The reconnoissance made by General Hamilton showed the necessity of having siege-guns. The troops were put into camp about two miles back from the river; urgent request was sent to Cairo for heavy artillery, and parties were pushed forward every day to harass the garrison and keep them occupied. Colonel Plummer (soon after brigadier-general and commanding a division of his own) was detached from Hamilton's division and sent with the Eleventh Missouri, Twenty-sixth and Forty-seventh Illinois Infantry, four guns of the First Missouri Light Artillery, and one company of engineer troops, together with two companies of cavalry, to act as outpost toward the interior--to Point Pleasant. The object was to attempt by field-pieces to stop the passage of transport steamboats up and down the river. Colonel Plummer, leaving camp at noon, March 5th, proceeding by a circuitous road to avoid passing along the river-bank, halted for the night in bivouac, without fires, within three or four miles of the town. A gunboat prevented his cavalry and artillery from occupying the town next day, but was driven away by the fire of the infantry. The infantry and engineers prosecuted the work of digging rifle-pits, and in the night places were sunk for the field-pieces by excavating near the edge of the bank. By morning of March 7th the four guns were in position, planted apart, with lines of rifle-pits connecting them. When discovered, the gunboats immediately began a furious assault. Plummer's artillery wasted no ammunition in useless fire upon the iron-plated boats, and his guns were so shielded by their position in sunken batteries, back from the edge of the bank, that the fire of the gunboats passed harmless overhead. The deliberate fire of sharpshooters from the rifle-pits, however, searching every opened porthole, pilot-house, and every exposed point, was so annoying that the fleet withdrew. Every day the gunboats opened upon the position, either in stationary attack or while passing up and down the river. But, to avoid the harassing fire from the rifle-pits, they kept, after the first few attacks, near the opposite shore of the river. The steamboats used as transports did not venture to pass up or down the river in face of Plummer's batteries, and the enemy was restricted to the landing at Tiptonville and boats below for all communication. [Illustration: New Madrid and Island Number Ten.]