About three in the afternoon, a horseman, dressed in the Mexican costume, was galloping along the banks of a stream, an affluent of the Gila, whose capricious windings compelled him to make countless detours. This man, while constantly keeping his hand on his weapons, and watching for every event, urged his horse on by shouts and spur, as if anxious to reach his journey's end. The wind blew fiercely, the heat was oppressive, the grasshoppers uttered their discordant cries under the herbage that sheltered them; the birds slowly described wide circles in the air, uttering shrill notes at intervals: coppery clouds were incessantly passing athwart the sun, whose pale, sickly beams possessed no strength; in short, all presaged a terrible storm.