Note 173 — Chapter III

"It has been concluded that the dry land occupies about 49,800,000 square statute miles. This does not include the recently discovered tracts of land in the vicinity of the poles, and allowing for yet undiscovered land (which, however, can only exist in small quantity), if we assign 51,000,000 to the land, there will remain about 146,000,000 of square miles for the extent of surface occupied by the ocean."—Sir J. F. W. Herschel, Physical Geography, 1861, p. 19.

It does not appear to which category Herschel assigns the inland seas and the fresh-water lakes and rivers of the earth; and Mrs. Somerville, who states that the "dry land occupies an area of 38,000,000 of square miles," and that "the ocean covers nearly three fourths of the surface of the globe," is equally silent on this point.—Physical Geography, fifth edition, p. 30. On the following page, Mrs. Somerville, in a note, cites Mr. Gardner as her authority, and says that, "according to his computation, the extent of land is about 37,673,000 square British miles, independently of Victoria Continent; and the sea occupies 110,849,000. Hence the land is to the sea as 1 to 4 nearly." Sir John F. W. Herschel makes the area of dry land and ocean together 197,000,000 square miles; Mrs. Somerville, or rather Mr. Gardner, 148,522,000. I suppose Sir John Herschel includes the islands in his aggregate of the "dry land," and the inland waters under the general designation of the "ocean," and that Mrs. Somerville excludes both.