The poison belt and other Professor Challenger's stories

Summoned from London, journalist Edward Malone, narrator of Arthur Conan Doyle's prehistoric-adventure novel 'The Lost World', finds himself reunited with his erstwhile travelling companions at the country home of their leader, the indomitable Professor Challenger, who, confining his guests in a sealed room with the cylinders of oxygen they have brought at his request, informs them that the Earth is passing through an immense miasma of poisonous ether that will likely extirpate all life. And so the isolated inmates begin a grim and terrifying vigil - but will the toxic vapour dissipate before their limited supply of oxygen is exhausted?