This would be a first disappointment to the spoilers.

If, however, they were not discouraged, but examined the passage with care, they would find in the roof, sixty-two feet distant from the door, a block of granite (Note 22) among the surrounding limestone.

It was so hard that the seekers, after having vainly tried to break or remove it, took the course of forcing a way through the softer stone around (Note 23).

This obstacle past, they came into an ascending passage which joins the first at an angle of 120 deg.

(Note 24), and is divided into two branches.