title: Find all items through two has_many associations
body: <p>Lets say I have a Rails app that is modelled as follows:</p>
  
  <ol>
  <li>There is a HOUSE class; it has_many ROOMS</li>
  <li>There is a ROOM class; it belongs_to a HOUSE and has_many FURNISHINGS</li>
  <li>There is a FURNISHING class; it belongs_to a ROOM</li>
  </ol>
  
  <p>Give this model setup, how would one find all FURNISHINGS in a given HOUSE? I would hope to be able to do something like <code>arbitrary_house.furnishings</code>.</p>
  
  <p>Is this possible without adding more associations? </p>