579-A, Adjustment and maintenance of Wheatstone relays and other types of polarized relays
name: label: Collection Creator
content: United Telegraph Workers.
label: Collection Creator
content: Western Union Telegraph Company
setName: label: See more items in
content: Western Union Telegraph Company Records
label: See more items in
content: Western Union Telegraph Company Records / Series 16: Plant Department Records / 16.3: Specifications
unitdate: label: Date
content: 1917
container: label: Container
content: Box 552, Folder 1
dataSource: label: Archival Repository
content: Archives Center, National Museum of American History
objectType: label: Type
content: Archival materials