a cylindrical collector of the rain gauge has a vertical distinctively colored stripe extending parallel to its vertical axis a focal length from its central axis on the opposite side of the rain gauge from rainfall indications . with this arrangement , the rain water in the rain gauge appears to have the color of a stripe which makes the water height easier to see . an open end of a parallelopiped interface receives the rain and has an area larger than the cross sectional area of the cylindrical collector to which it supplies the rain it receives . the numerals on the rain gauge indicating rainfall are scaled in proportion to the ratio of the area of the open end of the interface and the cross sectional area of the cylinder for easier reading . the parallelopipe design was selected to reduce the size of the shipping container and the dimension perpendicular to the holder is less than the width to permit the gauge to lie flat against a surface for hanging .