How could we tell time if there were no watches or clocks anywhere in the world？

如果世界上任何地方都沒有鐘或表，我們該怎么看時間呢？

The sun was probably the worlds first“clock”， except in the far north， where the Eskimos live. There， its dark most of the winter， and light most of the summer. But in most of the world， people have used the sun for a clock. Even today， if you dont have a clock， you still know that when the sun shines， its day， and when its dark， its night. The sun can also tell you if its morning， noon， or afternoon.

除了在愛斯基摩人居住的極北之地，太陽或許是世界上第一個“時鐘”。在那兒，冬季大部分時間都是黑夜，夏季大部分時間都是白晝。在世界上大多數(shù)地方，人們把太陽當做時鐘來使用。即使今天，如果你沒有鐘，你仍舊知道太陽照耀時，是白天；天黑了，就是夜晚。太陽還能告訴你是早上，中午還是下午。

People who live near the sea can tell time from the tides1. In the daytime， for about six hours， the water rises higher and higher on the beach. And then it goes down and down for about six hours. The same thing happens again at night. There are two high tides and two low tides every 24 hours.

住在海邊的人根據(jù)潮汐來看時間。白天的時候，大概在6個小時里，岸邊水位越漲越高。接下來的六個小時則會越來越低。同樣的事夜間又會重復(fù)一次。每24小時會有兩次漲潮和兩次落潮。

Seamen on a ship learn how to tell time by looking at the moon and the stars. The whole sky is their clock.

船上的船員會通過觀察月亮和星星來看時間。整個星空就是他們的時鐘。

In some places in the world the wind comes up at about the same time every day or changes direction2 or stops blowing. In these places the wind can be the clock.

世界上的某些地方會在每日相同的時間起風，或改變風向，或者停止刮風。這些地方的風可以當作時鐘。

A sand clock is an even better clock. If you had fine dry sand in a glass shaped like the one in the picture， you would have what is called an hourglass3. The sand in the hourglass goes from the top part to the bottom part in exactly one hour. When the hourglass is turned over， the sand will take another hour to go back again.

沙鐘是一種更好的時鐘。如果你將干燥的細沙放在如右圖中樣式的玻璃瓶中，你就有了一個所謂的“沙漏”。沙漏中的沙從頂部流到底部的時間就是整整一個小時。當沙漏翻轉(zhuǎn)過來的時候，沙子再次流回底部又要一個小時。