Civil Engineering Reference
In-Depth Information
Fig. 7.3
Quadrangles. four quadrangles are illustrated
Meridians were then established 24 miles east and west of the principal meridian.
These were called
First Guide Meridian East
and
First Guide Meridian West
. The
standard parallels and guide meridians created quadrangles 24 miles on each side.
7.4 Townships
Each of the quadrangles was then divided into 16
Townships
. Townships are
approximately 6 miles square. The townships are bounded by
Range Lines
which
run north and south and
Township Lines
which run east and west. The meridians
and parallels conform to the earth's curvature. So do the range lines and township
lines. These features can be seen in Fig.
7.3
.
When townships were created, the dimension of 24 miles along the base line
was held. Because of convergence, the range lines will become closer together the
more northerly they become. Consider the range lines beginning at the base line
and running north to the first standard parallel north. When the first standard paral-
lel north is reached, the convergence will be maximum for that particular quad-
rangle. This means that the east-west dimensions of the townships will be reduced
as they approach this parallel. The quadrangle distance along the first standard
