In compliance with his new orders, Cornwallis ordered a careful survey of Old Point Comfort and Hampton Roads to find the best location for such a naval station. This was done by Lt. Alexander Sutherland, of the Royal Engineers, who recommended against Old Point Comfort, which had been mentioned at length in the more recent correspondence between the British commanders in Virginia and New York as a possible location for a base to replace Portsmouth. Cornwallis wrote to Clinton: “This being the case, I shall, in obedience to the spirit of your Excellency’s orders, take measures with as much dispatch as possible, to seize and fortify York and Gloucester, being the only harbour in which we can hope to be able to give effectual protection to line of battle ships. I shall, likewise, use all the expedition in my power to evacuate Portsmouth and the posts belonging to it....” Having stated his intentions, Cornwallis began to take action. On July 30, the British transports, loaded with about 4,500 men, left Portsmouth and set sail for Yorktown, where they arrived on the night of August 1. On August 2, landings were made at both Yorktown and Gloucester. Banastre Tarleton, with his men and horses, crossed Hampton Roads in small boats and proceeded to Yorktown by road, arriving on August 7. By the 22d, the detachment which remained at Portsmouth to level the works completed its assignment and joined the main army. The construction of defenses was begun immediately at Yorktown and Gloucester, a job that Cornwallis estimated would require 6 weeks. On August 31, one of the British soldiers wrote from “Camp Yorktown” that “Nothing but hard labour goes on here at present in constructing & making Batteries towards the River, & Redoubts toward the Land.” Actually, the siege of Yorktown began before this task was completed. [Illustration: STRATEGY OF THE SIEGE] —Cornwallis entrenched with an army of approximately 7,500 (British, German, and American Loyalist forces). —About 4,500 troops with Lafayette, including over 3,000 militia under Thomas Nelson, Jr. —Approximately 8,000 troops under General Washington including a French force of more than 4,500 commanded by the Count de Rochambeau. —The French fleet under the Count de Grasse which blockaded the sea approaches to Yorktown. With de Grasse were 3,200 troops under St. Simon.