The lower valley of the Alatamaha basin is nar row, only one stream entering that deserves the name of a river, and that, the Great Ohoopee, from the is au unimportant branch, of about eighty miles comparative course. The entire basin of Alatamaha extends in length 260 miles from south-east to north-west, with a mean breadth of fifty miles; area 13,000 square miles. This basin is bounded by the higher valley of the Charahoochee north-west; by the valley of Flint river west; by the sources of Swanee and Santilla rivers south; basin of Great Ogeechee south-east; and the basin of Sa vannah to the north-east.
As a commercial and habitable basin, that of Ala tamaha is of great importance. There is at low tide 14 feet water on the outer bar, and ships of that draught can be navigated some distance up the main stream. Steam boats are navigated up the Oconee to Milledgeville, and both Oconee and Ocmulgee are navigable for down stream vessels to near their respective sources.
A minor basin, the Ogeechee, or Ogatchee, follows that of Alatamaha. The sources of the Ogeechee originate to the south-east of all the distinct chains of the Appalachian system, at about North Lat. 33° SO', Lon. 69 W. from NV.C., between Little river branch of Savannah and Oco nee, and in Greene county, Georgia. The valley or basin of Ogeechee is narrow, and lies in a direction from north-west to south-east. Length about 170 miles, with a mean width of 30; area 5100 square miles. The main stream receives but one tributary of any consequence, the Cannouchee. The latter has its valley between those of Ohoopee and the Great Ogeechee, and gains some importance from its position. The entire length falls short of ninety miles, but the lower part of its course above its junction with the Ogeechee being from west to east, the channel lies directly in the course of a projected canal to unite the Savannah and Alatamaha rivers. Ossaba• Sound, which receives and terminates the Great Ogeechee, is in North Lat. 31° 50', Lon. 4° 7' NV. from \V.C.
The very important basin of Savannah follows those of Alatamaha and Great Ogeechee. The two higher constituents of Savannah river, the Chatuga and Seneca, both originate in the Blue Ridge, at about North Lat. 35°, and Lou. 6° W. from W.C. According to Tanner's United States, both of the higher sources of Savannah rise in North Carolina.
The Chatuga, or western branch, flows first south westward, receives the Turoree, and, bending to south-east, takes the name of Tugaloo, and joins the Seneca at the passage through one of the Appa lachian chains, supposed the South East Mountain.
The Seneca rises in the Blue Ridge, to the east Ward cal' the sources of Chatuga, and westward of those of Saluda, and, flowing a little east or south, unites with the Tugaloo to form the Savannah. The comparative length of the two constituent branches are about equal to 50 miles each. Below South East Mountain the united waters now form the Savannah, and a navigable stream flows south-eastward, by comparative courses, to the entrance of Broad river, from the west.
Broad river, if length of course and surface drained are combined, is the largest confluent of Savannah. Its valley occupies the space between the higher sources of Oconee and Chatahoochec, and the valley of Savannah itself. Length about 70 miles, in a direction from N.W. to S.E. Below the influx of Broad river, the Savannah maintains nearly its original course or south-cast to North Lat. 33°. Here this river inflects to the south of s.s.w , and continues that direction about 80 miles, to the city of Savannah. Widening into a hay, the channel inflects to S.E. by E. below the harbour el Savannah, and, at a distance of about 14 miles, opens to the Atlantic Ocean between Tur tle and Tybee islands, at North Lat. 32°, and Lon. 4° W. from \V. C. According to Tanner's map, the two geographical lines intersect in the southern side of Savannah bay. The entire basin traverses a small fraction above three degrees of latitude, and two and two-thirds of longitude. The length is very nearly 250 miles, but for such a length the breadth is confined. For 60 miles from the mouth to the entrance of Brier river, the breadth falls short of 15 miles. Above the influx of Brier river, the basin slowly widens, but where the width is greatest, from the sources of Stevens creek to those of Lit tle river, it still falls under 70 miles, and the mean width is fully estimated at 40 miles, and the area at 10,000 square miles.
If the three basins of Alatamaha, Ogeechee, and Savannah are united into one physical section, it will comprise 27,300 square miles, lying between North Lat. 31° 19' and 35° 5', and between Lon. 4° and 7° 30' W. from W.C.