Parallel photographs of the spectra of the sun, of iron, and of iridium, from the line (H) to near the line (D), in six sections. Also separate photographs of the spectrum of titanic iron ore, in six sections.

Half-title. Reprinted from the Monthly notices of the Royal astronomical society, vol.XLIX, no.7.

Geology and ore deposits of the Afterthought Mine : Shasta County, California.

Mode of access: Internet.