Inside the middle building on Sumpter's block the detailing of the bottom stringer (tie beams) of the roof trusses can be appreciated.
Although they look like they should be resting on the piers, they are not and were cast in place at the top of the pour. The whole truss may have been erected but possibly just the stringer was put up and the truss assembled on it later as it is all strapped and pegged and held together by feathers and wedges. Lovely old carpentry.
These two buildings are remarkably modern looking and most visitors will have no idea they are standing in an 1875 space whilst they are browsing the items on sale.