\fdO'^ - Old Forge Coal Mines

(643
(644
SURVEYING. Ui
See Art. 1231 and Figs. 261 and 262.
For ^rst adjustment see Art. 1233. For
second adjustment see Art. 1234 and Fig. 263, and for
////W adjustment see Art. 1235 and Fig. 264.
(645) See Art. 1238 and Fig. 265.
(646) See Art. 1239 and Fig. 266.
(647) See Art. 1 240 and Fig. 267.
(648) See Art. 1 242 and Fig. 269.
(649) See Art. 1 242 and Fig. 269.
(650) To the bearing at the given line, viz. , N 55° 15' E,
we add the angle 15° IT', which is turned to the right. This
gives for the second line a bearing of N 70° 32' E.
(651) To the bearing of the given line, viz., N80°ll', we
add the angle 22° 13', which is the amount of change in the
direction of the line. The sum is 102° 24', and the direction
is 102° 24' to the right or cast of the north point of the compass.
At 90° to the right of north the direction is due east.
Consequently, the direction of the second line must be south
of east to an amount equal to the difference between
102° 24' and 90°, which is 12° 24'. Subtracting this angle
from 90°, the angle between the south and east points, we
have 77° 36', and the direction of the second line is S 77° 36' E.
The simplest method of determining the direction of the
second line is to subtract 102° 24' from 180° 00'. The difference
is 77° 36', and the direction changing from N E to S E
gives for the second line a bearing of S 77° 36' E.
(652) To the bearing of the given line, viz. N 13° 15' , W,
we add the angle 40° 20', which is turned to the left. The
sum is 53° 35', which gives for the second line a bearing of
N 53° 35' W.
(653) The bearing of the first course, viz., S 10° 15' W,
is found in the column headed Mag. Bearing, opposite Sta. 0.
For the first course, the deduced or calculated bearing
must be the same as the magnetic bearing. At Sta. 4 -\- 40,