seven o'clock
But the troops and artillery lining the shore now opened fire on the little gunboat , which consequently hauled off . The _ Merrimac _ , after firing several more shells into the _ Congress _ , moved away to attack the _ Minnesota _ , and the survivors of the 200 men who composed the crew of the _ Congress _ were conveyed to shore in small boats . The vessel was set on fire either by her own crew or the shells of the _ Merrimac _ , and by midnight blew up . Owing to the shallowness of the water the _ Merrimac _ could not get near enough to the _ Minnesota _ to use her own small guns to advantage , and the gunboat was driven off by the heavy ten-inch gun of the Federal frigate , and , therefore , at seven o'clock the _ Merrimac _ and her consorts returned to Norfolk . The greatest delight was felt on shore at the success of the engagement , and on riding back to Norfolk Vincent learned that the ram would go out again next morning to engage the rest of the Federal fleet . She herself had suffered somewhat in the fight . Her loss in men was only two killed and eight wounded ; but two of her guns had the muzzles shot off , the armor was damaged in some places , and , most serious of all , she had badly twisted her ram in running into the _ Cumberland _ .