black smoke vs cannons

Each of the Martians, standing in the great crescent I have described, had discharged, by means of the gunlike tube he carried, a huge canister over whatever hill, copse, cluster of houses, or other possible cover for guns, chanced to be in front of him. Some fired only one of these, some two--as in the case of the one we had seen; the one at Ripley is said to have discharged no fewer than five at that time. These canisters smashed on striking the ground--they did not explode--and incontinently disengaged an enormous volume of heavy, inky vapour, coiling and pour- ing upward in a huge and ebony cumulus cloud, a gaseous hill that sank and spread itself slowly over the surrounding country. And the touch of that vapour, the inhaling of its pungent wisps, was death to all that breathes.

Chapter 15