ng stingarees?" he asked quietly.

Scotty shifted position in his chair and looked at Rick quizzically.
"You don't expect an answer. But I can tell you a few things they are
not."

"Tell away," Rick urged.

"They are not flying saucers, aircraft, kites, sting rays, birds, fish,
or good red herrings. Beyond that, deponent sayeth not, as the legal
boys say."

"Uh-huh. And why are they not flying saucers?"

"For the same reason they're not aircraft. If you recall all the talks
with people who've seen them, they don't maneuver, and they don't travel
very fast. They appear--or they're noticed, let's say--and they just get
smaller and smaller until they vanish. They move, but not much."

Rick nodded. "The circle we drew around all the sightings doesn't cover
a very large territory. All the sightings have been within that circle.
People had to look toward Swamp Creek to see the objects. Yet, they did
something interesting. They grew smaller. What makes things seem to grow
smaller?"

"Apparent size decreases with distance," Scotty replied promptly.

"Sure. And how do you get distance, when the sightings are all within a
circle only a few miles in diameter?"

"Only one way. With altitude. The things had to be going up."

Rick agreed. "That's how I figure it, too. It also explains why the
circle of sightings is so small. Above a certain altitude, the objects
are no longer visible. Or they're not so visible that they attract
attention. I suppose we could work out some calculations. How large an
object can be seen readily at what distance? Then we could apply a
little trigonometry and figure their size."

"We could," Scotty agreed, "but do we need to? Let's assume the object
you saw was typical. How big was it?"

Rick thought it over. He had had only a quick glimpse, and the
background had been the gray of the storm. His vision had been obscured
because of the rain. "Maximum of ten feet across and maybe eight tall.
It was probably less."

"Okay. So the reason sightings are confined to this area is because the
objects are fairly small. When people see them, they're relatively
close, and fairly low. Even the small planes that fly from the airfield
are much bigger than the flying stingarees, but when the planes go over
at about five thousand feet, they seem tiny. At that altitude the flying
stingarees must be at the limit of really good visibility."

"I read you loud and clear. So the objects are sent from Calvert's