The Gobi desert has played a vital part in the history of the Burmans, as in that of many other peoples of Asia and Europe. Winds blow continuously between Paris and Peking—from east to west for half the year, from west to east for the other half. Surface soil, once broken (as in the early Neolithic), is loth to settle. Wind-blown soil, or loess, chokes all the rivers and prevents their exit to the seas. Fresh-water lakes go saline and undrinkable. And soon a vast country, from the centre outwards, becomes uninhabitable by man. The problem is still acute. With three of our four continents still desert-eroded, it remains a question whether our planet can be saved from going the way of Mars.