American B720-023B
Here's one of those shots that you could look at quick and say it's a 707, but it isn't -- this is a 720, regardless of Amercian's calling all their four-engine Boeings "707s."  This one (N7545A) is shown during a brief time of quiet on a gloomy summer afternoon.  It was operating AA's daily DAL-BWI-PHL-BWI-DAL turnaround.  

Philadelphia, July, 1965