When I returned to camp night had fallen.  The evening star stood high in the pale sky, all alone and difficult to see, yet the more beautiful for that.  The night appeared to be warmer or perhaps it was because no wind blew.  Nielsen got supper, and ate most of it, for I was not hungry.  As I sat by the camp-fire a flock of little bats, the smallest I had ever seen, darted from the wood-pile nearby and flew right in my face.  They had no fear of man or fire.  Their wings made a soft swishing sound.  Later I heard the trill of frogs, which was the last sound I might have expected to hear in Death Valley.  A sweet high-pitched melodious trill it reminded me of the music made by frogs in the Tamaulipas Jungle of Mexico.  Every time I awakened that night, and it was often, I heard this trill.  Once, too, sometime late, my listening ear caught faint mournful notes of a killdeer.  How strange, and still sweeter than the trill!  What a touch to the infinite silence and loneliness!  A killdeer—­bird of the swamps and marshes—­what could he be doing in arid and barren Death Valley?  Nature is mysterious and inscrutable.

Next morning the marvel of nature was exemplified even more strikingly.  Out on the hard gravel-strewn slope I found some more tiny flowers of a day.  One was a white daisy, very frail and delicate on long thin stem with scarcely any leaves.  Another was a yellow flower, with four petals, a pale miniature California poppy.  Still another was a purple-red flower, almost as large as a buttercup, with dark green leaves.  Last and tiniest of all were infinitely fragile pink and white blossoms, on very flat plants, smiling wanly up from the desolate earth.

Nielsen and I made known to Denton our purpose to walk across the valley.  He advised against it.  Not that the heat was intense at this season, he explained, but there were other dangers, particularly the brittle salty crust of the sink-hole.  Nevertheless we were not deterred from our purpose.

So with plenty of water in canteens and a few biscuits in our pockets we set out.  I saw the heat veils rising from the valley floor, at that point one hundred and seventy-eight feet below sea level.  The heat lifted in veils, like thin smoke.  Denton had told us that in summer the heat came in currents, in waves.  It blasted leaves, burned trees to death as well as men.  Prospectors watched for the leaden haze that thickened over the mountains, knowing then no man could dare the terrible sun.  That day would be a hazed and glaring hell, leaden, copper, with sun blazing a sky of molten iron.

A long sandy slope of mesquite extended down to the bare crinkly floor of the valley, and here the descent to a lower level was scarcely perceptible.  The walking was bad.  Little mounds in the salty crust made it hard to place a foot on the level.  This crust appeared fairly strong.  But when it rang hollow under our boots, then I stepped very cautiously.  The color was a dirty gray and yellow.  Far ahead I could see a dazzling white plain that looked like frost or a frozen river.  The atmosphere was deceptive, making this plain seem far away and then close at hand.