[pct-l] When's an ounce not and ounce?

[Ronald Moak <ronm@fallingwater.com>]

Reading Roy's comments about fuel weights the other day left me a powerful
bit confused. That night, as I lay in my bed, I mulled over my experiments
of the previous couple of week's trying hard to reconcile his comments with
my own measurements.

Surely he wasn't wrong, after all he'd carried his stove over a thousand
miles and used it many times. Mine has barely made it to the garage and been
fired up a couple dozen times. 

Still I thought I'd been careful in my experiments. As I sat at the table
carefully measuring out my two tablespoons of fuel, gingerly empting them
into the alcohol burner so as not to loose a drop. Taking precise
measurements on my new electronic scale. A half dozen measurements, a half
dozen weights. Each time the scale returned .4 oz for 2 table spoons of
fuel. 

To this I added .1 oz as a safety margin. Making it .5 oz of fuel per meal.
At 2 hot meals per day times 7 days that makes 7 oz of fuel per week.
Reading Roy's number of 16 oz's per 8 days really had me boggled. How could
I be so far off. I mean a half pound is a lot of weight if we're trying to
shave off ounces. 

Finally after letting the thoughts bounce around my empty brain a couple of
hours, my mind wandered back some 20 years to college chemistry. The old
term Specific Gravity (SP) popped back into my thoughts. I remembered a pint
of fluid only weight 16 ounces when it's water.  Because water has a SP of
1. All other fluids are either heaver or lighter than water. 

So sure enough I when back and measured a quarter cup of water and a quarter
cup of alcohol. As expected the water weighed 4 oz. On the other hand a
quarter cup of alcohol weighs in at 3 oz.  So Roy is your pack feeling any
lighter? 

I'm still got a few more measurements to make before I've got all my
differences worked out, but I've at least resolved one mystery. The rest can
weight until I can finish making my tarp. 

Ron "Fallingwater" Moak
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