J. & C. Walker Sculpt. Published as the act directs, April 1827, by J. Murray, Albemarle St. London.

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CHAPTER X.

OBSERVATIONS ON THE GULF AND SHORES OF THE GREATER SYRTIS.

The Dimensions of the Gulf, according to Ancient Writers, considered, and compared with those resulting from the Observations of the Expedition — Difference in the Statements of the several Writers quoted — Reasons why a Difference may be expected in their Accounts — Observations of Major Rennell on the Measurements of the Ancients — Ptolemy’s Outline of the Gulf more correct than any hitherto given — Number of Square Miles of Error in modern Charts of the Greater Syrtis — The Ideas of Ancient Writers (Herodotus excepted) with respect to the Nature and Resources of the Syrtis (the Territory, not the Gulf of the Greater Syrtis is here meant) more erroneous than the Dimensions which have been assigned to the Gulf itself — The General Character of the Syrtis not that of a Sandy Plain — Incorrectness of the Arab Accounts of what is termed by them the Desert of Barka — Account of Herodotus considered — Apparent Accuracy of his Statements — Inferences drawn from them — Ancient Accounts of the Gulf of the Greater Syrtis, dimensions excepted, very correct — Accumulation of Soil on the Shores of the Gulf accounted for — Apparent Elevation of the General Level of the Syrtis — Advance of the Sea on the Northern Coast of Africa — Appearance of the Coast at Alexandria and Carthage consistent with that of the Shores of the Greater Syrtis and Cyrenaica — Observations of Major Rennell and Dr. Shaw on the Elevation of the Coast of Tunis, and the Advance of the Sea in that quarter — Observations of Lucan on the Level of the Greater Syrtis — Dangers of the Navigation of the Gulf of Syrtis considered — Inset into the Gulf still existing to a great extent — Flux and Reflux of the Sea mentioned by Strabo and Mela considered — Remarks on the Derivation of the term Syrtis.

In considering the dimensions which have come down to us of the Greater Syrtis, those allotted to it by Strabo (in the seventeenth book) are so singularly inconsistent with each other, that there appears to be no possible mode of reconciling the measurements he has given of its diameter, with those which he has in the same place ascribed to its circumference, without material alterations in the text. “The circumference of the Greater Syrtis” (observes the geographer) “is about nine hundred and thirty stadia[1]; and its diameter, at the bottom of the Gulf, is one thousand five hundred stadia: the breadth of the entrance (or mouth) is about the same[2]:” that is, about fifteen hundred stadia. Here we have a circumference considerably less than its diameter, and no way of getting rid of a difficulty so formidable to mathematicians, without making such decided alterations in the text as no sober-minded editor would hazard[3]. Various readings have been given, by different commentators, of this passage; but it will be useless to compare their several merits; since both the measurements in question will be found to be no less inconsistent with the truth than they have been seen to be with each other. For the actual circumference of the gulf of the Greater Syrtis may be estimated at four hundred and twenty-two geographic miles, and its diameter at two hundred and forty-six[4]: so that it would be necessary to alter both the circumference and diameter given by Strabo before any use could be made of his dimensions; and then the measurements must be taken on the authority of the commentators, since they would be no longer those of the geographer. In short, the difficulty appears to be scarcely surmountable; for though it is evident that the passage is not as Strabo left it, we have no sufficient data for deciding what it really was originally[5]. The measurements given by Pliny are somewhat nearer the truth[6]; indeed his diameter of the gulf may be considered as remarkably accurate; for it is stated at three hundred and thirteen Roman miles, equal to two hundred and forty-eight and a quarter geographic miles, and there is consequently no more than two miles and a quarter difference between these dimensions and the actual diameter. His circumference, however, is not by any means so accurate; it is given at six hundred and twenty-five Roman miles, which are equal to four hundred and ninety-four geographic miles, and will therefore leave a difference of seventy-two geographic miles between this measurement of the circuit and the actual one. The difference also exists on the wrong side; that is to say, the whole distance of Pliny is not only much more than the actual distance by observations, but much more than the actual road-distance, which is the longest which can be allowed. The diameter of the gulf, already stated, of this author, will be found to coincide remarkably well with the measurement which may be deduced from the distance he has given us in another place, between the cities of Leptis Magna and Berenice, of three hundred and eighty-five Roman miles[7]: for the distance between Lebida (Leptis Magna) and Mesurata, the western extremity of the gulf, may be reckoned at fifty-eight geographic miles, equal to seventy-three Roman miles; so that this being deducted from the whole distance given, of three hundred and eighty-five M. P. we shall have a remainder of three hundred and twelve of the same for the distance between Mesurata and Bengazi, leaving a difference of only one mile between the diameter of the gulf thus deduced and that above stated of three hundred and thirteen. But although we may infer, from the coincidence of the two measurements, that the three hundred and twelve miles in question may be taken as distance across the gulf, they are by no means stated to be such in the text; and if they had chanced to coincide with the circumference instead of the diameter of the gulf, they might just as well have been taken for the road-distance between Mesurata and Bengazi; the measurements which we find in the Itinerary of Antoninus, of the distance between Leptis Magna and Berenice, come nearer to the actual road-distance between these places, by one hundred and thirty Roman miles, than that which is obtained by adding the seventy-three miles between Lebida and Mesurata to the circumference of the gulf given by Pliny; for the whole distance of the Itinerary from Leptis to Berenice is not estimated at more than five hundred and sixty-eight Roman miles, while those above mentioned being added together would make no less than six hundred and ninety-eight. So that the circumference of the gulf which may be deduced from the Itinerary differs only from the actual circuit by road-distance in thirty-seven Roman miles, or twenty-nine and a half geographic.

But instead of being surprized at the differences which obtain between the measurements which have descended to us from the ancients, we ought rather, perhaps, to wonder that they do not differ even more than they are usually found to do from each other. It is true that abundant materials were furnished to the early geographers, by the numerous military and naval expeditions which enterprizing or ambitious states had fitted out for the purposes of conquest or discovery[8]; but the maps and charts which resulted from them were laid down without the aid of astronomy; and the distances between the places described in them were either measured or computed along the roads which the armies traversed, or deduced from the track of vessels along the coast. Major Rennell has observed, that the difference which will generally be found between the measurements of Eratosthenes and Strabo, and those which appear in modern geography, will be that which exists between the measure of a direct line, drawn from one place to another, and that of the road distance between them. “Nothing can speak more strongly to this point,” (says the well-informed and intelligent writer here quoted,) “than the circumstance of Strabo’s giving the number of stades in Nearchus’s coasting navigation for the lengths of the coasts of Persia and Caramania[9].”

In fact it was not till the time of Ptolemy that geography began to be placed upon that solid basis on which it now stands so conspicuously; and it certainly appears somewhat singular, that the writers on this subject who flourished between the time of Hipparchus and that of the Alexandrian geographer (among whom were Strabo and Pliny,) should not have availed themselves of the discoveries of the former to check the measurements which appear in their works[10]. Various errors have been pointed out in the geography of Ptolemy; but as it can scarcely be supposed that he had sufficient observations to regulate the position of all the places which he has laid down, we ought not to be surprized at this circumstance. His outline of the Gulf of Syrtis, though it cannot be called correct, is notwithstanding more so than those which have since been given of it; and the prolongation of the gulf at its southern extremity, so erroneously marked in modern charts, as well as the inlet called the Gulf of Zuca, which we have stated does not exist, are neither of them laid down in it at all. It may therefore be said, that the true character of the gulf is much better preserved in the loose outline of Ptolemy than in any other of which we are aware. Whatever may be the reasons which have induced modern geographers to introduce into the Gulf of Syrtis the errors which we have alluded to, it is certain that the best chart which they have hitherto produced of it must undergo a correction of ninety miles in longitude, and upwards of thirty miles in latitude, that is to say, it must part with nearly six thousand square miles of ground, before it will be consistent with the truth.

Should we pass from the measurements to the general character of the Syrtis, we shall find that if the ancient authorities have erred in their dimensions of it, they have been no less deceived with regard to its nature and resources. The whole country from Bengazi to Mesurata appears to have been generally considered by the writers of antiquity as a dreary tract of sand, without water or vegetation, and swarming with venomous serpents. But we have already shewn that there are spots in this tract where vegetation is very luxuriant, and where water may be readily procured; and although the extent of marshy ground is in many places considerable, yet the proportions between the barren and the productive parts of the Syrtis are not so little in favour of the latter as appears to have been generally imagined. The whole tract is so thinly inhabited, that a very trifling portion of it only is cultivated; but this circumstance is owing more to the character of the Bedouins who frequent it, and to the government to which they are subjected, than to the incapacity of the soil itself.

The Bedouin, though active, is far from industrious; and if he can gain a livelihood from the flocks which he possesses, he will seldom trouble himself to cultivate even the most productive soil; indeed, if he were to do so, he has in general no security that any part of the produce or the profits of it would be his own. His tent and flocks may be removed at a few minutes’ notice, but his crop of corn or vegetables could not be so disposed of; and they who came as his friends, for the purpose of collecting tribute, or as enemies, for the purpose of spoliation, would take care to be with him before his crops were cut, and make sure of the object of their visit. We remember asking an Arab, in the district of Syrt, why his tribe would not trouble themselves to dig a few more wells in a place which they frequented, where there was plenty of water, at no great depth from the surface of the soil: his answer was that, if they were to do so, the Bashaw’s troops who collected the tribute would more easily overtake them, when they chose to run away, than if the supply of water were more scanty: for without a good supply of water the troops could not advance more than a short distance into the interior, and would consequently be less likely to overtake them in their flight. This reason was sufficient in his opinion to account for the circumstance; but it is probable that, if there were no grounds for apprehension on this head, neither our friend himself, nor any Arab of his tribe, would have had resolution enough to sink a single well, however much they might chance to be in want of it; and that they would have preferred removing their whole establishment to another place, which might be better provided with water, to the trouble of digging for it where they were.