Drawing of part of a transit circle instrument - the reading microscopes. Derived from Norton, William A. (1867) A Treatise on Astronomy, Spherical and Physical
{{Information |Description=Drawing of part of a transit circle instrument - the reading microscopes. Derived from Norton, William A. (1867) ''A Treatise on Astronomy, Spherical and Physical'' |Date=7 Jun 2012 |Source={{own}} |Author= ~~~~ }}