Historical Innovations in Telescope Technology in England in the 17th, 18th, and 19th Centuries-A Tour with the Antique Telescope Society

  Following the invention and initial improvement of the telescope in the Netherlands in early 17th Century, most of the innovation in telescope technology passed into England in the late 17th Century with important contributions by the French and the Germans. Most notable of these were the invention of the reflecting telescope by Isaac Newton in 1668 and the achromatic lens beginning around the 1730s by Chester Moore Hall and John Dolland in England, and Samuel Klingenstierna in Sweden. These innovations improved the most pressing defect of telescopes at the time which was chromatic aberration as well as spherical aberration. They allowed telescopes to be built with much shorter and more manageable focal lengths while giving better images. Improvements in metal working technology driven by the Industrial Revolution in England and glass making technology in France and Germany allowed larger and more mechanically precise telescopes to be manufactured by the 18th and early 19th Centuries. I will give a travelogue of some of the places where some of these innovations took place along with visits to several other important places in the history of astronomy in England during our 1996 Antique Telescope Society visit. Among the places we visited was the house in Bath, England where William and his sister, Caroline Herschel lived and discovered the planet, Uranus, in 1781, and the Royal Greenwich Observatory where research was begun to establish a method to determine longitude at sea, the most pressing maritime navigational problem of the 17th and 18th Centuries.

Speaker: Dr. Ken Lum