In 1876 Common became a Fellow of the Royal Astronomical Society. About this time he also moved to Ealing outside London where he would live for the rest of his life operating an astronomical observatory from the back garden of his house. Common realised he would need very large telescopes to gather enough light to record the images of stars photographically so he began building a series of ever larger Newtonian reflecting telescopes using the then new technology of silver coated glass mirrors. For the first of these, a telescope of his own design constructed in 1876, he tried to grind and polish his own 17 inch mirror but gave up on the idea and ordered an 18-inch (46 cm) mirror from the optical firm of George Calver of Chelmsford. In 1877 and 1878 he published several articles on his visual observations of the satellites of Mars and Saturn.