One end was open, or at least looked as though the end had been
shoved several inches into the interior of the box. I looked into
one of the boxes and saw a slit in the wall that had been shoved
in. Kennedy was busy adjusting the apparatus, and paused only to
remark that the boxes contained two sensitive selenium surfaces
balanced against two carbon resistances. There was also in the box
a clockwork mechanism which Craig wound up and set ticking ever so
softly. Then he moved a rod that seemed to cover the slit, until
the apparatus was adjusted to his satisfaction, a delicate
operation, judging by the care he took. Several of these boxes
were installed, and by that time it was quite late.

Wires from the apparatus in the art-gallery also led outside, and
these as well as the wires from the coils down in the basement he
led across the bit of garden back of the Spencer house and up to a
room on the top floor. In the upper room he attached the wires
from the storeroom to what looked like a piece of crystal and a
telephone receiver. Those from the art-gallery terminated in
something very much like the apparatus which a wireless operator
wears over his head.

Among other things which Craig had brought down from the
laboratory was a package which he had not yet unwrapped. He placed
it near the window, still wrapped. It was quite large, and must
have weighed fifteen or twenty pounds. That done, he produced a
tape-measure and began, as if he were a surveyor, to measure
various distances and apparently to calculate the angles and
distances from the window-sill of the Spencer house to the
skylight, which was the exact centre of the museum. The straight
distance, if I recall correctly, was in the neighborhood of four