A shell every five minutes, and no reply
The guns shelling Charleston were finally located — light Parrotts at the foot of the scarp of the main work at Battery Gregg. The bombardment ran steadily through the day at about one round every five minutes and was still unabated at midnight: 244 shells thrown, 112 of them falling short. Not one Confederate gun answered all day.
Journal of Operations in Charleston Harbor, OR I, 35, Pt. 1