>>Neil, thanks for the informative dissertation. It bolsters my opinion, which is merely based on common sense and observation. One of your points about the air rising hits home. Doesn't it cool at a rate of something like 2 degrees farenheit per 1000 ft above sea level? I've seen this when travelling to the mountains and my airplane pilot buddies have told me about that for years.
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>2 degrees C per 1000' (approx 3.5 degrees F)

I sit corrected. I guess you would know from all your dreaming about how you wish you were 10,000 feet (35 degrees cooler) higher!<vbg>