How can you find the direction a stream flows on a topographic map?

A contour map shows lines which connect areas equal in height. These lines are called contours and should be labelled to show the height that each contour represents. A stream flows downhill, this is due to gravity. Thus, to determine which way a stream flows, find contours, at least two, that intersect the path of the stream, then look at the heights these contours represents(their labels). The stream will flow from the contour labelled with the higher number towards the contour labelled with the lower number. PS. sometimes not all the contours are numbered, but only say every fith contour is numbered, then you can assume that all contours are equally incremented i.e. the height difference from one contour to the next stays equal.