The observer moves back to pole (C) and pole (D) is reset in line with (C) and (B) (see Fig. 13c Setting out a straight line over a long distance, Step 3 The observer moves Co pole (D) and pole (C) is reset in line with (D) and (A) (see Fig. 13b Setting out a straight line over a long distance, Step 2 The observer moves to pole (C) and pole (D) is set in line with (C) and (B) (see Fig. 13a Setting out a straight line over a long distance, Step 1 Pole (C) is approximately set in line with (A) and (B) at about one third of the distance between (A) and (B), closer to (A) (see Fig. 13 Setting out a straight line over a long distance A flag is attached to ranging pole (B) to make it more visible.įig. 13, ranging pole (B) is at quite a distance from pole (A) and it is hard to see pole (B) clearly. 2.3.2 Setting out straight lines over a long distanceĪs shown in Fig. In other words, poles (A), (B), (C) and (D) are in line if the observer, standing 1 or 2 metres behind pole (A), sees pole (A) only, while the other poles are hidden behind pole (A). 12 Setting out a straight line over a short distance 12c) placed behind (B), which is hidden behind poles (A), (B) and (C), is on the extension of the straight line connecting (A) and (B) (see Fig. The observer remains in the same position and any pole (D in Fig. 12b) placed by the assistant in between (A) and (B), which is hidden behind pole (A), is on the straight line connecting (A) and (B) (see Fig. The observer remains in the same position and any pole (C in Fig. The observer stands 1 or 2 metres behind pole (A), closes one eye, places himself in such a position that pole (B) is completely hidden behind pole (A) (see Fig. Short distance, over a long distance and over ridges or hills.Ģ.3.1 Setting out straight lines over a short distanceĪs shown in Figure 12a, pole (B) is clearly visible for the observer standing close to pole (A). This section indicates, step by step, how to set out straight lines over a Setting out straight lines over a ridge or a hill Setting out straight lines over a long distance Setting out straight lines over a short distance with a plumb bob, or a carpenter level (see Fig. Once in place, it should be checked if the ranging pole is vertical, e.g. The sharp bottom point of the ranging pole leaves a mark on the soil exactly where the pole has to be placed. ![]() When the observer indicates that the ranging pole is in the right position, the assistant loosens the pole. ![]() The correct way to hold a ranging pole is to keep it loosely between thumb and index finger, about 10 cm above the soil (see Fig. A straight line is the shortest distance between two points on a map or between two points on the field (see Fig, 9).
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