|The majority of significant material in the Nelson F. Davis Family Collection is composed of the negatives, original photographic prints, and slides of Dr. Nelson F. Davis, Professor of Biology at Bucknell University from 1898 – 1939. Much of his innovative photographic work depicts the range of topics he taught. Dr. Davis documented his far-flung interests with skillfully executed, extensively detailed photographic compositions. His work is remarkable in its clarity of image, and diversity of subject. These compositions include 268 black and white images of Pennsylvania covered bridges photographed from 1935 to 1937, with the largest number of photographs taken in 1936 and 1937. The images are organized first by county, then town/city, and finally, by date when the image was photographed.