caused by this stroke was so great that Montcalm hastened from Beauport to take command in person; but when he arrived the British had already retired, content with their success. None the less the French from the highest to the lowest now grew seriously uneasy. Their army was on short rations. All its supplies were drawn from the districts of Three Rivers and Montreal; and, from want of transport overland, these were perforce sent down the river where the British ships lay ready to intercept them. Now was seen the error of sending the frigates up the river and allowing the British squadron to assemble by small detachments above Quebec; but it was too late to repair it. The British fleet had discovered the true method of reducing the city by severing its communications both above and below. The only hope for the French was that winter might drive the shipping from the St. Lawrence and put an end to the campaign, before Quebec should be starved out. [Sidenote: June 15.] [Sidenote: July.] [Sidenote: July 24.] Meanwhile Amherst's operations to south and west began likewise to tell upon the situation. Taking advantage of the latitude allowed to him by Pitt, he determined to add the reduction of Niagara to the enterprises prescribed to him. This duty he assigned to Brigadier Prideaux with five thousand men;[316] Brigadier Stanwix was entrusted with the relief of Pittsburg; and Amherst in person took charge of the grand advance by Lakes George and Champlain. The operations of Prideaux and Stanwix were to be conducted in combination; for it was intended that while Prideaux was engaged with Niagara, Stanwix should push a force northward against the French posts on Lake Erie, and thence on to Niagara itself, thus releasing Prideaux for an advance to the St. Lawrence. Prideaux was the first to take the field. His force having been assembled on the Mohawk at Senectady, he moved up the stream, left a strong garrison at Fort Stanwix to guard the Great Carrying-place, and moved forward by Lake Oneida and the river Onandaga to Oswego. There leaving nearly half of his force under Colonel Haldimand to secure his retreat, he embarked with the rest on the lake for Niagara. The fort stood in the angle formed by the river Niagara and Lake Ontario, and was garrisoned by some six hundred men. Prideaux at once laid siege in form, though the trenches were at first so unskilfully laid out by the engineers as to require almost total reconstruction. At last, however, the batteries opened fire. Prideaux was unluckily killed almost immediately by the premature explosion of a shell from one of his own guns, but Sir William Johnson, who had joined the force with a party of Indians, took command in his place and pushed the siege with great energy. The fort after two or three weeks of battering was in extremity; when a party of thirteen hundred French rangers and Indians, which had been summoned from the work of harassing the British on the Ohio