Photographed spectra; 136 photographs of metallic, gaseous, and other spectra printed by the permanent autotype process, with introd., description of plates and index, and with an extra plate of the solar spectrum (showing bright lines) compared with the air spectrum
Photographed spectra; 136 photographs of metallic, gaseous, and other spectra printed by the permanent autotype process, with introd., description of plates and index, and with an extra plate of the solar spectrum (showing bright lines) compared with the air spectrum