Book excerpt: A partial reflection experiment, conducted on Aitutaki, Cook Island, before, during and after the 1965 Solar Eclipse, is described. A small portion of the data collected during the expedition is presented in the form of ten electron density profiles collected between the times of 13 minutes before totality until two and one half hours after totality. Also included is a three day noon-time average electron density profile for comparison purposes. The statistics of D-region echoes are described and their implications are discussed. The general conclusion from the data is that the solar eclipse caused little, or no changes in the electron density distribution at altitudes below 75 km. The predominant eclipse effects were noticed at altitudes of 78 km and higher. The data presented also suggest that the D-region electron density recovered to near normal in a time interval of about 80 minutes after totality. Even though the data analyzed are too few to reach definite conclusions regarding the electron density history during the eclipse, the trends evident from the results are sufficiently well defined to establish the usefulness of the experimental technique for D-region investigation during a solar eclipse. (Author).