with an adiabatic exponent 7 = 1.308. This value of 7 corresponds to the value v = 0.25 used in our calculations. It is clear from the graphs that the accuracy of expressions (9) and (10) falls with increase in pressure. This is due, on the one hand, to the increase in the nitric oxide content of the air, and, on the other, to a displacement of the region of dissociation toward higher temperatures, i.e., to an increase in the part played by processes of excitation of new energy levels of the particles. The difference between the calculated and accurate curves at temperatures of 6000°~8000° is mainly due to ionization of the air. Note that calculation based on Eqs. (2), (7), and (8) somewhat improves the accuracy of the curves corresponding to p = 1000 technical atm. In conclusion we shall give values of the constants entering into the expressions written out in the foregoing :