We study the thermodynamics of SU(N_c) pure gauge theories for N_c=3, 4 and
6. The continuum and thermodynamic limits of bulk quantities such as the
pressure, energy density and the entropy density are taken by using several
different lattice spacings and volumes. There is no window of temperature in
which a non-trivial conformal theory describes bulk thermodynamics. We extract
the latent heat of the first-order deconfinement phase transitions and observe
good scaling with N_c. For all quantities that we measure, strong N_c scaling
holds, except, possibly, very close to the transition temperature, T_c; however
we are unable to find strong evidence for scaling with the 't Hooft coupling in
thermal quantities at the small values of N_c which we study
