EXCEPT for certain conspicuous instances of coastal erosion and so on, the face of the country seems quite permanent and unchanging, but to the geologist the whole of the landscape is in an almost fluid state. Rivers, sea, ice and wind arc constantly at work wearing away or ' building up valleys, sandbanks, dunes, etc., and even in our own time we can see a tiny cross-section of the long process of change that is going on through the centuries. This process will be the subject of Mr. Scott's series of talks, of which this afternoon's is the first.