Charles Chevalier (1804-1859) was the son of Vincent Chevalier (1771-1841) who established himself as designer of achromatic lens systems for microscopes. They were in business together when they invented the first useful achromatic objectives in 1823. The Chevaliers discovered how to control the spherical abberations that previous designs produced. In 1834, after separating from his father's business, Charles produced the first commercially successful achromatic microscope. This model probably dates between 1834 and 1841.*

*Courtesy of  R. K. Smeltzer, Princeton University