at night
verso Plate II, facing (and showing some variety of offset from) Plate III (including Position Flag, Annulling Flag, Powder Flag, Flag of Truce; At Night : Danger or Distress),
90ยบ cw, inv., 40-1.00-255
ex General Signal Book of the Navy of the United States of America (1876)
Phillips Library, PEM copy/scan : link
2572 Ice is breaking up above.
2573 Ice is breaking up below.
5280 Ice bound.
5589 Ice Sound
2340 Blue light . . burn...