Abstract: In the present note the mechanism of conversion of the internal and potential energy into kinetic energy is discussed,The potential energy first changes into the work to stretch an air column in vertical dimension,it then changes into the kinetic energy of.horizontal motion through horizontal divergence,The internal energy changes into kinetic energy through three dimensional divergence.It is further found that it is only in compressible fluid the internal and potential energy reserved in baroclinity can be converted into kinetic energy.The effect of earth's rotation is to reduce the possibility to release the internal and potential energy in the atmosphere.Starr's conclusion that anticyclone is the source of kinetic energy is eritized.Finally the maximum possible release of.the internal and potential energy in the mean summer and winter atmosphere is estimated.