The northern light of September 27, 1938

On September 27, 1938, a very brilliant display of northern lights was observed at State College, Pennsylvania (latitude 40° 47′.8 north, longitude 77° 51′.8 west). The phenomenon was first observed as a faint gleam at 19 h 30 m 75° west meridian time and increased in brightness so that at 20 h 10 m there could no longer be any doubt that it was actually an aurora. It developed several arcs and streamers and became so pronounced that it was decided to take some measurements of its extent. These measurements started at 21 h 30 m and were continued until 23 h 15 m .