A 24-in. diffusion cloud chamber filled to 14 atmospheres with tritium-free deuterium gas, operating in a magnetic field of 6 kilogauss, has been placed in the 1040-Mev "hardened" bremsstrahlung beam of the Cornell synchrotron. A total of 310 events of the type $\ensuremath{\gamma}+d\ensuremath{\rightarrow}p+p+{\ensuremath{\pi}}^{\ensuremath{-}}$ have been observed and analyzed. Using the "spectator model," a total cross section has been determined for the reaction $\ensuremath{\gamma}+n\ensuremath{\rightarrow}p+{\ensuremath{\pi}}^{\ensuremath{-}}$ from threshold to 1 Bev, in good agreement with the results obtained from the measurement of the negative-to-positive pion ratio together with the measured cross section for the reaction $\ensuremath{\gamma}+p\ensuremath{\rightarrow}n+{\ensuremath{\pi}}^{+}$.The momentum distribution of the low-energy protons in the laboratory system compares very favorably with the internal momentum distribution of the deuteron as calculated from the Hulth\'en or Gartenhaus wave functions. The validity of the spectator model for photons above 200 Mev is experimentally justified, as is expected in consideration of the assumptions of the impulse approximation.A study of the forward-backward asymmetry of the spectator protons in the laboratory system indicates that above photon energies of 250 Mev, there is a 15% deviation from isotropy, favoring the forward beam direction, indicating that the spectator proton is being "pulled along" with the net forward momentum of the rest of the system, through an average forward momentum transfer of about 10 Mev/c.