COLOURATION • FREE TRANSLATOR.ORG • Definition of Colouration

... course of time with a great difficulty. The magnified image of the object observed was not quite pure; its edges, indeed, were fringed with rainbow-like colours. This defect was found to be aggravated with increase in the size of object-glasses. A method was, however, discovered of diminishing this colouration, or chromatic aberration as it is called from the Greek word [chroma] (chroma), which means colour, viz. by making telescopes of great length and only a few inches in width. But the remedy was, in a way, worse than the disease; for telescopes thus became of such huge proportions ...

— Astronomy of To-day - A Popular Introduction in Non-Technical Language • Cecil G. Dolmage