They balanced on large main ropes stretched over the water.

他们依靠水面上方的粗缆绳保持平衡。

And the earliest known Indian mathematical texts, written between 800 and 600 B.C., state that a rope stretched across the diagonal of a square produces a square twice as large as the original one.

已知最早的印度数学记录出现在公元前 800 至 600 年间，其指出穿过正方形对角线的绳子，可以产生比原来正方形面积大一倍的正方形。

A rope stretched across the main gate and a policeman by it kept out the curious, but little boys soon discovered that they could enter through my yard and there were always a few of them clustered open-mouthed about the pool.

外面的大门口有一根绳子拦住，旁边站着一名警察，不让看热闹的人进来，但是小男孩们不久就发现他们可以从我的院子里绕过来，因此总有几个孩子目瞪口呆地挤在游泳池旁边。