Electrical Ground? I am putting a sub-panel and found out the main panel don't...

I am putting a sub-panel and found out the main panel don't own a ground bar or ground anywhere. This is an antediluvian building, so can I just bolt & nut my subpanel ground to the major panel casing.
Something falling down the flue?
Answers:    Yes..The grounding bars(lugs) contained by the sub-panel can be connected to the case of the box,.IF....the adjectives wires are not... Then the grounding bar is run to floor using a grounding cable & rod or connecting the cable to a water pipe which go to earth.
Electricians! How much wattage would these items filch...
You requirement to use a ground rod.