Tom in the meantime was busy with the vernier of his transit.
This is an ingenious device for showing the smaller divisions
into which the circles of the compass are divided. Tom quickly
jotted down his field note in degrees, minutes and seconds. One
chainman now held an end of a hundred-link chain at the nail head
on the stake, while a second man started toward the rodman, unfolding
the chain as he went.

Tom remained over his transit. The traveling chainman frequently
glanced back for directions from Reade whether or not he was off
the course of a straight line to the next stake.

Soon the chain-bearer was a little to the left of the line.

Tom held a hand over the telescope of the transit, moving it very
slowly to the right. The chain-bearer, glancing slowly back,
stepped slowly to the right of the course until Tom's hand fell
abruptly. Then the chain-bearer stopped, knowing that he was
on the right line. A metal stake, having a loop at the top from
which fluttered a marker of red flannel, the man stuck upright
in the ground. Tom took a peep, signaling so gently that the
man moved the stake just half an inch before Reade's hand again
fell.

"That stake is right; go ahead," ordered Tom, but he said it not by
word of mouth, but merely with a slight gesture of pushing forward.

"You've been well trained, I'll bet a hat," smiled Butter. "I
can tell that by the practiced way that you signal. O'Brien!"