In order to associate the idea of the _relation_ between _lowlands_ and _highlands_, and of the successive gradations in the elevation of the soil, with actual data based on accurate measurements, I subjoin a table, in which the heights of the elevated plains of Europe, Africa, and America are given in an ascending scale. With these numbers we may then further compare all that has as yet been made known regarding the mean height of the Asiatic plains, or true _lowlands_. Toises. Feet. Plateau of Auvergne 170 1,087 „ of Bavaria 260 1,663 „ of Castille 350 2,238 „ of Mysore 460 2,942 „ of Caracas 480 3,070 „ of Popayan 900 5,755 „ of the vicinity of the Lake of Tzana, in Abyssinia 950 6,075 „ of the Orange River (in South Africa) 1000 6,395 „ of Axum (in Abyssinia) 1100 7,034 „ of Mexico 1170 7,482 „ of Quito 1490 9,528 „ of the Province de los Pastos 1600 10,231 „ of the vicinity of the Lake of Titicaca 2010 12,853