why.

"Burning wax is a liquid. The melting point is around 250 degrees
Centigrade. Wax ignites at 750. It has no boiling point, unless that's
the burning point. Throw water on a wax fire and you get a steam
explosion, just as you would if you threw it on molten metal, and that
throws the fire around and spreads it."

"If it melts that far below the ignition point, wouldn't it run away
before it caught fire?"

"Normally, it would. That's why I'm sure this fire was a touch-off. I
think somebody planted a thermoconcentrate bomb. A thermoconcentrate
flame is around 850 Centigrade; the wax would start melting and
burning almost instantaneously. In any case, the fire will be at the
bottom of the stacks. If it started there, melted wax would run down
from above and keep the fire going, and if it started at the top,
burning wax would run down and ignite what's below."

"Well, how in blazes do you put a wax fire out?" he wanted to know.

"You don't. You just pull away all the wax that hasn't caught fire
yet, and then try to scatter the fire and let it burn itself out....
Here's our chance!"

All this conversation we had been screaming into each other's ears, in
the midst of a pandemonium of yelling, cursing, siren howling and bell
clanging; just then I saw a hole in the vertical traffic jam and edged
the jeep into it, at the same time remembering that the jeep carried,
and I was entitled to use, a fire siren. I added its howls to the
general uproar and dropped down one level. Here a string of big
manipulators were trying to get in from below, sprouting claw hooks
and grapples and pusher arms in all directions. I made my siren
imitate a tail-tramped tomcat a couple of times, and got in among
them.

Bottom Level Broadway was a frightful mess, and I realized that we had
come down right between two units of the city power plant, big
mass-energy converters. The street was narrower than above, and ran
for a thousand yards between ceiling-high walls, and everything was
bottlenecked together. I took the jeep up till we were almost scraping
the ceiling, and Murell, who had seen how the audiovisual was used,
took over with it while I concentrated on inching forward. The noise
was even worse down here than it had been above; we didn't attempt to
talk.

Finally, by impudence and plain foolhardiness, I got the jeep forward
a few hundred yards, and found myself looking down on a big derrick
with a fifty-foot steel boom tipped with