A real Cavendish balance is set up in the basement. A real-time image of this setup can be sent to the classroom via closed circuit television. In Hoyt auditorium, a laser beam bounced off a mirror attached to the wire in the torsion balance is directed through a hole in the floor and can be projected onto the wall. Over the span of a classperiod, students can observe the movement of the beam and thus the change in the angle of the torsion balance.