further to notice that Alexander’s visit to Margiana, the city now so well known as Merv, could not have been made, as Curtius informs us, from Bokhara, which is 215 miles distant and separated from it by a terrible intervening desert, all but entirely destitute of wells, but was probably made from Sarakhs in the earlier part of the march from the Caspian Gates. We turn now to Major-General Haig’s _Memoir_ on the Indus-Delta country—a work of which about a fourth part directly concerns our subject. The sections which are of this nature discuss the following points:—1. The Geography and Hydrography of the Delta Country (chap. i.); 2. The Delta at the time of Alexander’s Expedition (chap. ii.); 3. The Delta according to later Greek Accounts (chap. iii.); 4. The Lonibare Mouth of the Indus (Append. Note A); 5. The general course of the Indus in Sindh in ancient times (Append. Note C); 6. Itineraries in the Las Bêlâ Country (Append. Note D); 7. The March to the Arabios (Append. Note E); 8. The voyage of Nearchos from Alexander’s Haven to the Mouth of the Arabios (Append. Note F). Our author could scarcely have chosen for his subject one that is more beset with problems of aggravating perplexity. The Indus is notable even among Indian rivers for the frequency, and sometimes also for the suddenness, with which it changes its courses. As Colonel Holdich well observes, “The difficulty of restoring to the map of India an outline of the ancient geography of Sindh and the Indus Delta is one which has baffled many generations of scholars. The vagaries of the Indus, even within the limits of historic record, ... render this river, even before the Delta is reached, a hopeless feature for reference with regard to the position of places said once to have been near its bank. Within the limits of the Delta the confusion of hydrography becomes even more confounded.” In my note on Alexander in Sindh, which will be found at page 352, I have noticed that the channel in which the Indus now flows lies much farther to the west than the channel in which the Macedonians found it flowing. This _westing_, as it is called, is due to the operation of the law, first discovered by K. E. von Baer, that the difference of the velocity of the earth’s rotation at the Equator and at the Poles causes eroding rivers in the Northern Hemisphere to attack their right bank more than the left, and to push their beds sideways—while in the Southern Hemisphere, this action is reversed. From the _Memoir_ we learn how this law, and the other natural laws by which its action is modified, have affected the Indus. The river, we learn, pursues from the confluence of the Panjnad a very uniform S.W. direction for nearly 300 miles, till it reaches lat. 26° 56´, long. 67° 53´. At this point the river changes its general direction to one due south, and maintains this for about 60 miles, till it strikes, in lat. 26° 20´, long. 67° 55´, the eastern base of the Lakî Hills, just under the peak