One feature of the house I expected to miss greatly when I should leave it, and this was the sleeping chamber which I had built under the foundations.
I could not have slept in the city at all, with its never ceasing nightly noises, if I had been obliged to use an upstairs chamber.

But to this subterranean room no murmur from the upper world ever penetrated.

When I had entered it and closed the door, I was surrounded by the silence of the tomb.

In order to prevent the dampness of the subsoil from penetrating the chamber, the walls had been laid in hydraulic cement and were very thick, and the floor was likewise protected.

In order that the room might serve also as a vault equally proof against violence and flames, for the storage of valuables, I had roofed it with stone slabs hermetically sealed, and the outer door was of iron with a thick coating of asbestos.