Sketcher, architect and surveyor. In 1865 McMinn was involved in a disastrous expedition to northern Australia to map the Adelaide River. To return to civilisation McMinn and six others purchased a 23-foot open boat, named it the Forlorn Hope, and sailed 2000 miles south to Geraldton, WA. In his later years as an architect McMinn was responsible for designing the original Venetian Gothic building of the University of Adelaide, now known as the Mitchell Building (in partnership with Edward John Woods), Marble Hill at Norton Summit, the summer residence of the governors of South Australia and the original part of the Adelaide Children's Hospital.