Rydberg constant can be measured with reasonable precision. The more spectral lines measured and analyzed, the closer the value of will be to its accepted value of approximately.Hydrogen discharge lamp with supply, grating with 600 lines/mm, two spare Hydrogen discharge lamps, spectrometer with least count of 30 seconds, vernier scales of German Silver or equivalent, Ramsden eye-piece 8x, cross-hairs, focal length 175 mm or more, micro-metre slit on collimator, Adjustable (three screws) brass prism table with tangent screw for fine circular motion, objective aperture 30 mm, centre spindle made of brass, separate spirit level for to be included.