[1] As governor, Forrest advocated for a gymnasium to improve students' wellbeing; he personally subsidised its construction in the old brewery between 1882 and 1885.

[3][5] In October 1880, Munro promised to endow a second chair, in history and political economy, at a salary of $2,500,[3] on the condition that it be awarded to Forrest.

Forrest duly resigned his position at St John's Church,[1][3] and was inaugurated as the George Munro Professor of History on March 15, 1881.

He opened a Faculty of Engineering in 1905, but it was ceded to the provincial government to found the Nova Scotia Technical College in 1907,[1] which would merge into Dalhousie University in 1997.

[1] Students called him 'Lord John',[1][3] and he was distinguished for his memory of faces and names, as memorialised in one student's poem:[3] Fine me again, Lord John, fine me again.Please soak me for sups and swat me for ten.But grasp my hand firmly, say it out loud:“Of course I know you, you’re Donald MacLeod.”Forrest retired as President of Dalhousie University in 1911, and was succeeded by Arthur Stanley Mackenzie.

[1] Forrest served as President of the Royal Nova Scotia Historical Society from 1905 to 1906 and as Moderator for the Presbyterian Church in Canada in 1910.