Our President Gilbert Satterthwaite gave us a talk about the Longitude Problem, and in particular about Harrison’s Clocks. He illustrated it with many slides, and also explained the alternative favoured by the Astronomer Royal of the day. The Lunar solution involved measuring the position of the moon relative to two or more background stars and then performing a complicated calculation, and could not be expected to produce an answer in less than two or three hours. Unfortunately for Harrison the Astronomer Royal had a seat on the Longitude Board, so Harrison didn’t receive the prize due to him until the King himself intervened. The clocks Harrison made are now kept at the Royal Observatory , Greenwich.