Tom @Yulsman photo peering into the “Cretaceous on fire,” a porthole in an old coal-fired power plant. Brings me right back to Loren Eiseley’s “Man the Firemaker”!
As I explained in my 1992 book on global warming: 

In his 1954 essay “Man the Firemaker,” Loren Eiseley correlates human progress with the use of ever-more-potent fuels. First came firewood, which enabled humans to cook meats and thus increase food’s nutritive value. Then came charcoal. The Iron Age would have been meaningless without the hot charcoal fires over which metals become malleable. Mastery of glass, ceramics, and steel was a function of rising temperatures in kilns, forges and furnaces.
As Eiseley put it, “Man’s long adventure with knowledge has, to a very marked degree, been a climb up the heat ladder…. Today the flames grow hotter in the furnaces…. The creature that crept furred through the glitter of blue glacial nights lives surrounded by the hiss of steam, the roar of engines, and the bubbling of vats…. And he is himself a flame — a great, roaring, wasteful furnace devouring irreplaceable substances of the earth.”

Tom @Yulsman photo peering into the “Cretaceous on fire,” a porthole in an old coal-fired power plant. Brings me right back to Loren Eiseley’s “Man the Firemaker”!

As I explained in my 1992 book on global warming

In his 1954 essay “Man the Firemaker,” Loren Eiseley correlates human progress with the use of ever-more-potent fuels. First came firewood, which enabled humans to cook meats and thus increase food’s nutritive value. Then came charcoal. The Iron Age would have been meaningless without the hot charcoal fires over which metals become malleable. Mastery of glass, ceramics, and steel was a function of rising temperatures in kilns, forges and furnaces.

As Eiseley put it, “Man’s long adventure with knowledge has, to a very marked degree, been a climb up the heat ladder…. Today the flames grow hotter in the furnaces…. The creature that crept furred through the glitter of blue glacial nights lives surrounded by the hiss of steam, the roar of engines, and the bubbling of vats…. And he is himself a flame — a great, roaring, wasteful furnace devouring irreplaceable substances of the earth.”