By daylight on the 9th we began to skirt Kauehi, and had now an opportunity to see near at hand the geography of atolls. Here and there, where it was high, the farther side loomed up; here and there the near side dipped entirely and showed a broad path of water into the lagoon; here and there both sides were equally abased, and we could look right through the discontinuous ring to the sea horizon on the south. Conceive, on a vast scale, the submerged hoop of the duck-hunter, trimmed with green rushes to conceal his head--water within, water without--you have the image of the perfect atoll. Conceive one that has been partly plucked of its rush fringe; you have the atoll of Kauehi. And for either shore of it at closer quarters, conceive the line of some old Roman highway traversing a wet mor
