of admonition, I resolved not
to regard the thing as impracticable, until I had exhausted all my
powers of contrivance.

I persevered, therefore, and in less time than I must take in describing
it, I hit upon a plan for "gauging" the butt.

CHAPTER THIRTY.

MY MEASURING-RULE.

The details of my plan suggested themselves in the following order:--

While examining the cask, to find if there was not some means of
ascertaining its different diameters, I discovered the very way itself.
All I wanted was a straight rod or stick, of sufficient length to reach
quite across the butt at its thickest part. It was plain to me, that by
inserting such a stick into a hole in one side of the cask, and passing
it on till it touched the staves on the other side, at a point
diametrically opposite, I could thus obtain the exact measurement of the
diameter of that part of the vessel, since the portion of the rod
reaching from side to side would be the diameter itself. The diameter
once obtained, it needed only to multiply by three to get the
circumference. But in the calculation which I was desirous of making,
it was the diameter itself I wanted to find, and not the circumference.
I only thought of the latter, because, under ordinary circumstances,
when a cask is bunged up, it is easier to measure the circumference of
the swell than its diameter. In no case does it signify which, as the
figure three will always reduce the one to the other, near enough for
most practical purposes, though not mathematically exact.

Now, it so chanced that one of the holes I had cut through the staves
had been made in the very middle of the swell, where the butt was
thickest. Therefore a straight stick passed into this hole, and pushed
on till it touched the opposite side, would give the greatest diameter
of the cask.

You may imagine that this might have been obtained by simply planting
the stick in a vertical position _outside_ the butt, and notching it at
a point on a level with the top of the vessel. True, this might have
been done had I been operating with a barrel lying upon a plain surface,
with nothing around it to obstruct me, and plenty of light to observe
the true level. Even thus it would have been rough guess work, and not
to be depended on when a calculation was to be made involving life or
death in its consequences--for such it really did involve--at least, I
supposed so. But the butt was so placed, resting upon the timbers of