This paper was illustrated by two large charts of the world showing, by ISOHYETAL LINES, the rainfall over the different continents in January and July; two large charts showing the months of least and greatest rainfall in Europe, north Africa, and west Asia; and by six sets of smaller charts of thirteen each, showing, by isohyetal lines, the monthly and annual rainfall of Europe, Asia, Australasia, North America, Africa, and parts of South America. The data laid down on these eighty-two charts were taken from a Table comprising about 2000 good averages of rainfall, calculated or collected by the author.