CSIRO: Research the history of total solar eclipses
Eclipses Throughout the Ages
CSIRO: History of total solar eclipses
NASA: Solar Eclispses of Historical Interest
Wikipedia: Solar Eclipse 1868
History of Absorption Spectra
The science of exclipses
WARNING. Never look directly at the bright surface of the Sun without suitable eye protection as permanent eye damage may result. This applies at any time and especially during the partial phases of a solar eclipse. Refer to “How to observe the Sun safely”.