"quick, washington!" cried the professor. "jump in the engine room and start the gas generator. mark, you bring in from the cabin all those wheels and things on the walls! jack, load those packages there into the locker in the after part of the monarch! but handle them carefully! they contain explosives and ammunition for the machine gun!"

if there had been hurry and bustle before, there was ten times as much now. the professor gave one look at the place where taggert had been concealed. the man had worked off his bonds and escaped while his captors were in the airship's cabin.

soon there was a queer hissing noise from the engine room of the monarch. the gas bag began to distend.

"she's fillin', perfessor!" cried washington.

"we must tie her down," muttered the old man. "otherwise she will rise and take the shed with her. i say, washington!"

"yes, perfessor."

"we must get some one to help us open the shed roof to let the ship rise out. we can't do it alone."

"guess it's a extraunordinary contract," agreed the negro.

"then you go out and see if any one is in sight. try to hire them for the work, but don't tell them about the ship. they can work up on the roof. i will see to the gas machine while you are away. hurry now!"

the colored man went out. in the meanwhile the professor and the two boys continued to load up the monarch. they had nearly everything that the inventor intended to take along piled in its proper place, when footsteps were heard outside. then the noise of some persons on the roof was audible. in a few minutes washington came in.

"i found three men," explained the negro. "one is dat old hunter as helped us before, andy sudds. he was goin' huntin' but he said he'd help take the roof off fer a dollar. de oder two is does farm hands, tom smith an' bill jones. dey was goin' down to do post-office, but dey said dey'd help fer fifty cents apiece. all three is up on de roof now."

"good!" exclaimed the professor. "it's lucky i had the roof made in sections when i built this shed. now it can be taken off in a hurry. come on, boys! there are some more things that must go in the ship!"

thus urged, mark and jack worked with a will. washington helped, and then went up on the roof to aid the three emergency toilers. by this time several sections of the covering to the shed had been taken off and the place was quite light.

all the while the gas machine in the ship continued to generate the vapor. it flowed into the cigar-shaped bag through two rubber tubes. as the bag distended more and more, the monarch tugged and pulled at the anchoring ropes on the floor of the shed, as if anxious to be away.

the boys worked with a will. the last articles were placed in the various rooms of the airship's cabin, until the balloon shed was stripped quite bare. the professor was busy in the engine room. the noise of the gas generating machine increased.

then came a series of sharp explosions as one of the gasolene engines was started. this was followed by the hum of an electric dynamo, and the whizz and purring of a big motor.

the inventor was testing the many machines to see that all worked right. suddenly he switched on the incandescent lights in the ship's cabin. next he turned on the powerful searchlight in the bow, and the shed was illuminated by a glare that rivaled the sun. the professor then revolved the big propeller slowly and tested the rudder.

"everything is in good shape!" he cried. "we will start in five minutes if they get the roof off so we can rise. those anchor ropes will not hold much longer!"

up on the roof, however, the men were working with a will. board after board was torn away and the different sections moved to one side. at last the whole top of the shed was off. all that remained was to let the monarch out.

suddenly from where the three emergency helpers were working there came a cry of astonishment, mingled with fear. for the first time andy sudds, tom smith and bill jones, characters well known to amos henderson, had looked down into the shed, and caught sight of the tugging, swaying airship. the interior had been quite dark up to this point, which accounted for them not having noticed the ship before. but when they saw the strange affair so close beneath them they were startled.

"jumpin' rattlesnakes!" cried andy sudds. "what have i struck?"

"it's a yellow elephant!" exclaimed tom jones.

"a sea serpent!" ejaculated bill smith.

they leaned over from the edge of the roof eaves to which they were clinging and peered down into the big balloon shed. certainly the airship presented a queer sight to the three men.

"is everything ready?" asked the professor of washington.

"eberyt'ing am circumulated to completeness," replied the negro.

"jump in, boys! untie the ropes, washington. we'll start!"

"hurry! hurry! perfessor!" cried washington, as he looked out of a side window. "here comes dat man we tied up in de shed! he's got anoder man wid him, an' dey got guns!"

"it's taggert! he is after me!" exclaimed the inventor. "he must not be allowed to get on the ship! come on, mark and jack! never mine unknotting the ropes! cut 'em! we have no time to lose! jump in, washington!"

the boys clambered over the sides of the airship. washington followed their example. the anchor ropes were cut.

"hi, there! stop!" cried a voice from outside. "don't you dare start that ship!"

"here we go!" shouted professor henderson in a joyful tone. "now to see if the monarch fulfills her promise!"

he hurried into the engine room. the noise of the gas generating machine increased. the gasolene engine went faster, and the motors and dynamos added to the noise. there was a loud hissing sound. the professor had opened a valve admitting the full force of gas into the oiled silk bag. then came a snapping sound as several anchoring ropes that had not been cut, broke.

up rose the monarch like some immense bird, through the opened shed roof. out into the air went the big yellow bag. and then a strange thing happened.

andy sudds, the hunter, and bill jones and tom smith, the two farm hands, who had been peering over the edge of the shed down at the airship, leaned over too far in their anxiety to observe everything. as the gas bag brushed past them they were startled. they lost their balances and the next instant all three toppled right into the bow of the monarch as she arose, and were lifted up into the air with her.

"hold on, there! stop!" cried taggert, who by this time had come close to the shed.

"it's too late!" shouted back the professor, poking his head from a window in the engine room.

"hey, there! you're carrying me off in your ship!" yelled andy sudds as he scrambled to his feet after his tumble into the bow of the monarch.

"and me!" ejaculated bill jones.

"and me!" exclaimed tom smith. "i didn't figure on coming with you."

"it's too late!" the old inventor cried. he turned some wheels and levers and the airship arose faster. then he switched on the electric machinery. the big propeller began to revolve. swifter and swifter it went. the monarch, which had risen several hundred feet, started forward at a swift pace. "we are off for the north pole!" shouted the inventor. "hurrah! the ship works! i knew it would!"

"here!" roared andy sudds. "i don't want to go to the north pole. i want to hunt muskrats down by the creek."

"you can hunt seals and whales up north," the professor called to him.

"but i've lost my gun!" the hunter exclaimed, soberly, yet a little appeased at the prospect of big game.

"i'll give you a better one," promised mr. henderson. "you shall have all the hunting you want."

"i can't go to the north pole," fairly yelled bill jones, starting back toward the engine room. "i had a job plowing on a farm. if i don't go back i'll lose my place."

"you can hire out to me," suggested the professor. "i need a crew, and i didn't have time to ship one."

"what about me?" asked tom smith. "i was working on a farm like bill."

"i'll hire you also," spoke the inventor of the monarch.

"hi, perfessor! shall i shut off de gas?" washington suddenly cried.

"for a while," was the inventor's reply. "we are high enough now. then oil up the engines and dynamos, they need it. you boys can help," he said to mark and jack. "i must see to my instruments and find whether everything is working right."

the two boys were delighted to have a chance in the engine room. under washington's direction, the colored man showing quite a knowledge of the apparatus, they oiled the various bearings until everything was running smoothly.

until now they had no time to realize what an experience they were going through. things had happened so quickly that it was hard to realize they were sailing through the air in a wonderful ship, probably the most successful navigator of the upper regions ever invented.

it was not until jack looked over the edge of the airship from the engine room window that he felt what a trip up among the clouds meant. below the earth was spread out like a good-sized map, with little threads of silver for rivers, patches of green for big fields, and narrow gray ribbons where there were roads.

"it's wonderful!" he cried to mark.

"and to think we were chased out of town yesterday by a constable," spoke his companion. "this is a great change. i'd like to see him catch us now."

"dis prolonguated elevation into de airy space ob de zeneth am extremely discommodatiousness to a pusson what ain't used to it," remarked washington with a broad grin as he oiled a whirring motor.

"yes—er—i guess it is," admitted mark.

"are your teeth all fast after that effort?" asked jack with a laugh.

"neber yo' mind my teeth," said washington. "golly! what's de matter now?"

the monarch was darting from side to side like a kite that has lost its tail in a high wind.

"it's only the professor trying the steering apparatus," said jack, looking forward toward the conning tower. this proved to be true, for, in a moment, the airship resumed a straight path, and the professor, coming back to the engine room, cried:

"she answers her helm perfectly. it certainly is a success in every way! but now, since the machinery is working well, and i have the monarch headed due north, in which direction she will sail alone for a while, i want you boys to come into the dining room, while we talk over matters with our unexpected visitors. we must lay plans and divide up the work of running the ship."

jack and mark went with the old man into the middle room of the craft. there they found the old hunter and the two farm hands. none of the three had quite gotten over his fright at being suddenly carried off through the air.

"everything has turned out for the best," the inventor began. "i feared my forced start would spoil my plans, but you see i got a crew almost at the last moment. now we will—"

he was interrupted by a sudden cry from the engine room.

"help! help!" rang out the voice of the colored man. "hurry up an' help, perfessor. i'm caught in some cantankerous conglomeration an' i'm bein' killed! help! help!"

followed by the boys and the three men the old inventor hastened aft, alarm showing on his face.