For a hundred and fifty years, between the plod of packhorse trains and the arrival of the railways, canals were the high-tech water machine driving the industrial revolution. Amazing feats of engineering, they carried the rural into the city and the urban into the countryside, and changed the lives of everyone. And then, just when their purpose was extinguished by modern transport, they were saved from extinction and repurposed as a 'slow highways' network, a peaceful and countrywide haven from our too-busy age. Today, there are more boats on the canals than in their Victorian heyday. ...