Of course, we had to organize a secret society, to occupy our subterranean dwelling. In that I fear we overstepped the rules of the school. Of course, Mr. Clark knew of our cave, in fact he visited us there once, lowering his dignity sufficiently to squeeze into the narrow passageway, and playing Bill a game of chess at our club table. He seemed quite pleased with our work, and complimented us very highly on the masterful way in which we had built the underground house. We told him that we had organized a club of the older fellows to play indoor games and have occasional spreads, but we did not tell him that most of our spreads were held at the dead of night, when there was no moon and the stars were hidden by clouds. At 10 o'clock each night the bell rang for us to turn out our lights, and after that the six members would each, in turn, keep a half-hour watch, that is, first one would sit up and try to keep awake for half an hour, after which he would waken the next fellow, who at the end of a half hour would rouse the third, and so on, until 1 o'clock, when the sixth watcher would wake up the entire club. Then we would all creep out the back window in the hall, onto the roof of the rear annex of the schoolhouse, and thence climb down a rope ladder to the ground.

Fig.186. A Section through the Completed Cave.