Ascension Island 228
Issued to commemorate the centenary of Sir David
Gill's visit to Ascension Island in 1877 to measure the parallax of
Mars, the stamp has two maps. The one in the lower right is Sir David
Gill's map, published in Mrs. Gill's account of the visit. The larger
is a map of the southwest part of the island. On both maps the site of
Sir David's observatory is labeled in red.