Assuming the copper pipe was a continuous run of unbroken cold water pipe it would have carried any load to ground and blown the fuse or tripped the breaker. It would also throw the current to plumbing fixtures until it blew or tripped. It is not a legal procedure now and may or may not have been in 1962.
To the best of my unlicensed knowledge a continuous ground wire may be run separately provided it returns to the panel box and that panel box is properly grounded.
The gottcha with that is that in the early 60's the house water main was often used as the only ground and that is why someone chose this shortcut method to ground the bath and kitchen.
I would encourage you get the proper grounding installed if that condition stills exists.
To the best of my unlicensed knowledge a continuous ground wire may be run separately provided it returns to the panel box and that panel box is properly grounded.
The gottcha with that is that in the early 60's the house water main was often used as the only ground and that is why someone chose this shortcut method to ground the bath and kitchen.
I would encourage you get the proper grounding installed if that condition stills exists.