From the measured distances of the diffraction bands the width of the slit may be easily deduced.
By this procedure the width of the central band in the diffraction pattern is halved, and so far an advantage is attained.
In 1799 he was induced by his fellow-student, Henry Brougham, to study the diffraction of light.
If the image of the line be =o, the intensity at any point E, n of the diffraction pattern may be represented by ?2a2t2 S A2f2 the same law as obtains for a luminous point when horizontal directions are alone considered.
Gouy has studied the more simple case of diffraction at a straight' edge.