Micrometer

1638

Micrometer

The book of science

Tom Sharp

William Gascoigne metrology

Micrometer

Measuring comets

Measuring

Researchers at the University of Virginia report that the Greenwich prime meridian, once bisecting the Airy Transit Circle at the Royal Observatory in Greenwich, is now 102 meters to the east, the original line having been deflected because the local direction of gravitation affected the determination of the vertical.

See also in The book of science:

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