The phenomenon of ebullition. Fanned by a constant updraught of ventilation between the kitchen and the chimneyflue, ignition was communicated from the faggots of precombustible fuel to polyhedral masses of bituminous coal, containing in compressed mineral form the foliated fossilised decidua of primeval forests which had in turn derived their vegetative existence from the sun, primal source of heat (radiant), transmitted through omnipresent luminiferous diathermanous ether.

Heat (convected), a mode of motion developed by such combustion, was constantly and increasingly conveyed from the source of calorification to the liquid contained in the vessel, being radiated through the uneven unpolished dark surface of the metal iron, in part reflected, in part absorbed, in part transmitted, gradually raising the