Page:Historical eclipses.djvu/18

From Wikisource
Jump to navigation Jump to search
This page has been validated.
14
HISTORICAL ECLIPSES

correct date and whether the reference to Fang does or does not tie it down to the five days which the Sun takes to pass through the asterism now known by that name. This narrow interpretation of Fang agrees well with the reading 'last month of autumn', but cannot be reconciled with the reading 'first month of summer', and Schlegel and Kühnert have supposed that the reading 'last month of autumn' was substituted for the reading found in Tso's text in order to cohere with the falsely interpreted Fang. But as the reading which they reject is at least as old as the Annals of the Bamboo Books, I prefer to leave the question open.

Among modern investigators Oppolzer,[1] who reads 'last month of autumn' and takes Fang in the narrow sense, has proposed to identify the eclipse with that of B.C. 2137 October 22, while Schlegel and Kühnert, reading 'first month of summer', and confining their investigation to eclipses which attained a magnitude of 10 digits (i. e. in which five-sixths of the Sun's diameter were eclipsed) at the Chinese capital, conclude that the eclipse was either that of B.C. 2165 May 7, or that of B.C. 1905 May 12, and they express a preference for the earlier date. But it would appear that there are numerous Chinese observations of eclipses which were less than five-sixths total[2] and so the assumption on

  1. 'Über die Sonnenfinsterniss des Schu-king', Monatsberichte der kön. preuss. Akad. der Wissenschaften zu Berlin, 1880, 166-85.
  2. I have computed the three earliest dated Chinese eclipses, those of B.C. 776 September 6, B.C. 720 February 22, and B.C. 709 July 17, of which the first is recorded in the Book of Poetry and the other two in the Annals of Lu, the eclipse of B.C. 709 July 17 being described as total. Introducing my elements as corrections into Schram's 'Tafeln zur Berechnung der näheren Umstände der Sonnenfinsternisse', Denkschriften der Kaiserlichen Akademie der Wissenschaften, math.-nat. Cl., li (1885), pp. 385-576, a useful set of tables where extreme accuracy is not required, I find that the first of these eclipses was not visible in the Chinese capital or anywhere in the royal domain, but would be visible as a small eclipse in northern China, the second attained a magnitude of 5·2 digits in K'euh Fow, the capital of Lu, while the third was total in that city.