A pair of Fresnel mirrors and a biprism, small metal rods and round openings of different diameters, slits of different widths, a metal rod with a long, thin point.
There is also a small plate of glass with a round, opaque disk with a diameter of about one millimetre to perform the experiment with which Fresnel showed that at the centre of the geometric shadow of a round opaque disk a clear fringe always forms.
A small plate of blackened glass about 2 mm wide is used to show diffraction by reflection.
Also available are one Young's apparatus consisting of two round openings and another one consisting of two identical slits in which a small mobile screen allows the covering of one of the apertures to show that the interference figure of the two apertures is superimposed on the diffraction figure of one of them; in one of the accessories a small, thin, sliding plate of glass can cover one of the slits of one of Young's apparatuses to show the consequent shift of the interference fringes from the part of the covered slit.
Using the edge of a razor blade to cover one of the edges of one of the small metal rods present among the accessories, it is possible to perform the experiment in which Young discovered interference by observing that in the shadow of a wire (or rod) the internal fringes are generated by the superimposition of beams diffracted by its edges. ...continues