Collection of photographs, catalogs, notebooks, blueprints and other material from the Risdon Iron Works and Union Iron Works in San Francisco, California, particularly concerning the manufacture of dredges.

"In 1897 the Risdon Iron Works, adjoining the Union Iron Works and soon to merge with it, built the first successful gold dredge in America. It was called the Archimedes and was designed by and built for R. H. Postlethwaite, chief dredging engineer for the Risdon Iron Works, who operated it in the Yuba River east of Marysville, Calif. The dredge was a success during its first year of operation. Then disaster struck. The Yuba River flooded and the Archimedes was lost. A year later the Risdon Works also built a second successful gold dredge. This was known as the Couch No. 1 and was built for Captain Couch and W. P. Hammon, founder of the Yuba Consolidated Gold Fields. It operated for many years in the Oroville Gold Fields and set the pattern for gold-dredging operations in California.

12 Linear Feet (22 boxes, oversize folders, tube)

While Special Collections is the owner of the physical and digital items, permission to examine collection materials is not an authorization to publish. These materials are made available for use in research, teaching, and private study. Any transmission or reproduction beyond that allowed by fair use requires permission from the owners of rights, heir(s) or assigns. Most of these materials are believed to be in the public domain. There are no restrictions on use of public domain materials.

Open for research. Note that material must be requested at least 36 hours in advance of intended use. Audiovisual materials are not available in original format, and must be reformatted to a digital use copy.