I don't think it is a matter of metaphors at all, but simply a limited understanding of laws and forces. There wasn't a force known at the time that could produ

I don't think it is a matter of metaphors at all, but simply a limited understanding of laws and forces. There wasn't a force known at the time that could produce so much light and heat for so long with the mass of the sun. The only conceivable way to produce light and heat like that was to burn vast quantities of fuels.