VII. Note on 'spectroscopic papers'
In a recent communication to the Royal Society, Mr. Lockyer has criticised our statement of Young’s wave-length identifications of certain chromospheric lines. As to the wave-length, we have throughout our table omitted all figures after the decimal point merely for the sake of not cumbering the table. The numbers, Young tells us, are not his own, but taken from Ǻngström’s catalogue. Moreover, as to Young’s identifications with metallic lines, he states expressly that they were taken from the maps of Kirchhoff, Ǻngström, and Thalén, and Watts’s “Index of Spectra.” But our object was not to criticise Young’s work, but only to use it for the purpose of comparing the behaviour of certain metals on the earth and in the sun, and the conditions under which certain lines appear, or do not appear, or are reversed.