《论衡·卷十一·说日篇》
站在靠近大湖的水边，看见大湖四面的边沿都与天相连。实际上并不相连，是因为远了，看起来好像相连一样。
临大泽之滨，望四边之际与天属；其实不属，远若属矣。
Standing near the water of the big lake, I saw the edges of the big lake on all sides connecting with the sky. In fact, it is not connected, because it looks like it is connected because it is far away.