The death of energy and the second law of thermodynamics, with particular reference to the thermodynamics of the atmosphere

Dr. Steinmetz introduced his subject by defining the second law of thermodynamics as that law which states that in any cyclic transformation of energy, the total amount of unavailable heat energy increases. Another way of stating this law is that in any system, heat flows only from a higher to a lower temperature unless energy is added to the system. An example of this law is the energy obtainable from the steam produced by a steam boiler and then superheated. It is well known that the energy available for driving a steam engine is represented by the difference between the temperature of the steam leaving the superheater and the temperature of the steam entering the condenser. The energy remaining in the steam as it passes into the condenser is unavailable for transformation into mechanical energy. Any method which will reduce the temperature of the steam entering the condenser, such as a partial vacuum, will increase the amount of heat energy rendered available for transformation into mechanical energy.