Figure 7-25.—Coordinate entries for computation of figure 7-24.
Figure 7-26.—First step for tabulated computation of figure 7-24.
Figure 7-25 shows the coordinate entries. You can
see that the Y coordinate of A equals the latitude of DA,
or 591.64 feet, while the X coordinate of A is zero. The
Y coordinate of B equals the Y coordinate of A plus the
latitude of AB or 591.64 + 255.96 = 847.60 feet.
The X coordinate of B equals the departure of AB,
or 125.66 feet. The Y coordinate of C equals the Y
coordinate of B minus the latitude of BC o r
847.60 – 153.53 = 694.07 feet.
The X coordinate of C equals the X coordinate of B
plus the departure of BC or 125.66 + 590.65 = 716.31
feel.
The Y coordinate of D obviously is zero; however,
it computes as the Y coordinate of C minus the latitude
of CD of 694.07 – 694.07, which serves as a check. The
X coordinate of D equals the X coordinate of C minus
the departure of CD or 716.31 – 192.69 = 523.62 feet.
‘This is the same as the departure of DA, but with an
opposite sign—a fact which serves as another check.
7-18
