We commence exploring.

An experiment, by which the existence of a new vein would be proved, is rendered impossible by stoppage of fissures.

Notwithstanding this, the examination is carried out, the vein discovered.

We return as we came, a prodigious gust of air meets us, our lamp is broken, utter darkness surrounds us.

Nevertheless, we make our way along the gloomy passage until, on reaching the entrance, we find it blocked up.