In this photo you can see the dew that the sun has not yet burnt off. The shadow itself is mostly moving right to left in this picture, leaving the thin band of wet wood in the shade all the time. This thin band is a rough east-west line at all times of the year, but quite an accurate one at times like this, close to the spring and autumnal equinoxes.
The small patch of moisture that is in the sun reveals the direction that the shadow is shortening, a crude north-south line as we near the middle of the day.
Tags: autumnal, compass, direction, equinox, moisture, shadow, shadows, sun, time
