Aerial Assault at the Siege of Petersburg?

I recently noticed on Google Reader the bizarre, quixotic story of Roderick Davidson, would be airplane inventor in the Civil War era.  His plan was to create flying machines he named Artis Avis, or “bird of art”, to drop 50 pound bombs on the Union lines at Petersburg, driving the Yankees away and snatching victory from the jaws of defeat.  Interestingly, the North was up to the same thing, trying to get a helicopter like bird off the ground.