Assertion: spark plug's temperature | /r/CapableOf | soften to state
Facets:
Source sentences:
text: The temperature of the flue gases in a steam engine firebox can reach 1000 °F (550 °C), at which temperature copper, from which historically most fireboxes were made, softens to a state which can no longer sustain the boiler pressure and a severe explosion will result if water is not put into the boiler quickly and the fire removed or extinguished.