"Although the introduction of the Cuff "New Constructed Double Microscope" was not an optical advance, it was the first time in some 40 years that a solidly built and stable microscope was put on the market. Cuff's design was of such sound quality that it was rapidly copied or slightly modified by numerous instrument makers. One of the earlest modifications of Cufff's instrument was made by Mann and Ayscough. The front projection of the Maltese cross-shaped stage was omitted, forming a two-arm stage. The stage, rather than the body, was moved in focusing. The substage mirror was double (plane on one side and concave on the other) instead of single, and the mirror was mounted on a sliding block at the base of the pillar. George Adams the Elder made additional modifications by providing interchangteable eyepieces, a sliding device for changing the objectives, and a sliding substage condenser. He also kept Mann's and Ayscough's two-arm stage and double mirror"
(18th-Century Microscopes McCormick, 1987).