i'd said:
 >so... 3 May @ 5pm >>>>> 23 May @ 7am     is er, well you do the 
math. 
 > It ran a long time.
 
then Tim had to add: 
> But was this a true test, 

well, What Is Truth?  one of the only truths that i know is when that 
exhaust stud snaps off... there is NO question what has happened.  
the end of the broken stud protrduing from the socket proclaiming 
"You're an idiot!"

> including the placing and retrieval of critically 
> cooled masses contained in capped cylindrical glass vessels? 

all temp measurements were made with an ASTM certified mercury filled 
thermometer with 0.5C divisions.  the bulb was immersed in a 
glycerin-filled glass vessel.  and if you believe that...

>Done on at  regular intervals, with subsequent temperature 
>verification by a suitable 
> organic based, non-grounded, temp sensor? 

yes.  you were asking if i stuck my hand in there to see if it was 
cold, right?

>Or were you just passing gas for 3  weeks (new age math at work).  

funny you should mention that.  i see Dometic has an accessory that 
isn't widly publicised but is meant for extened trips into the 
outback.  it consists of a 4 meter length of Tygon tubing that is 
valved into the low-pressure side of the regulator.  when one is 
remaining in the van for an extended period, say a long drive or 
overnight one simply inserts the other end of the Tygon tube in, er, 
well, a suitable methane source and then shuts the main tank valve 
off.  field tests have found that running time can be extended up to 
two weeks using the 'supplemental' combustible gas source.  the 
length of the tube permits freedom of movement about the van though 
there was a caution about dramatic results if one forgot about the 
tether and ran out of the van.  

-dan