From Karachi to the Persian Gulf, a voyage undertaken 300 years B.C., of which a log has been kept from day to day, is necessarily of exceeding interest, if only as an indication of a few of the changes which have altered the form of that coast-line in the course of twenty-two centuries. This old route from Arabia to the west coast of India can hardly be left unnoticed, for it illustrates the earliest beginning of those sea ways to India which were destined finally to supplant the land ways altogether. I have already pointed out that, judged by the standard of geographical aptitude only, there is no great difficulty in reaching Persia from Karachi. But geographical distribution of mountain, river, and plain is not all that is necessary to take into account in planning an expedition into new territory. There is also the question of supplies. This was the rock on which Alexander's enterprise split. In moving out of India towards Persia he adopted the same principle which had stood him in good stead on the Indus, viz. the maintenance of communication between army and fleet. Naturally he elected to retire from India by a route which as far as possible touched the sea. This was his fatal mistake, and it cost him half his force. We need not trouble ourselves further with the ethnographical conditions of that extraordinary country, Makran, in Alexander's time; nor need we follow in detail the changes which have taken place in the general configuration of the coast-line between India and the Persian Gulf during the last 2000 years, references to which will be found in the _Journal of the Royal Society of Arts_ for April 1901. Apart from the enormous extension of the Indus delta, and in spite of the disappearance of many small islands off the coast, the general result has been a material gain by the land on the sea in all this part of the Asiatic coast-line.