Hemrione opened her mouth, as though to start detailing all the different sub-fields of mechanics, before pressing her lips shut when Billy moved on. She wasn't quite as well-versed in the subjects as she'd want to be to teach someone else, after all, and she was pretty sure that his question had been more of a rhetorical one than a true expression of curiosity.

"Let's go with larger, just in case," she said with a nod, rubbing her cheek briefly. "Did you want help transporting this back to your apartment? I can Apparate with it if you let me know your address — or I can get movers to ship it through more traditional means. Whatever your preference."