It's time to celebrate the creepiest, crawliest, eeriest week of the year ...

Black and white photograph of a group of workers - some of the men appear transparent as a result of an error in the photographic process.

It's time to celebrate the creepiest, crawliest, eeriest week of the year! To help you get into the spirit, here's a December 1905 photograph of E.I. du Pont de Nemours & Company pipefitters at the company's powder yards in Wilmington, Delaware.

While the photographic process that turned workers into ghostly apparitions in this photograph was probably an accident, other photographers working around this time used it intentionally to create "spirit photographs", a photographic genre that was very popular from the mid-19th to early 20th century. This effect could be created using a double-exposed glass plate, or by capturing a photograph in dim lighting using a long-exposure that included a period of time in which the subject was not in the frame.

This photographic print is part of Hagley Library’s collection of Pierre A. Gentieu Brandywine River Valley photographs (Accession 1970.001).  Pierre A. Gentieu (1842-1930) was a long-term employee of E.I. du Pont de Nemours & Company. He was also a photographer and artist, and the du Pont family allowed him to photograph the family, their employees, and the built world and daily lives that made up their lives along the Brandywine.

His work, now the Hagley Library’s collection, provides an invaluable photographic record of the company's Brandywine Mills at the turn of the century. To view the collection online now in our Digital Archive, click here.