Gutta-percha Craig microscope base, ca. 1860s. Approx. diam. 2 1/3  in., h. 6 1/4 in. 

Henry Craig (d. 1864) patented his microscopic lens, not included in this example, in 1862, while working as a janitor at the Western Homeopathic College in Cleveland, Ohio. Craig microscopes consisted of the lens and a body of either brass or gutta percha, as exhibited in this example, and would have cost $2.00 or $2.50, respectively.

His developments made the world of microscopy not only more affordable than competitors but also more accessible. A selling point for the device was the lack of necessity to focus the lens. Slides would be inserted into the slot near the top of the base, and the small mirror would be angled with the handle to reflect a light source, illuminating the slide from below. 

[Civil War, Union, Confederate] [Medical History, History of Science, History of Medicine, Patents, Patent History]