Stacy picked it up.
"I know why it doesn't work," he said.
"Why?" demanded the other boys.
"'Cause—'cause there isn't any water to make it work," he replied wisely.
The boys groaned.
Shortly after returning to camp, they found the fat boy standing over a pail of water holding the stick above it.
He was talking to the stick confidentially, urging it to "do something," to the intense amusement of the whole outfit.
"Now, where's your theory?" questioned the Professor.
"Why, it doesn't have to work, does it? Don't we know there's water here? If we didn't the stick would tell us, maybe. Take my word for it, this outfit won't have to go dry after this. Stacy Brown and his magic wand will find all the water needed," continued the fat boy proudly.
"Your logic is good, at any rate, even if the rod doesn't work at command," laughed the Professor.