Coast ?oinr or the Usiitid States.—The Portland Adrertiser states that the steamer Corwin, Lieat. Com. Temple, is now in that harbor, and will continue the hydrographical survey in Casco Bay, and as far east as Cape Small Point. The surveying schooner Gallatin, Lieut. Com. Treocbard, U. 8. N., is hourly expected to arrive from Savannah, Ga. She will remain some weeks for repairs and supplies and will then proceed to •urrey to the eastward of Cape Small Point, and about the mouth of the Kennebec. The coast sur-Ter schooners Meredith and Hassler, under charge of Messrs. Longfellow and Huger, assistants U. S. Coast Surrey, are now in Portland harbor, and will continue the topography of that section.— Professor Bache, with the main party, is catting a road and measuring a base line in Colombia, Washington county.