Most of the photos on this site were extracted from reference images (high-resolution tiffs, 20 to 200 megabytes in size) from the Library of Congress research archive. (To query the database click here.) Many were digitized by LOC contractors using a Sinar studio back. They are adjusted by your webmaster for contrast and color in Photoshop before being downsized and turned into the jpegs you see here.
"Watts Bar steam plant. Large opening leads to lobby which gives access to stairs, overlook balcony, and toilets. Lobby is separated from turbine hall by a similar glazed opening. A direct view can be had from outside toward impressive generators. Note hooded slits which take place of windows in boiler room. Design facilitates blackout." View full size. Circa 1942; photographer unknown.