It is proper to be remarked, that the people of Siwah, report the distance of Cairo, from that place, to be twelve journies only: but it becomes necessary to inquire what kind of journies these are, in order to turn this, and other reports of the same kind to use. These journies then, are meant for those of light travellers, going few in number together; and not of caravans, where, amongst a number of camels, there must of course be some of slow pace, (to which the whole caravan must, of necessity, conform,) not to mention the increased number of delays by accidents. The people of Siwah reported the length of the following journies, which are in point: Siwah to Charje, in the Greater Oasis 12 days. Derna 14 Faiume (through the Lesser Oasis) 12 Cairo 12 A mean of these, gives about 20,6 per day; the journies to Charje and Faiume giving 19⅔, the others 21½.[16] As Siwah lies directly between Derna and the Greater Oasis, we have one line of 26 days, pretty satisfactorily determined in point of distance, and here the result is 20,6 also. Twelve such days would give only 247, of course, for the distance between Cairo and Siwah: so that a rate of 21½ is required. Pliny, lib. v. c. 9, reports twelve journies between Memphis and Ammon, requiring a rate of 21 per day. There is yet another statement of the distance, and that is, fifteen ordinary _caravan_ journies, taken at 16¼ or 16½. The result is 247½; about equal to the 12 days of light travelling. Possibly, I have taken the distance rather too high, at 259½; but I know not how to do away Mr. Browne’s line from the neighbourhood of Parætonium, considering that Mr. Horneman must have given _his_ time from recollection. At all events, Siwah cannot be many miles out, in its longitude; but whilst the longitudes of the places on the sea coast remain in a state of uncertainty, one is not likely to get nearer the truth. Mr. Browne appears to have been 17 days from his station in lat. 28° 40′, and not far to the SW of Siwah, to Alexandria. A rate of 15⅓ miles is the result; but Mr. Browne being exceedingly ill, the whole way, it is most probable that his attendants relaxed in their speed. II. _Siwah to Augila._ Mr. Horneman’s time from Siwah to Augila is 87½ hours,[17] which, at 2,05 G. miles, give 179,35: but taken on the road distance at 2½ B. miles, as before, 181½. Taken on Horneman’s 11 _mean_ days, at 16½, it is also 181½. The Arabian geographers reckon it 10 days, implied of 19 G. miles each, equal to 190. Herodotus also allows 10 days between Ammon and Augila.