Precision glass tube with precisely fitting aluminum cylinder for determining the adiabatic exponent cP/cV of air by Rüchardt's method, used in conjunction with Mariotte flask (U14327). If the glass tube is placed vertically on a glass flask of 10 l volume and the aluminum cylinder is allowed to slide into the glass tube, it can be made to undergo harmonic oscillations on the air cushion resulting from the enclosed volume of air. cP/cV can then be calculated from the period. Specifications: