Proper motions of the individual features in the jets of CRL 618. First-epoch [S ii] image of CRL 618 together with the boxes in which the cross-correlations were made (see text). The red boxes correspond to individual knots. Features that include more than one knot (as E1, E9 and W3) are marked in green. The blue boxes were used to measure the proper motion of the J1, J2, J1′ and J2′ jets. The arrows show the computed proper motions. The length of each arrow is proportional to the proper motion. The vertical arrow at the top right shows a proper motion of 300 km s^-1.