The short wavelength wing of the pure rotation emission spectrum of water vapor (between 10 and 22 μ) has been measured at temperatures between 500° and 2200°K and at a nearly constant optical depth of 2·4 × 10⁻⁴ g/cm². Apparent line positions and relative intensities agree with those determined from previous work. An approximate calculation of the local mean spectral absorption coefficient has been performed. This calculation is the weighted mean value of results obtained using energy levels of the prolate spheroidal top and of the “most asymmetric” top. A comparison of the results of the calculation (applying the statistical band model using broadening parameters obtained in vibration-rotation bands) with the experimental data indicates that the calculation is acceptable for the long wave-length contribution to the total emissivity of hot water vapor. An estimate of the integrated band intensity has been obtained.