Translating the Model - The model can be translated by holding down the right mouse button and wait for the drag mouse pointer 
to appear, then drag out a pan vector. Dragging towards the top or bottom translates the model up or down. Dragging towards the left or right translates the model left or right.
Zooming the Model - The model can be zoomed by rotating the mouse wheel, or holding down both the left and right mouse buttons and wait for the drag mouse pointer 
to appear, then dragging out a zoom factor. Dragging towards the top zooms the model out. Dragging towards the bottom magnifies the model.
The model can also be translated and zoomed using the translation toolbar or keyboard keys
Related Topics:
Selecting special view positions
You can adjust the drag wait time using