admire the various beautiful forms and colors of the sand, and we noticed an interesting mirage, which I have since found that Hitchcock also observed on the sands of the Cape. We were crossing a shallow valley in the Desert, where the smooth and spotless sand sloped upward by a small angle to the horizon on every side, and at the lowest part was a long chain of clear but shallow pools. As we were approaching these for a drink in a diagonal direction across the valley, they appeared inclined at a slight but decided angle to the horizon, though they were plainly and broadly connected with one another, and there was not the least ripple to suggest a current; so that by the time we had reached a convenient part of one we seemed to have ascended several feet. They appeared to lie by magic on the side of the vale, like a mirror left in a slanting position. It was a very pretty mirage for a Provincetown desert, but not amounting to what, in Sanscrit, is called "the thirst of the gazelle," as there was real water here for a base, and we were able to quench our thirst after all.
Professor Rafn, of Copenhagen, thinks that the mirage which I noticed, but which an old inhabitant of Provincetown, to whom I mentioned it, had never seen nor heard of, had something to do with the name "Furdustrandas," i. e. Wonder-Strands, given, as I have said, in the old Icelandic account of Thorfinn's expedition to Vinland in the year 1007, to a part of the coast on which he landed. But these sands are more remarkable for their length than for their mirage, which is common to all deserts, and the reason for the name which the Northmen themselves give,—"because it took a long time to sail by them,"—is sufficient and
