I've mentioned my fondness for happenstance before, but I must tell you again that I get pretty excited when I stumble upon an answer! Today, I was browsing through Alumni News from 1969 and there on the front page of the February issue was Mystery Image #10! The photo pictures the Henry Sage Estate or "Fernbrook" located in Menands, NY. The estate was bequeathed to Rensselaer Polytechnic Institute by Cornelia Cogswell Sage, widow of Henry M. Sage. She retained use of the property until her death in 1972. The estate was costly to maintain so the Institute sold the property in 1973. The mansion house became the headquarters of Albany International Corp. Much of the estate property was developed into upscale residences in the late 1980s.