We are unable to account for those movements of General Howe, on any other grounds than the following; viz. that his march from Brunswick to Somerset afforded him an opportunity of trying the disposition of the States of New Jersey and Pennsylvania, and finding that the militia of both States were turning vigorously out to support our army, he might reasonably conclude from thence, that his situation in the Jerseys was too dangerous to be continued, and therefore decamped to Amboy, from whence he might, by his bridge of boats, intended for the Delaware, throw himself into a safe retreat on Staten Island. We give you circumstances as they are, with such natural inferences therefrom as our situation and knowledge of things enable us to draw. The memorial, presented by Sir Joseph Yorke to the States-General, mentioned in ours, of June 18th, you will find in the newspapers of the 11th inst. The said memorial does not come sufficiently authenticated to us, to give you any particular instructions respecting your conduct thereon, but as the progress of friendship depends much on the improvement of accidents and little circumstances, we doubt not you will be attentive to the conduct of the States-General at all times, and let us know whenever it appears to you that a commissioner from Congress would be favorably received there. B. HARRISON, R. MORRIS, T. HAYWARD, J. LOVELL. * * * * * FROM THE COMMITTEE OF FOREIGN AFFAIRS TO THE COMMISSIONERS. Philadelphia, July 2d, 1777. Gentlemen, Since our last of the 26th ult. which mentions the enemy being retreated to Amboy, we have to inform you, that General Washington dismissed the Jersey militia, except about 2000, and likewise countermanded the reinforcement of 3000 men from General Putman's Division, at Peekskill. We suppose General Howe to be apprized of these circumstances, as he immediately after returned with his whole force from Amboy, and made an attempt to cut off a Division of our army under General Sterling, but without success. For particulars we refer you to General Washington's letters, in the newspapers of the 3d inst. A letter from General Washington, just received, informs us, that the enemy have totally evacuated the Jerseys, and are retreated to their last year's quarters on Staten Island.