Original: By the mid-1850s he was receiving commissions for decorative schemes such as the sixty foot frieze for the Sheffield Mechanics ’ Institute and for interiors of houses commissioned by some of Sheffield ’ s leading citizens.
Simplified: By the mid-1850s he was being paid to decorate buildings.  He created the 60 feet frieze for the Sheffield Mechanics' Institute.  He was also paid to decorate houses owned by some of Sheffield's most important citizens.