Over at House of Mirth, esteemed vernacular photo collector Robert E. Jackson posts about the allure of collecting cyanotypes with some wonderful examples. The ghostly image above is from the collection of Erin Waters. Jackson posted this fascinating bit from the cyanotype Wikipedia entry:
The English scientist and astronomer Sir John Herschel discovered this procedure in 1842. Though the process was developed by Herschel, he considered it as mainly a means of reproducing notes and diagrams, as in blueprints. It was Anna Atkins who brought this to photography. She created a limited series of cyanotype books that documented ferns and other plant life from her extensive seaweed collection. Atkins placed specimens directly onto coated paper, allowing the action of light to create a silhouette effect. By using this photogram process, Anna Atkins is regarded as the first female photographer.