Here there is a paved walk, so there was no necessity to make tracks.

Now, there was but one thing more, and that was a noise to sound like the falling of the sash, and which was to wake the old man so that he might jump up almost in time to catch the robber.

I had almost forgotten this, and now it puzzled me.

The vault-room, a narrow apartment, is between the old man's room and mine, and I could have left the window up, propped with a stick, and from my window jerked out the prop, but the cool air would have shown the old man that the window was raised, and this would have ruined everything.

Finally I decided that the falling of my own window--both are old-fashioned and are held up by a notched button--would arouse him and that he would think that the noise came from the vault-room.