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Pronunciation Guide
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Listen to native speakers pronounce “plumb line” in real conversational contexts with synchronized timestamps and subtitles.
There's an inventor named Timothy Clark who sent Jefferson his design for a device for finding the longitude.And the way he explained it is that there would be a plumb line with the weight that what you would fix at a particular longitude.Then as you rolled this thing east to west, this line would tilt to stay gravitationally locked at your original longitude.