Now let's do the experiment. It should be
done as close to noon as practical and on a
clear, cloudless day. Your instructor will supply
you with the items listed above. Measure 200
ml of cool water (close to ambient air temperature)
and pour it into the bottle. Then add a few
drops of India ink to the water until it is fairly
black.
Place the thermometer and cork in the bottle
and put the bottle in the shade close to where
you will do the experiment. This is to let the
water and thermometer come to ambient air
temperature. After several checks, a few minutes
apart, indicate that the temperature of the
water is neither rising nor falling (record this
temperature), you may prepare to place the
bottle in the direct sun.