this shore, running my new line at an angle of
sixty degrees from the true course. Then, with my compass at _E_, I
sight another line at an angle of sixty degrees from my last. I am
making what is called an equilateral triangle; that is, a triangle with
equal sides and equal angles. Each angle must measure sixty degrees.
With two angles and one side, we can always get the other two sides; and
the other angle will be where those two sides meet. They will meet at
_C_. Now, since the sides are of equal length, the distance from _D_ to
_C_ is the same as from _D_ to _E_,--that is, four rods and thirty
links, just the distance we wish to go; _C_, then, is the place for your
corner stake."

"It looks very well on paper," said the old man, "but"--casting his eye
across the bog--"how in the name of seven kingdoms are ye ever gwine to
fix yer stake thar?"

"That is easy. Go round to the other side of the slew, get yourself in
range with our line from the tree, by sighting across the stakes, and
walk down toward the slew,--that is, on this dotted line. Having got my
angle of sixty degrees at _E_, I will sight across and stop you when I
see you at _C_. There stick your last stake."

"Banged if that ain't cute! Young man, what mout be your name?"

"I was only boy a few minutes ago," said the young surveyor, slyly.
"Now, if you are ready, we'll set to work and carry out this plan."

The line from _D_ to _E_ was measured off. Then the youth set his
compass to obtain the proper angle at _E_; while the old man, with his
axe and a fresh stake, tramped around to the eastern side of the slough.
Having got the range of the stakes, he was moving slowly back toward
them, holding his stake before him, when the youth signalled him to stop
just in the edge of the quagmire.

The new stake stuck, the young surveyor, taking up his tripod and
compass, went round to him.

"That stake," said he, "is not far from your corner. Are there any
signs?"

"I've been thinkin'," said the old man, "the 'arth yer looks like it had
been disturbed some time; though it's all overgrowed so with these
clumps of slew-grass, ye can't tell what's a nat'ral hummock and what
ain't. Don't that look like a kind of a trench?"

"Yes; and here's another at right angles with it. Surveyors cut such
places on the prairies, pile up the sods inside the angle, and drive
their corner stakes through them. But there must have been water here
when this job was done, which ac