“They made trouble enough as it was,” declared Nara, with a dry chuckle. Then, turning to Mr. Brewster, he said, “Let’s see what’s left of that map Lew Kirby gave you. Then we can figure what to do next.”

Mr. Brewster produced the torn corner from the map. It showed the mine, the stream bed, the lake, and the trail that continued into the jungle, where it reached a river that was marked on the map.

“The route is an easy one,” stated Nara, “as you can see. But first, I want you to estimate the value of the mine. Then pick out the ore you want, so we can take it to the river. From there, we will go downstream to the Casiquiare Canal and work our way through to the Orinoco River.”

They camped that night beneath the trees that fringed the jungle. The next day, Mr. Brewster returned to the mine and studied it in detail. They stayed in the same camp another night and on the following day, the Indians brought down loads of ore that Mr. Brewster had selected.

Those loads were carried several miles through the jungle to the river that Nara had mentioned. Biff and Kamuka helped make a new camp there. Then they swam in the river while they waited for the Indians to bring the packs. The water was very clear, and the boys brought up handfuls of glittering sand from the bottom. When Mr. Brewster saw it, he commented:

“There’s a fortune in gold to be dredged from this stream. But we still have the problem of getting it down the Orinoco.”

Joe Nara had the answer to that problem. His Indians showed up with a small flotilla of odd-looking craft that resembled the monterias of the Amazon. Nearly thirty feet long, each boat had an open cockpit at the front with a thatched cupola at the stern, serving as a sort of cabin.

Nara’s boats were different, however, from the more antiquated river craft. His boats were low in the stern, so that the big steering paddle could be replaced by a sizable outboard motor. Nara had such motors and the gasoline to fuel them.

“Every trip I made downriver,” explained Nara, “either over the mountain and down the Rio Negro, or down this stream to the Orinoco, I bought motors and gasoline and brought them back here. I knew that some day, Lew Kirby would talk some company into a big deal for our mine.

“What’s more, I knew the first thing they would ask would be if they could transport either the gold or the ore once they mined it. My answer is, yes, and I’ve got the boats to prove it—and the motors, too. I’ve kept them for a long time.”