undflyboy06,

You are correct. This FAA digram is inaccurate. Not that it's a big deal, but it made me second guess myself when someone asked me why the needle shows a decent when the bellows compress for a climb.

I had not touched any of my old books in awhile, but I'm getting back into instructing and discovered that the FAA has all the updated manuals for download on their website. The newer versions of The Pilot's Handbook of Aeronautical Knowledge and the the Instrument Flying Handbook are pretty nice. My old books didn't have any color diagrams, but the new stuff is color and goes into glass cockpit stuff. I'm impressed.