Incredible.

不可思议
You must forgive me. I have no background in navigational techniques.

请原谅我没有航海技巧方面的经验
To plot an exact position, you need three things:

要找到精确的位置你需要三样东西
a sextant, an accurate chronometer and a celestial almanac.

六分仪精准的经线仪和一本天文年鉴
The almanac tells us the

年鉴上有
exact time at which the sun hits its zenith.

太阳到达最高点的精确时间
- Exact noon. - Shall I bring some more, sir?

-正午时分 -需要再来点吗先生
Leave it! Please.

别动拜托
It's all right, Percy. Get another.

不用珀西再去倒一杯
If your watch is set to Greenwich Mean Time, you can calculate

若你的表是格林威治标准时间就能算出
how far east or west of Greenwich, London you are.

你距伦敦的格林威治以东或以西有多远
Twelve. . .Twenty-seven. Twenty-eight, rather.

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