this is what had happened.
at the time of the rain storm, two days before, buck and his cavalcade were in camp on the bank of the dry chusco, sixty miles north of clarkeville. the experienced scout knew that a water supply was now assured, and he at once followed prearranged orders by instructing bob to return with the smaller wagon. this was a sad blow to the young reporter, but it was a part of his contract and he knew that it was his duty to obey. and with necessity before him, he acted promptly. emptying the heavy casks, bob started on the back trail at five the following morning, and by night had made thirty miles with the light wagon. all day he wondered if it might not be possible to reach clarkeville again before the cibola sailed.
the next morning, spurred on by the hope that he might do this, he started at daybreak. by the middle of the morning he was on the old wagon trail and making better time. some time after two o'clock he came up over the rise of the last foothills and saw, eight miles away, the glistening shape which he at once knew was the inflated balloon. he hesitated a moment and then, unhitching the horses, mounted one bareback and began a dash for the town. the animals were tired and worn, and progress was slow, but it beat walking, and bob urged them on.
as the young reporter came nearer and the balloon grew more distinct he knew that it would be a close call. from time to time as the winded horses dropped into a walk bob wondered why he was making such a race. "i can't go with them," he argued. but, like the trained reporter, he decided that no effort was wasted that gave him new information. and it was something out of the ordinary to see the most complete balloon ever made start on a mysterious flight into the wilderness.
so he spurred up the horses anew. the hot sun reflected from the yellow sands burnt his face and his muscles were sore, but he stuck to it. when half a mile from the town he could see the boys on the bridge of the cibola. when a quarter of a mile away he decided that he could beat the horses by going afoot, and, throwing himself to the ground, he ran onward, knowing that the tired animals would follow. out of breath he reached the edge of the town and stumbled on toward the corral.
with head down he plunged forward. almost at his goal he threw his head up for breath just in time to notice a kneeling man with a rifle at his shoulder.
"hey!" yelled bob with what breath he had.
then he saw that the man was aiming directly at the balloon swaying above the nearby corral fence. he also recognized the man instantly as one of the sullen court spectators, and jellup's crony. the rifleman dropped the muzzle of his gun and turned.
"i guess i am something of a gun man," explained bob later to the boys, "for i had that new revolver of mine on the 'greaser' before i knew what i was doing myself. i didn't even then realize what he was about to do. but i had the drop on him and when i figured out that he meant to put a hole in the balloon, why, i just had him right. and here he is."
alan looked at ned. both boys were puzzled. a few moment's talk with russell explained the whole situation. the balloon was ready and the relief expedition was undoubtedly now in camp awaiting them. it needed only the words and they would be off with the inquisitive reporter left safely behind. and yet the word did not come. ned and alan stood looking at bob, and the reporter gazed in turn at the beautiful straining car. bob's face was a study. he had now made some return to ned for possibly saving his own life, but none of the boys was thinking of that. in bob's fine young face was the longing of a child. in ned's and alan's faces were the traces of boyish sympathy.
the young aeronauts were very close to each other and all were silent. then alan turned slowly to ned and with a little quaver in his voice whispered, "shall we?"
ned made no answer. a smile lit up his face and he sprang down the little ladder into the engine cabin followed by his chum. almost instantly the trap door in the floor of the car dropped down. a moment later three fifty-pound sacks of ballast tumbled through the door to the ground beneath. the bag tugged and strained as ned reappeared above.
"hurry up, bob, if you're going with us," he said quietly, leaning over the net of the bridge, "and close the door as you come up."
bob hesitated, as if he had not heard aright, but then he understood, and with tears in his eyes be sprang forward. there was a jar and ned knew the new passenger was aboard.
"all ready?" he called sharply from the bridge.
"aye, aye, captain," came in a choking but jubilant voice from the inside of the cabin.
"stand by, everybody," sharply ordered ned. and then, as bob's shoulders appeared through the hatchway, the commander of the air ship gave a final look about.
"let go all," he cried sharply. "everybody!"
for a moment only one clinging workman careened the buoyant craft and then, straight up, the cibola bounded like a rubber ball.
"good-bye, all," came from ned, cap in hand, as he leaned from the bridge.
there were cheers from below and the cibola was at last free and afloat.
"sit down here and keep quiet," sharply ordered ned as bob crawled out on deck. then the commander of the balloon disappeared below.
there were almost immediately several sharp, muffled explosions, and then the white propeller began to turn. the balloon was drifting quickly toward the northwest and rising—bob could see its shadow following on the sandy plain. then the arms of the propeller turned faster and faster and a velvet whirr in the cabin showed that the engine was falling to work. as the propeller blades settled into a steady hum the vibration of the car indicated increased speed. this bob could also detect from the more swiftly flying shadow.
the shadow was also growing smaller, and this meant that the cibola was still ascending. now the shadow paused and turned. alan had thrown the rudder over and the balloon had responded instantly. the aeroplane arms stretched out horizontally on each side of the car. ned, reappearing, took a quick look at the altitude gauge and again disappeared. the aeroplane arms dipped in front almost forty-five degrees and the current, blown back by the propeller, struck them with a jar. the craft again responded and slowly took a downward slant.
propeller, rudder and aeroplane being at work, ned again appeared.
"go below," he ordered sharply, "and bear a hand when needed."
bob did so. alan was on the pilot platform with his hands on the wheel controlling the rudder wires. his eyes were fixed straight ahead.
"see that lever," he said, jerking his head to the left.
bob quickly discovered the aeroplane guider control and sprang to it.
"wait for orders," added alan.
