Who knew algae could take on such ethereal, beautiful forms?
These 19th-century photos of algae hold up today as art, but they're also a window into the development of photography. They're part of a new digital archive the New York Public Library put online.
The images were made by English amateur botanist and photographer Anna Atkins (1799-1871), who may have been the first woman to create a photograph, according to the library. Atkins is also the author of Photographs of British Algae: Cyanotype Impressions, which is thought to be the first book illustrated entirely by photography.
To photograph the algae, Atkins used the cyanotype process that had been invented by her friend Sir John Herschel in 1842. A version of that technique is still used to make blueprints today.
Atkins said the new photographic process was a solution to "the difficulty of making accurate drawings of objects as minute as many of the algae."
For the book, Atkins collected and photographed hundreds of samples of seaweed, working in her home in Sevenoaks, Kent.
The New York Public Library owns one of only 13 known copies of the original book, a copy that was inscribed by Herschel and preserved by his descendants.
Click through to the algae photos.