[en] Fission yields induced in the ²³⁸U(n,f) and ²³²Th(n,f) reactions were determined as a function of incident neutron energy (E/sub n/). The ratio of ¹¹⁵Cd-to-¹⁴⁰Ba yields as a function of E/sub n/ is analyzed by means of the equation Y₁/Y₂ = exp[2(a₁(E/sub n/+E₁)/sup 1/2/ -2(a₂(E/sub n/+E₂)/sup 1/2/] to give values of a/sub i/, the level density parameter, and E/sub i/, the excitation energy for E/sub n/=0. The energies E/sub i/ are interpreted on the basis of the liquid drop model with shell and pairing corrections. Values are deduced for the energy dissipated by viscosity effects in the descent from the saddle point to the point where masses are fixed in the fissioning nucleus. These values are 1.7 MeV for ²³²Th(n,f) and 4.8 MeV for ²³⁸U(n,f). These values are consistent with the experimental observation that anti ν/sub p/ is approx. 0.6 neutron greater for ²³⁹U fission than for ²³³Th fission and that strong odd--even (nucleon pairing) effects are found in the fragment total kinetic energy distribution for ²³⁰Th fission but not for ²³⁴U fission. The low dissipation energy values together with the low values of pre-scission kinetic energy deduced by Guet, et al., [Nucl. Phys. A134 (1971)1] indicate a shorter path from the saddle point of the fissioning nucleus to scission than is generally assumed in theoretical calculations. 31 references