There has never been conceived or made by man any instrument, machine, or contrivance, capable of such a diversity of usefulness as the human hand. Nothing has ever existed with such infinite adaptability to various needs, or capable of being trained to such degrees of dexterity and versatility. Nor is it likely that as perfect a machine will ever be produced by man skill, for the only thing the man hand cannot do is to create an instrument as perfect as itself.