I found these images back in December while going through The New York Public Library's digital archive
. They are fascinating and a bit mysterious. When I couldn't track down any more information about these online I spoke to the (very helpful) special collections archivists/researchers. They weren't able to find any substantial information on them either. The next step was for me to come into their research center and do a little digging - but my schedule caught up with me and I never made the trip. I'm posting these now to see if anyone else knows their history - or perhaps to prod myself in doing a bit more research in person.
See more photos from the History of the NYPL > Research Library photo set