Page 365 - 89 history of astronomy_opt
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sector was purchased for the observatory.
                                         An instrument like this, specially designed
                                         for zenith stars, is capable of greater rigid-
                                         ity than a more universal instrument; and
                                         there is no trouble with refraction in the
                                         zenith. For these reasons Bradley had set
                                         up this instrument at Kew, to attempt the
                                         proof of the earth’s motion by observing the
                                         annual parallax of stars. He certainly found
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