- He also experimented with making an achromatic telescope.
- The 'Barlow lens', a modification of this telescope lens, is a negative achromatic combination of flint glass and crown glass.
- This behavior is also common in two-material waveplates such as achromatic waveplates constructed from quartz and magnesium fluoride plates.
- The modern achromatic compound microscope was invented in 1878, and it was this instrument that added the extra dimension of the microscopic study of tissues to anatomical teaching.
- The invention is applicable, in particular, to the production of a main beam with a blurred, achromatic, cut-off at the bottom; this beam may be autonomous, or it may be complementary to a dipped or passing beam.
- The system had to be achromatic and diffraction limited for two specific wavelengths spaced about 35 nm apart.