《Tetrabiblos》Application, Separation, And Other FacultiesClaudius Ptolemy（Ashmand 英譯 1822）
The precise meaning of the word κεντρον is “centre,” rather than “angle”; but Ptolemy uses it throughout this work, in speaking of the four angles of heaven, and I conceive he uses it here to signify an angle at, or on, the earth.
段落 tetra-1-applicatio-6public-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。