That’s the Hotel Pontchartrain, circa 1907, in Detroit. By then, steel-skeleton construction was well established, so its use for a smallish mid-rise hotel is not surprising. The photo negative was damaged at some point, but the picture is very clear and shows a lot of details of the construction.
The steel frame is complete. We know that because we can see it, but also because we can see the topping-out flag. The brick portion of the curtain wall, which is quite plain, is just about done. The ornamental base – probably stone veneer with brick back-up – is in construction. You can see that the window frames for the second floor have been set in place before the masonry, a detail that allowed the weight boxes to be set deeply into the wall. The top floor will probably also get a heavily ornamented facade – stone or terra cotta – beneath the rather large cornice. One of the side-effects of steel framing was that the size of cornice overhangs could be determined by architectural rules of proportion for the full building height, rather than being limited by masonry corbelling.
In addition to the big crane at the center of the roof, we have five smaller jibs mounted along the street facades. The small ones are obviously being used to lift the large blocks of stone for the lower facade. They are held by cables back to the steel frame: the jib just to the right of the big arched door in the center has a cable tied to a seventh-floor column where a portion of a brick pier was temporarily omitted for this purpose. There’s a similar missing pier for a cable on the left, and a small opening through the brick for a cable on the left-center corner. Note that some of the cables you’re seeing in the photo are trolley wires for the tracks that people are blithely walking across.
It’s odd that the windows all seem to be boarded up, as that must have greatly limited the amount of light inside. Most likely, there was not much interior work taking place until the facade was complete.
Most importantly, of course, is the fact that a big masonry wall was constructed in mid-air, with no masonry below it. This is the hallmark of skeleton construction, and was remarked on a number of times in the 1890s with the sort of awe about new technology that we now associate with computes. By 1907, people in big cities had become used to the sight.
One last item: the sign over the big door says (if you look at the high-res version of the photo) “Westinghouse, Church, Kerr & Co. Engineers”. That was a New York based company, affiliated with Westinghouse Electric, that apparently did all sorts of engineering design. For example, at Penn Station, they were responsible for “work connected with the mechanical and electrical engineering together with civil engineering design for construction at the terminal station.” So WCK & Co may have designed the superstructure of the hotel, the mechanical systems, the foundations, or all of them.
