Ah, yes. I remember many trips in the 1960s riding NEC trains with P70 coaches, not air conditioned, with open windows. Also the MP54 EMUs on the Paoli Local were similar. Not air-conditioned, and, in the summer, with the windows open, the ride was really noisy. Of course, being that the NEC was electrified, we didn't have to deal with sooty smoke and cinders coming through the windows. I did get a chance to experience that last summer on the Western Maryland, though, and the sulfurous tang of the coal smoke and the cinders in my hair were part of the experience. I can only imagine what big cities were like back in the day, when there were lots of coal-powered steam trains running through.