1670 1680 1690 Showing the relative importance and fluctuations of the staple crops cultivated in South Carolina from 1670 to 1880. The money value of each crop is estimated for the year of its maximum production anterior to 1880, and a point assigned it above the line A B. From this point the distance of the line of each above the line A B is determined by the amount procrop duced without regard to prices. CHAPTER II. THE COAST REGION. LOCATION AND AREA. The coast of Carolina, from the mouth of the Savannah river to that of Little river, on the North Carolina line, is about one hundred and ninety miles in length. East of the outlet of the rivers, that is northeast of Winyaw Bay, the coast line curves inland, there are no islands, and the smooth hard beach (noted for its delightful seaside residences during the summer months) that forms the continuous shore line, is of little interest agriculturally. South of Winyaw Bay, whence issue the waters of Black and Lynch's rivers, and of the Great and Little Pee Dee, with the Waccamaw, the Santee river, with its great watershed in North and South Carolina, draining an extensive region stretching to the highest elevations of the Apalachian range, dikes its delta out into the ocean, and the shore line swelling seaward becomes lined with numerous islands. From this point to Charleston Harbor the islands, though numerous, are small and low, and in this distance of more than fifty miles not more than seven hundred acres are planted in cotton, yielding about two hundred and seventy-five bales of long staple. South of Charleston Harbor the islands increase rapidly in size and number to the waters of Port Royal, where they line the shore in tiers three and four deep. They attain their maximum development around Broad river, and diminish again in size and number more rapidly even than they had increased, as they approach the Georgia line at the mouth of Savannah river. The Sea Islands are separated from the mainland by numerous salt water rivers, creeks and inlets of the sea. GEOLOGY. The coast region corresponds almost exactly with the post-pleiocene formation. Its strata of sand, clay and mud, have an estimated thickness of about sixty feet, stretching inland some ten miles and thinning out at a slight elevation above tide water. They rest in Horry and Georgetown on the pleiocene, and for the remainder of the coast, on the eocene, in which occur the phosphate deposits of the Ashley, the Cooper and the Coosaw rivers. The origin and formation of the sea islands may be accounted for by one of four possible suppositions. 1st. By a subsidence of the coast resulting in the submergence of the lower lands. This explanation was offered by Sir Charles Lyell, and recently by Professor G. H. Cook, who believes that the whole Atlantic. seaboard is sinking. 2d. By the elevation of the sea bottom. This theory has not been maintained by any one and need not be considered. 3d. By the erosive action of the tides and currents of the sea, cutting into the shore line and detaching, as it were, portions of the mainland. A theory of Professor Shaler. 4th. By an outgrowth of the land into the sea, resulting from the deposition at the mouths of the rivers of the detritus brought down by their currents from the interior. Mr. Tuomey shows in detail that the instances of the submergence of oak, pine and cypress trees, and other landmarks, adduced as evidence of subsidence of the coast, occur in localities of restricted area. That the lands immediately adjacent show no signs of participation in this movement, which they would do if the cause were so general a one as the subsidence of the coast. That encroachments of the sea of a purely local character after storms explain the phenomena. And lastly, that if it were admitted that the submerged live oak and pine stumps near Little River, or the dead cedars and cypress of the "Church Flats," on Wadmalaw island, were evidence of a subsidence of the coast, the rate at which it is progressing, according to this data, is so rapid that on this low lying shore, sea water would long since have been admitted to the rice plantations, totally destroying them, and that St. Michael's Church, the ornament of Charleston, would now be a geological monument of the greatest interest, with its tall spire only protruding above the waves. If the sea islands resulted from the erosive action of ocean currents, we should expect to find them most numerous in localities where the erosive action is most manifest. Such a locality is the recess of Long bay, hollowed out by the action of the sea, between Winyaw bay, the outlet of the great rivers of South Carolina and the outlet of the rivers of North Carolina at Cape Fear. So far is this from being the case, however, that there is not a single island on this incurving line of erosive coast. On the contrary, it is only when the land bellies out into the sea near where the great rivers deliver their detritus to its waves that the sea islands make their appearance. At this point, namely, at Georgetown entrance, we look in vain for evidence of erosion. The records all point the other way, to a gradual encroachment of the land upon the sea. Thus, in the year 1700, the "Rising Sun," a large vessel, with three hundred and forty-six passengers, that could not cross the Charleston bar, made its way without a pilot to the present site of Georgetown, a thing utterly impossible during the last one hundred years. Moreover, a comparison of the soundings on Chart No. 428, of U. S. Coast Survey of 1877, with a Chart of the same locality, published in Drayton's View of South Carolina, in 1802, shows that, instead of any scouring out or erosion, there has been a great filling up in the interval. Seaward from Georgetown Light House, Drayton gives depths of 9 feet to 30 feet, where Captain Boutelle only found 63 feet to 19 feet of water. Inside the entrance, where the water once was 30 to 36 feet, the mean level of low tide now only gives a depth of 9 to 31 feet. Ten soundings taken off South Island average now 73 feet, while ten soundings in the same locality on Drayton's Chart average, 18 feet. It would seem, then, according to the fourth and remaining hypothesis, that the Sea Islands were an outgrowth of the mainland into the sea. And that this is but a continuation of the process by which the tertiary plain, stretching back to the feet of the ancient and lofty Apalachian chain, was itself formed. The broadest portion of this plain lies under the loftiest and broadest vestiges of this mountain chain, whose denudation furnished the most abundant material. Northward, under lesser elevations, which could only furnish less material, the tertiary plain gradually wedges out and the sea approaches the mountains. The slow uniformity of this long process of growth is further shown by the gentle and uniform slope with which this plain approaches the sea. Nor does it end abruptly there. For one hundred miles or more the sea scarcely exceeds one hundred fathoms, until it suddenly deepens to two thousand fathoms under the gulf stream. The sea islands are not isolated phenomena peculiar to this period. In the interior the intricate network of swamps and bays corresponding with the present inlets, creeks and rivers of the coast, represent the old channels and deltas through which the waters flowed, when the pine flats and ridges, still resting in the meshes of this network, were themselves veritable sea islands. Prof. Toumey refers to Murphy's island, south of South Santee inlet, as furnishing a typical illustration of the manner in which this occurs. A bar is formed at the mouth of the river by the action of the ocean. "Breakers make their appearance seaward, and gradually push forward the sand as they approach the shore. When the sand rises above the surface, the water becomes too shallow to produce breakers; they disappear, and commence again off the shore, and further south. An eddy is formed between the sandbar and the shore, in which the river deposits its sediment. From an eddy it is changed, first into a lagoon, and then into a mudflat, which increases until the level of high water is reached. It then becomes a marsh and is taken possession of by the marsh reed, to be succeeded, when the debris collected. by their growth has raised the locality above high water, by tufts of rushes. Meanwhile seaward, the sands, first pushed up against the outflowing current of the river by the ocean, are dried by the sun, and then blown forward and heaped into hills and ridges, forming a protection against the encroachments of the waters whence they came. Every breeze blowing landward carries along with it particles of fine sand, till they meet with a log or bush, or other obstacle, when they begin to accumulate in proportion to the velocity of the wind, sometimes with extraordinary rapidity-piling up and running over the top, rising in ridges and hills to the height of thirty or even of forty feet. The prevailing winds of this region, the southwest and northeast, are indicated by valleys running in this direction through these hills." In the manner thus described, the salt water of the ocean being excluded, the surgent island is prepared for the growth of fresh water plants, such as the cypress and other swamp trees, while pines and palmettoes, the advance guard of the vegetable kingdom, establish outposts wherever a few inches of intervening sand renders them safe from immediate contact with sea water. This theory will also account for certain topographical features observed on these islands and in their vicinity. The highest land is usually found on the margin of the island. A fact which, viewed in connection with the general observation that the banks of streams are higher than the adjacent alluvial lands, strongly sustains the view of their deposition from river currents. The prevailing shape of the islands is triangular. The apex is directed southwest, often terminating in marshes, while the higher and dryer base faces northeast. From Mr. Tuomey's observations, it appears that it is the sandbar on the northeast that first rises above the waves, remaining the most elevated, while the growth proceeds in a southwesterly direction. This southwardly growth results from a deflection of the river current that is transporting the material of which the island is to be formed. Whether this deflection toward the right (or the southwest) be due, as Prof. Kerr thinks, to a force arising from the earth's rotation, which deflects all moving bodies to the right in the northern hemisphere, or to the prevailing southwestwardly current along these shores, or to both, it is certain that such a deflection clearly exists. Seaward it may be clearly noted in the charts of the coast survey in the depositions now taking place at the mouths of the rivers. The ship channels are always found to the south of the harbors. Inland, the south and southwest bend of the rivers has been already mentioned; and coupled with it is the observation made long since by Mr. Ruffin, that the bluffs are on the west |