FOES IN AMBUSH.

I.

The sun was just going down, a hissing globe of fire and torment.  Already the lower limb was in contact with the jagged backbone of the mountain chain that rimmed the desert with purple and gold.  Out on the barren, hard-baked flat in front of the corral, just where it had been unhitched when the paymaster and his safe were dumped soon after dawn, a weather-beaten ambulance was throwing unbroken a mile-long shadow towards the distant Christobal.  The gateway to the east through the Santa Maria, sharply notched in the gleaming range, stood a day’s march away,—­a day’s march now only made by night, for this was Arizona, and from the rising of the sun to the going down of the same anywhere south of that curdling mud-bath, the Gila, the only human beings impervious to the fierceness of its rays were the Apaches.  “And they,” growled the paymaster, as he petulantly snapped the lock of his little safe, “they’re no more human than so many hyenas.”

A big man physically was the custodian and disburser of government greenbacks,—­so big that, as he stepped forth through the aperture in the hot adobe wall, he ducked his head to avert unwilling contact with its upper edge.  Green-glass goggles, a broad-brimmed straw hat, a pongee shirt, loose trousers of brown linen, and dust-colored canvas shoes made up the outer man of a personality as distinctly unmilitary as it was ponderous.  Slow and labored in movement, the major was correspondingly sluggish in speech.  He sauntered out into the glare of the evening sunshine and became slowly conscious of a desire to swear at what he saw:  that, though in a minute or two the day-god would “douse his glim” behind the black horizon, no preparation whatever had been made for a start.  There stood the ambulance, every bolt and link and tire hot as a stove-lid, but not a mule in sight.  Turning to his left, he strolled along towards a gap in the adobe wall, and entered the dusty interior of the corral.  One of the four quadrupeds drowsing under the brush shelter languidly turned an inquiring eye and interrogative ear in his direction, and conveyed, after the manner of the mule, a suggestion as to supper.  A Mexican boy sprawling in the shade of a bale of government hay, and clad in cotton shirt and trousers well-nigh as brown as the skin that peeped through occasional gaps, glanced up at him with languid interest an instant, and then resumed the more agreeable contemplation of the writhings of an impaled tarantula.  Under another section of the shed two placid little burros were dreamily blinking at vacancy, their grizzled fronts expressive of that ineffable peace found only in the faces of saints and donkeys.  In the middle of the enclosure a rude windlass coiled with rope stood stretching forth a decrepit lever-arm.  The whippletree, dangling from the end over the beaten circular track,