Halley Crowd Sourcing

Here’s another snippet fro ‘Shaping the Day’ by Nigel Thrift & Paul Glennie.

When Edmund Halley was Savillian Professor of Geometry at Cambridge in 1714 he wanted to get accurate measurements of the size of the earth and the moon and their distance from the sun, so he set up one of the first examples of mass observation: he asked astronomers across Britain to time as accurately as they could the time of the total eclipse. That would provide him with the speed if the clocks were accurate enough. He received an impressive number of precisely timed measurements that were consistent, so showed how widespread was the ownership of pendulum clocks, and formed the basis of Newton’s work on mechanics. Pendulums were not just the most accurate at the time, their swings were generally for 1/2or 1 sec, accompanied by a click sound, so they could make their observations visually whilst timing with their ears. Many observations stated the type of clock, and the markings of time on it. This was repeated when another eclipse happened in the North of England so giving many Scots a chance to do their measurements. Later broadsheets published astronomical events that were expected, and the accuracy of these broadsheets were in turn judged by the accuracy of their predictions. The widespread ownership of precise clocks does not suggest the country was awash with astronomers, though there were a lot of gents fond of the past time. It also shows how precise instruments were often ahead of the need, similar to many of our laptops and smart phones which have capacities far beyond the needs of most of us.

One thing I found fascinating about this was the absence of interest in Bristol, the major port after London at the time. They had no almanacs published, they did not seem to contribute to the mass observations, and in 1754 when Halley’s comet returned, it was not reported in local papers. So, a gap between those who research astronomy and navigation and those who go to sea. Or the lack of gentry and aristocracy in Bristol at the time.

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