Now take the main body part and place it head down on the table and lift up the back and place the arms in the middle like so: (a stone is holding down the top part).

Pennsylvania's nickname is the keystone State. Just as a keystone holds together a stone arch, Pennsylvania was seen as holding together the young American republic.

The holding period of art works is also a key factor for generating return. Mr Stone says relatively long holding periods are necessary to generate returns.