3 3 c m
40cm
actual image size: 32cm x 25cm
Description
Photograph of a large fixed transit circle by Ertel, taken at the Pulkowa Observatory, St Petersburg, Rusia. The transit circle was used to measure both the right ascension and declination of a star - the celestial equivalent of latitude and longitude.
Image Details
Image Ref.
10418847
© Science Museum / Science & Society Picture Library