—, Mauvais's, xlix, 220.
—, second of 1845, xlix, 220.
—, third of 1845, xlix, 220.
—, on the observations of, P. J. Rodriguez, xvi, 94.f
—, nature of, W. A. Norton, xlvi, 104.
—, on the tails of, x, 395; xxxiii, 5, 11.
—, —, W. Mitchell, xxxviii, 35; xl, 59.
—, —, of Halley's, B. F. Joslin, xxxi, 142, 324.
—, —, formation of, W. A. Norton, xlvi, 104.f
—, possible collision of two, J. J. Littrow, xxiv, 346.