Jace retracted his outstretched hand, shrugged, inclinded his head toward the professor and turned to go back to his seat. Surprisingly, he wasn't offended at all. At least he won't feel guilty about not helping a man down. Flamsteed's loss really.

Eyes and attention back up front, the Ravenclaw scribbled down important notes in his parchment, highlighting the incantation, wand movement, and the effect of said spell. Hastily, he moved his writing implements on one side, got his wand and placed the apple right smack on the center of his table.

"Derivo Gravitatem...Derivo...Gravitatem...Derivo Gravitatem." sitting straighter in his seat, Jace did the wand movement three times, and closed the motion by saying the last syllable of the incantation.

Hmm. Will that work? It should work. The incantation may be a mouthful, but the effect isn't hard to intend upon the object.