As soon as New Madrid was reduced, General Pope busied himself in establishing a series of batteries at several prominent points along the right bank, as far down as opposite Tiptonville. The river was thus practically closed to the enemy's transports, for their gunboats were unable to drive out the Union gunners. Escape was thus rendered impracticable, and the ultimate reduction of the place assured; but to bring about a speedy favorable result it was necessary for the army to cross the river and come upon the rear of the enemy. The latter, recognizing this fact, began the erection of batteries along the shore from the island down to Tiptonville. On the 15th of March the fleet arrived in the neighborhood of Island No. 10. There were six ironclads, one of which was the Benton carrying the flag-officer's flag, and ten mortar-boats. The weather was unfavorable for opening the attack, but on the 16th the mortar boats were placed in position, reaching at extreme range all the batteries, as well on the Tennessee shore as on the island. On the 17th an attack was made by all the gunboats, but at the long range of two thousand yards. The river was high and the current rapid, rendering it very difficult to manage the boats. A serious injury, such as had been received at Henry and at Donelson, would have caused the crippled boat to drift at once into the enemy's arms; and an approach nearer than that mentioned would have exposed the unarmored sides of the vessels, their most vulnerable parts, to the fire of the batteries. The fleet of the flag-officer was thought none too strong to defend the Upper Mississippi Valley against the enemy's gunboats, of whose number and power formidable accounts were continually received; while the fall of No. 10 would necessarily be brought about in time, as that of Fort Pillow afterward was, by the advance of the army through Tennessee. Under these circumstances, it cannot be doubted that Foote was justified in not exposing his vessels to the risks of a closer action; but to a man of his temperament the meagre results of long-range firing must have been peculiarly trying. The bombardment continued throughout the month. Meanwhile the army under Pope was cutting a canal through the swamps on the Missouri side, by which, when completed on the 4th of April, light transport steamers were able to go from the Mississippi above, to New Madrid below, Island No. 10 without passing under the batteries.