The Sensitiveness of the Eye to Light and Colour

Abstract

THERE may be some here who have had the pleasure or the pain—of rising very much betimes in a Swiss centre of mountaineering in order to gain some mountain peak before the sun has had power enough to render the intervening snow-fields soft, or perhaps dangerous. Those who have will recollect what were the sensations they experienced as they sallied out of the comfortable hotel, after endeavouring to swallow down breakfast at 2 am., into the darkness outside, Perhaps the night may have been moonless, or the sky slightly overcast, and the sole light which greeted them have been the nervous glimmer of the guides’ lanterns. By this feeble light they may have picked their way over the stony path, and between the frequent stumbles over some half hidden piece of rock lying in the short grass they may have had time to look around and above them, and notice that the darkness of the night was alone broken by stars which gave a twinkle through a gap in the clouds, or if the sky were cloudless, every star would be seen to lie on a very slightly illuminated sky of transparent blackness. Although giant mountains may have been immediately in front of them, their outlines would be almost if not quite invisible. As time went on the sky would become a little brighter, and what is termed the petit jour would be known to be approaching. The outlines of the mountains beyond would become fairly visible, the tufts of grass and the flowers along the path would still be indistinguishable, and most things would be of a cold grey, absolutely without colour. The guide's red woollen scarf which he bound round his neck and mouth would be black as coal. But a little more light, and then some flowers amongst the grass would appear as a brighter grey, though the grass itself would still appear dark; but that red scarf would still be as black as a funeral garment. The mountains would have no colour. The sky would look leaden, and were it not for the stars above it might be a matter of guesswork whether it were not covered over with cloud.