Inclinometer + 'optical illusions' :- )

You bring to mind one time before I had an inclinometer and I was traveling 
 up/east toward Washington Pass in the North Cascades, I experienced the  
'illusion' *  you mentioned for the first time.  And, ..... it would  not 
stop.  I knew I must be traveling 'upwards' but was simply not real  sure of 
such being truly the case.  At first I tried to look to watch the  water level 
in my water bottles, but that did not work very well.  My best  solution 
proved to be looking to the side of the road where there was a small  stream 
of water from the melting snow .... I could see the direction of the  water 
flow and that became my best way to 'know.'
Fred
Atlanta
 
 
In a message dated 2/13/2011 2:27:22 P.M. Eastern Standard Time,  
[email protected] writes:

This  type of optical * illusion is not at all uncommon in  mountainous
terrain.  You would swear that you are going downhill,  when in fact you are
going uphill.  An inclinometer is definitely  needed in this  instance.

John