A collection of images, some showing Kaichi Watanabe demonstrating the cantilever principle and others showing the bridge and abutments in various stages of construction.
The pictures are from the private collection of the family of Sir John Fowler, chief engineer for the bridge’s construction.
Along with William Henry Barlow and Thomas Elliot Harrison, Sir John was appointed in 1881 to a commission to review Sir Thomas Bouch’s design for the Forth Rail Bridge.
Bouch had designed the Tay Bridge, which had collapsed two years previously, in 1879.
The commission recommended a steel cantilever design, partly designed by Fowler, that was then constructed between 1883 and 1890.
He received an honorary degree of Doctor of Laws from the University of Edinburgh in 1890 for his engineering work on the bridge.
Sir John also worked on the Metropolitan Railway and the Millwall Dock.
• The items will be auctioned by Special Auction Services. The sale will be held in Newbury