do not quite coincide,the two will be approximately correct.If you have no compass,there are many ways ofmeasuring an inaccessibledistance by angles otherwisedetermined, providedthere is enough level landon your side for the purpose.One of these is shownin Fig. 20. Sight a conspicuousobject, as before.Plant a stake about 5 feethigh at A J as nearly oppo-the mean ofFig. 20.—MeasuringWidth withoutCompasssite and "square" as you can judge. Set up anotherstake at B, as nearly at a right angle as you can, andat about one-half the estimated distance to yourmark.Continue AB straight to C and plant anotherstake. AB must equal BC. Now set a stake at D,at right angle to base, wherever the line DB continuedwill strike the object across the river that youhave been sighting at. Then DC equals the widthacross.To Measure an Inaccessible Height orHtipth.-—Suppose vou wish to measure the height