. Military sketching and map reading. directly under the weight,and, with a sharpened stick attached to the other end ofthe string, describe an arc with a radius equal to the dis-tance from the peg to the shadow of the tip of the a peg on the arc where the shadow of the tip of thepole rested. About an hour after noon watch the shadowof the tip as it approaches the eastern side of the arc, anddrive another peg where it crosses. By means of atape or string, find the middle point of the straight linejoining the last two pegs mentioned. A straight linejoining this middle point and the p
. Military sketching and map reading. directly under the weight,and, with a sharpened stick attached to the other end ofthe string, describe an arc with a radius equal to the dis-tance from the peg to the shadow of the tip of the a peg on the arc where the shadow of the tip of thepole rested. About an hour after noon watch the shadowof the tip as it approaches the eastern side of the arc, anddrive another peg where it crosses. By means of atape or string, find the middle point of the straight linejoining the last two pegs mentioned. A straight linejoining this middle point and the peg under the weight willbe in the true meridian. Place a pole about a hundredyards in prolongation of this line, and with the compasssight back on the tip of the inclined pole, and the declina-tion will be obtained. Orientation, Distance, and Direction 21 Third Method By aid of the watch and sun.—Lay the watch on somelevel surface and revolve it until the hour hand points di-rectly under the sun. Then by reference to the divisions. Fig. 4 on the dial, determine a point on it midway between thehour hand and twelve oclock. A line through this pointand the pivot of the hands will be approximately in thetrue meridian. (See Fig. 5.) The operation of pointing the hour hand directly underthe sun is made^easy by easting^the_shadow of a vertical \ 0
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectmilitarytopography
