Vertical-incidence ionospheric measurements and magnetograms, made during the annular solar eclipse of November 23, 1965, are presented and discussed. A marked change in the F2-layer virtual height and considerablle stratification of the F layer were observed, including formation of an F1.5 layer. The magnetograms indicate a large (approximately 25 percent) diminution relative to the normal solar disk was observed at about 1009 hours local time (0309 GMT) at Bangkok, which was approximately 290 km from the center of the eclipse path.