R-V line, V indicating valley and R ridge
or hill. Note first the difference in sharpness in the contour
bends; also how the valley contours point to the highland and
the ridge contours to the lowland.

The contours go thus:

[Illustration]

The streams flow down the valleys, and the sharp angle of the
contour points always _up_ stream. Note also how the junction
of a stream and its tributary usually makes an angle that points
_down_ stream.

"Which way does this stream run?"

Water flows down hill. If you are in the bed of a stream, contours
representing higher ground must be to your right and to your
left. Get the elevations of these contours. Generally the nearest
contour to the bank of the stream will cross the stream and there
will be an angle or sharp turn in the contour at this crossing.
If the point of the angle or sharp turn is toward you, you are
going downstream; if away from you, you are going upstream.

If the contours are numbered, you have only to look at the numbers
to say where the low and where the high places are; but to read a
map with any speed one must be quite independent of these numbers.
In ordinary map reading look, first of all, for the stream lines.
The streams are the skeleton upon which the whole map is hung.
Then pick out the hilltops and ridges and you have a body to
clothe with ail the details that will be revealed by a close and
careful study of what the map maker has recorded.

As to closed contours, they may outline a depression or a hill.
On the map, "881" or "885" might be hills or ponds, as far as
their shape is concerned. But, clearly, they are hills, for on
either side are small streams running _away_ from them. If
they were ponds, the stream lines would run _toward_ the
closed contours. The rest of "hill, valley, hill," will always
solve the problem when there are not enough stream lines shown
to make evident at once whether a closed contour marks a pond or
a hill. Look in the beginning for the stream lines and valleys,
and, by contrast, if for no other reason, the hills and ridges
at once loom up.

To illustrate the subject of contours to aid those who have
difficulty in reading contoured maps the following is suggested:

1. Secure modeling clay and build a mound.

2. Use wire and slice this mound horizontally at equal vertical
intervals into zones; then insert vertical dowels through the
mound of clay.

3. Remove the top zone, place on paper, and draw outline