Comparison of white dwarfs with known masses and radii from the Hipparcos survey at the 1 σ level (Vauclair, Schmidt, & Koester 1997; Provencal et al. 1998) with our calculations from Figs. 1, 3, and 5. The upper curves are for ﹩^{4}﹩He and ¹²C white dwarfs. The lower curves are for ﹩^{56}﹩Fe white dwarfs.