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the point whose distance is to be measured.
The Inferior Planets .–When the tele-
scope was invented, the phases of Venus at-
tracted much attention; but the brightness
of this planet, and her proximity to the sun,
as with Mercury also, seemed to be a bar
to the discovery of markings by which the
axis and period of rotation could be fixed.
Cassini gave the rotation as twenty-three
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