CHAP. III. SIAM. 405 the capital. It is by no means certain whether this migra- tion downwards was caused by political events and increasing commerce, or from the country gradually becoming drier and more fit for human habitation. Judging from what happened in Bengal in historical times, I should fancy it was the latter. In India we find civilised nations first established in the Panjab and on the watershed between the Satlaj and the Jamna. Between 2000 and 3000 years B.C. Oudh seems to have become dry enough for human habitation, and Ayodhya (from which the Siamese capital took its name) became the chief city. Between 1000 and 500 B.C. Janakpur on the north, and Rajagriha on the south, were the capital cities of Bengal ; but both being situated on the hills, it was not till A^oka's time (250 B.C.) that Patna on the Son and Vaijalt on the Ganges, became capi- tals ; and still another 1000 years elapsed before Gaur and Dacca became important, while Murshidabad, Hugli, and Calcutta, are cities of yesterday. 1 The same phenomenon seems to have occurred in Siam, and, what is of still more interest, as we shall presently see, in Cambodia. As Ayuthia was for three centuries the flourishing capital of one of the great building ^ Ruins of a Pagoda at Ayuthia races of the world, we should, of course, look for considerable magnificence having been displayed in its architecture. From the accounts of the early Portuguese and Dutch travellers who visited it in the 1 For the particulars of this desiccation of the Valley of the Ganges, see the 'Journal of the Geological Society,' April, 1863.
