A rigorous equation is set up for the velocity of sound in gases. This is used to calculate the velocity of sound in dry air at standard conditions from data taken in independent measurements. The result of this calculation is 331.45±0.05 meters sec.−1An extensive survey of previous reported measurements has been made. After proper corrections are taken into account, the weighted mean is 331.464±0.05 meters sec.−1The results of very precise interferometer measurements by the authors give 331.44±0.05 meters sec.−1.