492 TRANS. ST. LOUIS ACAD. SCIENCE. 



of the vernal equinox, near the middle of the constellation Pisces, 

 the sun was, one month prior to the vernal equinox, as the Chi- 

 nese say, in conjunction with the first stars of Pisces about the 

 year — 2460; and, indeed, in this very year the conjunction of 

 five planets, referred to, actually took place, as the following 

 approximate computation, according to Lalande's Tables, demon- 

 strates : 



Longitudes of the Planets in — 2460, March 12, yulian style. 



Heliocentrically. Geocentrically. 



The Sun lo^ 30°= ii^ 0° 



The Moon •• 10 30 =11 o 



Mercury 5^ 27° 33' 10 24 



Venus II 27 28 10 29 



Jupiter II 16 13 10 24 



[Mars 78 26° 42'= 98 i°] 



[Saturn 6 22 15 z= 6 26 ] 



On the vernal equinoctial day in — 2460, April nth, yh. 36m. 

 Pekin time, the longitude of the sun was 11*29° 23'i ''^iid that of 

 the moon o^ 17° 7' ; hence the crescent (luna prima) was visible 

 on the vernal equinoctial day, which Thouen-Hio made the be- 

 ginning of the year, after sunset, namely, 30 days subsequent to 

 that conjunction of five planets. 



Such a conjunction of the said planets, whilst the sun stood 

 between the constellations Aquarius and Pisces, occurs but once 

 within 164,000 years: for the siui stands again in conjunction 

 with the moon, on the corresponding day of the year, first after 19 

 years, with Mercury not until after 26 years, with Venus not until 

 after 4 years, with Jupiter not until after 83 years ; consequently 

 a similar conjunction of the same planets returns after 19 X 26 X 

 4 X 83 years. This observation, then, of the year — 2460 proves 

 that the history of China, according to which Tchuen-Hio, the 2d 

 regent of the ist Chinese dynasty reigned from — 2513 to — 2435, 

 cannot be very wrong, because the planetary configuration referred 

 by the Chinese annals to tl:is king occurred in — 2460 only. 



The same annals report that Emperor Thong-khang, the 4th of 

 the 2d dynasty, reigned from 2158 to 2145 B.C., and about that time 

 a total eclipse of the sun occurred in Pekin, as the Chou-king, a 

 compilation of the oldest religious books of the Chinese, testifies. 

 This Chou-king contains the following passage, according to P. 

 Gaubil's translation in "Histoire de I'Astronomie Chinoise," Par., 



