A previous paper described an investigation of the attenuation of ultrashort radio waves when transmitted directly along the earth's surface. The present paper reports the progress made in the continuation of this research, the particular wave-length to which attention has recently been given being 1.6 metres. A brief description is given of the simple, but efficient, transmitting and receiving apparatus which has been employed for the experiments on this wave-length. Measurements of the field-intensity at different distances from the transmitter have been carried out for various heights of the apparatus above the ground level. When both transmitter and receiver are used very close to the ground, the attenuation curve obtained is similar to that encountered at longer wave-lengths. When, however, the apparatus is elevated by an amount comparable with, or greater than, the wave-length, the field-intensity-distance curves have maximum and minimum values, the positions of which depend upon the actual heights employed. These maxima and minima are due to interference between waves transmitted directly from the transmitter to the receiver, and those which arrive at the receiver after reflection from the earth's surface. Theoretical curves having the same characteristics have been calculated from a consideration of the reflection coefficient of the earth's surface, account being taken of the electrical properties of the earth. By a comparison of such theoretical curves with the experimental results, the effective conductivity of the earth appears to be about 95 × 108 e.s.u. (resistivity 95 ohm-cm.) at the very high frequency of 190 megacycles per second employed. This is higher than the values of 5 × 108 to 30 × 108 e.s.u. previously obtained at frequencies of 30 to 60 megacycles per second, and these in turn were higher than the values obtained in earlier work, at a frequency of 1 megacycle per second. Owing to this considerable increase in the value of the conductivity as the frequency is raised, the experimental method does not enable the dielectric constant of the earth to be ascertained with any great accuracy, although a value of 10 gives suitable agreement between the theoretical and experimental results in the present case. At the same time this consideration indicates that, from the point of view of practical communications, the value of the dielectric constant of the earth is not a controlling factor in determining the propagation of waves over the earth's surface on either long or short wave-lengths, except in situations where the conductivity of the ground is abnormally low.