Soon after quitting the country of the friendly Pimos and Maricopas, the Army of the West came upon the trail of an enemy, and at night fires were seen upon the opposite side of the Gila, which were thought to be those of the Mexican general, Castro. Mr Emory took a few dragoons and went to reconnoitre. It was not Castro, but a party of Mexicans conveying five hundred horses to Sonora for his use. This was a precious capture, for long marches and scanty forage, besides frequent want of water, had dismounted most of the American cavalry. Unfortunately, the prize horses were unbroken, and ill adapted for immediate service. They were good for meat, however, for by this time the expedition was on horseflesh rations. On the 28th November, "Major Swords found in a concealed place one of the best pack-mules slaughtered, and the choice bits cut from his shoulders and flanks--stealthily done by some mess less provident than others." The next day, it is recorded by Mr Emory that a horse was killed for food, which was eaten with great appetite, and all of it consumed; and when the expedition reached the beautiful valley of the Agua Caliente, all waving with yellow grass, and halted at the farm of an American named Warner, so sharp set were they that Mr Emory assures us that seven of his men ate, at one single meal, a fat full-grown sheep. Near Warner's _rancheria_ is the fountain whence the valley derives its name. From the fissure of a granite rock, there gushes forth a magnificent hot spring, of the temperature of 137° Fahrenheit. The volume of water is very large, and for a long distance the air is loaded with the fumes of sulphuretted hydrogen. Flowing down the same valley is a cold spring, of the temperature of 45°; and, without the aid of machinery, the cold and warm water may be mingled to the required temperature. "The Indians have made pools for bathing. They huddle round the basin of the spring to catch the genial warmth of its vapours; and in cold nights immerse themselves in the pools to keep warm. A day will come, no doubt, when the invalid and pleasure-seeking portion of the white race will assemble here to drink and bathe in these waters, to ramble over the hills which surround them on all sides, and to sit under the shade of the great live oaks that grow in the valley."