palm over all others, had now been established; and
Thomas Henderson, then working at the Cape of Good
Hope, but afterwards the Astronomer Royal of Scotland.
Henderson's observations had actual precedence
in point of time, but Bessel's measurements were so
much more numerous and authoritative that he has
been uniformly considered as deserving the chief credit
of the discovery, which priority of publication secured
him.

By an odd chance, the star on which Henderson's observations
were made, and consequently the first star
the parallax of which was ever measured, is our nearest
neighbor in sidereal space, being, indeed, some ten billions
of miles nearer than the one next beyond. Yet
even this nearest star is more than two hundred thousand
times as remote from us as the sun. The sun's
light flashes to the earth in eight minutes, and to Neptune
in about three and a half hours, but it requires
three and a half years to signal Alpha Centauri. And
as for the great majority of the stars, had they been
blotted out of existence before the Christian era, we of
to-day should still receive their light and seem to see
them just as we do. When we look up to the sky, we
study ancient history; we do not see the stars as they
ARE, but as they WERE years, centuries, even millennia
ago.

The information derived from the parallax of a star
by no means halts with the disclosure of the distance of