An area of sky containing the ionized hydrogen regions IC 1795, IC 1805 and IC 1848, and the supernova remnant HB 3, has been observed with the 10 MHz radio telescope at the Dominion Radio Astrophysical Observatory. The results imply that the brightness temperature of the non-thermal radio emission arising in the line of sight to the ionized hydrogen regions is between 85000 °K and 140000 °K at this frequency. The mean non-thermal emissivity of the galactic disk in this direction ( lII ≈ 140°) is estimated to be between 4.5 and 9 × 10 −41 W m −3 ster −1 Hz −1 at 10 MHz. This result is combined with measurements of the flux of primary cosmic ray electrons at the top of the Earth's atmosphere to estimate the strength of the interstellar magnetic field in this region of the disk. It is suggested that the supernova remnant HB 3 is of exceptional linear size.