Signed First Day Cover

This Norwegian-born explorer and geographer led nine Antarctic expeditions, the first in 1933, exploring over 3600 miles via dogsled; he proved that Antarctica is a continent; "Edith Ronne Land" he named after his wife, and the "Ronne Ice Shelf" is named after him; he recorded his exploits in his 1961 memoir "Arctic Command." Signed First Day Cover, 6½" X 3½", cancelled in Washington, DC on 23 June 1971 and with "First Day of Issue" boldly stamped. Single 8-cent "Antarctic Treaty 1961-1971" stamp at upper right. At lower left, beneath the postal cancellation, Ronne signs large and bold in blue ballpoint. Below his handsome signature he inkstamped: "CAPTAIN FINN RONNE, USNR / Military Commander - Scientific Leader / Ellsworth Station, Edith Ronne Land / ANTARCTICA." He's also placed a large octagonal inkstamp on the cover's verso about the "International Geophysical Year." A superb signature on a superbly appropriate cover.