What else was this intended to be used for? Why else was it financed by the military? If you're not ready to admit it to the public, at least admit it to yourself: You knew, or at least suspected it all along
… it makes steam so you can power a steam engine.
And you never wondered what this engine would be?
Magnifying things?
Does this look like magnifying to you, Ender? Or should I call you Bean?