442 PHILOSOPHICAL TRANSACTIONS. [anNO 1754. 



was in his own time, but 272 years before. So that from hence we see nothing 

 certain can be concluded with regard to his age. 



Kepler, in his Epitom. Astronom. supposes that from the time of Hesiod to 

 the year after Christ 1618, are 2400 years, and that the annual motion of the 

 fixed stars is 51", which, in 2400 years, gives 34°. From which, and several 

 other assumptions, he concludes, that in Hesiod's time Arcturus rose achroni- 

 cally March 3, in the Julian year reckoned backward, when the sun was in 

 ^ 5° ir. 



Riccioli, in his Almagest, supposes, that Hesiod flourished about the year 

 before Christ 775, when the place of the sun's apogee was y 20"; and therefore 

 the sun's true motion for 60 days was 6l° lO', which added to the place of the 

 winter solstice, or the beginning of VJ, gives the sun's place ^ 1° 10', the point 

 opposite to that point of the ecliptic which rose along with Arcturus, or It^ 1° 

 10'. Hence he computes the place of Arcturus to have been r^ 12" 15'. But 

 at the end of the year 1644, the place of Arcturus, he says, was ih 18° 19'; 

 therefore from the time of Hesiod, before assumed, to the end of the year 1644, 

 that star had moved through 36° 4'. But this it would do, he says, in 2597 

 years. From which therefore subtracting 1 644, there remains the year before 

 Christ 953. He concludes therefore, as Longomontanus suspected before, that 

 Hesiod speaks of the achronical rising of this star, not as it was in his own time, 

 but two centuries before. Besides, as the refraction of Arcturus would accelerate 

 his rising, and the sun's refraction would retard his setting ; and as the time of 

 the solstice was then known, at best, but in a very gross manner ; he is of opi- 

 nion, that this method is not much to be depended on ; contrary to what Scaliger 

 ^nd Vossius both thought. 



As there are however several errors in this computation, it may not be amiss 

 perhaps to form another, on supposition, with Sir Isaac Newton, that Hesiod 

 flourished about the year before Christ 879, or in round numbers the year 880, 

 and let us see what will be the result of it. At the end of the year 1 68g, the 

 place of Arcturus, in the British catalogue, was ii 19° 53' 52", or 6' 19" 53' 

 52": and from the year before Christ 880, to the end of the year 1689, are 

 2569 years, the precession for which time is 1^ 5° 40' 50'' : this, subtracted from 

 the place of Arcturus 6' 19" 53' 52", gives his place, in the year before Christ 

 880, = 5' 14° 13' 2". The latitude of this star is, in the same catalogue, = 

 30° 57'- Hence is computed the declination of Arcturus = 34° 22' 40", and his 

 right ascension 180° 37' 10". 



Where this observation on Arcturus was made, is not said ; we may suppose 

 it to have been at Ascra, where Hesiod's father lived, as he tells us himself. But 

 as the situation of this place is not very well known, we may, without any sen- 



