3 hollow prisms with yellow plugs (1 with water, 1 with alcohol, 1 with mineral oil)
acrylic equilateral prism
specially marked brown plastic box
Put metal slit vertically into projector. Turn it on. Place the water prism in the holder on the box. A spectrum should be seen on the screen. (Have a student go to screen and point at spectral position)
Replace the water prism with alcohol prism. The alcohol spectrum will be slightly to the right. (Have student point to the new position)
Replace the alcohol prism with the oil prism. The oil spectrum should be significantly to the right.
Finally place the acrylic prism in the slot. The spectrum should be a bit more to the right.