labor and their own liberal wages were deposited at the Fairview Bank by
Professor Gray and the boys were given a drawing account thereon, with a
simple expense book to keep.

That afternoon, dressed in new overalls and blouses, with a big,
good-natured colored man to help with the laboring work, the boys were
early on the job, at first making a cement mixing box; then Bill drove
the center stake thirty feet below where the dam was to be placed and
from which, using a long cord, the curve of the structure twenty-nine
feet wide, was laid out upstream.

At the spot chosen the rock-bound hillsides rose almost perpendicularly
from the narrow level ground that was little above the bed of the
stream; it was the narrowest spot between the banks. George, the colored
fellow, was set to work digging into one bank for an end foundation; the
other bank held a giant boulder.

The boys were giving such close attention to their labors that they did
not see observers on the hilltop. Presently the gruff voice that they
had heard before hailed them from close by and they looked up to see Mr.
Hooper and the slim youth approaching. The boys had heard that this
Thaddeus was the old man's nephew and that he called the Hooper mansion
his home.

"What you drivin' that there stake down there for? Up here's where the
Perfesser said the dam was to set," Mr. Hooper demanded.

"Yes, right here," Bill replied. "But it is to be curved upstream and
that stake is our center."