Scatterplot with external links and tooltips. Clicking on any point symbol
    representing a car will link to google image search for that car.
  </p>
  <div id="interaction4" class="view"></div>

  <p>Drag out a rectangular brush to highlight points.</p>
  <div id="interaction5" class="view"></div>

  <p>
    Area chart with rectangular brush. Dragging is in the horizontal direction
    only to allow a time frame to be highlighted.
  </p>
  <div id="interaction6" class="view"></div>

  <p>
    Mouse over 