To reach their work Malipieri and Masin had to go down the grand
staircase and pass the porter's lodge. Masin wore the rough clothes of
a working mason and Malipieri appeared in overalls and a heavy canvas
jacket. Very soon the garments of both were so effectually stained
with mud, green mould and water that the two men could hardly have
been distinguished from ordinary day labourers, even in broad
daylight.

They began work on the very spot at which the snuffy little expert had
stopped to listen to the water. It was evidently out of the question
to break through the wall at the level of the cellar floor, for the
water could be heard running steadily through its hidden channel, and
if this were opened the cellars might be completely flooded. Besides,
Malipieri knew that the water might rise unexpectedly to a
considerable height.

It was therefore best to make the opening as high as possible, under
the vault, which at that point was not more than ten feet from the
ground. The simplest plan would have been to put up a small
scaffolding on which to work, but there was no timber suitable for the
purpose in the cellar, and Malipieri did not wish to endanger the
secrecy of his operations by having any brought down. He therefore set
to work to excavate an inclined aperture, like a tunnel, which began
at a height of about five feet and was intended to slope upwards so as
to reach the interior chamber at the highest point practicable.

It was very hard work at first, and it was not unattended by danger.
Masin declared at the outset that it was impracticable without
blasting. The wall appeared to be built of solid blocks of travertine
stone, rough hewn on the face but neatly fitted together. It would