Letter, from Johannes Hevelius to Henry Oldenburg, dated at Danzig (Gdansk) Queries the views of the Parisian astronomers about Saturn; sends his figure of Saturn as seen through a 55-foot telescope; concerning the progress of his work 'Machina coelestis'; asks again for the micrometer to be sent which can be inserted into the telescope tube Read to the Royal Society on 6 November 1672 29 October 1672