reducing vibration from the washing machine

[mrbigstuff]

It's not doing a salsa dance, but it is vibrating through the walls, enough so that I feel it about 25 feet away on the other side of the house. So, no "excessive" vibration but I do need something of a solution to this as this is an old house and I don't want to cause problems over the long term.

And, no, I can not move to the basement....