H i channel maps of 3C 58 taken at the peaks in the absorption spectra at +1 (top left), −7 (top centre), −34 (bottom left), and −41 km s^-1 (bottom centre). The right panels show ten channels averaged over the inter-arm velocities between the Local and Perseus arm (top) and ten channels averaged over the velocities just outside the last absorption feature. The continuum emission of 3C 58 is indicated by the white contours. The black dashed lines represent the H i contours at the levels indicated by the labels of the colour bars.