In H.G. Wells’ The War of the Worlds, the Martian fighting machines are called tripods. The name describes their three tall, articulated legs, which carry a large metallic body and a hood-like compartment for a Martian operator.
The tripods are the principal weapons of the Martian invasion. They move rapidly across the English landscape, using grasping tentacles to seize people and equipment. Their most famous weapon is the heat-ray, while another weapon releases poisonous black smoke. Wells’ novel, first published in 1898, presents the machines as terrifying examples of technology far beyond that of Victorian Earth.
“Flying machines” is a separate type of Martian craft mentioned in the novel, while “cylinders” are the spacecraft in which the invaders arrive. “Heat rays” are weapons carried by the tripods, not their name. Later films and television adaptations changed the machines’ designs, but the three-legged tripod remains their canonical identity in Wells’ book.