翻刻
食算ノ術未タ細密ナラサルカ故ナリ一行カ
コレヲ君徳ノ有無ニ託スルハ王侯ヲ誡ルノ
方便タルベシ性理大全ノ治世ニ少ク乱世ニ
多シト云ル説実ニ思ハサルノ甚シキナリ其
頃ハ治世ハ稀ニシテ多分乱世ナリ故ニ治世ニ
少ク乱世ニ多キナリ今世ヲ以テ云ハ乱世ニ
ハ少ク治世ニ多シト云フヘシ程子朱子ノ答
モ食ノ常数アルコトヲ悟明セサルノ疑慮ヨリ
起レリ信用スルニ足ラス食算ノ法漢朝ニ漸
ヲ定リ唐宋ニ及テ猶未タ細密ナラス元朝ノ
郭守敬出ルニ至テ稍備ルト雖猶全備ニ非ス
明季胡清ニ及テ西洋ノ天学渡来シテヨリ暦
数大ニ明ニ考験精密ニ其理委ク成テ食限ノ
考ヘ百ニ一ッ失セサルニ至レリ我日本ハ上
代ハ云フニ及ハス近代マテモ暦術ニ疎クシ
テ定朔ヲ錯リシ事多ク有リ天明六年丙午正
月朔日ノ日蝕モ暦面ニハ皆既ト記シタレトモ
実ハ九分ノ食ニテアリキ其後寛政以来西洋
ノ暦術漸々ニ行レ考験細密ヲ尽シテ分釐ソ
違ヒ無キニ至レリ是レ誠ニ昇平ノ賜ナリ
現代語訳
食算の技術がまだ細密ではないからである。一行がこれを君主の徳の有無に託すのは、王侯を戒める方便であろう。『性理大全』の「治世には少なく乱世には多い」という説は、実に思慮が足りないことが甚だしい。その頃は治世は稀で、大部分が乱世であった。故に治世には少なく乱世には多いのである。今の世を以って言えば、乱世には少なく治世には多いと言うべきである。程子・朱子の答えも、食の常数があることを理解していない疑念から起こったものである。信用するに足りない。食算の法は漢朝に漸く定まり、唐・宋に及んでもなお細密ではなかった。元朝の郭守敬が出るに至ってやや備わったとはいえ、なお完全ではなかった。明末・清初に及んで西洋の天学が渡来してから、暦数が大いに明らかになり、考証が精密になって、その理論が詳しく整い、食限の計算で百に一つも間違わないに至った。我が日本は上代は言うに及ばず、近代まで暦術に疎くて、朔日を間違えたことが多くあった。天明六年丙午正月朔日の日食も、暦面にはみな皆既と記したけれども、実は九分の食であった。その後寛政以来、西洋の暦術が漸々に行われ、考証を細密に尽くして分厘も違いがないに至った。これは誠に平和な世の賜物である。
英語訳
This is because the techniques of eclipse calculation were not yet precise. Yi Xing's attribution of eclipses to the presence or absence of the ruler's virtue was likely a expedient method to admonish kings and nobles. The theory in the "Xingli Daquan" that eclipses are "few in times of good government and many in times of disorder" is extremely thoughtless. In those times, periods of good government were rare, and most times were disordered. Therefore, eclipses were few in times of good government and many in times of disorder. Speaking in terms of the present world, one should say they are few in times of disorder and many in times of good government. The responses of Cheng Zi and Zhu Xi also arose from doubts due to their failure to understand that eclipses have regular patterns. They are not worthy of trust. The methods of eclipse calculation gradually became established during the Han dynasty, but even during the Tang and Song dynasties they were still not precise. Although they became somewhat complete when Guo Shoujing of the Yuan dynasty appeared, they were still not fully perfected. From the late Ming and early Qing periods, when Western astronomy was introduced, calendrical calculations became greatly clarified, investigations became precise, and the theories became thoroughly developed, reaching the point where calculations of eclipse limits do not err even once in a hundred times. In our Japan, not to mention ancient times, even until recent times we were ignorant of calendrical techniques and often made errors in determining new moon days. The solar eclipse of the first day of the first month of Tenmei 6 (1786), year of the fire horse, was recorded on calendars as a total eclipse, but it was actually a nine-tenths eclipse. Since then, from the Kansei era onward, Western calendrical techniques have gradually been adopted, investigations have been conducted with utmost precision, and we have reached the point where there are no discrepancies even to the smallest fraction. This is truly a blessing of peaceful times.