_July 19th._--It was late in the day when all our stragglers came up. I was much concerned to find that the mussacks[9] (or water-bags) had leaked considerably, and that I should be under the necessity of replenishing them from the wells of this post. I must here observe, that General Baird had caused, both at this and other posts on the desert, wells to be dug, in order to procure a supply of that greatest of all necessaries of life (in such a climate as this)--water. In these scanty sources, it was thick and muddy; however, even this, could we have obtained it in abundance, would have been reckoned a luxury; but, alas! a very limited supply was all we could get: therefore, at half-past five, P.M., I marched. We passed for some hours through a long and winding valley; high, brown, rugged mountains, with here and there a solitary eagle perched upon a projecting crag, were the only gloomy objects that presented themselves. We continued our route northerly, through the same desolate wilderness, and at one o’clock I judged it necessary to halt; but this halting-place was not to be distinguished from any accommodations, not from a spring or rivulet of water, not from any shelter from the scorching sun, and more suffocating hot wind, but it became a place of repose merely from the total incapacity of the troops to move a mile further: here then I ordered the baggage to be unloaded, and the detachment to lie down to rest. I never suffered the tents to be pitched until just before sunrise, as I found the soldiers always marched more refreshed by letting them take their rest the instant they halted, than to undergo the fatigue and confusion of pitching their tents in the dark. No dew falls in the desert; the air is so greedy of moisture, that the least wet is instantly absorbed, and sleeping in the open air was here a luxury.