322 R. D. Oldham — On iwohahle Changes in tlie Geography [No. 4, 



would be of anything like so great a range as that just found, a range 

 from maximum to minimum of about 11 per cent, of the mean heating 

 effect. 



XVIII. — On prohahle Changes in the Geography of the Punjab and its 

 Mivers : an Historico- Geo graphical Study. — By R. D. Oldham, A. R. 

 S. M., Deputy Superintendent, Geological Survey of India. 



[Received SOtli September ;— Read December 12tli, 1886.] 



(With a Map— PL XIX.) 



Introductory. — Of all the problems with which we are brought in 

 contact when we try to unravel the ancient geography of India, none 

 surpass in interest or difficulty those connected with the rivers of the 

 Punjab and Sind. Both interest and difficulty result from the fact that, 

 previous to the advent of the English, all civilization and every invader 

 have entered India from the North- West, and their difficulty from the 

 changes that appear to have taken place in the courses of these rivers 

 during the last three thousand years. It cannot be said that this subject 

 has been neglected by previous writers on the ancient geography of India, 

 but their efforts have mainly been addressed to the identification of towns 

 or countries, and their references to the rivers are often marked by an 

 ignorance, or neglect, of the fundamental principles of physical geology ; 

 yet the matter is one on which the geologist must be heard as well aS 

 the scholar, for, whatever dependence may be placed on history or 

 tradition, the conclusions that are drawn are only valid so long as they 

 are possible, and no one that has not studied the mode of action of 

 rivers on a geological basis can decide whether any particular change in 

 the course of a river, of which there appears to be historical indication, 

 can or cannot have taken place.* 



* Thronghout the following paper, I am largely indebted to the anthor of an 

 anonymous essay in the Calcutta Review, on the " Lost River of the Indian Desert", 

 (vol. lix, pp. 1 — 29, understood to be by Surgeon-Major C. F. Oldham). I am 

 indebted to this writer for having first drawn my attention to the subject, for having 

 suggested most of the opinions supported in the following paper, and for many of 

 the references given below. I have, however, except where the contrary is expressly 

 stated, vex^ified them in every case ; and, to save wearisome repetition, I must request 

 all who wish to see how little I diverge from the opinions expressed by the writer 

 referred to, and to what extent this paper goes beyond the matter he has treated 

 of, to compare the two, promising that the perusal of the article in the Calcutta 

 Review will prove anything but a waste of time. 



