n of the work. One can easily distinguish the genuine from the
spurious copies, for it is absolutely impossible for an imitator to make
a copy that will stand the X-ray test.

"You see," he went on enthusiastically, "the most striking feature of
these radiographs is their revelation of details of the first sketch,
which have been altered in the finished picture. We actually obtain an
insight into the methods of an artist--" he paused, adding--"who has
been dead for centuries."

It was wonderful what Kennedy was getting out of those, to us, blurred
and indistinct skiagraphs. I studied the faces before me. None seemed to
indicate any disposition to break down. Kennedy saw it, too, and
evidently determined to go to the bitter end in hammering out the truth
of the mystery.

"One moment more, please," he resumed. "The radiograph shows even more
than that. It shows the possibility of detecting a signature that has
been painted over, in order to disarm suspicion. The detection is easier
in proportion to the density of the pigment used for the signature and
the lack of density of the superposed coat."

He had laid the radiographs on the table before him, with a finger on
the corner of each, as he faced us.

"At the bottom of each of the paintings in question," he shot out,
leaning forward, "you will find nothing in the way of a signature. But
here, in radiograph number two, for instance, barely discernible, are
the words, "R. Fleming," quite invisible to the eye, but visible to the
X-ray. These words have been painted over. Why? Was it to prevent anyone
from thinking that the owner had ever had any connection with Rhoda
Fleming?"

I was following Kennedy, but not so closely that I missed a fearful
glance of Rita from Faber to Jacot. What it meant, I did not know. The
others were too intent on Kennedy's exposure to notice. I wondered
whether someone had sought to conceal the fact that he had a copy of the
famous Watteau, made by Miss Fleming?

"Look at the bottom of the other radiograph, number one, further toward
the left," pursued Kennedy resistlessly. "There you will discover traces
of an 'A' and a 'W,' which do not appear on the painting. Between these
two are marks which can also be deciphered by the X-ray--'Antoine
Watteau.' Perhaps it was painted over lightly so that an original could
be smuggled in as a copy. More likely it was done so that a thief and
murderer could not be traced."

As Kennedy's voice rang out