Original photograph used to make a heliogravure for Baldus’ Palais du Louvre et des Tuileries. This was Baldus’ first publication of his own photographic work in photogravure form.
Originally trained as a painter and having also worked as a draughtsman and lithographer before switching to photography in 1849, Édouard Baldus (1813–1889), became a central figure in the early development of French photography and acknowledged in his day as a pioneer in the still-experimental field, was widely acclaimed both for his aesthetic sensitivity and for his technical prowess. Establishing a new mode of representing architecture and describing the emerging modern landscape with magnificent authority, he enjoyed high patronage in the 1850s and 1860s. Beginning in the mid 1860s and lasting until t he early 1880s, Baldus primary commercial activity centered on the production of photogravures, a process he first explored in 1854. This work had nothing to do with promoting artistic photography or his own photographic work; instead it was an industrial application of photography that brought credit and financial gain to Baldus as an inventor and entrepreneur rather than an artist. 
 https://www.metmuseum.org/toah/hd/bald/hd_bald.htm cited 2/25/23