On the basis of earlier work of Giovanelli (1949), the characteristics of the radiation fields of Ha, La, L�, and the Lyman continuum have been calculated for model solar atmospheres consisting of a photosphere and an overlying chromosphere which scatters coherently, and which is isothermal at one of a number of kinetic temperatures in the range 1 � 104 to 2�5�l05 �K.