The paper discusses the theory of electron emission in intense electric fields, focusing on the work of Fowler and Nordheim. They extend Nordheim's results to include the effect of an external field using Sommerfeld's electron theory. They derive a formula for the current, which is valid for both strong fields and thermionic emission. They argue against Millikan and Lauritsen's suggestion of a general formula for the current, as it is not supported by the theory. They also show that the emission coefficient depends on the potential energy step and the external field. The paper presents a detailed calculation of the emission coefficient for electrons incident on a potential energy step, showing that the emission is dominated by the external field at high field strengths. The results are compared with experimental data, and it is concluded that Sommerfeld's theory provides a satisfactory explanation of the phenomenon. The paper also discusses the effects of temperature and the potential energy curve on the emission. The results are applied to the case of cold metals, and the current is calculated as a function of the field strength and temperature. The paper concludes that the theory is consistent with experimental observations and that the phenomenon of electron emission in intense fields can be explained by Sommerfeld's theory.The paper discusses the theory of electron emission in intense electric fields, focusing on the work of Fowler and Nordheim. They extend Nordheim's results to include the effect of an external field using Sommerfeld's electron theory. They derive a formula for the current, which is valid for both strong fields and thermionic emission. They argue against Millikan and Lauritsen's suggestion of a general formula for the current, as it is not supported by the theory. They also show that the emission coefficient depends on the potential energy step and the external field. The paper presents a detailed calculation of the emission coefficient for electrons incident on a potential energy step, showing that the emission is dominated by the external field at high field strengths. The results are compared with experimental data, and it is concluded that Sommerfeld's theory provides a satisfactory explanation of the phenomenon. The paper also discusses the effects of temperature and the potential energy curve on the emission. The results are applied to the case of cold metals, and the current is calculated as a function of the field strength and temperature. The paper concludes that the theory is consistent with experimental observations and that the phenomenon of electron emission in intense fields can be explained by Sommerfeld's theory.