Update 4 1 horizontal scalar field

4-1-horizontal-scalar-field.md

@@ -31,7 +31,7 @@ On _Horizontal Plane_ menu category of _Menu Bar_, you will find _Vertical Level
 You can control the size and location of the plane by using _Rendering Pane_ only. To do this, you do :
   1. switch from _Globe_ mode to _Map_ mode,
   2. double-click one of the corners of the plane, to reveal the control handles,
-  3. drag the control handles to change the size and height. 
+  3. drag the control handles to change the size and/or height. 
 
 ##### 5. Change the settings for color mapping (optional).