  We determine the gluino condensate $< \Tr \lambda^2 >$ in the pure ${\cal
N}=1$ super Yang-Mills theory (SYM) for the classical gauge groups $SU(r+1)$,
$SO(2r+1)$, $USp(2r)$ and $SO(2r)$, by deforming the pure ${\cal N}=2$ SYM
theory with the adjoint scalar multiplet mass, following the work by Finnell
and Pouliot, and Ritz and Vainshtein. The value of the gluino condensate agrees
in all cases with what was found in the weak coupling istanton calculation.
