In 1885 Common embarked on building a Newtonian reflecting telescope. He chose to buy the raw glass blank and do the grinding and polishing himself. The first mirror he made performed poorly, showing an elliptical deformation of the stars, causing him to fabricate a second mirror in 1890. After a near fall from the high staging needed to reach the Newtonian focus of the telescope Common decided to convert the telescope to a Cassegrain configuration for safer use. To avoid having to bore a hole in the 60 inch primary mirror he mounted a diagonal flat mirror just in front of it to bring the image out to a focus at the lower side of the telescope. He was not satisfied with how this configuration worked and that, combined with his attention being diverted to other projects and the ever more light polluted skies west of London, meant the telescope fell into disuse. After Common's death the telescope with its two 60 inch mirrors and other secondary optics was purchased from his estate and installed at the Harvard College Observatory."Waywiser, the online database of Harvard's Collection of Historical Scientific Instruments", Object Name: 15.875-inch secondary mirror for 60-inch reflecting telescope Inventory Number: 1996-1-0684 Classification: Mirror In the 1933 the primary mirror was re-figured and a new mount built. It was then set up as the 1.5-meter Boyden-UFS reflector (also called the "60-inch Rockefeller") at Boyden Observatory in South Africa.
