Page:Handbook of Meteorology.djvu/299



The formula $$1090\sqrt{1 + \tfrac{t^\circ}{273}}$$ for Centigrade, and $$1090\sqrt{1 + \tfrac{t^\circ}{459}}$$ for Fahrenheit scales is practically the same. For all ordinary purposes the value 1110 ft per sec when the temperature of the air is 50° F (30° C) or 1148 ft per sec when the temperature is 86° F (30° C) will meet all requirements.