Achromatism

Ivory's paper on Equations, Achromatism of microscope,

Autobiography Airy, George Biddell, Sir 1896

I also wrote a draft of my Paper on Achromatic Eye-pieces, and on May 17th, 1824, it was read at the Philosophical Society under the title of 'On the Principles and Construction of the Achromatic Eye-pieces of Telescopes, and on the Achromatism of Microscopes,' including also the effects of separating the lenses of the object-glass.

Autobiography Airy, George Biddell, Sir 1896