"No, I guess we've lost track of him and his father," spoke Tom. "I've kept watch of the back trail as much as I could, and haven't seen them following us. Of course they may pick up our trail later and come here, and they may join forces with the Mexicans. But I don't know that they can bother us, once we're off in the balloon."
To Tom's disappointment, the next day proved stormy, a heavy rain falling, so it was impossible to test the balloon with the gas. The camp was a disconsolate and dreary place, and even Eradicate, usually so jolly, was cross and out of sorts.
For three days the rain kept up, and Tom and Ned thought they would never see the last of it, but on the fourth morning the sun shone, wet garments and shoes were dried out, tents were opened to the warm wind and everyone was in better spirits. Tom and his chum at once set about making gas for the big bag, their operations being closely watched by the Mexicans.
As I have explained before, Tom had the secret of making a very powerful gas from comparatively simple ingredients, and the machinery for this was not complicated. So powerful was it that the bag of the dirigible balloon did not need to be as large as usual, a distinct saving in space.
In a short time the bag began to distend and
