August Meeting

Finding Longitude by Observing the Moon by Frank Reed

Mr. Frank Reed of Reed Navigation, Jamestown RI, will describe the famous method of finding longitude by lunar distances, usually known for short as “lunars”. Lunars were widely used at sea in the early 19th century in the era before chronometers became inexpensive and common. By observing the position of the moon relative to the sun or stars, navigators used the moon as a great natural clock in the sky. The method of measuring lunar distances was championed by the Astronomer Royal in the 18th century as the Astronomical substitute to using chronometers. It was the belief at Greenwich that no mere mechanical contrivance could solve the most challenging practical Astronomy problem of the day. Thus the measurement of lunars competed against Mr. Harrison’s famed chronometers for King Charles’ prize.

Frank Reed earned his BA in Physics from Wesleyan University in 1984. He teaches various navigation courses and has developed the Centennia Historical Atlas. He has been the guest of Neil deGrasse Tyson’s StarTalkRadio.

A Unique 1960's Catadioptric Telescope in the Trewongy Planetarium Collection by Jeff Dunn

Mr. Jeff Dunn is the supervisor of the Treworgy Planetarium at Mystic Seaport. While giving a tour of the back room of the Mystic Seaport Planetarium to Steve Siok, he opened the box containing a catadioptric telescope. Short tube, corrector plate and an 8” primary mirror. But the resemblance to a garden variety Meade or Celestron ends there. Please join us as Jeff describes this strange and expensive instrument. He will also describe the mission of the Treworgy Planetarium at the Seaport. 

Jeff received his B.S. in elementary education from Kutztown University in Pennsylvania and M.A. in geography and remote satellite sensing from West Virginia University. He pursued a PhD in geography at the University of Connecticut.