Page:Popular Science Monthly Volume 21.djvu/880

 Geographical and geological unit ${\displaystyle =}$ 24° ${\displaystyle =}$ 360°15 Greatest width and length of continents ${\displaystyle =}$ 3 x 24° ${\displaystyle =}$ 72° ${\displaystyle =}$ 360°5 Radius for continents ${\displaystyle =}$ 36° ${\displaystyle =}$ 360°10 Half radius ⁠" ${\displaystyle =}$ 18° ${\displaystyle =}$ 360°20
The measure for oceanic distances is the complement of 24° ${\displaystyle =}$ 66°. The ratio of land to water, as shown by Professor Dana, is as 100: 275. The ratio of 24°: 66°:: 100: 275. All measurements are to be estimated at the equator.