3900265 Portrait of Jesse Ramsden, The Astronomical Observatory "Giuseppe Piazzi", the Pisana Tower by Unknown artist, (18th-19th century); Palazzo dei Normanni, Palermo, Sicily, Italy; (add.info.: Jesse Ramsden (1735-1800): British mathematician, astronomical and scientific instrument maker. Palermo, The Royal Palace or Palazzo dei Normanni (Palace of the Normans), the Pisana Tower, The Astronomical Observatory "Giuseppe Piazzi": painting which portrays Jesse Ramsden. Jesse Ramsden was a British mathematician, astronomical and scientific instrument maker. His reputation was built on the engraving and design of dividing engines which allowed high accuracy measurements of angles and lengths in instruments. He produced instruments for astronomy that were especially well-known for maritime use where they were needed for the measurement of latitudes and for his surveying instruments which were widely used for cartography and land survey both across the British Empire and outside. An achromatic eyepiece that he invented for telescopes and microscopes continues to be known as the Ramsden eyepiece. Palermo, Palazzo Reale o Palazzo dei Normanni, Torre Pisana, Osservatorio Astronomico "Giuseppe Piazzi": ritratto di Jesse Ramsden, che fu uno dei piu famosi costruttori inglesi di strumenti scientifici della seconda meta); Ghigo Roli; out of copyright.