Explanation:
those poor Esgaroth people. Assuming Erebor is mainly composed of Volcanic igneous rock, I'm guessing that Smaug's fire is cooler than 1200 degC, since he didn't melt the tunnel the Dwarves were hiding in. Most minerals that comprise igneous rock begin to become molten before temperatures reach ~1200 degC.
I think this is coming from the Henry Ford quote, which is "Whether you think you can, or you think you can't--you're right."
This quote basically means that what you think you can do is all in your mind and how you perceive yourself. if you think you can do something, then you'll be able to do it. If you think you can't do something, then you won't be able to, because you have already given up in your mind.
Does that make sense?