Define the axis by clicking two points on a View window. Each point is projected to the axis to get a deformation parameter. Points that project to near the first end of the axis get smaller deformation parameters than points that project near the second end. The control curve is then evaluated by the deformation parameter to get the amount of deformation. Click two points on a View window to define the scaling center and scale. Move the mouse to deform and click to accept the tool.
The Scale1D tool has the following options: