— —, —, motion and mode of revolution, xl, 53.

— —, —, velocity, perihelion distances, position, xl, 53, 54.

— —, Fisher, F. G., origin of, atmospheric, and connected with electricity, xxviii, 289.

— —, Gruithuisen, origin of, beyond the earth's atmosphere, from metallic vapors, xxviii, 290.

— —, Halley, E., suggested the determination of longitude by means of, xlii, 399.

— —, Herrick, E. C., on the number of showers of, in a year, xxxiii, 360; xxxv, 366; xxxix, 334.

— —, —, facts establishing the August period, xxxiii, 177, 354.

— —, —, observations on the August period, in early times, xxxvii, 337;

–in 1800, 1815, 1819, 1822, 1836, xxxvii, 335, 336;

–in 1837, xxxiii, 176, 354, 401; xxxiv, 180;