Over an extensive area, the soil consisted of that igneous gravel called "tuff," reddish in color as if made from crushed bricks. The ground was covered with slag, lava flows, and pumice stones.
De bodem was met roodachtig zand, als met fijn gestampte tichelsteenen bedekt; daartusschen zagen wij stukken lava, puimsteen en andere vulkanische producten.