Attic ventilation without soffit vents
 

I recently gutted out the top floor of my home that was built around 1850. The rafters are about 32" oc. There are no gable vents or soffit vents. Unfortunately, there is definitely no easy way to install soffit vents. What is the best way to insulate the rafters and ceiling joists with proper ventillation? Any suggestions would be appreciated. Thanks!