At twenty minutes past two we quitted the Bel Alp. The moon, which seven hours previously had cleared the eastern mountain-tops with a visible motion, was now sloping to the west. The light was white and brilliant, and shadows of corresponding darkness were cast upon the earth. The larger stars were out, those near the horizon especially sparkling with many-coloured fires. The Pleiades were near the zenith, while Orion hung his sword a few degrees above the eastern horizon. Our path lay along the slope of the mountain, parallel to the Oberaletsch glacier, the lateral moraine of which was close to us on our right. After climbing sundry grass acclivities we mounted this moraine, and made it our pathway for a time. At a certain point the shingly ridge became depressed, opening a natural passage to the glacier. We found the ice 'hummocky,' and therefore crossed it to a medial moraine composed of granite _débris_ and loaded here and there with clean granite blocks of enormous size. Beyond this moraine we found smoother ice and better light, for we had previously journeyed in the shadow of the mountains.
We marched upwards along the glacier chatting sociably at times, but at times stilled into silence by the stillness of the night. 'Es tagt!' at length exclaimed my companion. It dawns! Orion had moved upwards, leaving space between him and the horizon for the morning star. All the east was belted by that 'daffodil sky' which in some states of the atmosphere announces the approach of day in the Alps. We spun towards the east. It brightened and deepened, but deeper than the orange of the spectrum it did not fall. Amid this the mountains rose. Silently and solemnly their dark and dented outlines rested against the dawn.
The mass of light thus thrown over the shaded earth long before the sun appeared above the horizon came not from illuminated _clouds_, but from matter far more attenuated than clouds--matter which maintains comparative permanence in the atmosphere, while clouds are formed and dissipated. It is not light reflected from concentric shells of air of varying density, of which our atmosphere may be rightly assumed to be made up; for the light reflected from these convex layers is thrown, not upon the earth at all, but into space. The 'rose of dawn' is usually ascribed, and with sufficient correctness, to _transmitted_ light, the blue of the sky to _reflected_ light; but in each case there is both transmission and reflection. No doubt the daffodil and orange of the east this morning must have been transmitted through long reaches of atmospheric air, and no doubt it was during this passage of the rays that the selective winnowing of the light occurred which gave the sky its tint and splendour. But if the distance of the sun below the horizon when the dawn first appeared betaken into account, it will become evident that the solar rays must have been caused to swerve from their rectilineal course by _reflection_. The _refraction_ of the atmosphere would be wholly incompetent to bend the rays round the convex earth to the extent now under contemplation.