The illustrations of the constellations in Urania's Mirror are redrawings from those in Alexander Jamieson's A Celestial Atlas, published about three years earlier, and include unique attributes differing from Jamieson's sky atlas; one of these is the "Norma Nilotica" – a measuring device for the Nile floods – seen here held by Aquarius, the water bearer.Lithograph credit: Sidney Hall; restored by Adam Cuerden