Chapter VI. "Beware the Head-Hunters!"

"That's what I want!" exclaimed the young inventor, as he finished the perusal of the missionary's missive.

"What is it?" asked Mr. Swift, entering the shop at that moment.

"News from Africa, dad. Mr. Illingway went to a lot of trouble to get more information for us about the city of gold, and he sends a better map. It seems there was one among the effects of the white man who died near where Mr. Illingway has his mission. With this map, and what additional information I have, we ought to locate the underground city. Look, dad," and the lad showed the map.

"Humph!" exclaimed Mr. Swift with a smile. "I don't call that a very clear map. It shows a part of Central Mexico, that's true, but it's on such a small scale I don't see how you're going to tell anything by it."

"But I have a description," explained Tom. "It seems according to Mr. Illingway's letter, that you have to go to the coast and strike into the interior until you are near the old city of Poltec. That used to be it's name, but Mr. Illingway says it may be abandoned now, or the name changed. But I guess we can find it."

"Then, according to what he could learn from the African natives, who talked with the white man, the best way is to hire ox carts and strike into the jungle. That's the only way to carry our baggage, and the dirigible balloon which I'm going to take along."

"Pretty uncertain way to look for a buried city of gold," commented Mr. Swift. "But I suppose even if you don't find it you'll have the fun of searching for it, Tom."

"But we are going to find it!" the lad declared. "We'll get there, you'll see!"

"But how are you going to know it when you see it?" asked his father. "If it's underground even a balloon won't help you much."

"It's true it is underground," agreed Tom, "but there must be an entrance to it somewhere, and I'm going to hunt for that entrance. Mr. Illingway writes that the city is a very old one, and was built underground by the priests of some people allied to the Aztecs. They wanted a refuge in times of war and they also hid their valuables there. They must have been rich to have so much gold, or else they didn't value it as we do."

"That might be so," assented Mr. Swift. "But I still maintain, Tom, that it's like looking for a needle in a haystack."

"Still, I'm going to have a try for it," asserted the lad. "If I can once locate the plain of the big temple I'll be near the entrance to the underground city."

"What is the 'plain of the big temple,' Tom?"

"Mr. Illingway writes," said the lad, again referring to the letter, "that somewhere near the beginning of the tunnel that leads into the city of gold, there is an immense flat plain, on which the ancient Aztecs once built a great temple. Maybe they worshiped the golden images there. Anyhow the temple is in ruins now, near an overgrown jungle, according to the stories the white man used to tell. He once got as near the city of gold as the big temple, but hostile natives drove him and his party back. Then he went to Africa after getting an image from someone, and died there. So no one since has ever found the city of gold."

"Well, I hope you do, Tom, but I doubt it. However, I suppose you will hurry your preparations for going away, now that you have all the information you can get."

"Right, dad. I must send word to Mr. Damon and Ned at once. A few more days' work, and my balloon will be in shape for a trial flight, and then I can take it apart, pack it up, and ship it. Then ho! for the city of gold!"

Mr. Swift smiled at his son's enthusiasm, but he did not check it. He knew Tom too well for that.

Naturally Mr. Damon and Ned were delighted with the additional information the missionary had sent, and Ned agreed with Tom that it was a mere matter of diligent search to find the underground city.

"Bless my collar button!" cried Mr. Damon. "It may not be as easy as all that, but Tom Swift isn't the kind that gives up! We'll get there!"

Meanwhile Tom worked diligently on his balloon. He sent a letter of thanks to Mr. Illingway, at the same time requesting that if any more information was obtained within the next three weeks to cable it, as there would not be time for a letter to reach Shopton ere Tom planned to leave for Mexico.

The following days were busy ones for all. There was much to be done, and Tom worked night and day. They had to get rifles ready, for they might meet hostile natives. Then, too, they had to arrange for the proper clothing, and other supplies.

To take apart and ship the balloon was no small task, and then there were the passages to engage on a steamer that would land them at the nearest point to strike into the interior, the question of transportation after reaching Mexico, and many other matters to consider.

But gradually things began to shape themselves and it looked as though the expedition could start for the city of gold in about two weeks after the receipt of the second letter from the missionary.

"I think I'll give the balloon a trial to-morrow," said Tom one night, after a hard day's work, "It's all ready, and it ought to work pretty good. It will be just what we need to sail over some dense jungle and land down on the plain by the great temple."

"Bless my slipers!" exclaimed Mr. Damon. "I must think up some way of telling my wife that I'm going."

"Haven't you told her yet?" asked Ned.

The eccentric man shook his head.

"I haven't had a good chance," he said, "but I think I'll tell her to-morrow, and promise her one of the gold images. Then she won't mind."

Tom was just a little bit nervous when he got ready for a trial flight in the new dirigible balloon. To tell the truth he much preferred aeroplanes to balloons, but he realized that in a country where the jungle growth prevailed, and where there might be no level places to get a "take off," or a starting place for an aeroplane, the balloon was more feasible.

But he need have had no fears, for the balloon worked perfectly. In the bag Tom used a new gas, much more powerful even than hydrogen, and which he could make from chemicals that could easily be carried on their trip.

The air craft was small but powerful, and could easily carry Tom, Ned and Mr. Damon, together with a quantity of food and other supplies. They intended to use it by starting from the place where they would leave the most of their baggage, after getting as near to the city of gold as they could by foot trails. Tom hoped to establish a camp in the interior of Mexico, and make trips off in different directions to search for the ruined temple. If unsuccessful they could sail back each night, and if he should discover the entrance to the buried city there was food enough in the car of the balloon to enable them to stay away from camp for a week or more.

In order to give the balloon a good test, Tom took up with him not only Ned and Mr. Damon, but Eradicate and Mr. Swift to equalize the weight of food and supplies that later would be carried. The test showed that the craft more than came up to expectations, though the trial trip was a little marred by the nervousness of the colored man.

"I doan't jest laik dis yeah kind of travelin'," said Eradicate. "I'd radder be on de ground."

Most of the remaining two weeks were spent in packing the balloon for shipment, and then the travelers got their own personal equipment ready. They put up some condensed food, but they depended on getting the major portion in Mexico.

It was two days before they were to start. Their passage had been engaged on a steamer, and the balloon and most of their effects had been shipped. Mr. Damon had broken the news to his wife, and she had consented to allow him to go, though she said it would be for the last time.

"But if I bring her back a nice, big, gold image I know she'll let me go on other trips with you, Tom." said the eccentric man. "Bless my yard stick, if I couldn't go off on an adventure now and then I don't know what I'd do."

They were in the library of the Swift home that evening. Tom, Ned, Mr. Damon and the aged inventor, and of course the only thing talked of was the prospective trip to the city of gold.

"What I can't understand," Mr. Swift was saying, "is why the natives made so many of the same images of gold, and why there is that large one in the underground place. What did they want of it?"

"That's part of the mystery we hope to solve," said Tom. "I'm going to bring that big image home with me if I can. I guess--"

He was interrupted by a ring at the front door.

"I hope that isn't Andy Foger," remarked Ned.

"No danger," replied Tom. "He'll keep away from here after what he did to my aeroplane."

Mrs. Baggert went to the door.

"A message for you, Tom," she announced a little later, handing in an envelope.

"Hello, a cablegram!" exclaimed the young inventor. "It must be from Mr. Illingway, in Africa. It is," he added a moment later as he glanced at the signature.

"What does he say?" asked Mr. Swift.

"Can he give us any more definite information about the city of gold?" inquired Ned.

"I'll read it," said Tom, and there was a curious, strained note in his voice. "This is what it says:"

"'No more information obtainable. But if you go to the city of gold beware of the head-hunters!'"

"Head-hunters!" exclaimed Mr. Damon. "Bless my top-knot, what are they?"

"I don't know," answered Tom simply, "but whatever they are we've got to be on the lookout for them when we get to the gold city, and that's where I'm going, head-hunters or no head-hunters!"