As seas had been bridged and continents cut through, so a volcano might and must be suppressed or extinguished.

A tunnel thirty miles in length was cut from a great lake nearly a thousand feet higher than the base of the volcano; and through this for a quarter of a year, say some six Terrestrial months, water was steadily poured into the subterrene cavities wherein the eruptive forces were generated--the plutonic laboratory of the rebellious agency.

Of course previous to the adoption of this measure, the crust in the neighbourhood had been carefully explored and tested by various wonderfully elaborate and perfect boring instruments, and a map or rather model of the strata for a mile below the surface, and for a distance around the volcano which I dare not state on the faith of my recollection alone, had been constructed on a scale, as we should say, of twelve inches to the mile.

Except for minor purposes, for convenience of pocket carriage and the like, Martialists disdain so poor a representation as a flat map can give of a broken surface.
On the small scale, they employ globes of spherical sections to represent extensive portions of their world; on the large scale (from two to twenty-four inches per mile), models of wonderfully accurate construction.

Consequently, children understand and enjoy the geographical lesson which in European schools costs so many tears to so little purpose.