onto the scene came a man named lewis aggasi who was two years early born in 1807. had ambitions to accomplish things at the very highest level of science. he was going to take on the world. and his foray into the world was his glacial hypothesis. he had grown up in switzerland and, of course, there are glaciers in switzerland and he was aware of the advanced and retreat of glaciers across seasons. and he noted, as did others, that when glaciers retreat in the summers they leave rocks behind them. they furrow up and plow up a lot of land. the glacier will move it and carry rock away and retreat. and that was his explanation for glaciers. they were moved by glaciers. when he got here he set up the museum of comparative zoology at harvard and set up a marine and botanical building and a great promoter and he knew he couldn't publish his ideas in small swiss journals. he had to take his ideas -- he had to travel with them. so in 1840 he came to britain and he toured the british isles with british geologists and said, ah, that was formed by a glacier. that was formed by