《Tetrabiblos》The Periodical Divisions Of TimeClaudius Ptolemy（Ashmand 英譯 1822）
In all these cases, the time occupied in proceeding round from any angle to the same again, must be everywhere equal in its duration, for it is marked by one sensible revolution; and the time occupied in passing from either meridianal angle to the angle diametrically opposite, is also everywhere equal; because it is marked by the half of one revolution.
段落 tetra-4-theperiodi-62public-domain (Ashmand 1822)
↗ 開啟公有領域原文（Wikisource）此段為公有領域典籍逐字擷取，零 AI 生成；原文亦存繁化前底本，可逐字審計。我們寧可少引、不可錯引——驗不過的引文一律捨棄。