Guy's Elements of astronomy : and an abridgment of Keith's New treastise on the use of the globes . Apindou/s V /////,s////////// o/ //i( ///ir-rrs/ J/ot V,. F7V/.3. M fV 7,y. O 4 0^ Eflips ejf 7^ i^^^x^:^^ i^^nr^ PRECESSION OF THE EaUINOX. l07 vears before. From this he judged the motion to be about 1° in about100 years; but he doubted wheLher the observations of Timocharlswere sufficiently accurate.—In the year 128 before Christ he found thelongitude of Virgins Spike to be 5 signs 24<^, and in the year 1750 itslongitude was found to be 6 s. 20^ 21. In the same year he fbmid Ikolongitude o
Guy's Elements of astronomy : and an abridgment of Keith's New treastise on the use of the globes . Apindou/s V /////,s////////// o/ //i( ///ir-rrs/ J/ot V,. F7V/.3. M fV 7,y. O 4 0^ Eflips ejf 7^ i^^^x^:^^ i^^nr^ PRECESSION OF THE EaUINOX. l07 vears before. From this he judged the motion to be about 1° in about100 years; but he doubted wheLher the observations of Timocharlswere sufficiently accurate.—In the year 128 before Christ he found thelongitude of Virgins Spike to be 5 signs 24<^, and in the year 1750 itslongitude was found to be 6 s. 20^ 21. In the same year he fbmid Ikolongitude of the Lions Heart to be 3 s. 29° 50, and in 1750, it was 4 ° 21. The mean of these gives in a year for the comparing the observations of Albategnius, in the year 878, Aviththose made in 1738, the precession appears to be 51 9.—^From a com-parison of fifteen observations of Tycho, with as many made by M. dela Caille, the precession was found to be about 50 20. By proceeding to shift a whole degree every 72 years,and a whole sign every 2160 years, the equinoctialpoints will fall back through the whole of the 12signs, and
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectastronomy, bookyear18
