agitating experiences, and it is for the scientific to explain why six hundred miles up the Nile, on the very threshold of the Tropic of Cancer, the afterglow should last almost thrice as long as it does elsewhere in the temperate zone. But so it is. To call it an epilogue of the mystery play of sunset is perhaps to describe it inadequately. In reality it is an additional and more profoundly interesting act of the great drama. It is the very reverse of the phenomenon depicted in Coleridge's two pregnant lines. The dipping of the sun's rim in these regions is followed by no out-rush of the stars, no striding forward of the dark. On the contrary, after some ten minutes or so of fading twilight, such as in other lands is a mere prelude to complete darkness, the whole heaven suddenly lightens up again.
The grey of dusk almost disappears, and objects near and distant which had been melting into obscurity start once more, as though touched by the wand of an enchanter,
