Dream travel is the safest - experience the past or future in the relative comfort of your own canopy bed.
Not very reliable but - a seance can send you back and forth in time. It can also give you psychic scars for life, or end your life!
If you are stuck away from the main house - try the I-Ching wands. But read up carefully to make sure you have the correct grouping. If it is anything other than Hexagram #49 - change - throw again and start over.