Prop performance in clouds question

Only flying after today for the next month will be as a passenger as
November 1943 lima has been delivered to Batesville for the extreme
interior makeover. I asked the interior guy if he could email me some
progress pics and he said he would.

Another pilot followed me up in his piper seen here at
http://picasaweb.google.com/allenlie...24852142956722

I **thought** air is less dense in a cloud, but when you watch the
prop strobing at http://www.youtube.com/watch?v=QniPjy0gkBI you can
see the regression of the prop strobing, and in my experiences when
the prop starts turning counter clockwise, the prop RPM is slowing
down.

We were in level flight, 6000 feet. Engine is 180 hp. I don't
remember what settings he had for the prop or engine.

Would the moisture in the cloud cause a change in the prop speed even
though we couldn't detect it via gauge or sound? Or is air inside a
cloud more dense?

What I found most fascinating is that we both left the same time, and
he only got there 2.5 minutes faster. I was 45 to a downwind when his
wheels touched down. He planned 130 knots, I planned 110 knots and
the trip was 116 NM.

This for sure verfied I don't need a high performance plane for my
kind of flying as even on my trips to Bessemer, who would really
notice 7 to 10 minutes longer flight time difference **in the full
scheme of things**.

Allen