Beach of encounter bay.

While the men were thus employed, I took Fraser with me, and, accompanied by M’Leay, crossed the sand-hummocks behind us, and descended to the sea-shore.  I found that we had struck the south coast deep in the bight of Encounter Bay.  We had no time for examination, but returned immediately to the camp, as I intended to give the men an opportunity to go to the beach.  They accordingly went and bathed, and returned not only highly delighted at this little act of good nature on my part, but loaded with cockles, a bed of which they had managed to find among the sand.  Clayton had tied one end of his shirt up, and brought a bag full, and amused himself with boiling cockles all night long.

If I had previously any hopes of being enabled ultimately to push the boat over the flats that were before us, a view of the channel at low water, convinced me of the impracticability of any further attempt.  The water was so low that every shoal was exposed, and many stretched directly from one side of the channel to the other; and, but for the treacherous nature of the sand-banks, it would not have been difficult to have walked over dry footed to the opposite side of it.  The channel stretched away to the E.S.E., to a distance of seven or eight miles, when it appeared to turn south under a small sand-hill, upon which the rays of the sun fell, as it was sinking behind us.

Curious effect of refraction.

There was an innumerable flock of wild-fowl arranged in rows along the sides of the pools left by the tide, and we were again amused by the singular effect of the refraction upon them, and the grotesque and distorted forms they exhibited.  Swans, pelicans, ducks, and geese, were mingled together, and, according to their distance from us, presented different appearances.  Some were exceedingly tall and thin, others were unnaturally broad.  Some appeared reversed, or as if they were standing on their heads, and the slightest motion, particularly the flapping of their wings, produced a most ridiculous effect.  No doubt, the situation and the state of the atmosphere were favourable to the effect I have described.  The day had been fine, the evening was beautiful,—­but it was the rarefaction of the air immediately playing on the ground, and not the haze at sunset that caused what I have noticed.  It is distinct from mirage, although it is difficult to point out the difference.  The one, however, distorts, the other conceals objects, and gives them a false distance.  The one is clear, the other is cloudy.  The one raises objects above their true position, the other does not.  The one plays about, the other is steady; but I cannot hope to give a proper idea either of mirage or refraction so satisfactorily as I could wish.  Many travellers have dwelt upon their effects, particularly upon those of the former, but few have attempted to account for them.