There were also a number of unarmed vessels present, whose duty it was to handle the fireboats that had been prepared--huge coal barges loaded with fat pine knots that might have made serious trouble had they all been turned loose together at the right time. And one of these unarmed boats was the _Mosher_, with a crew of six men under Captain Sherman--the bravest man in the Confederate squadron; but because he was only a tug captain no record was made of his first name, nor is anything said in history of his antecedents. Of the armament of the Confederate squadron little need be said. The _Louisiana_ was well armed, and the rest poorly. The _Moore_, under Beverly Kennon, had two thirty-two-pounders, and she was about as well off as any. While Farragut prepared his fleet a coast survey party under F. H. Gerdes triangulated the river, under fire at times, and set flags on the banks where the mortar schooners were to be moored. One division of these was placed on the west bank, under shelter of forest trees, and at an average distance of about 3,500 yards from the fort. The other division was on the east bank. The exact range was given to each schooner captain, and at ten o’clock in the morning on April 18, 1862, the bombardment of Fort Jackson began. The mortars were fired once in ten minutes, and the fire was continued for six days. [Illustration: Mortar Boats. _From an engraving._] Meantime Lieut. C. H. B. Caldwell had requested permission to break the chain barrier, and on the night of the 20th he was sent with his boat, the _Itasca_, and the _Pinola_, Lieut. Pierce Crosby commanding, to do so. While the mortar schooners dropped their shells in a shower on Fort Jackson to keep down the fire as much as possible, two of the barrier hulks were boarded, and on one of them it was found possible to slip her anchor chain. This was done, and she drifted away, leaving the barrier chain to sag down under water. Then Caldwell got above the barrier with his shoal-draft _Itasca_, passing through a narrow space between the hulks and what remained of the old raft barrier. Running up far enough for good headway, he turned back at full speed with the current to aid him, and headed for the place where the released hulk had been. As the _Itasca_ struck the sagging chain with her curved bow, she rose more than three feet out of water, and then the chain snapped under her weight, and away she went. The barrier was effectually broken, and the route to New Orleans was open. All this was done under heavy fire, but there was no picket boat guarding the chain. At this time the British frigate _Mersey_, Captain Preedy, and a Frenchman were lying with Farragut’s fleet. These two foreigners steamed up the river to examine the barrier, and on coming back were at great pains to inform the Union forces that the forts were in perfect order and the barrier absolutely impassable. The French were at that time planning to establish an emperor on a throne in Mexico.