  The main result is an explicit expression for the Pressure Metric on the
Hitchin component of surface group representations into PSL(n,R) along the
Fuchsian locus. The expression is in terms of a parametrization of the tangent
space by holomorphic differentials, and it gives a precise relationship with
the Petersson pairing. Along the way, variational formulas are established that
generalize results from classical Teichmueller theory, such as Gardiner's
formula, the relationship between length functions and Fenchel-Nielsen
deformations, and variations of cross ratios.
