Editing Openai/692cb06b-b484-800b-9bb9-7b819ce20d91 (section)

===== The other two images in the carousel aren’t Boston buildings specifically, but they show the kind of frame that begins to appear in the same period: =====
* The exposed steel (or iron) frame skeleton photo (urban building under construction) shows a full cage of columns and beams rising well above the street, with no masonry yet attached. - This is what Boston’s first true steel-frame buildings (like the Winthrop Building, 1893) would have looked like mid-construction: the frame stands on its own, and masonry/terra cotta/stone gets hung on it as cladding.
* The shot of a masonry building under construction with heavy scaffolding and partially completed stone walls gives a good feel for how load-bearing walls were erected, course by course, with floors inserted as you go.