the first time sara met robert was shortly after she had set up her camp for her summer of study : a sleeping tent under a shelter of hemlock trees and trenched around to keep rainwater from flowing beneath it , a desk she had made of rough boards across tree stumps she had rolled into place and evened out with wedges of flat stones from the river , a dining table that was nothing more than a telephone cable spool and a couple of folding canvas chairs that sat low to the ground designed for the beach .