envelope of the kind in the lot, but it told the whole story to the
eye that could penetrate its meaning. As the thimble passed along
the edge, it left the mark of the rim, then a smooth, narrow band,
followed by pointed elevations closely resembling continuous lines,
thus:

========
--------
........
........

On the opposite side of the same seal the wax flattened out so as
to cover a good deal of surface; and, to give it the desired
appearance, the manipulator resorted to the thimble again, but this
time USED A DIFFERENT ONE, the indentations on the surface being
perceptibly finer and more shallow.

The violation of that single seal betrayed the thief, for the
detective at once inferred that the job was done in a store where
the operator had access to a variety of thimbles. Only one was
required; and no person but a merchant would be likely to have more
than one within convenient reach. In a store, however, it would be
natural to take down a boxful, and place it on the counter, to be
selected from at random. One is picked up, used, and thrown back.
The operator now finds another spot that requires attention, and
without waiting to hunt for the thimble that has already served as
a seal,--for the wax is cooling and no time must be lost,--grasps
the first that comes to hand, too absorbed in the main issue to
give a thought to what would pass as an insignificant subsidiary
trifle. No rascal is sharp enough to guard every point,--a general