KUNDTS DUST TUBE
For showing the wavelength of vibrations in air in a closed tube, by depositing lycopodium powder at the nodes. Comprising a glass tube 80 cm long and 32 mm in dia. At one end is a tightly fitting but adjustable cork piston fitted to a metal rod 100 cm long and at the other end, a loose fitting piston attached to a rod, 100 cm in length and 8 mm dia. Overall length fully closed, 1.89 m approx.