Rail Clone
 

How would I duplicate a pattern along the path and at one end have the object smaller and larger on the other end?

One way to do this is to (1) clone the object with an offset on the X,Y, or Z and one of the scale settings less than 100%. This will give you a row of items each one smaller than the next. (2) Under the Modify tab, use Spline Guide. In nuimeric mode change the operation to bend. You can drag the spline around to the shape you want and the objects will all align to your curve. Use more curve points for smoother curves. You can also draw a spline in another layer and use that one to align to by using the Get Background... button.