2030, Valve rockers,  Category Z (Hoisting Engines "Hancock" and  "Pewabic")
name: label: Collection Creator
content: Calumet and Hecla Mining Company.
label: Collection Creator
content: Leavitt, Erasmus D., 1836-1916
setName: label: See more items in
content: Erasmus D. Leavitt Papers
label: See more items in
content: Erasmus D. Leavitt Papers / Series 3: Engineering Drawings
unitdate: label: Date
content: 03/20/1890
container: label: Container
content: Map-folder 35
dataSource: label: Archival Repository
content: Archives Center, National Museum of American History
objectType: label: Type
content: Archival materials