Figure 7-15.—Sample pages from traverse table.
in departure. The corrections, however, are opposite in
sign to the error of closure.
distances of from 1 to 100 feet. For a particular traverse
line, you determine the latitudes and departures by
breaking down the distance, moving decimal points, and
adding up results as in the following example:
Traverse Tables/Adjusting Bearings
and Distances
Suppose you want to determine the latitude and
departure for a traverse line 725.32 feet long, bearing
N15°30'E. To get the latitude, do it as follows. In the
latitude column under 15 1/2°, lookup the latitude for
70 feet. You read 67.45 feet. If the latitude for 70 feet is
67.45 feet, the latitude for 700 feet is 674.50 feet. Note
this in your notes.
In computing latitudes and departures, your
arithmetical calculations can be greatly expedited by the
use of a traverse table, in which latitudes and
departures for any bearing and distance can be
determined mostly by looking for them in the table.
Figure 7-15 shows sample pages from a table that
gives angle-of-bearing values to the nearest quarter-
degree (15'). More precise tables give angular values to
the nearest 01'.
Next, you look up the latitude for 25 feet under the
same 15 1/2° latitude column, which is 24.09 feet. The
latitude for 725 feet, then, is 674.50+ 24.09= 698.59
feet.
Under each of the bearing values at the head of the
page, a double column gives latitudes and departures for
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