IT WAS LESS THAN AN hour's walk to the Fair, strolling along gently sloped green banks with weeping-willows, beneath whose canopies were hidden various prostrate students. Black cattle mowed the grass unevenly and strewed cow-pies along their way. At first the river was shallow enough to wade across, and its bottom was carpeted with slender fronds that, near the top, were bent slightly downstream by the mild current. 'Now, there is a curve whose fluxion in the downstream direction is nil at the point where it is rooted in the bottom – that is to say, it rises vertically from the mud – but increases as it rises.'