MARGINALIA
Six Months in Ascension
Thanks in part to his intrepid wife, David Gill made the observations that metered the 19th-century solar system
J. Donald Fernie
Nearly fifty years ago my wife and I joined a handful of passengers
aboard a freighter out of New York bound for Cape Town, South
Africa. Our first landfall was a small island, only seven or eight
miles at its widest, that lies about eight degrees south of the
equator and halfway between South America and Africa. The island of
Ascension was a welcome sight—but not a pretty one. Even its
official Web site describes the island's surface, covered by old
basalt flows and cinder cones, as "rugged, dry, barren, and inhospitable."
Our ship anchored off Georgetown, the tiny, lone settlement, to
offload cargo. We passengers didn't go ashore, as the only way to
gain the headland was to leap from the gunwales of a small tender
onto the steep, slippery steps cut into the rock. When the swell was
heavy it became too dangerous. Later we sailed down the southwest
coast and gaped at the forbidding cliffs of ancient lava. Suddenly
there appeared between the gray-black rocks a small beach with
brilliant white sand, a sight that caused a stir among the
passengers at the deck rails. "That's Mars Bay," announced
a nearby ship's officer, and suddenly I realized: This was the place
where a young astronomer made the best 19th-century estimate of the
solar system's size!
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