Enderby and March $($ENDERBYJ$,.$ E$.,$ and MARCH,N$.$ H$.,1966,$ Proc. phys$.$ SOC$\mathrm{.}8,8,717.)$ calculated that there should be a simple relationship between surface energy $(),$ melting temperature $(T_m),$ and interatomic spacing $(r_0)$ for metals

$prop\frac{T_m}{r_0^2}$

Use the interfacial energies and melting points from table $3\mathrm{.}1$ in your book to plot $$ vs $\frac{T_m}{r_0^2}$ and perform a linear fit. You will find that while the theoretical expression is a direct proportion the y $-$intercept for actual data does not pass through the origin and instead has a positive $y-$intercept. Speculate on the physical meaning of the $y-$intercept.