As for the black bar, that's a shadow of the contrail. As for the "one sprays, one doesn't" it's called "Different altitudes".
You
can't tell what altitude a plane is flying at from the ground. Other than that I just saw the usual fear mongering going on.
[edit on 4/26/2007 by Zaphod58]


How would you administer those type of chemicals
over that much area at that altitude and not have prevailing winds mess up whatever calculations you may have had for dosage? And how did "they"
get the pilots to buy in to pressing the button to start the chemtrail? 
