\begin{table}%t4 \caption{\label{tab4}Depolarisation indices and RMs.} \small%\centerline { \begin{tabular}{lllcrrrrrrrrr} \hline \hline Name & & $z$ & Id& DP & DP & DP & DP & RM$_{\rm obs}$ & lm-1 & RM$_{\rm obs+TI}$ & lm-2 & RM$_{\rm rf}$ \\ & & & & $_{8.35/10.45}$ & $_{4.85/8.35}$ & $_{2.64/4.85}$ & $_{1.4/2.64}$ & [rad m$^{-2}]$ & & [rad m$^{-2}$] & & [rad m$^{-2}$]\\ \hline 3C 43 &0127+23 & 1.46 & Q & 1.00 & & & & & & $-$69 & 0.9965 & $-$419 \\ 3C 48 &0134+32 & 0.37 & Q & 0.87 & 0.69 & & & $-$79 & 0.9994 & $-$64 & 0.9900 & $-$120 \\ 3C 49 &0138+13 & 0.62 & G & & & & & & & & & \\ 3C 67 &0221+27 & 0.31 & G & 1.05 & & & & $-$1 & 0.9999 & $-$67 & 0.9945 & $-$115 \\ 4C 34.07 &0223+34 & 2.91*& Q & & & & & & & & & \\ 4C 16.09 &0316+16 & 0.97*& Q & & & & & & & & & $-$249 \\ &0319+12 & 2.67 & Q & 1.16 & 1.09 & 0.89 & 0.07 & $-$12 & 0.9521 & $-$19 & 0.7698 & $-$164 \\ 3C 93.1 &0345+33 & 0.24 & G & & & & & & & & & \\ 4C 76.03 &0404+76 & 0.6 & G & & & & & & & & & \\ OF247 &0428+20 & 0.22 & G & & & & & & & & & \\ 3C 119 & 0429+41& 1.023& Q & 0.66 & & & & & & 1928 & 0.9663 & 3900 \\ 3C 138 &0518+165& 0.76 & Q & 1.18 & 0.85 & 1.04 & 0.70 & $-$1 & 0.04 & $-$6 & 0.8786 & $-$19 \\ 3C 147 &0538+49 & 0.55 & Q & & & & & & & & & \\ 3C 186 &0740+38 & 1.06 & Q & & & & & & & & & \\ 3C 190 &0758+14 & 1.2 & Q & & & & & & & & & \\ 3C 216 &0906+43 & 0.67 & Q & & & & & & & & & \\ 3C 237 &1005+07 & 0.88 & G & & & & & & & & & \\ 3C 241 &1019+22 & 1.62 & G & & & & & & & & & \\ 4C 31.38 &1153+31 & 0.42 & Q & & & & & & & & & \\ 3C 268.3 &1203+64 & 0.37 & G & 0.93 & & & & & & 114 & 0.9853 & 213 \\ ON343 &1225+36 &1.973*& Q & & & & & & & & & \\ 3C 277.1 &1250+56 & 0.32 & Q & 1.15 & & & & & & $-$59 & 0.9961 & $-$102 \\ 4C 32.44 &1323+32 & 0.37 & G & & & & & & & & & \\ 3C 286 &1328+30 & 0.85 & Q & 0.99 & 0.91 & 1.01 & 0.61 & & & & & \\ 3C 287 &1328+25 & 1.06 & Q & 0.97 & 1.16 & 0.97 & 0.18 & $-$148 & 0.9957 & $-$146 & 0.9954 & $-$618 \\ 4C 62.22 &1358+62 & 0.43 & G & & & & 0.02 & & & & & \\ &1413+34 & & & & & & & & & & & \\ 3C 298 &1416+06 & 1.44 & Q & 0.86 & & & & & & 96 & 0.9911 & 573 \\ 3C 299 &1419+41 & 0.37 & G & & & & & & & & & \\ OQ172 &1442+10 & 3.52 & Q & & 1.18 & 1.73 & 0.29 & $-$66 & 0.9994 & $-$71 & 0.9376 & $-$1451 \\ 3C 303.1 &1443+77 & 0.2 & G & & & & & & & & & \\ 3C 305.1 &1447+77 & 1.13 & G & & & & & & & & & \\ 3C 309.1 &1458+71 & 0.91 & Q & 1.08 & 0.89 & 1.54 & 0.32 & 60 & 0.9996 & 46 & 0.9830 & 169 \\ 3C 318 &1517+20 & 1.57 & G & 0.72 & 0.52 & & & 498 & 0.9987 & 342 & 0.9995 & 2260 \\ &1600+33 & 1.1* & G?& & & & & & & & & \\ OS111 &1607+26 & 0.47*& G & & & & & & & & & \\ 3C 343 &1634+62 & 0.99 & Q & & & & & & & & & \\ 3C 343.1 &1637+62 &0.75 & G & & & & & & & & & \\ 3C 346 &1641+17 & 0.16 & G & & & & & & & & & \\ 4C 39.56 &1819+39 & 0.80 & G & & & & & & & & & \\ 3C 380 &1828+48 & 0.69 & Q & & & & & & & & & \\ 4C 29.56 &1829+29 & 0.84 & G & & & & & & & & & \\ 4C 11.69 &2230+11 & 1.04 & Q & 1.03 & 0.97 & 1.10 & 0.40 & $-$39 & 0.9694 & $-$38 & 0.9894 & $-$157 \\ 3C 454 &2249+18 & 1.76 & Q & 1.02 & & 0.62 & 0.62 & $-$88 & 1.000 & $-$88 & 0.9997 & $-$669 \\ 3C 454.1 &2248+71 & 1.84 & G & & & & & & & & & \\ 3C 455 &2252+12 & 0.54 & G & & & & 0.62 & $-$68 & 0.9402 & 82 & 0.9923 & 194 \\ &2342+82 & 0.74 & Q & & & & & & & & & \\ \hline \end{tabular}} \medskip Table~\ref{tab4} is organized as follows: Col.~1, source name; Col.~2, other name; Col.~3, redshift; redshifts marked with~``*'' are taken from the following pubblications: 0223+34 Willott et~al. (\cite{Willott98}); 0316+16 Labiano et~al. (\cite{Labiano07}); 1225+36 Lawrence et~al. (1994); 1600+33 photometric redshift from Stanghellini et~al. (\cite{Stanghellini05}); 1607+26 Stanghellini et~al. (\cite{Stanghellini93}); Col.~4, optical identification. The source~3C~455 has been re-classified as galaxy by Hes et~al. (1966); Cols.~5 to~8, depolarisation indices DP; Col.~9, rotation measure RM derived from our new Effelsberg observations; Col.~10, ls-1: the least square fit of the linear regression of the values in Col.~9; Col.~11, rotation measure RM derived from our new Effelsberg observations, complemented with data from Tabara \& Inoue (\cite{Tabara80}); Col.~12, ls-2: the least square fit of the linear regression of the RM~values in Col.~11; Col.~13, rest frame RM calculated using the RM$_{\rm obs+TI}$~values. \end{table}