I’ve been looking for photos appropriate for my talk at the General Society, and I came across an interesting gap: I could not find (readily, at least) a circa-1900 photo of the interior of an elevated train car. And once I started looking, I noticed a possible second gap: the photos taken from the elevated structure (from a station platform, for example) tend to not show any nearby trains. The picture above shows two trains – one on the far left at the Chatham Square station, and one off in the distance – but that picture was taken from a nearby rooftop. Here’s one looking north from the uptown platform of the Sixth Avenue el station at 14th Street, and the nearest train is up at the next station, at 18th Street:
Why the gaps? I suspect they are the result of primitive photographic technology of the era. There were two kinds of caerma in common use circa 1900: large, heavy, and accurate cameras that used glass negatives, and primitive, fixed-lens handheld cameras that used paper negatives. The earliest Kodak paper-negative cameras were sold in the 1880s, and made personal and hobby photography possible, but their pictures were low quality compared to the tripod-mounted glass-negative cameras. I have no idea if professionals used the small portable cameras as well as their big cameras, but their work product was made using the big cameras. Dry-plate negatives had reduced exposure times to a second or less long before 1900, so the weird ghosting issues of long exposure times and moving objects were not the problem.
I’d guess that getting a big camera on a tripod set up on a constantly moving and vibrating base (an elevated car) was a challenge simply not worth the effort. If there was a good reason to do so, a photographer would have, but there was no burning demand for a picture of the inside of a train. Similarly, it was easier to take a picture from a station platform when it wasn’t vibrating with the movement of a nearby train (and passengers walking around), or to take one from a nearby window or roof.
This entire topic is (a) not very important and (b) partially speculative, but it touches on the topic of my talk. Our picture of the past is distorted by what has survived. We have archives full of professional photographers’ work, but relatively few hobbyists’ shots. If you look at the data on the physical dimensions of the elevated cars, they were more cramped than most modern subway cars, and so probably felt even more crowded than the trains do now, but we don’t have the pictures that would give a good sense of that. The elevated trestles and platforms in New York were more lightly-built than the modern subway elevated structures, but we don’t have a good sense of how much they moved under load. But the linkage fascinates me: the state of (very much not engineering-related) photographic technology affects what we know about an engineering issue.