Messrs. Browne and Ledyard state the distance to be fifty caravan days; which at 16½, give 825 G. miles. Edrisi allows forty journies, between Cairo and _Tamest_ (Temissa). These, at 19 each, are equal to 760 G. miles: to which, if 73 are added, as Horneman allows, from Temissa to Mourzouk, the total is 833. This route leads through Bahnasa, in the Lesser Oasis; and, by circumstances, near Siwah also; as a river occurs at eight days from Bahnasa. Thence it goes to the south of Augila, and by _Seluban_, which may be intended for the Plain of Sultin.[20] It is obvious, that if Augila should lie yet more to the south, or nearer in a line between Cairo and Fezzan, this would lengthen the given line of distance; and that by 10 or 12 miles. The comparison of the different authorities, then, is as follows: By Horneman, 829 } } mean 827 By Browne and Ledyard, 825 } By Edrisi, (direct) 833 By Edrisi and Abulfeda, reckoned from Siwah only, and thence through Augila and Zala 877 By the bearing and distance from Mesurata 854[21] Thus Horneman’s account falls short of the interval between Cairo and Mourzouk, when the latter is placed in reference to Mesurata, by 25 miles only; and the reported caravan distance falls only four short of Horneman’s. The reports of the Arabian geographers ought not to be put in competition with either. IV. _Respecting the Position of Mourzouk, Capital of Fezzan._ Mr. Horneman in his Journal transmitted from Tripoly, states the latitude of Mourzouk, by observation, to be 25° 54′ 15″; a parallel so different from the result of the other authorities, that it becomes necessary to examine those authorities, minutely. The reported observation, differs nearly two degrees from the parallel assigned it in the Proceedings of the Association printed in 1798. Without attempting to account for so great an (apparent) error, I shall proceed to adduce the authorities for its parallel, as assumed in the present map. 1. Mr. Beaufoy, from the information of certain Tripoline merchants, has given 17½ journies of the caravan, in a direct south bearing, from Mesurata on the sea coast.[22] These journies are given at 8 hours, or 20 British miles per day: and I allowed for them 15 geographical miles, in direct distance; but I shall now, finding by experience that the paths in the Desert are generally very straight, allow 16½; whence the 17½ days will be found to produce 288¾, or say 289 G. miles. If these miles were entirely difference of latitude, Mourzouk would not be lower than 27° 22′ 2″, as Mesurata is said to lie in 32° 10′.