The miniature sheet from the German Democratic Republic is based on a manuscript map drawn by Waldimer Köppen in 1876 which has lines showing wind speed.

     "The design of the Meteorological Readings postage stamp incorporates an authenticated section of a recent surface weather map prepared by the Meteorological Branch of the Canadian Department of Transport."

Canada Post Office Department
Postage Stamp Press Release, 1968

     The contours on the map indicate barometric pressure. H and T indicate "Highs" and "Lows." The symbols in the weather map below indicate the nature of the weather in the area. The blue points indicate cold fronts; red half circles, warm fronts; triangles, showers; circles with a line, wind coming from the direction of the line to the circle; one bar at the top of the line,8-12 knot wind; the amount of black in the small circle, the amount of cloud cover.