the largest merchant ships. Pliny, lib. vi. 29, allows only 100 feet for the breadth, but 30 for the depth ; which relative proportions are as improbable as the absolute statement of the depth is exaggerated.

Since this Section went to the press, the Author has had the satisfaction to peruse Mr. Browne's Travels in Africa, which, he conceives, will be classed amongst the first performances of the kind. The aids it brings to geography are great, and will probably lead to further discoveries, as it forms a link between Abyssinia on the east, and Bornou on the west. Moreover, it confirms, in a great degree, two positions advanced in the present system of African geography: first, that the Niger does not join the Nile: and, secondly, that the most remote head of the Nile is not situated in the quarter of Abyssinia, but far to the south-west of it. These remarks belong properly to Section XVI.

Mr. Browne has also a remark, which applies to the present Section. He says (p. 177), that although his guides refused to accompany him, when he wished to view the eastern portion of the canal, which extends from Birket-es-Sheib to Suez, as they had previously agreed, yet that "all consented that marks of the canal existed, and some of them arose to his own observation." He adds, that " remains exist of a stone pipe for conveying water to the site of Kolsúm, from Bir Naba." This is a well, situated some miles to the east of Suez, and on the opposite

side of the shallow inlet of the sea that passes before it. (Niebuhr, vol. i. 178.) One may conclude that this work was unnecessary during the existence of a canal from the Nile.

SECTION XVIII.

GENERAL OBSERVATIONS ON THE

FLOODS AND ALLU

VIONS OF RIVERS; APPLIED MORE PARTICULARLY TO THE NILE AND ITS DELTA: WITH THE CHANGES THAT HAVE TAKEN PLACE IN THE FORM AND DIMENSIONS OF THE DELTA; AND AN INQUIRY CONCERNING THE SITE OF THE CITY OF MEMPHIS.

Preliminary Observations—All capital Rivers do not form Deltas; these being composed of Alluvions, deposited only in shallow Seas-Two different Degrees of Slope in the beds of Rivers-no arguments required to prove the progress of Alluvions; but the rate of their progress uncertain—vast length of Time required to form them-Manner in which they are extended into the Sea-Bars of Rivers, how formed, with Remarks on them-The Alluvion, which is originally formed on a Level with the Sea, is raised by the Surge: and afterwards formed into a regular Slope, by the Depositions of the Land Floods— Sea alluvions, slope a different way from those of RiversThe Delta of the Nile, originally covered with water; and was afterwards in the state of a Marsh; according to Herodotus— Sesostris drains the Land by means of Canals, and distributes it-Deltas comprise Tracts of Land, in an imperfect State of Formation-their progress towards Completion, shewn by the Rivers confining themselves to fewer Channels-Some of the Causes that produce the Changes in the Courses of Rivers— Position of Memphis, deduced from ancient authorities, and proved by modern Travellers—A Branch of the Nile turned aside to prepare the ground for it-Report of Herodotus re

garding this fact, confirmed by appearances-Ancient course of the Nile traced along the foot of the Libyan Hills-Conjecture respecting the Lake Moris-Proofs of the change of Place of the Apex of the Delta; which has advanced downwards-opposite to Heliopolis, in the time of Strabo-The western arm of the Nile grows shallower-Proofs of the Rise of the soil in Egypt-Remarks on the Inundations of Rivers.

Ar a time when some new matter respecting the geography of Egypt may reasonably be expected, it would be premature to enter into any other kind of dissertation respecting it, than such as may serve merely to render the present subject intelligible. The construction of the geography of the Delta, &c. that appears in the map, at page 55, is therefore to be regarded as an outline only; though, as such, it is formed of the best materials that we have been able to procure. Those furnished by M. Niebuhr are the first in point of value, as they not only include the whole form of the Delta, and the relative situations of the city of Cairo, the Pyramids, and the sites of Memphis and Heliopolis, to the upper angle of that celebrated tract; but are also adjusted by the aid of celestial observations'. A chart of the coast, between Alexandria and Rosetta, brought to England by a naval officer of great distinction, from Lord Nelson's fleet, adds very much to the accuracy

1 See M. Niebuhr's Voyage en Arabie et en d'autres Pays Circonvoisins, &c. vol. i. p. 71, &c.-French edition.

The Map, No. VII. at page 55, contains both the ancient and modern Delta; the former according to the ideas of Herodotus, the latter according to the latest observations.

of that part and for the rest, we have referred to M. D'Anville's map of Egypt.

It has been stated that we do not profess to enter farther into the geography of Egypt, than what relates to the alluvions of the Nile, and certain other particulars, since M. D'Anville has already entered so deeply into the subject of the geography at large, ancient as well as modern; and, moreover, that when a new body of materials does appear, the subject will require more time and room than can be allotted to any particular division of this work. What we propose, therefore, to undertake in this and the succeeding Section, is to remark the changes in respect of form and extent that have happened to the Delta, since the early times of history, together with the probable cause of those changes: and also to inquire into the position occupied by the city of Memphis, and the change of course of the Nile in its neighbourhood. The Egyptian Oases, and the position of the temple of Jupiter Ammon, will form the subject of a future Section.

It is a circumstance well known to the generality of readers, that rivers which deposit great quantities of matter, do also very often separate into two or more branches, previous to their discharge into the sea; thus forming triangular spaces, which the Greeks aptly called DELTAS, from the resemblance they bore to the form of that letter of their alphabet and also that these Deltas almost universally encroach on the sea, beyond the general, and it may be supposed, original line of the coast.

However, the formation of such Deltas, even by