I am trying to follow the tutorial on designing a database in firebase, but I am getting the following error in the JavaScript console:

Uncaught ReferenceError: Firebase is not defined

Here is the link to the tutorial, and the code snippet that I was trying to run in the JavaScript console is: https://www.firebase.com/blog/2014-11-04-firebase-realtime-queries.html

var ref = new Firebase(https://dinosaur-facts.firebaseio.com/dinosaurs);

ref.orderByChild(height).on(child_added, function(snapshot) {

  console.log(snapshot.key() +  was  + snapshot.val().height +  meters tall);

});