My Family, the Surgeons were originally from Wetheral in Cumbria and he would have been their local photographer. The scans that I have are from the collection of one of my relations. They appear to have been take arround the 1880s but I can't be sure.
I know absolutely nothing more about Farrar as the photos are my only connection. Sounds like a really interesting story that you have unearthed.

John