Original Elisha Perkins' patented metallic tractors.
Licence: Attribution 4.0 International (CC BY 4.0)
Credit: Original Elisha Perkins' patented metallic tractors. Wellcome Collection. Source: Wellcome Collection.
Licence: Attribution 4.0 International (CC BY 4.0)
Credit: Original Elisha Perkins' patented metallic tractors. Wellcome Collection. Source: Wellcome Collection.