Photograph of Afro-American and Caucasian employees for the Bureau of Standards and Sewer Maintenance working on a sewer, ca.1920. At center, two men can be seen kneeling over an open sewer hole, while a third man stands behind the hole looking down into it. An automobile can be seen behind the third man, and has "Department of Public Works 2380" painted on the passenger side door. A fourth man can be seen at left sitting on the ground with his back leaning against the back of the car, while thin tubes can be seen running from inside the sewer to a machine in the back of a pickup truck at right. Pine trees and homes are visible in the background.; Photoprint reads: "Department of Public Works. Operating manual air line gas mask in 30 foot manhole. Note operation of air pump, electric homelite generator, red flags, trucks blocking man hole for safety, with top and equipment men ready for instant action".