Two hours after our departure it only marked 10 deg.

(50 deg.
Fahr.), an increase of only 4 deg..

This gave reason for believing that our descent was more horizontal than vertical.

As for the exact depth reached, it was very easy to ascertain that; the Professor measured accurately the angles of deviation and inclination on the road, but he kept the results to himself.
About eight in the evening he signalled to stop.

Hans sat down at once.