4 ms·
> To determine the speed, you count how many knots pass through your hand in a certain time. But how did they count "a certain time"? (Before stopwatches).
by logicallee 10y ago
> To determine the speed, you count how many knots pass through your hand in a certain time.
But how did they count "a certain time"? (Before stopwatches).
- deleted 10y ago[deleted]
- ebbv 10y agoMechanical pocket watches or ship's clocks. They were expensive but accurate enough.
- Isamu 10y agoSandglasses were around for a long time.
- taneq 10y agoWell, we assume it was a long time but maybe sandglasses were really inaccurate.
- iaw 10y agoI'm not sure if it would matter if they were really inaccurate if the ship used the same sandglass and rope. I've read about the shipping log -> world map work [1] where it details that the speeds/distances for a given group of boats had different errors which the gentlemen developed a technique to resolve. [1] https://priceonomics.com/a-map-of-the-world-made-from-shipping-logs/ https://priceonomics.com/a-map-of-the-world-made-from-shippi...
- deleted 10y ago[deleted]
- nitroll 10y agohttps://en.wikipedia.org/wiki/Marine_sandglass https://en.wikipedia.org/wiki/Marine_sandglass
- lazyant 10y agoThe origins of precise clocks is because ships needed to calculate how far they had travelled in terms of longitude (eastwast/westward. How far you've travel north/south is easy to calculate by how high the sun goes). The British crown established an award for whoever could come up with a precise clock of this reason, it's a fascinating story, I recommend the book "Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time" by Dava Sobel.
- Fuzzwah 10y agoAlso if you're interested in inventors from the late 17th Century, I highly recommend: "The Man Who Knew Too Much: The inventive life of Robert Hooke"