A Popular History of Astronomy During the Nineteenth Century / Fourth Edition

by Agnes M. Clerke

[599] Phil. Mag., vol. xlii., p. 377.

[600] Frost-Scheiner, Astr. Spectroscopy, pp. 184, 423.

[601] Proc. Roy. Soc., vol. xvii., p. 302.

[602] Astr. Nach., No. 1,769.

[603] Am. Jour. of Science, vol. xv., p. 85.

[604] Journ. Franklin Institute, vol. xl., p. 232a.

[605] Pogg. Annalen, Bd. cxlvi., p. 475; Astr. Nach., No. 3,014.

[606] Astr. Nach., Nos. 3,006, 3,037.

[607] This device was suggested by Janssen in 1869.

[608] Astr. and Astrophysics, vol. xi., pp. 70, 407.