In 1838, at the age of 46, John Herschel returned to England after 5 years in South Africa with his wife and children. He published the results of his research in astronomy. William and Caroline Herschel – his father and his aunt – had discovered Uranus, John inventories and names its satellites as well as those of Saturn and finishes their “Catalogue of Nebulae and Star Clusters”.
His stay in Africa also allowed him to catalogue the flora of Cape Code, his wife Margaret and him illustrated it with watercolours – as was customary in botanical illustration before photographic plates – and to finish presenting the extent of his skills, he also studied the local geology and minerals.

Researcher with a wide field of action, John Hershel is prolific, he is going to mark at the same time the astronomy and to initiate the photography… The legend wants that it is by looking for a way to copy his numerous scientific observations that he found the process of the cyanotype…
In his scientific career, John Herschel became interested in light at a very early age; to understand his observations in astronomy, he conducted numerous experiments and thanks to chemistry, he was able to detail the light spectrum, measure it and restore a portion of it on a fixed support, paper or glass… The beginnings of his contribution to photography then began. For a long time, John Herschel was considered to be the author of this term, but it seems that the word (and the appearance of photography) was in the air at the time, a French inventor, Hercule Florence on an expedition to the depths of Brazil had begun to use “Photography” in his notes as early as 1834, in French please.