Plot of the Hβ/Hα ratio as a function of galactocentric distance for all of the SNRs. The dashed lines indicate the unabsorbed value of Hβ/Hα = 1/3.1 and the value corresponding to the Galactic foreground absorption, ﹩E(B-V)=0.059﹩. Many of the objects show evidence of signficant local extinction above the foreground level. However, the ratios we use in our figures are from closely spaced lines with little sensitivity to reddening.