One harvest only is permitted, the second stripping of feathers and the rebuilt nest being left undisturbed. The caverns are lined with a white guano, now some feet thick, since it has ceased to be sought for manure; the Martialists having discovered means of saturating the soil with ammonia procured from the nitrogen of the atmosphere, which with the sewage and other similar materials enables them to dispense with this valuable bird manure. Whether the white colour of the island, perceptible even in a large Terrestrial telescope, is in any degree due to the whiteness of the birds, their nests, and leavings, or wholly to reflection from the bright spar-like surface of the rock itself, and especially of the flat table-like summit, I will not pretend to say.
From this point we held our course south-westward, and entered the northernmost of two extraordinary gulfs of exactly similar shape, separated by an isthmus and peninsula which assume on a map the form of a gigantic hammer. The strait by which each gulf is entered is about a hundred miles in length and ten in breadth. The gulf itself, if it should not rather be called an inland sea, occupies a total area of about 100,000 square miles. The isthmus, 500 miles in length by 50 in breadth, ends in a roughly square peninsula of about 10,000 square miles in extent, nearly the whole of which is a plateau 2000 feet above the sea-level. On the narrowest point of the isthmus, just where it joins the mainland, and where a sheltered bay runs up from either sea, is situated the great city of Amâkasfe, the natural centre of Martial life and commerce. At this point we found awaiting us the balloon which was to convey us to the Court of the Suzerain. A very light but strong metallic framework
