Rigg, R., carbon a compound body, xlvii, 211.
—, Chemical and Agricultural Researches of, noticed, xlvii, 211.
Right angled triangles, expressions for sides of, xxiv, 68.
Rio Janeiro, meteorological register kept at, from 1832-1843, xlvii, 290.
Ripple-marks in transition rocks, T. A. Conrad, xxxv, 248.
— — in the rocks of the Connecticut valley, C. Lyell, xlv, 394.
— — in the new red sandstone of New Jersey, xliv, 136.
— — and mud furrows in rocks, J. Hall, xlv, 148.
— — in New York, xxxvi, 46.
Rise of land, see [Elevation.]