LII. Hydrographical Notices:—Remarks on the method of investigating the direction and force of the currents of the ocean; presence of the water of the gulf-stream on the coasts of Europe in January 1822; summary of the currents experienced by his Majesty's ship pheasant, in a voyage from Sierra Leone to Bahia, and thence to New York; Stream of the River Amazons crossed, three hundred miles from the mouth of the river