Races, human, their geographical distribution, and unity, 351, 359.
Rain drops, temperature of, 220; mean annual quantity in the two hemispheres, 333, 334.
Reich, mean density of the earth, as ascertained by the torsion balance, 170; temperature of the mines in Saxony, 174.
Reisch, Gregory, his "Margarita Philosophica," 58.
Remusat, Abel, Mongolian tradition on the fall of an aerolite, 116; active volcanoes in Central Asia, at great distances from the sea, 245.
Richardson, magnetic phenomena attending the Aurora, 197; whether accompanied by sound 200; influence on the magnetic needle of the Aurora, 201.
Riohamba, earthquake at, 204, 205, 208, 213, 214.
Ritter, Carl, on his "Geography in relation to Nature and the History of
Man," 48, 67.
Robert, Eugene, on the ancient sea-line on the coast of Spitzbergen, 296.
Robertson on the permanency of the compass in Jamaica, 181.