Carbon arc spectra on an autochrome plate, showing the sensitiveness of the plate to different parts of the spectrum, by J McIntosh, 1907. One of two autochrome plates showing spectra. Carbon arc spectra on an autochrome plate
Solar spectra on an autochrome plate, showing the sensitiveness of the plate to different parts of the spectrum, by J McIntosh, 1907. One of two autochrome plates showing spectra. Solar spectra on an autochrome plate