<p>'Divine beauty all. Here I could stay tethered forever with just bread and water, nor would I be lonely.'<br>In the summer of 1869, John Muir joined a group of shepherds in the foothills of California's Sierra Nevada mountains, that he might study and expand his knowledge of the plants, animals and rocks he found there. My First Summer in the Sierra ? first published in 1911 ? is the detailed and colourful diary he kept while tending sheep and...